stantec_engineering_services_secondary_clarifier_rehabilitationWHEN THE BEST SOLUTION
DOESN’T EXIST, WE CREATE IT
PROPOSAL FOR ENGINEERING SERVICES FOR SECONDARY CLARIFIER REHABILITATION
JULY 16, 2019
Onsite, South Lake Tahoe, CA
1. TRANSMITTAL LETTER 1
2. FIRM EXPERIENCE 2
3. APPROACH TO PROJECT 5
4. PROJECT TEAM 10
Organizational Chart 10
Qualifications 11
5. MANHOURS 12
6. SCHEDULE 13
7. LIST OF DOCUMENTS OR INFORMATION THE DISTRICT NEEDS TO PROVIDE 14
8. APPENDIX A - SAMPLE WORK PRODUCT 15
City of Madera WWTP - Equipment Assessment 15
City of Madera WWTP - Concrete Rehabilitation 31
Marin Municipal Water District - Clarifier Mechanism Specifications/Drawings/Seismic Analysis 44
Santa Clara Valley Water District Rinconada WTP - JDH/Stantec Condition Assessment 96
9. APPENDIX B - RESUMES 122
TABLE OF CONTENTS
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Steven Beck, PE
Principal-in-Charge/Project Manager | (916) 826-3665 | steven.beck@stantec.com
Stantec | 3875 Atherton Road, Rocklin, CA 95765
TRANSMITTAL LETTER1
July 16, 2019
Attention: Stephen Caswell, PE, Principal Engineer | South Tahoe Public Utility District
1275 Meadow Crest Drive | South Lake Tahoe, CA 96150 | (530) 543-6202 | scaswell@stpud.dst.ca.us
Reference: Engineering Services for Secondary Clarifier Rehabilitation
Dear Mr. Caswell:
The South Tahoe Public Utility District (STPUD/District) requires experienced, reliable consultant partners
to complete the critical tasks for its projects. Stantec Consulting Services Inc. (Stantec) is ready to be that
partner. Our proposed team is passionate about the unique challenges this project presents and has the right
qualifications that will provide value to you in the following ways:
Excellent Leadership and Qualified Team: We understand that your unique goals include the criticality of
maintaining service to the District’s customers. Our project team, led by Steven Beck , includes individuals with
recognized industry experience directly related to wastewater treatment plant (WWTP) planning, analysis, design,
construction and operation. Our team has continuity from past projects and perspective from working at other
treatment plants. We offer the skills, experience, and knowledge to help ensure a successful project, keep costs
low, and add value.
Unparalleled Seismic Rehabilitation Experience: Stantec is well-known as a wastewater treatment firm;
however, we are also at the forefront of seismic/structural upgrades of existing treatment plant and water facility
structures in California and in the Bay Area specifically. Not only have we improved the seismic reliability of the
treatment plants, but we have also improved clarifier performance.
Tailored Approach: Our approach is tailored to the STPUD wastewater treatment facility (WWTF) and your
scope of services. It begins with a structural seismic analysis of the clarifiers by David Palmer and his team
of structural engineers who specialize in treatment plants and water-retaining structures. They understand
that structural solutions can have major impacts on the cost for construction and to operational treatment
processes, and they have pioneered the use of techniques that reduce cost and minimize the impacts on other
plant components.
Committed and Available Staff: We understand the need to stay on a strict schedule to take advantage of the
limited window of construction for this unique location. Our team is dedicated and committed to meet the tight
deadlines this work requires. We have access to more than 1,400 available subject matter experts (SMEs) in
California and have teamed with JDH Corrosion Consultants, Inc. (JDH) to provide expert corrosion assessment
and engineering specific to clarifier equipment. Together, we will effectively and efficiently address your project.
Acknowledgments:
−Our proposal is signed by Steven Beck—an official authorized to bind Stantec.
−We acknowledge receipt of addendum number 1 (7/3/2019) and 2 (7/9/2019).
−We have reviewed your proposed RFP/contract terms and believe that should we be selected for this
assignment, we will be able to conclude a mutually satisfactory contract with you.
−Per the RFP, we have included our cost proposal as a separate file.
Sincerely,
1. TRANSMITTAL LETTER
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 2
FIRM EXPERIENCE2
WHY STANTEC?
Selecting the Stantec team brings numerous
advantages. Stantec offers a full range of structural
assessments that include recommendations
for remediation of potential failure risks. The
recommendations can be coupled with cost
estimates for immediate planning purposes.
Stantec also formulates structural design criteria,
structural equipment evaluations, design of retrofit
modifications, and site studies. Our structural
engineering capabilities include new design, retrofit,
and design review services. We use a variety of
specialty programs, including Microstation Triforma
for 3D modeling, STAAD for finite element analysis
and Enercalc for component design.
We specialize in designing seismically resistant
water retaining structures and have significant
expertise is the following areas:
−Reinforced concrete water retaining structures for
water and wastewater treatment plants
−Earth retaining structures
−Foundation systems
−Seismic engineering
−Structural evaluation and upgrades
−Structural analysis
−Steel water tanks
−Prestressed concrete water tanks
−Pump stations
−Vibration analysis
−Concrete evaluation, rehabilitation, and repair
−Design-build
−Troubleshooting construction issues
−Failure analysis
Stantec structural engineers have contributed to
the Editorial Committee of the 6th and 7th Editions,
Construction Inspection Manual, BNI Books. They
are actively participating in leadership roles for
the following organizations: Chairman, ASCE
Structural Design Practices Committee; Board
Member, ASCE SEI Professional Practices 2009-
2014, Associate Member, ASCE/SEI Standards
Committee on Seismic Rehabilitation (ASCE 41-
13), Member, ASCE 7-16 Seismic Subcommittee
(TC 5 and TC-13).Onsite, South Lake Tahoe, CA
WHO WE ARE
Stantec is a global engineering company
specializing in services to municipal, industrial,
and governmental clients in the areas of water,
wastewater, and environmental compliance. We
share a commitment to advance the quality of life
in our communities around the world. That’s why at
Stantec, we always design with community in mind.
OUR EXPERIENCE
Stantec has planned, designed, permitted, and
provided services during and through construction
for hundreds of seismic and process retrofits,
including clarifier upgrades. This combination of
seismic upgrade experience, together with local
and worldwide application of technology, offers the
District a team with the experience and capabilities
needed to accomplish the goals for this project.
Clarifier Design and Retrofit Qualifications
Overview | Stantec has extensive experience in
wastewater treatment clarifier equipment design,
sizing and retrofit work. Led by Akram Botrous, our
wastewater engineering staff has proven experience
in engineering alternatives, equipment selection
and unique ideas to meet your expectations.
Stantec Seismic/Structural Engineering
Qualifications Overview | Stantec has extensive
experience in seismic retrofit analysis and design
of a wide variety of structures. Our structural
engineering staff has analyzed and designed similar
engineering issues and designed resulting related
to structural failure assessment, retrofit design and
construction as well as comprehensive capability in
structural engineering and design.
2. FIRM EXPERIENCE
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 3
MADERA WWTP REHABILITATION PROJECT, MADERA, CA
Client Name:
City of Madera
Project Status: 2018
(completed, currently under construction)
Summary of Services Provided: helped identify critical
infrastructure that required rehabilitation to allow for
safe and reliable wastewater treatment operations
Team Members: Steven Beck and Beth Cohen
Reference: Humberto Molina, Chief Plant Operator |
(559) 661-4961 | hmolina@madera.gov
Description: The City owns and operates the Madera WWTP that treats an existing average flow rate of 5 MGD and has a design
capacity of 10.1 MGD. Much of the treatment plant infrastructure was built in the 1970s. Although some equipment was replaced
during the 2006 expansion project, there are still many assets that were installed nearly 45 years ago and have reached their life
expectancy. With an annual income of less than 70% of the national average, the City’s rate payers have limited means to offset
the rising demand for wastewater treatment. Years of lean budgets and staffing shor tages led to near catastrophe: system wide
outages that impacted reliability and performance of the WWTP. Some process equipment was out of service due to catastrophic
failure and many facilities provide unreliable treatment with frequent maintenance outages. The City requested the Stantec team
provide a condition assessment of wastewater facilities, help determine the cause of wastewater infrastructure failures, and
identify risks associated with operating the WWTP with malfunctioning equipment.
Challenges and Solutions: Our engineering team designed the Phase I Rehabilitation project to restore operation to three primary
clarifiers (repairing concrete and coating channels, installing new sludge and scum collectors, and replacing primary sludge
and scum pumps), overhaul the anaerobic digesters (new sludge mixing systems, new sludge and gas valves, coating the tanks
and roofs, and refurbishing a heat exchanger), repairing the corroded centrate drain line with a new cured in place pipe (CIPP),
constructing a new primary effluent pump station, and installing a new plant water well with hydropneumatic tank.
SAN JOSÉ-SANTA CLARA REGIONAL WASTEWATER FACILITY CAPITAL IMPROVEMENT PLAN PROGRAM, SAN JOSÉ-SANTA CLARA, CA
Client Name: San José Environmental Services
Department
Project Status: 2013 - Present
Summary of Services Provided: program, project,
design, construction, value, and document management;
planning; controls and tools; QA/QC; SME reviews;
permitting; scheduling; cost estimating; sequencing; start-
up and commissioning; as-built drawing/O&M manual
development; GIS; mobilization/rapid response, and more
Team Members: Lloyd Soohoo
Reference: Tina Pham, PE, LEED AP, Senior Engineer |
(408) 635-2099 | tina.pham@sanjoseca.gov
“I confidently recommend Stantec for Program
Management services due to their technical
expertise, understanding of programmatic delivery,
dedication to meeting our goals, and commitment of
their staff.” - Napp Fukuda, Assistant Director
Description: The San José-Santa Clara Regional WWTF operates one of the largest advanced WWTFs in the western United States
serving eight cities and four sanitation districts with 1.4 million residents and a business sector with more than 17,000 main sewer
connections. The facility treats an average of 110 MGD of wastewater, and has the capacity to treat up to 167 MGD. Built in 1956,
an extensive rehabilitation program was launched to address the aging infrastructure as well as the development of new processes
and improvements for portions of the existing plant. The City selected Stantec and Carollo in 2013 to provide program and project
management staffing to support the planning and management of the capital improvement program. Stantec is responsible for the
Clarifier Rehabilitation project, planning, preliminary design, detailed design and construction phase services. The Project includes
retrofitting 16 clarifiers. The planning phase included a structural and seismic evaluation of the clarifier mechanism center pier footings,
a site and clarifier structural survey, and a condition assessment of clarifier groundwater pressure relief systems.
Challenges and Solutions: As program manager and the structural/seismic subject matter experts, the Stantec team administered a
detailed structural analysis and seismic evaluation and review of the existing clarifier center pier footings. This was done to evaluate
whether the existing footing could support the clarifier retrofit with a new mechanism. A detailed structural analysis and seismic
evaluation of the two existing clarifier footing designs (one c. 1975; one c. 1981) was performed for seismic forces generated by the
proposed new clarifier mechanism. The analysis, performed in conformance with the California Building Code (CBC) and American
Society of Civil Engineers ASCE 7-10, was based on forces provided by qualified process equipment manufacturers under the sloshing
water forces as an immersed element. The tasks included checking as-built drawings of the existing structures and center piers to
document existing anchorage components. Recommendations for support and anchorage of the proposed replacement mechanism
based on forces (i.e., internal forces members sizing and connections) were coordinated with qualified equipment manufacturers
Westech, Ovivo and Evoqua.
DONNER SUMMIT PUBLIC UTILITY DISTRICT WASTEWATER FACILITIES UPGRADE AND EXPANSION, SODA SPRINGS, CA
Client Name: Donner Summit Public Utility District
Project Status: 2007 - 2015
Summary of Services Provided: conventional - design/
bid/build; provided water and wastewater engineering,
design, environmental services, and funding assistance
to the District since 1985
Team Members: Steven Beck, Akram Botrous, and
Beth Cohen
Reference: Tom Skjelstad, General Manager |
(530) 426-3456 | tskjelstad@dspud.com
Description: The Stantec team has provided water and wastewater permitting, engineering, design, environmental, and funding
services to the Donner Summit Public Utility District (DSPUD) since 2007. The Donner Summit wastewater plant expansion project
included major rehabilitation and repurposing of the two existing package plants including secondary clarifiers into four stage reactor
basins to meet stringent discharge requirements. Our team completed a facilities plan preforming lifecycle cost analysis of various
treatment alternatives and was selected to design the recommended alternative. We also provided construction management
and PLC/ SCADA programming services. The DSPUD project and STPUD project have a lot of similarities in terms of rehabilitation
requirements, weather, short construction season, and seasonal flow variations.
Challenges and Solutions: DSPUD provides wastewater treatment services for a community consisting primarily of a ski resort
that contributes large seasonal and daily variations in flows and loads, which coincides with very low temperatures. To meet strict
discharge requirements, we designed an MBR process that re-used and re-purposed existing package plants with secondary clarifiers
into four stage reactor basins by removing the mechanisms and installing new baffle walls, resulting in significant cost savings.
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 4
Additional, Relevant Experience Beyond Five Years:
CITY OF MERCED WWTF PHASE IV UPGRADE AND EXPANSION PROJECT, MERCED, CA
Client Name: City of Merced
Project Status: 2007 - 2011
Summary of Services Provided: permitting, planning, and
design services
Team Members: Steven Beck, Akram Botrous, and
Beth Cohen
Reference: Bill Osmer, WQC Manager | (209) 385-6892 |
osmerb@cityofmerced.org
Description: The City of Merced WWTF was originally constructed in the 1950s and was upgraded to an activated sludge
secondary treatment facility in the 1970s. Since 2003, Stantec has provided wastewater permitting, planning and design services
for the City on multiple upgrade and expansion projects at the WWTF. In 2011, the plant was upgrade to a Title 22 tertiary treatment
plant and expanded from an average dry weather flow capacity of 8 MGD to 12 MGD. We provided planning and design services
for the City of Merced WWTF Phase IV Upgrade and Expansion to 12 MGD which included new headworks with influent pumps,
screens and grit removal equipment, secondary treatment process improvements for simultaneous nitrification/denitrification, new
blower for aeration basins, rehabilitation of primary and secondary clarifiers, primary effluent equalization basin, tertiary pump
station, tertiary flocculation basins, cloth media filters, UV disinfection system, outfall with cascading
aerator, chemical building and storage facility, standby generator, plant water pump station, and improvements to existing
operations building.
Challenges and Solutions: Similar to the STPUD project, the existing clarifier mechanisms had to be custom-fit to the existing
structure. Our team performed a structural seismic analysis on the mechanism and structure as part of the retrofit.
Additional, Relevant Experience Within Five Years:
RINCONADA WTP SOLIDS RESIDUALS REMEDIATION PROJECT, LOS GATOS, CA
Client Name: Santa Clara Valley Water District
Project Status: 2018 - Present
Summary of Services Provided: pre-design of retrofit of
existing solids handling system; condition assessment
of gravity thickeners and mechanisms
Team Members: Steve Chavez and Sean Carey (JDH)
Reference: Client policy prevents us from listing a reference
Description: The Rinconada WTP serves the Santa Clara community and surrounding areas. They recently designed and
constructed a new Solids Handling Facility that was found to be inadequately sized to serve the current needs. Stantec was hired to
analyze the system and design upgrades to increase capacity and resolve other system deficiencies. The scope of work included a
condition assessment of the relatively new Gravity Thickeners and their mechanisms.
Challenges and Solutions: Several challenges included access and confined space planning for inspection of the gravity thickeners
due to the ongoing Reliability Project construction and the need to maintain operations. Stantec developed an entry plan that met
the Owner’s approval and limited impact to operations and the surrounding construction. Inspections were carried out and specific
findings and solutions are not available to disclose at this time due to Client request, but generally include coating and corrosion
protection solutions that may be directly applicable to the STPUD project.
SAN GERONIMO WATER TREATMENT PLANT (WTP) CLARIFIER SEISMIC UPGRADE PROJECT, WOODACRE, CA
Client Name: Marin Municipal Water District
Project Status: 2019 - Present
Summary of Services Provided: condition assessment,
clarifier performance evaluation, clarifier seismic evaluation
and preparation of bid documents for clarifier replacement
and associated structure improvements
Team Members: Lloyd Soohoo, David Palmer, and
Jim Loucks
Description: The Marin Municipal Water District prepared a Treatment Plant Master Plan which identified a need for major
seismic rehabilitation of the existing filters, clarifiers and other structures, to meet the District’s level of service goal of producing
water within 24 hours of a major earthquake. Stantec was selected to design upgrades for the San Geronimo Treatment Plant
(SGTP) under the Clarifier Seismic Upgrade Project, the next project on the path identified in the Water Treatment Plant Master
Plan to help ensure continued, reliable operation of the Treatment Plants for the next 50 years. We reviewed available record
drawings, interviewed operations staff, performed an existing condition analysis, evaluated existing and new clarifier performance
and efficiency, performed seismic analysis of the existing clarifier structures, developed detailed design and construction bid
documents for clarifier replacement, consulted with clarifier manufacturers to confirm ability to comply with specified design
criteria, developed an opinion of probable cost (OPCC), and provided bid phase and engineering services during construction
(ESDC) services.
Challenges and Solutions: To meet the Owner’s schedule and critical milestones, our team carried out the design in an accelerated
2-1/2 month period, performing various condition assessments, analyses, calculations and reporting. During construction, the
Stantec team has worked with the general contractor and multiple clarifier manufacturers to achieve a custom design capable of
meeting the District’s process and seismic performance criteria.
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 5
APPROACH TO PROJECT3
GOALS AND OBJECTIVES
The District has benefited from the secondary clarifier
equipment meeting and exceeding the useful life,
and as noted in the 2013 condition assessment
report, there continue to be issues with coatings,
corrosion and functional drive mechanisms. In
addition, the clarifier structures themselves are
approaching 60 years in useful life which may
require specific actions for rehabilitation to extend
its life cycle. Our approach is to find the best solution
for the District that meets the following criteria:
−Reliability: Prioritize the solution that
provides the longest term useful life
−Cost: When considering alternatives,
prioritize cost within the District’s budget,
or at least develop the incremental cost
and benefit beyond the current budget
−Operational Efficiency: Alternatives may
provide opportunities to improve and enhance
operational efficiency. Our approach is to
evaluate these type of improvements and
provide a cost analysis to evaluate the benefit
−Schedule Awareness: In any alternative, we need
to be aware of the complexity and duration of
schedule and impacts to Plant operations; an
alternative that requires long-lead items or extended
periods of plant shutdown may be possible, but
not practical, so we have to keep this in mind
DATA COLLECTION AND REVIEW
At project onset, we will collect certain information
or obtain data from field testing to aid in making the
necessary engineering decisions.
Onsite, South Lake Tahoe, CA
Perform Preliminary Investigations
−Outage Coordination: To adhere to the pre-design
and design schedules, a quickstart approach is
needed to perform the preliminary investigations of
the secondary clarifiers. Similar to an approach we
typically use during construction, Stantec prepares
a detailed Outage Request Form for each clarifier
entry and presents it to the District engineering and
operations staff for review and comment. If needed,
a site visit is held with operations staff to coordinate
details for the outage and such as confined space
entry protocol, responsibilities, communications,
and emergency plans. The outage form is revised,
finalized, and approved prior to entry.
Our staff is trained in OSHA confined space entry and
qualified to conduct the preliminary investigations.
−Outage Sequence: Preliminary investigations of the
secondary clarifiers will be planned and scheduled
during periods of low flow with limited impact
to operations. Shortly after the proposed early
September notice to proceed, Stantec will submit
and schedule the outages in a sequence that is
agreeable to the District.
The following order and sequence is thought
to have the least impact to operations:
• Clarifier #3 while #1 and #2 are running
(in series) – by 9/13/19
• Clarifier #2 while #1 and #3 are running
(in parallel) – by 10/4/19
• Clarifier #1 while #2 and #3 are running
(in parallel) – by 10/8/19
3. APPROACH TO PROJECT
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 6
−Conduct Investigation for Concrete and
Mechanical Equipment: During the preliminary
investigations we will review the concrete and
coatings evaluation report and verify the findings
from 2013. Most of the information from the 2013
report is sufficient and not too much additional
duplicated effort is expected. However, some
additional core sampling from Clarifier #1 and
Clarifier #3 may be required to base final structural
recommendations. If necessary, we are prepared to
utilize our subconsultant, JDH Corrosion Engineering
to assist with this effort, as they are familiar with this
type of work having just complete similar evaluations
with Stantec at the Rinconada WTP gravity
thickeners 1 and 2.
−Survey Slab and Wall Elevations of Each Clarifier:
Stantec’s Reno, Nevada, Geomatics group will
provide surveying services which will include a
topographic survey of the existing secondary
clarifiers and other pertinent structures and facilities.
The survey will be completed with GPS, robotic and/
or scanning methods and utilize existing survey
control information or establish new survey control
information, if required. The topographic base
mapping will include accurate horizontal and vertical
locations of the existing improvements for use in
the development of the improvement plan set and
allow for consideration of custom equipment.
PRELIMINARY DESIGN
Seismic Considerations
With the primary goal being to address the
condition of the mechanisms, an evaluation of
the structure itself is prudent to determine what,
if any, repairs or retrofits are necessary.
−Conduct Preliminary Calculations: We have
started some preliminary seismic evaluations and
calculations of the existing secondary clarifiers
as part of a top-down approach to understand
whether they can meet current seismic code. Further
detailed calculations are necessary during the pre-
design phase, but knowing this as soon as possible
allows us to start in on the pre-design work with a
good understanding of the type of rehabilitation or
replacement recommendations and decisions are
more or less likely.
In preparation for this proposal, we performed a
preliminary seismic assessment of the existing
clarifier structures assuming typical material
strengths for concrete structures of this vintage.
The preliminary results look favorable but will require
further detailed evaluation during pre-design as
described in the Seismic Analysis approach section
below, and using known geotechnical values.
−Contact Manufacturers Regarding Constructability,
Seismic, Delivery, and Cost: Our recent experience
with other project clarifier rehabilitation projects
finds that most of the mechanism equipment
vendors/suppliers are challenged with meeting the
equipment anchoring requirements to meet seismic
design. Lloyd Soohoo, our mechanism structural
lead, is currently managing these issues for our
similar project with Marin Municipal Water District,
where several lessons learned can be directly applied
to this project and benefit in several ways such
as more focused pre-design effort, collaborative
coordination with vendors, and clear and concise
specification requirements for bid documents.
The critical issue, whether replacement equipment
is of the conventional or custom-made type, is
the design of mechanism’s center column anchor
bolt attachment to the existing clarifier slab. Most
vendors we have worked with find it a challenge
to come up with an easy way to meet the anchor
requirements under the latest seismic design criteria.
To maintain the cantilevered column-
supported clarifier mechanisms, the
existing center pier foundation may need to be
replaced with a significantly thicker section.
−Seismic Analysis: We understand that the District’s
goal is to achieve an additional 50 +/- years of service
life from the Secondary Clarifiers. If the clarifier
mechanisms are replaced, or repairing or retrofitting
them substantially increases their weight, a seismic
evaluation and retrofit of the mechanism foundations
will be required to meet current California Building
Code standards. If the rehabilitation measures do
not result in new loads to the existing walls, then the
building code does not mandate retrofitting the walls.
However, considering that the Secondary Clarifiers
were constructed when seismic forces were often
not considered or were considered at a much lower
force level than current building code requirements,
we propose to include a seismic evaluation of the
walls to identify areas of seismic deficiency and
preliminary retrofit alternatives. The findings from
this evaluation will be submitted as a technical
memorandum to the District. At that time, the District
can decide whether or not to include voluntary
seismic retrofit work as part of the current project.
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 7
Alternatives Analysis
−Analyze Effects On Plant Hydraulics: As
part of the pre-design, we perform a hydraulic
analysis of the secondary clarifier process
to verify performance and effects of new
equipment and piping improvements.
−Analyze RAS Piping Modifications: Several ideas
are currently being looked at for replacement
equipment if rehabilitation is not recommended.
One idea is presented in Figure 1 showing a
method to bore pipe below the clarifier and
connect to the hopper, extended up into the
clarifier mechanism. This may allow for lower
cost conventional equipment to be used.
−Analyze Latest Clarifier Equipment Mechanisms,
to Adapt to Existing (conventional vs. matching
equipment): Should full replacement of the
mechanism equipment be considered, there
appears to be a couple different options
that would meet the District’s needs.
The current clarifiers mechanism equipment was
originally provided by the Dorr-Oliver company and
relies on rotating rake arms with small diameter
sludge suction pipes that withdraw sludge from the
bottom of the clarifier, and convey it to an overhead
RAS pipe supported by the bridge walkway. This
mechanism type is almost obsolete. The industry
standard mechanisms include beneficial features
such as energy dissipating inlets, flocculating wells,
efficient sludge collection, and scum removal.
Our initial discussions with vendors have
confirmed that clarifier mechanisms similar to
the existing equipment can still be manufactured,
even though not common. Matching the existing
equipment is usually custom-made and involves
higher equipment costs and relatively lower
structural/ mechanical facility retrofit costs.
Another option is a new mechanism design that
relies on RAS conveyance below the structure. For
this alternative, the equipment cost will be less
than the custom-made equipment, but this cost
saving may be offset by the higher facility retrofit
costs, mainly due to the installation of the RAS
pipe under the clarifier. Since the cost of either
option may be close. We recommend replacing
the existing mechanism with a modern type
mechanism because of all the added benefits.
−Analyze Impacts to Plant Operations/Sequencing:
As part of the pre-design constructability review
and development of sequencing plans, bypass
pumping considerations during construction will
be evaluated. The goal of the sequencing and
constraints is to control District’s operational
risk while providing enough information in the
construction bid documents for bidders to
find the best methods to price the work.
Figure 1
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 8
DETAILED DESIGN
−Project Management, Manage the Project: To
aid in successful delivery of projects, Stantec has
developed and implemented the Global Project
Delivery Framework for all projects. Stantec
has focused in a prioritized manner on the
following five key project delivery components:
• Right person
• Right job
• Consistent practices
• Standard tools
• Accountability
Right Person, Right Job
We have instituted a company-wide requirement
that only highly qualified, approved and trained
staff will serve as project managers. Approval is by
the Operational Director of Project Management
and is based on meeting required levels of training
and experience. Stantec has implemented Project
Management Institute (PMI) or equivalent training
for all project managers. Stantec also requires
that a Project Technical Lead (PTL) be assigned
to every project. The PTL works closely with the
project manager and is focused on technical
quality of the project, i.e., the solutions proposed
must be sound, and all work must be approved by
subject matter experts at specific milestones.
Consistent Practices
We have rolled out a set of consistent practices that
all project managers and PTLs are required to follow.
These are closely based on the PMI’s approach to
project management. The consistent practices are
available to all project managers and PTLs from the
Stantec intranet-based Project Delivery System (PDS).
Standard Tools
Our project managers are provided access
to financial data on their projects through the
company’s proprietary project controls system. This
provides project managers a series of reports and
tools to manage their projects. These include:
−Summary financial information
−Detailed financial data by work breakdown
structure (i.e., budgets for individual staff by task)
−Integrated schedule and budget
management (ISBM) information
−Earned value and estimate to
complete tools and reports
−Accounts payable/receivable status reports
Additional tools for scheduling and resource
management such as Primavera’s P6 or Microsoft
Project are provided through the Stantec
project controls and monitoring group.
Accountability
Stantec has developed and implemented project
manager and PTL job descriptions, organizational
reporting lines, and key performance indicators
for project management and PTL staff and
line management. Monthly meetings are held
between project managers and line management
to review performance on projects.
Monthly Reports to District PM
The work for this pre-design will be condensed in a
tight schedule from notice of award to completion of
bid ready documents. Therefore it will be important
to keep the District updated on the status of the
evaluations and recommendations to be able to
make key decision to move the project forward. The
monthly report is a useful tool to summarize key work
completed and planned ahead, budget summaries and
potential issues, key decisions needed or upcoming by
the District, and any other overall updates of the work.
Project Meetings and Workshops
In addition to the important technical tasks, we will
include a series of meetings and workshops with
District staff. Our first meeting will be combined
with the project kickoff meeting. The purpose
will be to review project purpose and scope,
confirm project objectives, and obtain input from
operations, maintenance, and engineering staff on
changes that may have arisen since original RFP.
An important consideration will be the dates
when the plant can isolate a single clarifier.
Any specific data, information, and documents
needed for the analysis will also be submitted at
the meeting. Given the short pre-design duration,
holding a single design review workshop after the
preliminary investigations and Alternatives Analysis
are written is preferable. A followup meeting is
recommended to review the Design Memorandum
prior to the end of year holiday season, to maintain
the 90% Design Development schedule.
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 9
Prepare Draft Plans and Specs
An important part of the design and contract
development is providing guidelines and constraints
on the overall construction schedule and the time
periods during which the contractor can perform work
in and around the clarifiers. Working in an operating
plant carries special requirements for protection of
systems and coordination with operations staff. Our
proposed team members have upgraded operating
plants many times in the past and will bring that
experience to this project so that the improvements
can be done efficiently while the plant meets all
production and water quality requirements.
Keeping the plant operational with minimal disruptions
is a key imperative. In coordination with the pre-design
and design work, we propose to develop a detailed
schedule and construction sequencing plan that takes
into consideration plant flow constraints, seasonal
peak flows, staging and laydown areas, access,
interconnections, and key steps for equipment startup
and testing as part of the Division 01 specifications.
At a minimum, the sequencing plan will address:
−Required plant production capacity,
including seasonal requirements
−Approximate number and duration of key
plant outage periods to be integrated into
the overall construction schedule
−Intermediate construction milestones
−Durations for startup and testing activities
−Climatic/weather conditions and related
allowance for schedule float
−Procurement and delivery durations
of key equipment and materials
−Coordination with ongoing plant operations,
delivery of materials (e.g., treatment chemicals),
and pedestrian and vehicular circulation
Develop 90% and 100% drawings and specifications
Effective communication among Stantec and
our specialty subconsultants is essential to
the overall success of the project. We have
employed several tools in the past to assist
with project communications, and we believe
they would be great solutions to manage
communications during pre-design and design:
−Information Sharing Tools: ProjectWise file
sharing software will be used by all project
team members. All calculations, technical
memoranda, drawings, and specifications will
reside in this common, secure location. The
system maintains a single working version of each
document, and it automatically updates design
drawing references, thus minimizing rework.
−General Communication Tools: Stantec uses
tools such as videoconferencing and screen
sharing to communicate internally and with
subconsultants and clients. These tools allow for
effective and efficient communications and are
normal practice among our staff. Our meeting
with District staff are organized as presentations
of technical information with specific requests
for feedback and approval of project concepts.
We have found this approach to be effective and
given the short timeframe for completing the
design of the project, this familiar approach will
facilitate making decisions in a timely manner.
−Action Items And Decision Logs: Stantec will
maintain an ongoing list of action items from each
meeting to confirm that project commitments
are tracked and completed in a timely manner.
Similarly, all major decisions will be recorded
in tabular format to assure that the decisions
and rationale for those decisions are available
for reference as the project progresses.
Develop project construction costs in an OPCC
Our team will deliver a detailed contractors type of
cost estimate using commercial estimating software.
The Opinion of Probable Construction Cost (OPCC) will
be compatible with AACE Class 4 estimating criteria.
Under a cost driver approach, we will focus on the
minority project components that drive the majority of
the total project costs.
For cost estimating, we use our internal estimating
system, which is frequently updated with actual
data from recent and ongoing comparable projects.
In addition, we will obtain budget quotes for major
materials and special construction equipment.
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 10
PROJECT TEAM4
Onsite, South Lake Tahoe, CA
YOUR TEAM
Engaging the right people is the
cornerstone of any successful project.
We assembled a team of industry leaders with the
required experience, local knowledge, and time to
dedicate to your project. Our team will deliver clarifier
designs that provide a path to reliable capacity, and
improved resiliency, redundancy, and operations.
JDH Corrosion Consultants, Inc. (JDH) | JDH is
an engineering company that provides corrosion
consulting services. They specialize in conducting
corrosion investigations, providing corrosion
failure analysis, selection of materials for corrosive
environments, cathodic protection design and
engineering maintenance, stray current analysis,
conducting corrosion research projects, selection and
specification of protective coatings systems, failure
analysis of protective coatings, construction inspection
services, and expert witness consulting in litigations.
We recently collaborated with them on the Santa
Clara Valley Water District’s Rinconada WTP project;
they conducted a condition assessment; the report is
detailed in a subsection of Appendix A - Sample Work
Product. We are confident that JDH will supplement
our team by leading corrosion engineering.
ORGANIZATIONAL CHART
The chart below depicts the organization of the
project team, delineates lines of communication, and
presents roles/responsibilities. We have described the
specific roles, duties, availability, and selection criteria
for our project manager and key team members on
the following page. Detailed resumes are located in
Appendix B - Resumes.
STPUD
PRINCIPAL-IN-CHARGE/PROJECT MANAGER
Steven Beck, PE
Process Mechanical
Akram Botrous,
Ph.D., PE, BCEE
Seismic Review
David Palmer, PE, SE
Mechanism Structural
LLoyd Soohoo, PE, SE
Cost Estimating
Jim Loucks, PMP, CCE
KEY TECHNICAL LEADS
Concrete Rehab
Beth Cohen, PE, LEED AP
Civil Engineering
Matt Carpenter, PE
Instrumentation and Controls (I&C)
Phil Atkinson, PE, CEng.
Construction Sequencing
Steve Chavez, PE, CE/ME, CCM
Survey
Eric Snyder, PLS
Corrosion
Sean Carey (JDH)
OTHER TECHNICAL RESOURCES
4. PROJECT TEAM
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 11
KEY TEAM MEMBER ROLE YEARS OF EXPERIENCE EDUCATION LOCATION AVAILABILITY TOTAL LEVEL OF COMMITMENT* WHY SELECTED CONTACT INFORMATION
STEVEN BECK, PE
Principal-
in-Charge/
Project
Manager
34+
MS and BS, Civil
Engineering; BS,
Construction
Management
Rocklin, CA 60%40%
−Recognized leader in wastewater treatment design with 34+ years of experience
−Has managed all phases of water and wastewater treatment projects—including conceptual
planning, feasibility studies, design, and construction management
−Experience on water and wastewater facilities in Northern California
(916) 826-3665 |
steven.beck@
stantec.com
AKRAM
BOTROUS,
PH.D., PE, BCEE
Process
Mechanical
Lead
27
Ph.D., Environmental
Engineering; MS,
Sanitary Engineering;
BS, Civil Engineering
Rocklin, CA 30%70%
−27 years of wastewater experience
−Designed numerous secondary clarifiers
−Experience with WWTP rehabilitation projects
−Primary author of MOP8 (primary clarifiers chapter)
(916) 773-8100 |
akram.botrous@
stantec.com
DAVID PALMER,
PE, SE Seismic
Review Lead 21
MS, Civil and
Environmental
Engineering; BS, Civil
Engineering
Sacramento,
CA 25%75%
−Experienced in structural design in high seismic and cold weather applications for both
hydraulic and non-hydraulic applications, water/wastewater conveyance, containment,
and storage facilities, and industrial and institutional buildings; seismic evaluation and
retrofit of buildings and water/wastewater facilities; conducting condition assessments and
rehabilitating of existing structures exhibiting other forms of deterioration
(916) 418-8290 |
david.palmer@
stantec.com
LLOYD SOOHOO,
PE, SE
Mechanism
Structural
Lead
22
MS, Structural
Engineering; BS,
Civil Engineering
Walnut Creek,
CA 25%75%
−Experienced in structural design of reservoirs, industrial buildings, pump stations, and
WWTP/WTPs
−Coordinated seismic requirements with manufacturers in clarifier replacement project
−Certified California Safety Assessment Program (SAP) Evaluator
(925) 627-4550 |
lloyd.soohoo@
stantec.com
JIM LOUCKS,
PMP, CCE
Cost
Estimating
Lead
41 BS, Construction
Engineering
Walnut Creek,
CA 15%85% −40+ years of cost management experience
−In depth knowledge of AACE guidelines for construction and California rates and market
conditions
(925) 627-4652 |
james.loucks@
stantec.com
BETH COHEN,
PE, LEED AP Concrete Rehab Lead 16 BS, Environmental Engineering Rocklin, CA 25%75% −Design and planning experience in a wide range of water and wastewater projects
−Specializes in water and wastewater treatment and conveyance/distribution system master planning, and detailed water/wastewater treatment process design
(916) 773-8100 | beth.cohen@stantec.com
MATT
CARPENTER, PE Civil Design
Lead 20 BS, Civil Engineering Sacramento,
CA 15%85% −Senior associate in Stantec’s water group
−Experience on water and wastewater facilities in Northern California
−Experience in condition assessment of storage tanks
(916) 418-8282 |
matthew.carpenter@
stantec.com
PHIL ATKINSON,
PE, CENG. I&C Lead 35
BE/BEng, Electrical and
Electronic Engineering;
BTEC, Industrial
Measurement and
Control
Sacramento,
CA 15%85% −30+ years of experience specializing in instrumentation and control systems for both WTP
and WWTPs
−Engineering Design Lead (EDL) for Stantec’s design business group
(916) 924-8844 |
philip.atkinson@
stantec.com
STEVE CHAVEZ,
PE, CE/ME, CCM
Construction
Sequencing
Lead
24+ BS, Mechanical
Engineering
Sacramento,
CA 30%70% −20+ years of experience in water infrastructure, over 10 WTP/WWTP plants
−Demonstrated experience in condition assessment of clarifier structures and mechanism
equipment; developing treatment plant constructability, sequencing, and constraints
(916) 418-8241 |
stephen.chavez@
stantec.com
ERIC SNYDER, PLS Survey Lead 39 ---Reno, NV 40%60% −39+ years of survey experience which includes many water and water reclamation projects
(775) 398-1211 |
eric.snyder@stantec.
com
SEAN CAREY Corrosion
Lead (JDH)11 BA, Architecture Concord, CA 10%90%
−11+ years of corrosion project experience and member of the National Association of
Corrosion Engineers (NACE)
−Experience performing corrosion evaluation assessments, and produced corrosion
evaluation and soil corrosivity reports
(925) 927-6630 |
scarey@jdhcorrosion.
com
QUALIFICATIONS
At Stantec, we think a keen local focus needs to be at the core of any sustainable project initiative. We have
assembled a locally-based team with extensive national and international credibility.
For your convenience, this page contains hyperlinks. Click a key team member’s headshot image to redirect to
their detailed resume in Appendix B. Click the return icon at the top of on each resume to redirect to this page.
* Total commitment level of all other projects for each individual for the duration of the District’s project
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 12
MANHOURS5
MANHOURS
TOTAL MANHOURSSTANTEC JDH
NAMESTEVEN
BECK
AKRAM
BOTROUS
DAVE
PALMER
LLOYD
SOOHOO
JIM
LOUCKS
BETH
COHEN
MATT
CARPENTER
PHIL
ATKINSON
STEVE
CHAVEZ
ERIC
SNYDER
MITCHELL
PADILLA
PATRICK
KOHLMAN PA SEAN
CAREY
SERGIO
MACIEL
TASK ROLEPrincipal-in-Charge/
Project Manager
Process
Mechanical Lead
Seismic
Review Lead
Mechanism
Structural Lead
Cost
Estimating Lead
Concrete
Rehab Lead
Civil Design
Lead
I&C
Lead
Construction
Sequencing
Lead
Survey
Lead
Junior
Engineer
Junior
Engineer
Project
Assistant
Corrosion
Lead
Corrosion
Project
Engineer
1 DATA COLLECTION/
PROJECT MANAGEMENT 40 12 6 10 0 0 0 0 4 31 0 0 16 10 10 139
1.1 Collect and Review Data 4 4 2 2 ……………2 ………4 4 22
1.2 Preliminary Investigations 8 8 4 8 …………4 24 ………2 2 60
1.3 Project Management 28 …………………5 ……16 4 4 57
2 DESIGN 106 128 64 72 56 32 32 32 64 24 120 80 0 36 62 908
2.1 Perform Site Investigations 8 16 …24 …………24 24 ………30 30 156
2.1.1 Perform Alternatives Analysis 24 24 24 …32 4 ……………………108
2.2 Recommend Rehab
Improvements 16 16 ………16 …………………6 32 86
2.3 Prepare Design Memorandum 16 16 …………………………………32
2.4 Prepare 90% Design
Documents 42 56 40 48 24 12 32 32 40 …120 80 ………526
3 CONSTRUCTION
DOCUMENTS 12 40 32 40 0 32 32 32 8 0 80 80 0 0 0 388
3.1 Prepare Construction
Documents 12 40 32 40 32 32 32 8 80 80 388
4 BIDDING SERVICES 6 4 2 2 0 0 0 2 4 0 0 0 0 0 0 20
4.1 Attend Pre-Bid Conference 4 ……………………………………4
4.2 Provide Clarifications of Bid
Questions 2 4 2 2 ………2 4 ………………16
TOTAL MANHOURS 164 184 104 124 56 64 64 66 80 55 200 160 16 46 72 1,455
5. MANHOURS
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 13
SCHEDULE6
2019 2020
SPECIFIC DATESTASKSJULAUGSEPOCTNOVDECJANFEBMARAPRMAYJUN
Proposal Due Date Proposal due by 7/16
Consultant Selection/ Finalize Scope and Fee Consultant selection by 8/15
Board Award/ NTP Awarded by 9/15
Project Setup
Task 1, Data Collection and Review
Task 2, Review Facility Data
Task 2, Preliminary Investigations
Clarifier #3 Entry inspection by 9/13
Clarifier #2 Entry inspection by 10/4
Clarifier #1 Entry inspection by 10/18
Task 2, Develop/Present Alternative Analysis Deliverable by 11/8, PUD decision by 11/15
Task 2, Prepare Design Memorandum Deliverable by 12/6, PUD comments by 2/13
Task 2, Prepare 90% Design Documents Deliverable by 1/17, comments by 1/31
Task 3, Prepare Construction Documents Deliverable by 2/14
Task 4, Bidding Services
Onsite, South Lake Tahoe, CA
Reliable and flexible. We understand the
importance of timelines and quality. No matter
how aggressive the schedule, our resource capacity
will help ensure the project continues to run smoothly
and on schedule. We will also work closely with
you to determine key project milestones and then
adjust our schedule to meet those milestones.
6. SCHEDULE
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 14
7. LIST OF DOCUMENTS OR INFORMATION THE DISTRICT NEEDS TO PROVIDELIST OF DOCUMENTS OR INFORMATION
THE DISTRICT NEEDS TO PROVIDE 7
−Recent geotechnical report, including any related
information such as:
• Groundwater data
• Soil borings
• Soil factors
−Record drawings
−Rebar shop drawings for clarifiers
(archived submittals if available)
−Seismic parameters from the geotechnical engineer
−Splitter box to the three clarifiers
−Effluent pipe routing
Onsite, South Lake Tahoe, CA
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 15
APPENDIX A - SAMPLE WORK PRODUCT8
CITY OF MADERA WWTP - EQUIPMENT ASSESSMENT
This section includes information
regarding the City of Madera WWTP Phase
I Rehabilitation Project: WWTP Infrastructure
Assessment for Increasing Process Reliability
and Decreasing Risk of Operations
City of Madera WWTP Phase I Rehabilitation Project, Madera, CA
8. APPENDIX A - SAMPLE WORK PRODUCT
Memo
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To: Humberto Molina From: Beth Cohen, PE
City of Madera Rocklin, CA
File: 184030591 Date: March 17, 2017
Reference: City of Madera WWTP Phase 1 Rehabilitation Project: WWTP Infrastructure Assessment
for Increasing Process Reliability and Decreasing Risk of Operations
1. INTRODUCTION
The City owns and operates the Madera Wastewater Treatment Plant (WWTP) and is regulated by
Waste Discharge Requirements (WDR) Order No. 95-046. The plant treats an existing flow rate of 5
Mgal/d and has a design capacity of 10.1 Mgal/d, to accommodate future growth. The sanitary
sewer collection system delivers wastewater to the plant, where it is comingled with septage
receiving station effluent, processed by two mechanical screens, and pumped to grit chambers
and primary clarifiers. Primary effluent is pumped to oxidation ditches and secondary clarifiers,
before being discharged into percolation disposal ponds. Scum and waste sludge is sent to
anaerobic digesters and centrifuges, which produce Class B biosolids that are hauled off site for
disposal.
Much of the treatment plant infrastructure was built in the 1970s. Although some equipment was
replaced during the 2006 expansion project, there are still many assets that were installed nearly 45
years ago and have reached their life expectancy. Some process equipment is out of service due
to catastrophic failure, including primary clarifier effluent pump 2, oxidation ditch 3 aerator
gearboxes 5 and 6, ditch 3 anoxic selector basin mixer gearbox 5 and 6, and plant water well 1.
Further, many additional assets require refurbishment or complete overhaul and replacement to
provide appropriate levels of reliability and redundancy.
The City requested Stantec help determine the cause of wastewater infrastructure failures and
identify risks associated with operating the WWTP with malfunctioning equipment. Further, Stantec’s
team of engineers will prepare solicitation documents to restore operation to the facilities for the
Phase 1 Rehabilitation Project, which includes the following components:
• Digester 1 (sludge mixing and recirculation pumps, boiler and heat exchange system, and
automatic control valves)
• Primary Clarifiers No. 1-3 (collector mechanism components, sludge and scum pumps, gates,
and valves)
• Oxidation Ditch No. 3 (gear boxes for aerators and anoxic mixers)
• Plant Water Supply Wells and Hydropneumatic Tank
• Groundwater Extraction Wells
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PROJECT OBJECTIVES
The main objective for the Phase 1 WWTP Rehabilitation Project is to increase reliability of the
treatment processes, which ultimately benefits the City in the following ways:
• decreases risk of noncompliance and violation based fines,
• reduces labor costs by eliminating emergency operation staff called outside of normal
working hours
• minimizes temporary equipment rental required for emergency response,
• improves safety of staff and health of surrounding environment.
As stated above, increasing reliability and decreasing risks are centralized objectives of the
Rehabilitation Project and are further defined below.
Reliability
Robustness and reliability represent the degree to which the process is resilient and can perform
consistently well, even in problematic conditions, such as influent flow or load spikes, extreme
weather, or other challenging biological process conditions. For biological treatment systems that
rely on sludge settling (such as Madera’s secondary treatment process: primary clarifiers, oxidation
ditches and secondary clarifiers), there can be variability in effluent quality, which would lead to a
higher probability of potential permit violations (although still low if properly designed and
operated). In the case of the Madera WWTP, the importance of process reliability is amplified
because the operational staff is severely limited, with only three full time operators available (two of
which are Grade III certified and below) and therefore cannot immediately optimize the system
during plant upset conditions. The importance of facility resilient cannot be understated and
processes must be readily available to accommodate challenging conditions, including potential
operator error or lack of immediate operator attention, without compromising effluent quality.
Industry standard defines wastewater treatment reliability using the following compliance
techniques:
• Method 1: Redundant Facilities
o One method of compliance is to have multiple treatment units in service, such that,
even if the largest unit must be taken off-line, the remaining units would be able to
meet discharge requirements at the full design flow. This can be thought of as
having fully redundant systems (with one standby equipment installed and ready to
operate at all times). Alternatively, there are two reliability options that are based on
the use of emergency storage of untreated or partially treated wastewater.
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• Method 2: Emergency Storage
o A short-term emergency storage facility with a capacity to store untreated or
partially treated wastewater for at least twenty-four hours and standby equipment
(or equipment that is stored on site that can be put into operation quickly) that can
be used to replace a treatment unit that is taken off-line.
o A long-term emergency storage facility with capacity to store untreated or partially
treated wastewater for at least twenty days in case a treatment unit is off-line.
The Madera WWTP has an existing storage basin that is sufficiently designed for short term
emergency situations, but does not have access to land for long term storage (to accommodate
twenty days of bypassed flow). Therefore, in order for the Madera treatment plant to be considered
reliable, which is needed to successfully operate the facility within the regulated discharge permit
requirements, standby equipment must be functional and made available at all times. This follows
Method 2’s approach in obtaining reliable treatment, by providing short term emergency storage
facilities with standby equipment.
The standby equipment should be cycled into service, on regular intervals, to ensure it is operational
and allows for scheduled maintenance or emergency bypass of the largest unit without interruption
of treatment processes.
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Risk
There are inherent risks associated with operating a wastewater treatment plant. The key to
successfully running a facility is to minimize the risks factors that are within the City’s control. In order
to understand how to reduce risks, it is important to understand what is meant by risk, which is
defined as:
Risk = (Probability of Failure) x (Consequence of Failure)
In other words, as both the likelihood of failure and impact of such failure increase, the risk increases
exponentially. This can be seen in Figure 1, a graphical representation of risk.
Figure 1 Graphical Representation of Risk Based on Consequence of Failure and
Likelihood of Failure
A numerical value for the probability of failure can be easily assigned based on the condition of an
asset and its useful life expectancy. The consequence of failure is harder to quantify and an
accounting matrix should be customized to the City’s objectives, but is typically broken down into
three main categories: social, environmental, and economic factors (such as public/employee
health and safety, environmental impact, cost to repair, etc.). As one can imagine, regardless of
how the City operates and maintains the existing treatment facilities, there will be little impact on
the consequence of failure. Consequence of FailureLikelihood of Failure
Risk Assesment
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Therefore, in order to reduce the risk of operating the Madera Wastewater Treatment Plant, the City
must reduce the likelihood of failure (the only controllable risk source) by rehabilitating systems that
can be fixed and replacing equipment that has reached its life expectancy. The highest priority
equipment will be those with the worst consequences from failure, those that have impact on
safety, permit compliance, and overall costs.
It is the City’s desire to get the best value from this project and is understood that putting money into
retrofitting aged equipment with limited salvage potential is not appropriate, so rehabilitation will
only take place on equipment with sufficient salvageable value. It is recommended to start
controlling risk by dealing with the most critical equipment, with the highest probability and
consequence of failure.
Historical Plant Performance
Due to lack of funding and inadequate access to standby equipment, much of the treatment
facilities have not been properly maintained. The deferred maintenance has begun to cause
system wide outages that is impacting the reliability and performance of the treatment processes.
An evaluation of the equipment status is described herein.
2. PHASE 1 EQUIPMENT EVALUATION
In order to control risk, the existing Phase 1 equipment was evaluated to determine the required
level of remediation necessary to make the processes reliable.
ANAEROBIC DIGESTERS
Waste Activated Sludge (WAS) that is removed the treatment processes is sent to the digester
facilities. Digesters No. 1 and No. 2 are primary digesters that overflow into a gravity feed line into
secondary Digester No. 3. Sludge is pumped from Digester No. 3 into the centrifuge facility for
dewatering and, ultimately, hauled off-site for disposal. The purpose of the anaerobic digestion
process is to stabilize the biodegradable portion of the raw sludge and to convert the sludge into
inert organic and inorganic compounds. In addition to sludge stabilization, aerobic digestion
provides pathogen reduction, reduces amount of sludge that needs to be dewatered, and
produces methane that can be used as an energy source. In order to be get class B pathogen
reduction, the regulations require a minimum mean cell residence time of 15 days (at 98 oF) inside
the digester. At the current sludge feed rates, each digester gives the City approximately 8 days of
detention.
Digester No. 1 and 2 was originally constructed in 1972 and Digester 3 was built in 2006. Digester No.
1 still uses the original recirculation pump, automatic control valves and many ancillary valving. In
the last 15 years, the sludge mixing pump and heat exchanger were replaced. Digester 2 and 3
were rebuilt in 2006 with new equipment and Digester 2 recently had the mixing and recirculation
pump rebuilt. The oldest items on Digester 1 (recirculation pump, mixing pump, and valves) have
reached their life expectancy and require replacement. The heat exchanger must be rebuilt to
provide reliable operation of the anaerobic digestion process.
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On January 30, 2017, Stantec provided emergency support to the City when sludge began
overflowing the digesters and spilling onto the ground. As stated in the field report, the digesters
were filled with debris that must be cleaned to prevent clogging and further overflows. The City
hired Wastewater Solids Management Company to clean all three digesters. Digester No. 1 has
subsequently been cleaned and inspected (condition described below). Once the mixing pump
and mixing system has been replaced, it will be put back into service and Digesters No. 2 and 3 will
be cleaned and inspected.
Digester No. 1 Inspection
After cleaning Digester No. 1, the tank interior was inspected by a Stantec structural engineer and
was found to have minor concrete cracking and leakage that requires repair, as shown in Figure 2.
The interior coating (on the walls and roof lid) has also delaminated and requires removal and
replacement. Further, abandoned equipment supports and piping still remain inside the tank and
must be removed to allow proper mixing and recirculation of the sludge, which is necessary for the
tank to reliably function as digester.
Figure 2 Digester No. 1 Interior Tank Inspection
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In addition to the interior repairs, the fixed frame digester cover has begun to rust, as shown in Figure
3, and needs to be recoated to protect from further damage. The cover is critical to the operation
of the process because it prevents explosive digester gas from escaping.
Figure 3 Digester No. 1 Exterior Cover Inspection
As stated above, the Digester No. 1 mixing system (pump, valves, and nozzles) have reached their
life expectancy and must be replaced. Further, the existing system only has one pump (no standby
equipment available for scheduled maintenance or emergency outages) and the nozzles were
insufficiently placed to allow for complete mixing of the tank, see Figure 4. For ease of operation
and maintenance, it is recommended to replace the system with one that matches Digester No. 2
and 3.
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Figure 4 Digester No. 1 Mixing Pump
Digester No. 2 and 3 Inspection
Digesters number 2 and 3 will be cleaned after Digester No. 1 is repaired and put back into service.
Once cleaned, the interior of the two digesters will be inspected. Digester No. 2 had a new roof
installed in 2006, at the same time Digester No. 3 was constructed. Both digesters have new mixing
and recirculation pumps that are functional and do not require rehabilitation.
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PRIMARY CLARIFIERS
Screened and de-gritted raw sewage is sent to the primary clarifier facilities, where the sewage is
sent through one of three rectangular primary clarifiers before being pumping into the secondary
treatment system. The purpose of the primary clarifiers is to reduce the suspended solids and
organic load on the downstream biological treatment process (reduction of 55% TSS and 30% BOD).
These are critical processes to the WWTP and must remain operational at all times to ensure
wastewater is adequately treated in compliance with the discharge permit.
Primary Clarifiers No. 1 and 2 was originally constructed in 1972 and had new sludge collection
mechanisms installed in 2007. Primary Clarifier No. 3 was installed in 1990. Each clarifier has a
coupled sludge pump and the facility has one shared scum pump.
Primary Clarifier No. 1 Inspection
Primary Clarifier No. 1 is not aligned, the pins will no longer lock, the links are worn (likely due to
misalignment), the flights and cross collectors will not rotate around the sprockets and guiderails
without constant oversite, see Figure 5. In the past two years, the clarifier has not in operation for
more than a week without failing and, most recently, has not been able to operate for more than a
few hours. Based on the age, difficulty operating and critical nature of the process, it is
recommended to replace all mechanical equipment.
Figure 5 Primary Clarifier No. 1 Damaged Equipment
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Primary Clarifier No. 2 Inspection
Primary Clarifier No. 2 is the only operational clarifier, see Figure 6. It is believed that the clarifier’s
equipment has also reached its life expectancy because it was installed at the same time as the
now failed Primary Clarifier No. 1. Therefore, it is recommended to replace all mechanical
equipment.
Figure 6 Primary Clarifier No. 2 Equipment Inspection
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Primary Clarifier No. 3 Inspection
Primary Clarifier No. 3 was installed in 1990 and has equipment from a manufacturer that is no longer
around. The clarifier has not been in operation for nearly 15 years, see Figure 7. Without being
exercised and receiving constant exposure to the elements (wind, sun, rain) for over a decade,
Primary Clarifier No. 3 is not able to perform reliably. Similar to Clarifiers No. 1 and 2, it is
recommended to replace all mechanical equipment.
Figure 7 Primary Clarifier No. 3 Equipment Inspection
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Primary Sludge and Scum Pumps and Misc. Process Items
There are three sludge and one scum pump that is coupled to the primary clarifier treatment
process. Sludge Pump 1 and 2 act as duty and standby pumping for clarifiers No. 1 and No. 2.
Sludge Pump No. 3 is directly coupled to clarifier No. 3 and has no back pump. There is only one
scum pump that handles scum from all three clarifiers.
Primary sludge Pump No. 1 is the only operational pump, see Figure 8. Sludge Pump No. 2 and 3
have been out of operation for 2-years and 15-years, respectively. The pumps all are manufactured
by Moyno and were installed in 1990. They have all reached their life expectancy and must be
replaced.
Figure 8 Primary Clarifier Sludge Pump Inspection
Further, the influent to each clarifier is controlled by a 12-inch sluice gate at the opening of each
tank. The gates are now seized and must be replaced. In order to properly maintain or replace the
gates in the future, it is recommended to install an inlet channel isolation gate. Aggregate inside
the concrete effluent channel has been exposed, likely due to entrained corrosive hydrogen sulfide
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being released from the turbulent flow into the channel. It is recommended to fix the concrete and
mitigate the turbulence inside the channel with a funneled drop.
OXIDATION DITCHES
Three oxidation ditches were installed in to 2006 project. Oxidation Ditch No. 3 is currently out of
service due to catastrophic failure of gearboxes (see Figure 9) in aerator 5 and 6 and anoxic mixer
6, as well as anoxic mixer gearbox motor 5. These items must be repaired or replaced, to allow for
proper operation of the secondary treatment process. All other secondary treatment equipment is
functional and does not require rehabilitation.
Figure 8 Oxidation Ditch No. 3 Aerator Inspection
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WATER WELLS
Plant Water Supply Well No. 1, installed in 1972, is currently out of service due to excessive sand
infiltration and low performance. Plant Water Supply Well No. 2 was installed in 2006, but is unable
to maintain water pressure or the pumping capacity needed for critical equipment. The
hydropneumatic tank system was installed in 19 72. Well water currently feeds the operations
building, seal water at several pump stations (raw sewage, primary effluent, and sludge pumps), grit
classifier, screens spray water, washer/compactor, polymer dilution, centrifuge, and site hose bibs.
Current demands are assumed to be approximately 200 gpm, which is currently being produced by
Well No. 2. The plant is at extreme risk of running the facility with only one plant water pump
(without a backup supply).
Video inspection of Well No. 1 was reviewed found to be severely damaged with several holes in
the casing, a torn liner, and the screen is plugged. There is insufficient metal left in the casing to
allow rehab to remove encrustations. It is recommended to install a new well, by proceeding with
test boring and getting a new properly designed well on-line as soon as possible (not currently within
Stantec’s scope of services). In the meantime, the City is at risk of losing access to Well No. 2 water
and must have a temporary backup plan in place, so they can maintain operation of plant wide
equipment that rely on access to water.
Video of Well No. 1 is necessary to determine the condition of the well casings and sanitary seals.
After 44 years of operation, the hydropneumatic tank exceeded its life expectancy and must be
repaired or replaced to provide a reliable water source for critical plant operations and prevent
excessive pump cycling.
The three groundwater extraction wells, between effluent disposal ponds 1 through 6, are at various
states of failure. The wells have lifted from their foundation and show signs of shifted concrete. The
damage to the wells allow for a direct path from the effluent disposal pond to the groundwater and
must be mitigated to reduce risks of groundwater contamination. Video inspection of the three wells
are necessary to determine the condition of the wells and sanitary seals. An evaluation report will
be prepared based on the findings from the video inspection to determine what is required to
prevent short circuiting of the pond effluent to the water table.
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3. SUMMARIZED RECOMMENDATION
The below equipment must be replaced in order to maintain adequate plant performance and
provide reliable operation of the treatment processes:
Digester No. 1: mixing pump and nozzles, interior and exterior tank coating, recirculation
pump
Digester No. 2 and 3: requires cleaning and interior inspection
Primary Clarifier No. 1 – 3: internal equipment, sludge and scum pumps, gates, outlet
channel repair
Oxidation Ditch No. 3: Mixer and Aerator Motors and Gearboxes
Water Well No. 1: Replace with new well and pump (out of Stantec scope), replace
hydropneumatic tank
Water Well No 2 and Groundwater Wells: Require further inspection
Most items listed above have long lead-times between placing an order and receiving the
equipment, typically four months. Stantec’s recommended approach is to pre-purchase the
equipment to expedite the repairs and then bid the equipment installation to qualified
contractors. Our experience is that the equipment repairs cannot be done by operation and
maintenance staff unfamiliar with installing this type of equipment. The design engineers are
soliciting quotes from three manufacturers as an emergency purchase, in accordance with the
City’s procurement procedures. After pre-purchasing the equipment, the design specifications and
drawings will be produced for the Phase 1 Rehabilitation Project.
Stantec Consulting Services, Inc.
Beth Cohen, P.E.
Design Engineer
Phone: (916) 773-8100
Fax: (916) 773-8448
beth.cohen@stantec.com
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 31
CITY OF MADERA WWTP - CONCRETE REHABILITATION
This section includes specifications
associated with clarifier rehabilitation
of the City of Madera WWTP project.
Madera WWTP Rehabilitation Project, Madera, CA
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SECTION 03906
CONCRETE REHABILITATION AND PROTECTIVE EPOXY POLYMER LINING
SYSTEM
PART 1 GENERAL
1.1 DESCRIPTION
A. Scope:
1. An approved applicator (Applicator) shall provide all labor, materials, equipment and
incidentals as shown, specified and required to furnish and install a concrete
rehabilitation and protective lining system for the City of Madera WWTP.
2. The extent of the protective lining and concrete rehabilitation shall be:
a. all interior surfaces of the Primary Clarifier Effluent Channel and
Primary Clarifier Effluent Lift Station Wetwell, including walls, floors,
baffles, and ceilings. See contract drawings for dimensions of interior
surfaces.
b. Digester No. 3, corbel and 3-foot span surrounding concrete surfaces.
3. The protective lining system components for the concrete corrosion rehabilitation
work shall include:
a. Surface treatment prior to coating application
b. Structural reinforcement (rebar) coating
c. Cementitous resurfacing/underlayment compounds
d. Epoxy formulation filler compound
e. Corrosion-resistant, moisture tolerant, epoxy monolithic protective lining
f. Miscellaneous materials
g. Dewatering, environmental modifying heaters and/or fans, as necessary to
install materials specified herein.
B. General: Specification is written around single manufacturer responsibility (Sauereisen) for
entire rehabilitation and lining system components. If submitting on equivalent products,
provide written evidence from the manufactures that verify compatibility and performance
guarantee statements required, in accordance with this specification, for mixing multiple
manufactures components. Owner reserves the right to deny approval of any materials that
do not comply with the Specifications.
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C. Coordination:
1. Coordinate surface preparation of substrates to avoid later difficulty or delay in
performing the Work of this Section.
2. Review Specification Section 01020 for bypass pumping and drawings for
equipment, miscellaneous metals, and piping appurtenances that must be removed or
protected prior to restoration work begins and coordinate the installation of items that
must be installed prior to application of the protective lining system.
3. Remove all chemicals, films, loose or deteriorated concrete, laitance, compounds and
other materials from substrates to receive the Work of this Section.
4. All substrate surface preparation and lining application is to be completed by
manufacturer’s approved Applicator.
1.2 QUALITY ASSURANCE
A. Applicator Qualifications:
1. Engage a single surface preparation and coating installation applicator specialist
(Applicator) with specific experience in the application of the type of protective
lining system specified, and who is approved by the protective lining manufacturer
and agrees to employ only tradesmen with specific skill and experience in this type
of Work. Submit manufacturer certification to Engineer for approval.
2. The Applicator shall be trained and approved by the protective lining materials
manufacturer. Provide written documentation from the materials supplier that the
applicator is trained and approved to apply all products used to complete the Work
prior to commencement of any site Work.
3. The Applicator shall have performed at least three (3) wastewater treatment plant
projects with coating and concrete rehabilitation systems of similar or greater
complexity in the last five (5) years of similar size that demonstrate the Applicator’s
experience and qualification to construct this project; of which, the Applicator must
demonstrate the successful completion of at least two (2) wastewater projects each
with a dollar value of at least 65% of the value bid for this project. Submit contact
reference information and dollar value of projects completed.
B. Performance Criteria: The surfaces to receive the protective lining system shall be capable
of withstanding, under constant exposure, raw wastewater and withstand attack from
hydrogen sulfide, abrasive particles, and organic acids generated by microbial sources, with
no adverse effects. Products capable of only intermittent exposure resistance are not
acceptable.
C. Source Quality Control: Provide each component of protective lining system produced by
a single manufacturer, including recommended underlayment, fillers, repair products, base
coat, and top coat materials and ensure compatibility between all elements. If submitting
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multiple manufacturers, provide verification from each manufacturer that all products are
compatible and that mixing manufacturers will not void warranties.
D. Statement of Application: Upon completion of the Work under this Section submit a
statement to Engineer, signed by the protective lining system Applicator stating that the
installed protective lining system complies with the requirements of the Specifications, and
that the installation and materials comply with the manufacturer's printed recommendations
related to the condition of installation and use.
E. Manufacturer:
1. Single source protective lining system components specified are as manufactured by
Sauereisen, Pittsburgh, PA (412) 963-0303. Request for material substitutions to the
specified products shall be made in writing to the Engineer.
2. Alternative source for lining system components are Raven Lining Systems and Sika
Corporation, with compatibility and performance guarantee statements required, in
accordance with this specification, for mixing multiple manufactures components.
3. The naming of a manufacturer in this specification is not an indication that the
manufacturer’s standard system is acceptable in lieu of the specified component
features. Naming is only an indication that the manufacturer may have the capability
of engineering and supplying a system as specified.
1.3 SUBMITTALS
A. Samples: Submit for approval the following:
1. Protective lining manufacturer’s standard size finished sample of protective lining
system on ¼-inch board showing the installed lining system to be expected in the
finished Work. Show the full thickness, or a typical thickness when underlayment
requirements will vary, of system with all components in place. The protective
epoxy lining must be at full thickness. Sample submittals shall be reviewed for color,
texture, and pattern only. Compliance with all other requirements is the exclusive
responsibility of Applicator.
B. Shop Drawings: Submit for approval the following:
1. Copies of manufacturer's technical data sheets complete with installation instructions
for protective lining system required.
2. Maintenance Manual: Copies of manufacturer's written instructions for
recommended maintenance practices. Include the following information:
a. Product name and number.
b. Name, address and telephone number of manufacturer and local distributor or
representative.
c. Detailed procedures for routine maintenance and cleaning.
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d. Detailed procedures for repairs.
3. Test Reports: Verification from protective lining system manufacturer that all testing
for physical properties has been performed in strict accordance with referenced
ASTM standards. Submit spark and adhesion testing data to Engineer for approval.
C. Certificates:
1. Submit manufacturer's certifications that materials have been approved for the
installation in a municipal wastewater treatment plant, in the wetwell and inlet
channel of a primary clarifier and clarifier outlet pump station with the following
known conditions:
a. Primary clarifier and outlet pump station has continued exposure to high levels
of sulfur/H2S gas, abrasive materials, organic acids, and liquids pH range of 6.0-
9.0
b. Primary clarifier and outlet pump station does not have exterior waterproof
coating
c. Primary clarifier and outlet pump station is sitting in high groundwater that is
above the structures bottom elevation
d. Coating is moisture tolerant and can withstand groundwater intrusion
2. Submit manufacturer’s Materials Warranty certificate.
3. Submit certificate of Applicator’s training and manufacturer’s approval to apply all
materials.
D. Applicator’s successful project completion reference list.
1.4 PRODUCT DELIVERY, STORAGE AND HANDLING
A. Delivery of Materials:
1. Deliver material in manufacturer's original unopened and undamaged packages.
2. Clearly identify manufacturer, brand name, contents and stock number on each
package.
3. Packages showing indications of damage that may affect condition of contents are
not acceptable.
B. Storage of Materials
1. Store in original packaging under protective cover and protect from damage.
2. Store all materials at temperatures recommended by manufacturer.
3. Stack containers in accordance with manufacturer's recommendations.
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C. Handling of Materials: Handle materials in such a manner as to prevent damage to
products or finishes.
1.5 JOB CONDITIONS
A. Environmental Requirements: Maintain substrate temperature and air temperature before,
during and after installation in accordance with protective lining manufacturer’s written
recommendations and instructions. If dewatering, heating, cooling, humidity control, or any
other environmental modification is required for proper installation (according to
manufacturer’s literature), provide submittal on approach.
B. Provide adequate ventilation during application and curing periods.
1.6 WARRANTY
A. Protective Lining manufacturer shall warranty its products as free from material defects for
a minimum period of three (3) year. Provide associated Warranty Certificate.
B. Applicator shall warranty the installed protective lining system as free from material and
workmanship defects for a minimum period of three (3) year.
PART 2 MATERIALS
2.1 MATERIALS
A. The protective lining system shall be a multi-component protective lining system,
including:
1. Concrete reinforcing steel bars (rebar) coating / primer shall be placed on all exposed
rebar. Assume 700-lf of exposed bars, at no additional cost to the Owner.
2. Cementitous resurfacing/ underlayment compound that shall be placed all interior
surfaces. Assume application depth is 3” across entire structure, at no additional cost
to Owner.
3. Epoxy filler compound to fill all voids and bug holes in the concrete to provide a
properly prepared and uniform surface for the epoxy lining.
4. 100% solids epoxy, moisture tolerant, polymer lining designed specifically for
municipal wastewater exposure, at a thickness of 125 mils.
5. The applicator shall supply all accessory components such as sealers, infiltration
control products or other compounds or products as recommended by the protective
lining manufacturer for maximum protective lining adherence to substrate and long-
term service performance.
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B. Products:
1. Reinforcing steel bars (rebar) coating / primer:
Properties Sauereisen ConoWeld No. 501
Components 2 part
Application Time at 70°F
Working Time 20 minutes
Initial Set 6 hours
Material 100% solids epoxy
Minimum Thickness 10 mils
Rebar primer shall be applied to all exposed rebar to seal surface, prevent reinforcing
steel corrosion, and promote adhesion of the subsequent resurfacing layer.
Alternative manufacturer is Sika Amatec 110 EpoCem, with compatibility and
performance guarantee statements for mixing multiple manufactures components.
2. Cementitous Resurfacer:
Properties Sauereisen F-121 Substrate
Resurfacer
Components 1 part
Application Time at 70°F
Working Time 30-45 minutes
Initial Set 7 hours
Compressive Strength (ASTM C109)
@ 24 hours 3,900 psi
@ 7 days 5,000 psi
@ 14 days 5,500 psi
@ 28 days 7,000 psi
Shear Bond Strength (ASTM C882-91)
@ 7 days 2,200 psi
@ 28 days 2,540 psi
Flexural Strength (ASTM C580) 1,500 psi
Tensile Strength (ASTM C307) 550 psi
Density (ASTM C905) 137 pcf
Mix Ratio (powder to water, by weight) 6.25/L
Minimum Thickness 1/8”
Assumed Average Thickness (for bidding purposes) 3”
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Underlayment shall be a high strength, fast setting cement resurfacing material.
Mortar shall be trowel or pump applied. Existing structures which are being
rehabilitated shall receive the resurfacing compound cement within the entirety of the
interior surface at a minimum 1/8” thickness (and an average thickness assumed to be
3”) to fill all irregularities to provide uniform surface for the application of the epoxy
corrosion resistant lining system. Ensure amount of resurfacing compound does not
extend beyond the limits of the original designed floor elevations (to ensure the
existing pump and pipes fit without alteration to the discharge manifold).
Alternative manufacturer is Sika Repair 224 with compatibility and performance
guarantee statements for mixing multiple manufactures components. Allow Sika
Repair 224 to dry for a minimum of 7 days (at 70-degrees Fahrenheit and less than
50% relative humidity) prior to applying epoxy lining.
3. Epoxy Filler Compound:
Properties Sewergard No. 109
Color Off White
Compressive Strength 10,000 psi
Density (ASTM C905) 87.2 pcf
Flexural Strength (ASTM C580) 4,000 psi
Modulus of Elasticity (ASTM C580) 5.2 x 104 psi
Tensile Strength (ASTM C307) 2,200 psi
Bond Strength to Concrete (ASTM D4541) Concrete Failure
Moisture Absorption (ASTM C413) <0.25%
Shrinkage (ASTM C531) <0.2%
Working Time 15 minutes @ 70°F
Topcoat 3 hours @ 70°F
Filler Compound shall be an epoxy formulation specifically designed to fill small
voids, irregularities and air pockets in concrete surfaces, structures. The filler
compound shall provide a uniform surface for the application of epoxy monolithic
protective linings. The Filler Compound shall be confirmed by the manufacturer as
compatible with the protective lining.
4. Epoxy Base Coat and Sealer Coat Lining:
Properties Sewergard No. 210X
Adhesion (ASTM D4541) Concrete Failure
Application Time (ASTM C308 modified)
Working Time @ 70°F 30 minutes
Bond Strength to Concrete (ASTM D7234) Concrete Failure
Bond Strength by Slant Shear (ASTM C882 modified) 700 psi (49.2 kg/cm2)
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Properties Sewergard No. 210X
Compressive Strength (ASTM D695) 15,500 psi (1089.9 kg/cm2)
Components 2 parts
Elongation (ASTM D638) 12.9%
Flexural Strength (ASTM D790) @ 28 days 8,000 psi (562.4 kg/cm2)
Maximum Service Temperature (dry) 150°F (65°C)
Mix Ration (by volume) 1 part A-(Hardener):3 parts b (Resin)
Modulus of Elasticity (ASTM D790) 5.1 x 104 psi
Permeability (ASTM E96) 1.32 x 10-10
Shore D (ASTM D2240) 95
Tensile Strength @ 7 Days (ASTM D638) 4,300 psi (302.3 kg/cm2)
Minimum Thickness 125 mils
Protective epoxy lining is to be moisture tolerant and capable of withstanding
groundwater intrusion, as exterior of structure does not have waterproof coating and
the entire structure sits below the groundwater table.
Sewergard Epoxy 210X lining is to be applied in one to two coats for a total system
thickness of 125 mils dft.
Alternative manufacturer is Raven Lining Solution 405, with compatibility and
performance guarantee statements for mixing multiple manufactures components.
C. Product and Manufacturer: Provide one of the following:
1. Sauereisen, Pittsburgh, PA (412) 963-0303.
2. Or equal, in accordance with this specification.
PART 3 EXECUTION
3.1 INSPECTION
The Applicator shall examine the areas and conditions under which protective lining Work is to
be performed and notify Engineer in writing of conditions detrimental to the proper and timely
completion of the Work. Do not proceed with the Work until unsatisfactory conditions have been
corrected in a manner acceptable to Engineer.
A. Commencement of the Work of this Section shall indicate that the substrate and other
conditions of installation are acceptable to the Applicator and the Engineer and shall
produce a finished product meeting the requirements of the Specifications. All defects
resulting from such accepted conditions shall be corrected by Applicator at his own
expense.
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B. Contractor shall remove all piping, equipment and appurtenances as required to properly
conduct the Work. Any piping, flap gates, slide gates, guide rails, pipe supports, grating,
electronic instrumentation, or other appurtenances Contractor is unable to remove shall be
protected from surface preparation and coating activities. Any damage to existing piping,
equipment and appurtenances shall be repaired or replaced with new at the discretion of the
Engineer. See Drawings for Notes and piping, equipment and appurtenances inside
wetwell and primary clarifier channels.
C. Contractor shall provide cranes or lifting devices as required to conduct the Work. Use of
the City davit crane will not be allowed.
3.2 SURFACE PREPARATION
A. Prior to rehabilitation, remove all existing pumps, pipe supports, pump guide brackets,
anchors, gate frames, hatches, grating and appurtenances mounted to the structure, as
shown in the Drawings.
B. Existing Concrete Application - Existing concrete structures to receive protective lining
system must be capable of withstanding imposed loads. All oil, grease and chemical
contaminants must be removed from the surface of the concrete. All loose or deteriorated
concrete shall be removed by mechanical means. All surfaces must be firm, free of
damaged or contaminated concrete, laitance, form release agents, and standing water and
they must be structurally sound as determined by Engineer. Suitable surface preparation
methods include shot blasting, abrasive Blasting, or hydro-blasting. Surface preparation
procedures shall be in accordance with ICRI Guideline No. 03732. Surface preparation
requirement is to expose aggregate and obtain a uniform surface texture resembling an
ICRI CSP # 4-6 comparators.
C. Use the following procedures where reinforcing steel with active corrosion is encountered:
Sandblast reinforcing steel to remove all contaminants and rust. Abrasive blast to SSPC-
SP5, white metal. Remove contaminants, the substrate must be neutralized. Determine
section loss, splice new reinforcing steel where there is more than 15 percent loss as
directed by the Engineer. If more than half the diameter of the reinforcing steel is exposed,
chip out behind the reinforcing steel a minimum of 1/2 inch. The distance chipped behind
the reinforcing steel must also equal or exceed the minimum placement depth of the
accepted material. Coat rebar with primer and allow to cure for 6 hours prior to resurfacing
system is installed.
D. Use the following procedures where reinforcing steel is encountered without active
corrosion: Abrasive blast to SSPC-SP5, white metal. Remove contaminants, the substrate
must be neutralized. If more than half the diameter of the reinforcing steel is exposed, chip
out behind the reinforcing steel a minimum of 1/2 inch. The distance chipped behind the
reinforcing steel must also equal or exceed the minimum placement depth of the accepted
material. Coat rebar with primer and allow to cure for 6 hours prior to resurfacing system is
installed.
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E. Concrete surfaces that have been resurfaced must be allowed to cure in accordance with
protective lining manufacturer’s recommendations prior to application of protective epoxy
lining system, for a minimum of 7 hours, at conditions environmental required by
manufacturer. If alternative manufacturer is selected, provide a minimum of 7-days cure
time, at conditions environmental required by manufacturer.
F. Level or grind concrete substrates to protective lining system manufacturer's recommended
tolerances to produce a uniform surface profile, including removal of all sharp edges,
ridges or depressions.
G. Stopping Active Leaks: After surface cleaning and preparation, any visible leaks shall be
reported to the Engineer. Any minor leaks not requiring other repairs by the Engineer must
be sealed using Sauereisen InstaPlug No. F-180, No. F-370 Chemical Grout or approved
equal prior to proceeding with protective lining system installation.
H. New Concrete (no new concrete is used on this project):
1. Allow any new concrete is to cure for 28 days before protective lining system is
installed, unless otherwise recommended by the Applicator or protective lining
systems manufacturer.
2. New Concrete Application – All voids, holes and depressions shall be filled with
epoxy based filler compound material (section 2.1.B.1), re-establishing plan
finished grades and surface profiles.
3. Moisture Testing:
a. Floors - New concrete should be installed over a moisture barrier to eliminate
moisture transmission through the concrete floor. Prior to the application of
materials, the moisture content must be determined using a suitable Moisture
Detection System per ASTM F-1869 - “Measuring Moisture Vapor Emission
Rate of Concrete Subfloor Using Anhydrous Calcium Chloride.” One such
manufacturer is Sealflex Industries, 2925 College Ave. #B4, Costa Mesa, CA
(714-708-0850). An average value exceeding 3.0 lbs/1000 ft2/24-hr period is
unacceptable and shall require additional cure time, the application of a surface
penetrating vapor barrier or other corrective measures. Re-test after taking
corrective measure to ensure an average value below 3.0 lbs.
b. Moisture testing for walls and overheads - Test new concrete pours/block for
moisture after completing surface preparation. Utilize ASTM D-4263 “Standard
Test Method for Indicating Moisture in Concrete by the Plastic Sheet Method.”
Any indication of moisture shall require additional cure time, the application of
a surface penetrating vapor barrier or other corrective measures. Re-test after
taking corrective measure to ensure the absence of moisture.
c. Consult protective lining system manufacturer regarding all questions and/or
recommendations in reference to moisture problems or questions.
d. Expansion and construction joints shall be formed and filled as recommended
by the protective lining system manufacturer.
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3.3 APPLICATION
A. Protective lining systems shall be installed when ambient air and surface temperatures are
between 50o and 85oF. Store lining materials within the 60o to 85oF range for 48 hours prior
to use. Application and storage temperatures outside of this range shall require written
instruction from the protective lining manufacturer.
B. Application in direct sunlight and/or with rising surface temperatures is not recommended,
as this may result in blistering of the materials due to expansion of entrapped air or
moisture (out-gassing) in the concrete/concrete block substrates. In such cases, it shall be
necessary to postpone the application until later in the day when the temperature of the
substrate is falling. Concrete surfaces that have been in direct sunlight must be shaded for
at least 24 hours prior to application and remain shaded until the initial set has taken place.
Consult protective lining system manufacturer for application schedule guidelines specific
to temperature conditions and possible sealer application recommendations to reduce out-
gassing.
C. Resurfacing/Epoxy Filler Compound Application - Cementitous resurfacing and epoxy
filler compounds shall be used in accordance with this specification and in accordance with
protective lining manufacturer’s recommendations to provide a uniform and crack, void
and bug hole free surface for epoxy lining application.
D. Epoxy Base Coat and Sealer Coat Lining –Epoxy base coat and sealer coat lining shall be
applied and cured on the properly prepared surface in accordance with protective lining
system manufacturer’s written guidelines as outlined in product technical data sheets.
1. Epoxy base coat shall be applied to a total minimum thickness of 125 mils.
Application method and equipment shall be approved by the Engineer and shall be in
accordance with the protective lining system manufacturer’s recommendations.
E. High Voltage Spark Testing. Contractor shall provide high voltage spark testing. Installed
protective epoxy lining shall be tested for pinholes after a minimum 24-hour cure at a
temperature of 70°F. Pinhole testing shall be accomplished in accordance with ASTM D-
4787, using a Tinker Razor Holiday Detector, San Gabriel, CA, Model AP/W, or an
approved equal device. Test voltage of 100 volts/mil of coating thickness shall be applied.
All pinholes shall be marked and repaired using manufacturer’s approved Patch Kit, or
other approved method. Submit spark testing data to Engineer for approval.
F. Adhesion Testing – Contractor to perform adhesion testing. Adhesion testing shall be
conducted after the lining system has cured in accordance with manufacturer specification.
Adhesion testing shall be in accordance with ASTM D4541-Modified herein. Affix one
3/4 inch dolly (to the host structure) on every concrete slab, wall, and ceiling with a
maximum spacing of 500-sf . Prior to the pull test, the tester shall utilize a scoring device
to cut around the dolly and cut through the lining until the original concrete is reached.
Failure due to improper adhesion of the dolly shall require retesting. The pull test in each
area is to be a minimum of 200psi. Pull tests of a minimum 150psi to 200psi may be
acceptable if more than 50 percent of the substrate is adhered to the back of the dolly. A
July 2018 Concrete Rehabilitation and Protective Epoxy Polymer Madera WWTP Rehabilitation Project
Conformed Lining System 184030591
03906-12
test result may be disregarded by the Engineer if there is a valid non-statistical reason as
specified in section 8.4 and 8.5 of ASTM D4541. If the host structure fails the minimum
requirement then the Engineer and lining manufacturer shall be consulted. All voids
caused by the adhesion testing are to be prepared and repaired per lining manufacturer
recommendations. Submit adhesion testing data to Engineer for approval.
3.4 ADJUSTMENTS AND CLEANING
A. At the completion of the Work, Applicator shall remove all materials and debris associated
with the Work of this Section.
B. Clean all surfaces not designated to receive protective coating. Restore all other work in a
manner acceptable to Engineer. Re-install all removed equipment, piping supports, gates,
and appurtenances.
C. All finished protective lining Work shall be protected from damage until Final Acceptance
of the Work. Protective lining damaged in any manner shall be repaired or replaced at the
discretion of Engineer at no additional cost to Owner.
D. Clean all protective lining as recommended by the manufacturer to provide finished Work
acceptable to Owner, just prior to Final Acceptance.
END OF SECTION
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 44
MARIN MUNICIPAL WATER DISTRICT - CLARIFIER MECHANISM
SPECIFICATIONS/DRAWINGS/SEISMIC ANALYSIS
This section includes specifications,
drawings, and calculations from Marin
Municipal Water District’s San Geronimo
WTP clarifier seismic upgrade project.
Marin Municipal Water District WTP Clarifier Seismic Upgrade Project, Marin County, CA
STANTEC – JUNE 2018 CLARIFIERS/SEDIMENTATION TANKS, GENERAL
SAN GERONIMO TREATMENT PLANT CLARIFIER SEISMIC UPGRADES PAGE 46 43 00 - 1
SECTION 46 43 00 - CLARIFIERS/SEDIMENTATION TANKS, GENERAL
PART 1 --GENERAL
1.1 THE SUMMARY
A.The CONTRACTOR shall provide clarifiers, flocculators, launders, troughs and sludge
collectors, complete and operable, in accordance with the Contract Documents.
Type of Equipment
Clarifier No. 1
Clarifier No. 2
B.The requirements of Section 46 01 00 - Equipment General Provisions apply to the WORK
of this Section.
C.The requirements of this Section apply to clarifiers, skimmers, and sludge collectors in the
Contract Documents.
1.2 REFERENCE SPECIFICATIONS, CODES, AND STANDARDS
ASTM A 36 Structural Steel
ASTM A240 Standard Specification for Chromium and Chromium-Nickel Stainless Steel
Plate, Sheet, and Strip for Pressure Vessels and for General Applications Type 304
Stainless Steel
ASTM A666 Standard Specification for Annealed or Cold-Worked Austenitic Stainless
Steel Sheet, Strip, Plate, and Flat Bar, Type 304 Stainless Steel
ASTM A312 Standard Specification for Seamless, Welded, and Heavily Cold Worked
Austenitic Stainless Steel Pipes, Type 304 Stainless Steel Welded Pipe
ASTM D 570 Test Methods for Water Absorption of Plastics
ASTM D 638 Test Method for Tensile Properties of Plastics.
ASTM D 732 Test Method for Shear Strength of Plastics by Punch Tool
AGMA 908-B Geometry Factors for Determining the Pitting Resistance and Bending
Strength of Spur, Helical and Herringbone Gear Teeth
AGMA 2001-C Fundamental Rating Factors and Calculation Methods for Involute Spur
and Helical Gear Teeth
AGMA 6034-B Practice for Enclosed Cylindrical Wormgear Speed Reducers and
Gearmotors
CBC 2013 California Building Code
ASCE 7 American Society of Civil Engineers Standard 7-10 – Minimum Design
Loads for Buildings and Other Structures.NOT FOR BIDDING PURPOSES
STANTEC – JUNE 2018 CLARIFIERS/SEDIMENTATION TANKS, GENERAL
SAN GERONIMO TREATMENT PLANT CLARIFIER SEISMIC UPGRADES PAGE 46 43 00 - 2
ACI 318 Building Code Requirements for Structural Concrete (2011 edition)
ACI 350 Code Requirements for Environmental Engineering Concrete Structures
(2010 edition)
ACI 350.3 Seismic Design of Liquid Containing Structures Concrete Structures
(2010 edition)
1.3 CONTRACTOR SUBMITTALS
A.Furnish submittals in accordance with Section 01 33 00 - Contractor Submittals.
B.Shop Drawings: Drawings of equipment in this Section and in referenced Sections
covering the various types of clarifiers in Division 41. Include the following information:
1.Complete certified equipment drawings, showing dimensions, weights, materials of
construction, welds, torque ratings, etc.
2.Electric motor data, voltage, and electrical characteristics.
3.Foundation, installation, and grouting drawings.
4.Walkways, handrails, and kickplates.
5.Anchor bolts, bolts, nuts, sleeves, and inserts.
6.Equipment drive and drive guards.
7.List of spare parts to be furnished.
8.Operating and maintenance instructions.
9.List of special tools to be furnished under Section 46 01 00 – Equipment General
Provisions.
10.Lubricating instructions and lubricants for one year of operation.
11.Scope of services of manufacturer's representative.
12.Nameplate.
13.A list of the 3 most recent installations, where similar equipment by the manufacturer
is currently in service, including contact name, telephone number, and address
C.Record Drawings: Show the location and dimensions of clarifiers, associated equipment,
piping, supports, and walkways.
D.Technical Manual: Furnish complete manuals in accordance with Section 01 33 00 –
Contractor Submittals.
1.4 QUALITY ASSURANCE
A.Manufacturer's Experience: Unless indicated otherwise, equipment shall be furnished by
manufacturers with at least 10 years experience in the manufacture of similar equipment,
with a successful record of operation in wastewater or water treatment plants.NOT FOR BIDDING PURPOSES
STANTEC – JUNE 2018 CLARIFIERS/SEDIMENTATION TANKS, GENERAL
SAN GERONIMO TREATMENT PLANT CLARIFIER SEISMIC UPGRADES PAGE 46 43 00 - 3
B.Workmanship and Design:Each part of the equipment shall be amply proportioned for
long, continuous, uninterrupted service. Provision shall be made for easy access for
service or replacement of parts. Corresponding parts of multiple units shall be
interchangeable. Workmanship shall be first class, with welding in accordance with the
latest applicable code of the American Welding Society. The drive mechanisms shall be
designed for the maximum continuous running torque per AGMA 908-B and 2001-C for a
minimum life of 20 years or 175,000 hours, unless otherwise indicated, and a momentary
peak (stalled) torque of twice the maximum continuous running torque. The maximum
allowable stresses on structural steel members shall not exceed those permitted by the
latest AISC specifications for applicable design at twice the maximum continuous running
torque.
C.Certification: A certificate of design signed by a California Registered Professional
Engineer shall be submitted to the ENGINEER prior to the manufacture of the equipment.
The certificate shall include the following information:
1.Codes and specifications followed in the design.
2.Type and strength of materials for members.
3.Loading conditions used for the design.
4.Certification that equipment is designed to withstand maximum continuous running
torque and momentary peak (stalled) torque indicated.
1.5 SEISMIC DESIGN REQUIREMENTS
A.Commonly mounted mechanical system designs shall conform to the seismic
requirements as specified in Sections 01 33 17 – Structural Design, Support and
Anchorage and 46 01 00 - Equipment General Provisions.Additionally, refer to the loading
specified in the Contract Drawings.
PART 2 --PRODUCTS
2.1 EQUIPMENT
A.General: Each item of equipment shall be furnished and installed complete with supports,
electric drive units, sludge collector, mechanical equipment, launders, troughs, electrical
WORK, and appurtenances ready for operation. Mechanisms or parts shall be amply
proportioned for the stresses that may occur during operation or for any other stresses
which may occur during fabrication and erection. Guards shall be furnished for exposed
moving shafts, drives, or parts as required by the applicable safety codes. Main drive
assemblies shall be provided by the equipment manufacturer.
B.Power Supply: Power supply to the equipment shall be 208 V, 60 Hz, 3 phase, unless
otherwise indicated.
C.Workmanship: Welds on submerged surfaces and edges shall be the continuous type.
D.Motors: Motors shall comply with Section 26 05 10 - Electrical Motors.
E.Controls: Controls shall be housed in enclosures with NEMA ratings in accordance with
the area designations in Section 26 00 00 - Electrical Work, General.NOT FOR BIDDING PURPOSES
STANTEC – JUNE 2018 CLARIFIERS/SEDIMENTATION TANKS, GENERAL
SAN GERONIMO TREATMENT PLANT CLARIFIER SEISMIC UPGRADES PAGE 46 43 00 - 4
F.Overload Protection: Each drive mechanism shall be provided with an automatic overload
protection device of the mechanical type in a stainless steel or cast aluminum
weatherproof housing. The device shall incorporate the worm thrust bearing which shall
allow the worm shaft to move axially. A limit switch shall be furnished to provide an alarm
on disengagement of the drive.
G.The mechanical overload device shall be designed to resist the maximum thrust from the
worm shaft and shall have means to continuously indicate the load on the mechanism.
The overload indicator shall be oriented so that it may be easily read from the walkway.
H.Switches in a weatherproof enclosure shall be provided to actuate an alarm at 85 percent
of maximum continuous running torque and to shut down the motor at the maximum
continuous running torque. These switches shall be accurately factory-calibrated and
adjusted to twice the maximum continuous running torque.
2.2 MATERIALS
A.General: Materials used shall be suitable for service in a moist, corrosive environment,
as encountered in water and wastewater treatment plants.
B.Plates and Structural Members: Except where otherwise indicated, plates and structural
members designed for submerged service shall have a minimum thickness of 1/4-inch
Type 304 Stainless Steel.
C.Bolts and Nuts: Bolts, nuts, anchor bolts, and washers shall be stainless steel in
accordance with Section 05 50 00 - Miscellaneous Metalwork. For submerged service
they shall be of high strength and sized for the intended purpose. Stainless steel split
lockwashers or locknuts shall be used on bolted connections. Bolt heads and nuts shall
be hexagonal. Anchor bolts shall be cast in new concrete.
2.3 TANK BOTTOM GROUTING
A.For circular clarifiers, the completed sludge collector unit(s) shall be of sufficient structural
and mechanical strength to sweep in the 2-inch grout on the tank bottom under its own
power. The grout shall be in accordance with Section 03 60 00 - Grouting, and as
recommended by the manufacturer.
PART 3 --EXECUTION
3.1 GENERAL
A.The equipment shall be fabricated, erected, assembled, and placed in proper operating
condition in full conformity with the Drawings, Specifications, engineering data,
instructions, and recommendations of the equipment manufacturer as accepted by the
ENGINEER. Units shall be lubricated with food grade lubricant in strict accordance with
the manufacturer's instructions.
3.2 FINAL ADJUSTMENT
A.The CONTRACTOR shall obtain the services of a qualified factory service representative
to perform final adjustments and checking of the equipment in accordance with the
Specifications.NOT FOR BIDDING PURPOSES
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SAN GERONIMO TREATMENT PLANT CLARIFIER SEISMIC UPGRADES PAGE 46 43 00 - 5
3.3 MANUFACTURER'S SERVICE REPRESENTATIVE
A.Erection and Startup Assistance: The CONTRACTOR shall require the manufacturer to
provide the services of a trained, qualified factory service representative for not less than
2 Days at the plant to assist in the erection and startup of each clarifier.
B.Instruction of OWNER's Personnel: In addition to the above services the CONTRACTOR
shall include one full Day at the plant for a qualified factory representative, to inspect the
finished installation and instruct the OWNER's operating personnel.
3.4 ACCEPTANCE TESTS
A.After installation of the equipment and after completion of the services of the
manufacturer's representative, and when plant influent is available, the CONTRACTOR
shall operate each unit to demonstrate its ability to operate continuously without vibration,
jamming, or overheating, and to perform its indicated functions satisfactorily.
B.Defects shall be corrected promptly. Defective WORK shall be replaced.
C.Final adjustments necessary to place the equipment in satisfactory working order,
including leveling of the weir with reference to the liquid in the tank, shall be made at the
time of the above test.
END OF SECTION
NOT FOR BIDDING PURPOSES
THIS PAGE INTENTIONALLY LEFT BLANK
NOT FOR BIDDING PURPOSES
STANTEC – JUNE 2018 CIRCULAR, FLOCCULATING CLARIFIER MECHANI
SAN GERONIMO TREATMENT PLANT CLARIFIER SEISMIC UPGRADES PAGE 46 43 22 - 1
SECTION 46 43 22 - CIRCULAR,FLOCCULATING CLARIFIER MECHANISM
PART 1 --GENERAL
1.1 THE SUMMARY
A.The CONTRACTOR shall provide two (2) flocculating clarifier mechanisms for installation
in the basins shown on the Contract Drawings, complete and operable, in accordance with
the Contract Documents.
B. All clarifier mechanism components shall be 304 stainless steel. Refer to Section 05 55 00 –
Miscellaneous Metalwork materials of structural connections.
C.The CONTRACTOR shall provide lubricants for equipment during shipping, storage, and
prior to testing, in accordance with the manufacturer’s recommendations. Lubricants that
could come in contact with potable water shall be food grade certified.
D.The requirements of Section 46 01 00 -Equipment General Provisions, apply to this
Section.
E.The requirements of Section 46 43 00 - Clarifiers/Sedimentation Tanks, General apply to
this Section.
F.Single Manufacturer: A single manufacturer shall be responsible for a complete and
integrated package including the following:
1.Bridges and checkered floor plate walkways with handrails and toe plates
2.Support columns
3.Center cages
4.Truss support arms
5.Feedwells
6.Center drive mechanisms
7.Flocculator drive mechanisms
8.Local Control Panels including, but not limited to
a.Overload devices
b.Motor Controllers
c.Control Devices
9. Anchor bolts
10.Weir plates
11.Launders and TroughsNOT FOR BIDDING PURPOSES
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SAN GERONIMO TREATMENT PLANT CLARIFIER SEISMIC UPGRADES PAGE 46 43 22 - 2
12.Spare parts and assemblies
13.Any other components required for a complete, operable unit.
1.2 REFERENCE SPECIFICATIONS, CODES, AND STANDARDS
AGMA 2001-C95 Rating the Pitting Resistance and Bending Strength of Spur and
Helical Involute Gear Teeth
AGMA 2001-C95 Fundamental Rating Factors and the Calculation Method for
Involute Spur and Helical Gear Teeth.
AGMA 2004 Gear Materials and Heat Treatment Manual.
AGMA 908-B89 Geometry Factors for Determining the Pitting Resistance and
Bending Strength of Spur, Helical and Herringbone Gear Teeth
AGMA 6034-B92 Practice for Enclosed Cylindrical Worm Gear Speed Reducers
and Gear Motors
AISC Code of Standard Practice for Steel Bridges and Buildings
AISC Specifications for the Design, Fabrication and Erection of
Structural Steel for Buildings
ASTM A 36 Structural Steel
ASTM A 48 Gray Iron Castings
ASTM A 536 Ductile Iron Castings
ASTM A 370 Standard Test Methods and Definitions for Mechanical Testing
of Steel Products
AWS D1.1 Structural Welding Code
ABMA American Bearing Manufacturer’s Association
IEEE Institute of Electrical and Electronic Engineers
ICEA Insulated Cable Electric Association
NEC National Electric Code
NEMA National Electrical Manufacturers Association
UL Underwriters’ Laboratory
CBC 2013 California Building Code
ASCE 7 American Society of Civil Engineers Standard 7-10 – Minimum
Design Loads for Buildings and Other Structures.NOT FOR BIDDING PURPOSES
STANTEC – JUNE 2018 CIRCULAR, FLOCCULATING CLARIFIER MECHANI
SAN GERONIMO TREATMENT PLANT CLARIFIER SEISMIC UPGRADES PAGE 46 43 22 - 3
ACI 318 Building Code Requirements for Structural Concrete (2011
edition)
ASTM A240 Standard Specification for Chromium and Chromium-Nickel
Stainless Steel Plate, Sheet, and Strip for Pressure Vessels and
for General Applications Type 304 Stainless Steel
ASTM A666 Standard Specification for Annealed or Cold-Worked Austenitic
Stainless Steel Sheet, Strip, Plate, and Flat Bar, Type 304
Stainless Steel
ASTM A312 Standard Specification for Seamless, Welded, and Heavily Cold
Worked Austenitic Stainless Steel Pipes, Type 304 Stainless
Steel Welded Pipe
ACI 350 Code Requirements for Environmental Engineering Concrete
Structures (2010 edition)
ACI 350.3 Seismic Design of Liquid Containing Structures Concrete
Structures (2010 edition)
1.3 CONTRACTOR SUBMITTALS
A.In addition to the Shop Drawing and complete calculation requirements in Section 46 43
00 - Clarifiers/Sedimentation Tanks, General Provisions, the mechanical systems shall
conform to the seismic requirements as specified in Sections 01 33 17 – Structural Design,
Support and Anchorage. Additionally, refer to the seismic loading specified in the Contract
Drawings and furnish the following:
B.Product Data
1.Manufacturer’s literature, illustrations, specifications, and engineering data.
2.Certified motor data sheet for each type and size of motor.
3.Make and model of bearings.
4.Gear material specifications.
5.Manufacturer's material verification and hardness certification for main bearings.
C.Shop Drawings
1.All submitted calculations and drawings must be stamped by a California Registered
Professional Engineer.
2.Drawings shall show critical project-specific field dimensions and elevations drawn
accurately to scale.
3.Drawings showing sludge collector mechanism with dimensions, member thickness,
welds, and connection details.NOT FOR BIDDING PURPOSES
STANTEC – JUNE 2018 CIRCULAR, FLOCCULATING CLARIFIER MECHANI
SAN GERONIMO TREATMENT PLANT CLARIFIER SEISMIC UPGRADES PAGE 46 43 22 - 4
4.Sludge collector arm, torque cage, walkway bridge, and support column structural
calculations.
5.Walkway construction details and dead load deflection computations.
6.Velocity gradient calculations.
7.Sufficient design information to clearly describe the sizes, dimensions and
arrangement of major drive components. Design information shall be supplied for
gears except those contained in the gear motor speed reducer. The following
minimum data shall be supplied for each gear:
i.Number of teeth
ii.Net face width
iii.Outside diameter (external gears)
iv.Inside diameter (internal gears)
v.Normal diametral pitch (or axial pitch for worms)
vi.Normal generating pressure angle
vii.Lead angle (for worms)
viii.Operating center distance
ix.Quality number (AGMA 390.03)
x.Material alloy
xi.Type of heat treatment
xii.Tooth surface hardness
xiii.Tooth core hardness
xiv.For case hardened gears, The Effective Case Dept. to Rc 50
xv.Lubricant type (mineral/synthetic/EP)
xvi.Lubricant viscosity
8.Setting drawings, templates, and directions for the installation of anchor bolts and
other anchorages.
9.Control system data, schematics, and wiring diagrams.
10.Details and description of the overload protection assembly to clearly demonstrate
adequacy of the overload protection provided by the assembly. Overload alarm
contact shall be as indicated on the control diagram.
11.Anchor bolt placement measured from construction joints in the concrete structure.
Anchor bolt details shall include projections from concrete.NOT FOR BIDDING PURPOSES
STANTEC – JUNE 2018 CIRCULAR, FLOCCULATING CLARIFIER MECHANI
SAN GERONIMO TREATMENT PLANT CLARIFIER SEISMIC UPGRADES PAGE 46 43 22 - 5
12.Type and size of structural details, sludge drawoff pipes, including method of return
sludge flow control, and pipe connection details.
13.Type, specifications, details, input and output speeds, exact gear ratios, service factor
(24 hour continuous service), capacity, and efficiency of gear reducer units and drive
assembly. Diameter of ball race.
14.Motor and electrical drawings, including size, make, and type designation of electric
motors, including mounting details.
15.List of recommended additional spare parts beyond the items listed in the
Specifications, describing parts recommended for operating period of one year with
recommended quantities and unit prices.
16.AGMA calculations be performed and certified by a registered professional
mechanical engineer certified by AGMA. The calculation shall include the following:
i.Substantiation of the output torque rating and the overload torque rating
of every component of the drive mechanism.
ii.Demonstration that bearings in the drive mechanism meet the life
requirements required.
iii.Gear calculations demonstrating the ratings, stresses, and factor of safety
in accordance with AGMA.
17. Calculations shall be performed and certified by a registered professional structural
engineer registered in the State where the clarifier will be installed. The calculation
shall include the following:
i.Demonstration of compliance with structural criteria and requirements
herein.
ii.Details of structural design of static, dynamic, and seismic loads for the
center column and support system, maintenance walkway, and platform.
18.Complete field weld information including location, type, size, length, and explanation
of special conditions.
19.ABMA calculations shall be performed and certified by a registered professional
mechanical engineer. The calculation shall prove that the bearings are designed,
manufactured, and rated to meet the indicated bearing life. The calculations shall
include:
i.Number of balls
ii.Total hanging weight of equipment
iii.Rotational speed
iv.Raceway hardness factor
v.Weibull exponentNOT FOR BIDDING PURPOSES
STANTEC – JUNE 2018 CIRCULAR, FLOCCULATING CLARIFIER MECHANI
SAN GERONIMO TREATMENT PLANT CLARIFIER SEISMIC UPGRADES PAGE 46 43 22 - 6
vi.Nominal contact angle
vii.Thrust and radial raceway material factor
viii.Pitch diameter
ix.Ball diameter
20.Certifications
i.Manufacturer’s material verifications and hardness.
ii.Manufacturer’s installation instructions
21.Manufacturer’s field reports: Include the following:
i.Field test results
ii.Manufacturer’s certification that equipment was installed in accordance
with the manufacturer’s instructions, inspected by the manufacturer,
serviced with the proper initial lubricants, equipped with applicable safety
equipment, and installed with proper electrical and mechanical
connections.
D.Technical Manual in accordance with Section 01 33 00 -Contractor Submittals.
E.Warranties
F.The load distribution factor shall be determined as described in the referenced AGMA
standard under Section 46 43 00 - Clarifiers/Sedimentation Tanks, General. The net face
width for surface durability calculations shall not exceed 90 percent of the actual face width
of the narrowest of the 2 mating gears. For parameters that are material dependent, such
as allowable contact stress, the calculations shall include a full description of the materials
and heat treatments used.
1.4 OPERATION AND MAINTENANCE MANUALS
A.Operation and maintenance manuals will be provided by the flocculating clarifier
manufacturer at least two weeks prior to shipment of all major equipment components.
Each manual shall be a bound, indexed binder with drawings and parts lists prepared
specifically for this project rather than general instructions that are not designed for this
project.
B.As a minimum the manual shall contain:
1.General arrangement drawings.
2.General arrangement detail drawings.
3.Erection drawings.
4.A complete bill of materials for the equipment including the weights of all structural
steel components.NOT FOR BIDDING PURPOSES
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SAN GERONIMO TREATMENT PLANT CLARIFIER SEISMIC UPGRADES PAGE 46 43 22 - 7
5.Installation and maintenance instructions for the specific equipment including the
erection sequence, maintenance and trouble-shooting check points, and complete
lubrication procedures with recommended grades of lubricants.
6.Cut sheets for all items of equipment purchased from other manufacturers.
7.A list of the flocculating clarifier manufacturer's recommended spare parts specifically
denoting wear items, long delivery items, and all items convenient for stocking as
optional replacement items.
1.5 QUALITY ASSURANCE
A.Manufacturer’s Qualifications: Manufacturer which has been regularly engaged in
manufacture of sludge collectors for a minimum of 10 years, that have been successfully
utilized in domestic water treatment and wastewater treatment applications for a minimum
of 15 years. The complete center drive assembly shall be a regularly manufactured in-
house product of the clarifier manufacturer.
B.To show evidence of being able to provide the quality of equipment and services described
in this specification, the equipment supplier shall submit their ANAB-accredited ISO 9001
quality system certification. The quality procedures shall provide for a means of qualifying
all sub-vendors and shall specify that the fabrication facility is a critical vendor and shall
require inspection. The quality system shall be audited on-site by a third-party independent
registrar at least annually. Certification shall remain in effect throughout the project start-
up.
C.Welder Qualifications: Qualified and certified in accordance with AWS D1.1.
1.6 SPECIAL CORRECTION OF DEFECTS PROVISIONS
A.CONTRACTOR shall furnish manufacturer's warranty for 2 years on the clarifier drive and
components and 5 years on the mechanism structure after the ready for service date of
each clarifier.
PART 2 --PRODUCTS
2.1 GENERAL DESIGN
A.Clarifier mechanisms shall be of the center-drive type, supported on a stationary influent
column, with the flow entering at the bottom of the influent column and flowing upward to
the inlet openings near the water level. The clarifier shall be designed to remove the
sludge uniformly from the bottom of the tank. The flocculator mechanism shall be of the
vertical paddle type, and shall be capable of stirring, agitating, and mixing the water and
all suspended solids to promote the formation of floc of a suitable character.
B.Design Criteria
Identification Number Clarifier No. 1 and Clarifier No. 2 NOT FOR BIDDING PURPOSES
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SAN GERONIMO TREATMENT PLANT CLARIFIER SEISMIC UPGRADES PAGE 46 43 22 - 8
Influent Water Quality
Kent turbidity (NTU)0.5-1.5
Nicasio turbidity (NTU)5-25
Kent color (color units)5-35
Nicasio color (color units)100-250
Chemical Feed
Primary Coagulant Ferric Chloride (25-40 mg/L)
Coagulant Aid Polymer Cationic Polymer (0-1 mg/L)
Number of Units 2
Collector Type Plow Rake
Influent flow rates per tank (mgd)
average 14
maximum 17.5
Tank Diameter, ft Clarifier No. 1: 123 (to be field verified)
Clarifier No. 2: 125 (to be field verified)
Hydraulic Loading Rates (gpm/sf)
average Clarifier No. 1: 0.98 (to be field verified)
Clarifier No. 2: 0.94 (to be field verified)
maximum Clarifier No. 1: 1.22 (to be field verified)
Clarifier No. 2: 1.18 (to be field verified)
Side Water Depth, ft 14
Freeboard, ft 1.48
Bottom slope, in/ft 1
Walkway Clear width, ft 3
Drive Cage, ft 4.5
Feedwell (Flocculation Zone)
Diameter, ft 50NOT FOR BIDDING PURPOSES
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Depth, ft 11.5
Influent Pipe Diameter, in 36
Collector tip speed, fpm < 10
Collector motor HP, hp 1.5
Torque, ft-lbs
Design running 130,000
Momentary peak 260,000
Minimum ball race diameter,
in
60
Seismic Loads See Drawings.
Flocculator motor HP, hp 5
Max flocculator tip speed, fps 10
Average G value at Maximum
RPM
40
2.2 INFLUENT
A.Center Column: A cylindrical 36-inch diameter center column shall be provided to support
the drive, collector mechanism, and walkway. The top of the column shall have a drive
mechanism mounting plate that shall be set plumb with the centerline. The drive unit shall
be positioned and leveled prior to the center column being grouted in place. The column
shall be fabricated of minimum 1/4-inch thick 304 stainless steel plate with adequately-
sized supporting flanges, anchored to the concrete base with a minimum of eight 1-1/4
inch diameter stainless steel anchor bolts. The CONTRACTOR shall obtain a grout shield
and template from the equipment manufacturer to accurately locate these anchor bolts.
The structure shall provide adequate support for the entire mechanism plus live load
torque, with an adequate factor of safety to eliminate excess deflection or vibration.
Suitable influent openings shall be provided in the upper portion of the column to allow
unrestricted passage of flow into the flocculation well. In order to prevent excessive loss
of head, these openings shall not be less than 135% of the column area to allow
unrestricted passage of the flow not exceeding 1.75 ft per second into the influent well.
B.Center Cage: The center cage shall be of 304 stainless steel box truss construction. It
shall be provided with connections for the 2 (or 4) sludge removal arms and feedwell
supports. The cage top shall be bolted to the main gear, which shall rotate the cage with
the attached arms and feedwell. The cage and arms shall be designed to withstand twice
the maximum continuous running torque of the drive without overstressing the members.
If members are placed back-to-back, there shall be a space between them of at least 1/2-
inch to allow for cleaning and painting or there shall be a continuous weld around the
entire connection.NOT FOR BIDDING PURPOSES
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C.Feedwell: An energy dissipating feedwell shall be supported outside of the center cage to
diffuse the liquid into the tank and provide an enlarged zone for flocculation without
disturbance or formation of density currents. The feedwell shall be supported from and
rotate with the drive cage. The feedwell shall be made of not less than 3/16 inch thick 304
stainless steel plate with necessary alignment angles.
2.3 FLOCCULATION ARMS AND MIXERS:
A. Vertical flocculation paddle mixers extending downward shall be provided to blend the
water in the flocculation zone to provide a uniform mixture and promote flocculation.
Paddle arms, blades, and cage attachment plates shall be fabricated using 304 stainless
steel.
B.The CONTRACTOR shall provide equipment manufacturer-recommended stainless steel
anchor bolts, nuts, and washers, but the manufacturer shall furnish templates necessary
for setting the equipment. Placement of the anchor bolts shall be performed by the
CONTRACTOR from certified dimension prints supplied by the equipment manufacturer.
Anchor bolts shall be in accordance with Section 05 50 00 -Miscellaneous Metalwork.
2.4 RAKE COLLECTION ARMS
A.The mechanism shall include 2 sludge removal arms of 304 stainless steel truss
construction, with 304 stainless steel plow type raking blades and adjustable stainless
steel squeegees secured to the blades by Type 304 stainless steel bolts and nuts. The
blades shall be properly spaced to insure complete raking of the bottom twice per
revolution. The blades shall plow the heavy sludge to the center sludge hopper and shall
be minimum 6-inches deep. The members shall be of adequate size to be capable of
raking any normal sludge deposit encountered without distorting the truss arms or the
center cage. If rectangular box construction is used, there shall exist bracing in each bay
where the truss members meet. If members are placed back to back, there shall be a
space between them of at least 1/2-inch to allow for cleaning and painting or provide a
continuous weld around the entire connection.
2.5 EFFLUENT WEIRS
A.Radial and Annular Launders:The existing annular and radial launders and supports will
be removed and shall be replaced to match existing. Clarifier mechanism vendor is
responsible for the design of the new supports for the radial and annular launders. Material
shall be 304 stainless steel.
B.Weirs: All weirs shall be removed and replaced and shall consist of 1/4-inch thick by 9-
inch deep stainless steel plate sections with 2.5-inch deep 90 degree V-notches at 6-inch
intervals. The weir sections shall be curved and fastened to the tank wall with washers,
clamps, 316 stainless steel anchor bolts, and hex nuts to allow vertical adjustment.
2.6 CLARIFIER DRIVE SYSTEM
A.General: The drive system shall consist of the motor, intermediate gear reducer, and the
final gear reducer/drive head. The entire drive system shall be designed for installation
on top of the center column and shall be accessible through the walkway and platform
system.
B.DefinitionsNOT FOR BIDDING PURPOSES
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1.Running Torque: Running torque shall be the design torque used to select the size,
strength, and type of materials and components of the drive system, which will permit
continuous clarifier operation for 24 hours a day for 20 years under average design
conditions without premature failure. The running torque shall be the torque used for
calculating the AGMA wear of gears and other components of the clarifier mechanism
2.Alarm Torque: Alarm torque shall be 85 percent of the running torque.
3.Cutout Torque: Cutout torque shall be the torque for which the motor will be signaled
to stop and equal to 100 percent of the running torque.
4.Momentary Peak Torque: Momentary peak stall torque shall be 2 times the running
torque.
5.Drive System Type
6.Type B or C drive system type described below is acceptable.
Type B Type C
First reduction Helical gear motor Cycloidal speed reducer
coupled to motor
Second reduction Chain and sprocket -
Third reduction Worm gear -
Final gear reducer or
drive head
Oil-lubricated, spur gear and
pinion with precision anti-
friction bearings and no
replaceable strip liners
Oil-lubricated spur gear and
pinion with precision anti-
friction bearings and no
replaceable strip liners
C.Gear Motor: The motor shall be coupled to a gear reducer, a 1800 rpm synchronous
speed, squirrel cage induction type, totally-enclosed-fan-cooled (TEFC), Class F
insulation with B temperature rise severe duty, ball bearing heavy duty unit of ample power
for starting and operating the mechanism without overload, with a service factor of 1.15,
in accordance with Section 26 05 10 -Electric Motors. The motor shall be not less than
1.5 hp and the connected load shall not exceed 85 percent of the motor nameplate
horsepower rating under any anticipated operating condition. The motor and gear shall
be supported by anti-friction bearings rated for L-10 life of 100,000 hours, oil lubricated
helical type gear with a load class service factor of 1.25 plus ambient temperature and
ventilation factors based on the output horsepower of the motor. The gear unit shall be
designed and manufactured to AGMA standards and shall bear the AGMA nameplate.
D.Cycloidal Speed Reducer and Motor: The motor shall be coupled to a cycloidal speed
reducer, a 1800 rpm synchronous speed, squirrel cage induction type, totally-enclosed-
fan-cooled (TEFC), Class F insulation with B temperature rise, severe duty, ball bearing
heavy duty unit of ample power for starting and operating the mechanism without overload,
with a service factor of 1.15, in accordance with Section 26 05 10 - Electric Motors. The
motor shall be not less than 0.5 hp and the connected load shall not exceed 85 percent of
the motor nameplate horsepower rating under any anticipated operating condition. The
motor and speed reducer shall be supported by anti-friction bearings rated for L-10 life of
100,000 hours, oil lubricated cycloidal type speed reducer with a load class service factor NOT FOR BIDDING PURPOSES
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of 1.25 plus ambient temperature and ventilation factors based on the output horsepower
of the motor. The gear unit shall be designed and manufactured to AGMA standards.
E.Chain and sprocket drive: The output shaft of the gearmotor shall be attached to a
secondary reduction drive smaller sprocket with a roller chain conforming to ANSI B29.1
driving the larger sprocket. The larger sprocket shall be attached to the input shaft of the
third reduction worm gear. The size of the chain and sprocket shall be selected with a
service factor of 1.5 based on the output horsepower of the motor. Roller chain and
sprockets shall be enclosed in a fabricated stainless steel chain guard with service
openings.
F.Worm Gear: A worm gear shall be used as a third reduction gear. The input shaft of the
worm shall be driven by the large sprocket and the output shaft shall be attached to a
pinion which shall drive the turntable. A cylindrical-type worm and worm gear shall be
manufactured from the following materials:
Part List Material of Construction or Feature
Gear housing Cast iron housing conforming to ASTM A 48
Class 40 minimum or welded steel.
Worm 8620 Alloy steel, hardened, ground and
polished. Meehanite, cast iron or ductile iron
worm gears are not permitted.
Worm Gear Centrifugally cast bronze or ductile iron,
Grade 80-55-6
Washers Hardened steel used to prevent embedding of
the head or nut.
Worm and Worm Gear Shaft Supported by anti-friction bearings or a
combination of anti-friction tapered roller
bearings. Minimum L-10 life of 20 years based
upon running torque. Bronze sleeve bearings
are not permitted on the input worm shaft
Lubrication Food Grade Oil
Worm Gear Shaft Designed for rated torque required to drive the
final gear reducer or drive head
Worm and Worm Gear Set Service
Factor
Minimum 1.25 based on continuous running
torque
G.Drivehead
1.The gear teeth shall not be stressed to more than 80 percent of the yield strength at
a load equivalent to a value of the momentary peak (stalled) torque. The entire
mechanism shall be capable of withstanding an impact load of the momentary peak
(stalled) torque without sustaining damage or permanent deformation. The 20 year NOT FOR BIDDING PURPOSES
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maximum continuous running torque shall be a computed value according to the
referenced AGMA 2001-C95.
2.Gear Criterion:The load distribution factor shall be as described in the AGMA
standard referenced in Section 46 43 00 - Clarifiers/Sedimentation Tanks, General.
The net face width for surface durability calculations shall not exceed 100 percent of
the actual face width of the narrower gear tooth of the 2 mating gears. The pinion
face width shall be 1/4-inch larger than the mating gear to assure complete
engagement.
Drive Head with precision type bearing, non-renewable heat-treated alloy steel
bearing races fully encasing all bearings.
Parts List Material of Construction or Feature
Type Spur pinion and internal spur gear.
Spur Pinion 4140/4150 heat-treated alloy steel.
Internal Spur Gear Precision cut internal spur gear, high alloy
steel hardened to Brinell Hardness of
approximately 200 -255
Spur Pinon Forged and cut from heat-treated AISI 8620 or
SAE 4160 steel with ultimate unit strength of
120,000 psi and Brinnell hardness of 220 –
260
Main Gear Set With full depth teeth conforming to AGMA
2001-C95. Stub-pitch gear teeth shall not be
acceptable. Undercut gear teeth shall not be
acceptable
Load Capacity of Main Gear Set Rated according to AGMA 2001-C95
Power Rating of Gear Set The lower of the pitting resistance and the
bending strength power ratings for the pinion
and gear; based on continuous 24 hour/day
service and a 20 year design life or 200, 000
hours.
Main Gear Set Service Factor Minimum 1.25 based on continuous running
torque.
Momentary Peak Strength
(Bending Strength) of Main Gear
Set
Minimum 200 percent of indicated continuous
torque
Gear and pinion Minimum AGMA Quality Class 6
Center Drive Cage Bolted to internal spur gear.NOT FOR BIDDING PURPOSES
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Lubrication Oil Lubricated or fully grease lubricated with
passive condensate drainage through
drainage holes in the main gear housing
Turntable Base ASTM A 36 fabricated steel housing; able to
be bolted to center column and to provide
support for internal spur gear. The entire
rotating collector mechanism and one end of
the access bridge. Turntable shall have a
deflection of not to exceed 0.024-inch.
Raceways, Ball Bearings Food grade oil bath. Grease is not
acceptable.
Turntable Base and Internal Spur
Gear Annular Raceways
The turntable base shall have an annular
raceway for a ball race upon which the
rotating assembly rests. It shall have a
maximum allowable deflection of 0.024-
inches with an allowable modulus of elasticity
of 25 x 106 psi. The center cage and sludge
collection arms shall be fastened to and hung
from the gear casing. Ball bearings shall be
of the finest quality high carbon, chrome alloy
steel balls running in fully contoured races, as
part of a precision gear bearing set. The balls
shall run in an oil bath protected by a felt seal
or grease housing protected by a grease
shield.
Raceways Forged steel precision gear/bearing set with
fully contoured raceways
Ball Bearings Minimum 1-in diameter, SAE 52100, 58 Rc.
The drivehead bearings shall be designed for
the total rotating weight with a minimum L-10
life of 50 years, or 450,000 hours, for
continuous operation.
Turntable Base and Internal Spur
Gear
Provided with an oil bath protected by a felt
seal and a dust shield.
Lubrication Food grade oil
Indicator Devices An oil sight glass shall be provided for the
upper and lower oil reservoirs.Readily
accessible lubricant fill and drainpipes with
necessary fittings shall be provided.
Factory Finish Coat drive mechanism per Section 09 96 00 –
Protective Coating before shipping to Site.NOT FOR BIDDING PURPOSES
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H.Overload Protection: The overload device shall be provided in a stainless steel
weatherproof enclosure in accordance with Section 46 43 00 Clarifiers/Sedimentation
Tanks, General. The device shall be actuated by thrust from the worm shaft or rotation of
the secondary gear reducer, which shall operate 2 switches: the alarm switch at 85 percent
of maximum continuous running torque and the motor cutout switch at 100 percent of
maximum continuous running torque. These 2 switches shall be factory-adjusted to
accurately calibrate the alarm torque value and the overload position. A visual torque dial
indication shall be oriented so that it may be read from the walkway. It shall be calibrated
from 0 to 100 percent of maximum continuous running torque.
I.Condensate Removal: Each drive unit shall include a condensate removal system, which
shall include a one-inch bronze ball valve with vertical stem, one-inch stainless steel
piping, and condensate trap. The pipe arrangement shall be designed to provide constant
removal of condensate from the main gear housing. A minimum of 6-inches clearance
shall be provided below the low point drain to allow for easy access by plant personnel.
J.FLOCCULATOR DRIVE
1.A vertical paddle wheel mixer shall be provided for the flocculation zone. The mixer
shall blend the water in the flocculation zone to provide a uniform mixture and promote
flocculation.
2.The flocculation drive mechanism shall consist of heavy-duty (high-efficiency)rated
motor, variable speed mechanism, and primary speed reducer.
3.The flocculation paddle speed shall be infinitely adjustable through a 4:1 range by the
use of a variable frequency drive. Variable speed drives, speed control equipment,
and accessories shall be provided in accordance with Section 26 29 23 -Variable
Frequency Drive Units.If applicable, the motors should be rated for inverter duty, in
accordance with NEMA MG1, part 30 and 31, with a separate stainless steel
nameplate affixed to the motor.
a.The drive unit motor or VFD shall include an external on-off switch and an internal
contact for remote indication of operation.
b.Each drive assembly shall be of ample capacity to supply the required power and
torque output at speed settings within the speed range. Motor and gear reducer
shall be equipped with lifting lugs.
4.Gear Reducer: Each gear reducer shall be ruggedly encased in a cast iron or
fabricated steel heavy duty housing designed for the conditions it will encounter.
Gears shall be helical or spiral bevel type or a combination of both. Worm gear
arrangements will not be acceptable. The reducer shall be designed and
manufactured in accordance with the AGMA Standard and shall have a service factor
of 1.5 based upon the full motor nameplate horsepower at maximum operating speed.
Bearings shall be grease-or oil-lubricated with a minimum L-10 life of 100,000 hours,
sufficiently sized to stabilize the impeller assembly under operating conditions
throughout the range.
2.7 WALKWAY AND PLATFORM
A.Access Walkway:The clarifier shall be provided with a walkway consisting of rigidly
interlaced structural stainless steel beam members or of structural truss construction,
connecting the drive platform to the access stairs. The 36-inch clear width walkway shall NOT FOR BIDDING PURPOSES
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be fabricated of 1/4 inch stainless steel checkered floor plate with necessary stiffeners
and supports. Stainless steel handrails with the top rail 42-inches above the walkway shall
be installed on both sides of the walkway and around the center drive platform. Walkway
and handrails shall meet applicable OSHA standards. A 4-inch by 1/4-inch stainless steel
toe board shall be provided. If a structural truss system is provided, additional rails may
be required to meet safety codes. Access walkway flooring and stairs shall be 1/4 inch
stainless steel checkered floor plate with necessary stiffeners and supports attached
between the channels, including stainless steel stringers and stainless steel bolts.
B.Stainless steel bearing plates, UHMW PE slide plates, and anchor bolts for the wall
supports, including heavy hex nuts and washers, shall be provided by the equipment
supplier and installed by the contractor. Bearing plate dimensions and anchor bolt
diameter, length, quantity, and arrangement shall be supplied by the equipment supplier.
C.Walkway Support: The walkway shall be supported by the exterior wall and the drivehead
casing which, in turn, shall be supported by the center column. The walkway shall be
designed to safely withstand a live load of 150 lb/sq ft with a deflection of not more than
1/360th of the span. Maximum dead load deflection shall be 1/2-inch. Necessary
provisions shall be made for expansion and contraction of the walkway.
D.Center Drive Platform: A center drive platform shall provide access to the center assembly
and drive control. It shall consist of 1/4 inch stainless steel checkered floor plate with
necessary stiffeners and supports, resting on the center assembly and provided with
connections to the walkway. The entire platform shall be surrounded by handrails 42-
inches high, of 1-1/2 inch diameter double-row horizontal pipe and 4-inch high toe board.
The center platform shall provide not less than 3-feet of working clearance around the
drive unit and the control panel.
E.Submerged Structural Steel Parts: Steel parts of the clarifier mechanisms shall be 304
stainless steel minimum 1/4-inch thick plate or at least 1/4-inch by 2-inch by 2-inch angle
bars. The center well shall be 3/16-inch thick minimum. Edges shall be rounded or
chamfered by grinding to allow complete adhesion of coatings. Structural shape members
shall be designed in accordance with the AISC Steel Construction Manual. Connections
shall be welded for every component below the headgear drive. No bolted connection is
permitted. The center column mounting flanges located at the footing and headgear
connection shall be provided with gusset plates.
2.8 SPRAY BAR
A.A spray bar system shall be designed and provided by the manufacturer to control the
growth of algae on the feedwell walls. The system shall be 304 stainless steel and shall
provide a spay stream directed on both the inside and outside face of the feedwell and
extend from the top of the well down to six (6) feet below water surface. The system shall
be designed to operate with a utility water pressure of 60 psi provided at the edge of the
clarifier and the manifold and nozzles sized to provide a forceful spray pattern capable of
removing attached algae growth. The system shall operate continuously whenever the
clarifier is in operation and shall not interfere with the normal rotation of the
flocculation/clarifier mechanism. The flow of water shall be controlled by a manual isolation
valve also provided by the manufacturer and the valve, piping and spray bar shall be fixed
to and supported by the walkway. The control valve and system connection shall be
provided at the edge of the clarifier and placed in such a manner as to be easily accessible.
Spray nozzles shall be removable so they can be replaced as needed over time. NOT FOR BIDDING PURPOSES
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B.Alternatively, the clarifier mechanism vendor may propose an alternative method of
continuous algae removal on the feedwell walls.
2.9 Control Panel
A.A local control panel (LCP) shall be provided as part of the Circular Flocculating Clarifier
Mechanism package.The panel shall be in a NEMA 4X stainless steel enclosure. The
enclosure must be continuous seam welded, have a single front door with a continuous
hinge and a neoprene gasket. There shall also be provided a mechanism designed for
securing the enclosure with a padlock. The incoming power shall be 208 VAC, 3-phase.
Provide an LCP with a UL 508A SCCR of 22 kA (minimum) with labels and markings
required by NEC Article 409.
1.All internal wiring shall be neat and color-coded. Each wire shall be labeled at both
ends with a heat-shrinkable wire label. All incoming wires shall terminate into a box
clamp type terminal block. All control wires shall be 14 Ga. Type TEW, tinned copper,
rated for 105 degree Celsius.
2.A schematic diagram (showing wire color) shall be permanently fastened to the inside
of the enclosure. An Installation and Service Manual shall also be included with each
control panel.
3.Apply corrosion inhibitors inside the panel after fabrication and prior to shipment to
the jobsite. Inhibitor shall consist of agents that vaporize and then condenses on all
internal surfaces of the enclosure. Panel shall be factory wired and tested.
B.The local control panel shall have three feet of clearance in front of the full width of the
panel. A working space of 30 inches of width shall be available for access and
maintenance of the control panel.
C.The combination-type motor controller for the Clarifier shall consist of a protective circuit
breaker with external circuit breaker operating handle. The handle shall include locking
tabs that prevent the door from being opened with the breaker in the On position. The
motor starter with overloads shall be a NEMA rated full-voltage non-reversing type. It shall
have a 3-pole ambient compensated bimetal overload relay.
D.The VFD shall be part of local control panel package as specified in Paragraph 2.6.J.3.
E.Operator controls shall include an E-Stop pushbutton with a red, mushroom head
operator. E-Stop button is to be of the maintained contact, push-pull type. In addition, a
High Torque alarm light shall be hard-wired to interlock the unit from operating and have
a reset at the local control panel. A Reset pushbutton, Running light with a green lens,
motor overload Fault light (amber lens), Control power ON light (white lens) and an
elapsed time meter shall also be included on the control panel.
F.The local control panel must also interface with the plant control system. Each interface
point shall be in the form of a dry, relay contact wired to terminal blocks. The following is
a list of interface points required between the Local Control Panel and the Plant Control
System:
1. Status and Alarms to Plant Control System:
2.Remote status.NOT FOR BIDDING PURPOSES
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3.Running status.
4.Motor overload Fault alarm.
5.Clarifier High Torque alarm.
G.The local control panel will have an Ethernet port for future use. Communication between
the LCP and plant control system is accomplished using the Modbus TCP/IP protocol.
H.Control Functions – Flocculation Arm Drive Mechanism
1.The LCP shall be furnished with a LOCAL/OFF/REMOTE switch, a START and STOP
pushbuttons and a speed controller.
2.When the LOCAL/OFF/REMOTE switch is in the LOCAL position, the operator shall
be able to start or stop the flocculation arm drive mechanism via START and STOP
pushbuttons. Once started, the speed of the flocculation arm drive mechanism shall
be controllable via a speed controller potentiometer. There are no local automatic
controls.
3.When the LOCAL/OFF/REMOTE switch is in the REMOTE position, the local controls
shall be deactivated and the START/STOP and speed control functions shall be
enabled in the Plant Control System.There are no remote automatic controls.
4.The LCP shall provide a 4-20mA output speed signal. Signals other than 4-20mA
shall not be accepted.
I.Control Functions – Clarifier Drive System
1.The LCP shall be furnished with a LOCAL/OFF/REMOTE switch.
2.When the LOCAL/OFF/REMOTE switch is in the LOCAL position, the clarifier drive
shall start or stop when the START or STOP pushbutton is pushed.There are no local
automatic controls.
3.When the LOCAL/OFF/REMOTE switch is the REMOTE position, the local controls
shall be deactivated and the MANUAL/AUTO, START/STOP, AND run timer shall be
enabled in the Plant Control System.There are no remote automatic controls.
2.10 Electrical
A.The contractor shall supply and install all required electrical items not specifically called
for as furnished by the equipment supplier.
B.The contractor shall supply and install all field wiring required including but not limited to
proper size wire, conduit, fittings, and supports in accordance with Division 26
specifications
2.11 SURFACE PREPARATION PROTECTIVE COATING
A.All fabricated steel will be 304 stainless steel.
B.Coating shall be in accordance with Section 09 96 00 – Protective Coating. NOT FOR BIDDING PURPOSES
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2.12 Spare Parts AND SPECIAL TOOLS
A.The CONTRACTOR shall furnish the following spare parts to the Site or at a location
designated by the OWNER. The spare parts shall be delivered in a crate protected for
long term storage.
1.One (1) set of seals for each sludge collector drive
2.One (1) set of seals for each flocculation arm drive
3.One (1) set of overload control device switches
4.Replacement squeegees for each complete rake arm
B.Special Tools
1.Furnish in the same manner as spare parts.
2.Include tools that are required to assemble, disassemble, repair, and maintain
equipment, and that have been specifically made for use on clarifier equipment.
3.Include with each tool set the necessary hooks and rods for handling equipment parts
that are not permanently attached.
4.Mark or tag special tools with equipment identification numbers.
5.Include a list of special tools with the maintenance and operation data in the technical
manual.
6.Furnish each set of tools, eyebolts, hooks, and rods in boxes with hinged covers, with
provision for wall mounting
2.13 MANUFACTURERS, OR EQUAL
A.WesTech
B.Ovivo USA (formerly EIMCO Water Technologies)
PART 3 -- EXECUTION
3.1 DELIVERY, STORAGE, AND HANDLING
A.Prior to shipping, the equipment shall be inspected to assure that equipment is complete
and in compliance with the following requirements:
1.Match mark mating parts for ease of field assembly.
2.All components shall be erected immediately upon receipt from the flocculating clarifier
manufacturer or stored in strict conformance with storage recommendations provided
by the flocculating clarifier manufacturer in the operation and maintenance manual.
3.Lubricate moving parts as practical before shipment. When necessary to
disassemble components for shipping, coat exposed machined surfaces with suitable
rust-preventive compound before shipping.The units shall be lubricated in strict NOT FOR BIDDING PURPOSES
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accordance with the instructions of the flocculating clarifier manufacturer's field service
representative.
4.Shop photograph fabricated steel items, clearly showing piece marks.
5.Mount and securely bolt equipment to pallets.
6.Crate equipment (when required for additional protection). Securely attach one
packing list to each pallet or container.
7.Securely block or otherwise support components that may be subject to damage from
vibration or jarring during shipment.
8.At the Site, store materials to permit easy access for inspection and identification.
Keep steel members off the ground, using pallets, platforms, or other supports.
9.Store mechanical equipment in covered storage off the ground and prevent
condensation. Follow manufacturer’s recommendations for proper storage.
3.2 SCHEDULING
A.Furnish stainless steel template for placement of center column anchor bolts prior to
pouring concrete.
3.3 INSTALLATION
A.Clarifier equipment shall be installed in accordance with Section 46 43 00
Clarifiers/Sedimentation Tanks, General.
3.4 GROUTING THE TANK FLOOR
A.After the equipment has been erected, a 2-inch layer of grout shall be applied to the tank
floor, using screeds and templates installed on the mechanism rake arms, and the grout
shall be floated to form the finished surface. Grouting shall not be done until the
manufacturer has inspected the mechanism. Prior to grouting, the ENGINEER shall
inspect and accept preparation of the base slab surface. Grouting procedure and the
grout mix shall be in accordance with Section 03 60 00 -Grouting, and as accepted by the
ENGINEER.
3.5 FIELD TESTS
A.The clarifier mechanism and the alarm system shall be torque-tested to 100 percent of the
indicated running torque. Each arm shall be tested in the presence of the ENGINEER and
manufacturer by applying the load evenly to both arms before the mechanism is accepted
and placed into operation.
B.The test shall be a dynamic test performed on the clarifier mechanism to verify accurate
torque indication and adequacy of the mechanism to safely withstand the torque. The test
shall accurately depict actual operation of the mechanism and shall not apply impact
loading, jerky loading, or abnormal conditions that may reduce the life of the equipment.
C.A torque test device shall be attached near the outer end of each rake arm. The device
shall allow the load to be gradually applied uniformly to each arm as the arm rotates.
Readings of the load applied at the arm versus the torque indicator reading shall be taken NOT FOR BIDDING PURPOSES
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at 100 pound increments until the indicated cut out torque is achieved. This load shall be
applied over not less than one half revolution of the mechanism.
D.Actual torque versus indicated torque shall be accurately indicated within 7 percent of full
scale at torque readings across the range.
E.There shall be no permanent deformation of any component. If deformation does occur,
or the required torque is not achieved, the CONTRACTOR shall replace the defective
parts, and the clarifier shall be retested as part of the WORK.
END OF SECTION
NOT FOR BIDDING PURPOSES
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BID SET - VOLUME II - DRAWINGS
San Geronimo Treatment Plant
June 2018
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M-118
T
3T TMORTAR LINING ORLINING AS SPECIFIED
PIPE SHELL, FORCOATING SEESPECIFICATIONS
PROVIDE TWO 1/4"TAPPED HOLESWITH PLUGS
BUTT STRAP JOINT
(TYP)
(MIN)POINT WITH MORTAROR SAME AS LININGSPECIFIEDTMINIMUM 4" WIDEBUTT STRAP
(TYP)LOAD
(TYP)
SUPPORTING
PIPE FLANGE
5
6
7
8
9
10
10
12
13
14
16
18
19
21
24
28
32
33
9
10
11
12
13
15
16
16
18
20
22
24
27
30
34
36
40
6
8
10
12
14
16
18
20
22
24
26
30
34
36
42
48
54
60
66
72
4
4
4
4
4
4
4
5
5
5
5
5
5
6
6
6
6
6
6
6
12
12
12
12
12
12
12
12
12
12
12
12
15
15
18
18
18
18
18
18
6
6
6
6
6
6
6
6
6
6
7
9
6
8
9
11
12
13
14
15
18
19
21
23
26
27
31
36
40
45
49
53
12
13
15
17
17
19
20
21
24
24
27
28
32
32
36
42
46
52
56
60
10
11
12
13
14
15
16
17
18
19
20
22
24
25
28
31
34
37
40
43
STRAP
11
13
15
17
18
20
21
23
25
26
28
31
35
36
41
46
50
56
61
65
16
18
20
22
23
26
26
28
30
32
34
36
41
42
47
52
56
62
68
72
13
14
15
16
17
18
19
21
22
23
24
26
29
30
33
37
40
44
47
50
PIPE SUPPORT WITH STRAP M-110(MIN)90°'J' (APPROX)'F'
'G'
'A'
'E'
4 1/2"
1" 1"1 1/2"FLAT BAR STRAP.FOR THICKNESS SEETABLE AT RIGHT
2 1/8"(TYP)
1/4
NOTES:
(FOR PIPE 72" DIAMETERAND SMALLER)
1
1
1 BOLTSIZE36 44
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
1/2
1/2
5/8
5/8
5/8
5/8
5/8
5/8
5/8
5/8
5/8
5/8
3/4
3/4
3/4
3/4
1 1/8
1 1/8
1 1/8
1/2
1/2
1/2
1/2
1/2
1/2
1/2
5/8
5/8
5/8
5/8
5/8
5/8
3/4
3/4
3/4
3/4
3/4
3/4
3/4
1/4
1/4
1/4
1/4
1/4
1/4
1/4
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
3/8
4 1/2 6 1/2
7 1/2FLATBARDIMENSIONS IN INCHES
(TYP)
9
9
9
9
9
7
7
7
SEE NOTE 4
FINSHED FLOOR8"FLANG
E
O
D "
H"
NON-SHRINK GROUT,SEE NOTE 3
TWO HEX BOLTS WITHNUTS. FOR SIZE, SEETABLE AT RIGHT(TYP OF 3)
'A' 'B' 'C' 'D' 'E''F' 'G' 'J''H' 'F' 'G' 'H' 'J'
TWO HEX BOLTSWITH NUTS. FORSIZE, SEE TABLEAT RIGHT(TYP OF 3)
'D' DIAMETERANCHOR BOLTWITH TWO HEXNUTS AND WASHERSFOR LEVELING AFTERINSTALLATION(TYP OF 4)
SEE NOTE 4
NOMINALPIPEDIAMETER
'C' THICK PLATE
1. HOT DIP GALVANIZE PARTS AFTER FABRICATION.2. WHEN SUPPORTING PIPE AND FLANGE ALTERNATELY ON THE SAME LINE, CONCRETE PIERS FOR PIPE SUPPORTS SHALL ALL HAVE THE SAME DIMENSION 'H' FOR FLANGE SUPPORT.3. WHERE DIFFERENTIAL SETTLEMENT IS LIKELY TO OCCUR, OMIT GROUT AS DIRECTED BY THE ENGINEER.4. ANCHOR BOLT OR CONCRETE ANCHOR WITH TWO NUTS AND ONE WASHER. PROVIDE 4X1/2X4" BAR WELDED TO BOLT (TYP OF 4, MINIMUM)
1/4" THICKNEOPRENEEXPANSIONJOINT FILLER.WRAP AROUNDPIPE
3"
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 86
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 87
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 88
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 89
SGTP Clarifier Replacements
Structural Calculations
May 31, 2018
Prepared for:
Marin Municipal Water District
Prepared by:
Lloyd Soohoo
A1
1.0 CLARIFIER STRUCTURAL DESIGN CRITERIA
This project includes the evaluation of two existing clarifier structures and the design of new center pier foundations
to support new flocculating clarifier mechanisms.
Clarifier No. 1 was constructed around 1961 as a ~15.67’ high x 125’ inside diameter circular prestressed concrete
tank, with circumferential wire wrapping/shotcrete around a cast-in-place corewall. Water level is 14’ above finished
floor. The base slab was 12” thick beneath the wall, thickening to nearly 24” just inside the wall, and then tapering to
12”, and eventually 8” thick towards the middle. The slab reinforcement was laid out in orthogonal directions. In the
1990s, some of the wire prestressing failed and a repair was instituted. The repair removed or cut the prestressing,
and included the installation of a 12” conventionally reinforced concrete wall inside the existing.
Clarifier No. 2 was constructed around 1972 as a ~15.67’ high x 125’ circular conventionally reinforced concrete tank.
Water level is 14’ above finished floor. The base slab was 1’-6” thick at the perimeter tapering to 12”, and eventually
8” thick towards the middle. The slab reinforcement was laid out in radial and circumferential directions.
Historical geotechnical information from the May 1995 Clearwell Construction and Repair Project was used to
develop foundation design criteria (Geologic/Geotechnical Study San Geronimo Water Treatment Plant Clearwell
Project, Marin County, Geomatrix, 1994). Clarifier No. 1’s drawings indicate the structure was substantially founded
on rock (Franciscan melange), but the natural rock sloped down to the south and foundation walls were constructed
beneath the slab so the structure could be founded on rock. Clarifier No. 2’s drawings indicate portions of the
northwest, southwest, and southeast wall footing were cast atop lean concrete fill so the structure could be founded
on rock. The clarifier mechanism foundations are anticipated to be founded on rock, as they are anticipated to be 7-ft
thick.
1.1 STRUCTURAL DESIGN CRITERIA
This section presents a summary of the structural codes and design criteria that will be used for the project. These
requirements will be incorporated in the design.
1.1.1 Governing Codes and Design Standards
Structural design will be performed in accordance with the 2016 Edition of the California Building Code (CBC) 2016,
as allowed by Section 317.7 of the 2016 California Existing Building Code (CEBC), ACI 350, and ACI 350.3, except
where other applicable codes are more restrictive.
1.1.2 Design References and Standards
Structural design shall be in accordance with the following references and standards. Where the version is not listed,
use the version listed under Referenced Standards in CBC 2016.
• American Society of Civil Engineers (ASCE) 7-10 - Minimum Design Loads for Buildings & Other Structures
• American Concrete Institute (ACI) 318-14 - Building Code Requirements for Structural Concrete
A2
• ACI 350-06 – Code Requirements for Environmental Engineering Concrete Structures and Commentary
• ACI 350.3-06 – Seismic Design of Liquid-Containing Concrete Structures and Commentary
1.2 MATERIALS OF CONSTRUCTION
This section presents a summary of the structural codes and design criteria that will be used for the project. These
requirements will be incorporated in the clarifier evaluations.
1.2.1 Reinforced Concrete
The reinforced concrete used on this project shall be designed for strength, durability, shrinkage reduction, sulfate
resistance and aesthetics. See cast-in-place concrete specification for slump, aggregate sizes, and water/cement
ratios for different mixes.
Table 1 (new concrete)
Item Properties
Cement ASTM C150 Type II
Pozzolans No pozzolans (including flyash) shall be used in concrete for hydraulic concrete
structures
Admixtures A combination of water-reducing admixtures may be used in all concrete mixes
for ease of pumping and placement, to achieve the lowest possible water/
cement ratios to minimize shrinkage and control cracking. Admixtures
containing calcium chloride shall not be used.
Reinforcement ASTM A615 Grade 60
ASTM A706 Grade 60, if welded. Carbon Equivalent shall not exceed 0.55%
Welded wire fabric - ASTM A185
Concrete
Minimum concrete strength at 28 days:
Structural concrete – 4,000 psi
Site work concrete – 3,000 psi
Lean concrete – 2,000 psi
Table 2 (1961 and 1972 construction)
Item Properties
Reinforcement ASTM A615 Grade 40
Concrete f’c = 3,000 psi
Table 3 (1992 construction)
Item Properties
Reinforcement ASTM A615 Grade 60
Concrete f’c = 4,000 psi
A3
1.3 GEOTECHNICAL INFORMATION
The report for the 1995 Clearwell Construction and Repair Project entitled Geologic/Geotechnical Study San
Geronimo Water Treatment Plant Clearwell Project, Marin County, California by Geomatrix Consultants, dated
October 1994 was used to determine geotechanical design parameters. This project indicated the Clearwell would be
founded on Franciscan mélange (rock) and provided foundation design recommendations. The following geotechnical
information is based on this report.
1.3.1 Design Parameters
Table 4
Item Parameter
Allowable bearing pressure 5,000 psf w/ 1/3 increase for transient loads
Friction On class 2 permeable material: µ = 0.35
Passive 300 pcf
1.4 DESIGN LOADS
Design loads are summarized in the following paragraphs.
1.4.1 Dead Loads (D)
Includes the weight of the structure and all fixed equipment.
Table 5
Item Load
Reinforced concrete 150 pcf
Steel 490 pcf
1.4.2 Seismic Loads (E)
Seismic loads for design of the seismic force-resisting systems and nonstructural components will be determined per
the requirements of the CBC and ACI 350.3. Use the following parameters to calculate the seismic loads:
Table 6
Item Parameter
Risk Category IV
Seismic Importance Factor, IE 1.50
Mapped Response Acceleration Parameter (Site Class B), Ss 1.571g
Mapped Response Acceleration Parameter (Site Class B), S1 0.721 g
Site Class D
Site Coefficient, Fa 1.0
A4
Site Coefficient, Fv 1.5
Design Spectral Response Acceleration Parameter, SDS 1.047g
Design Spectral Response Acceleration Parameter, SD1 0.721g
Seismic Design Category D
Seismic Load Resisting System Hinged base tank
Impulsive Response Modification Coefficient 2.0
Convective Response Modification Coefficient 1.0
1.5 LOAD COMBINATIONS
1.5.1 Clarifier Structures
Clarifier structures shall be evaluated according to ACI 350 for seismic loads. Seismic load combinations do not
require consideration of the environmental durability factor (Sd). The following load combination considering liquid
load (F) and earthquake (E) shall be used:
• U = 1.2 F + 1.0 E
1.6 STRUCTURAL DESIGN REQUIREMENTS
Design requirements are summarized in the following sections for stability, deflection, vibration, and durability.
1.6.1 Stability
Design structures to resist sliding, overturning, and flotation using the following criteria and factors of safety:
Table 7
Condition Factor of Safety
Sliding
Normal
Seismic
1.50
1.10
Overturning
Normal
Seismic
1.50
1.10
Keep resultant force within the middle third of the foundation base if possible.
Resistance to lateral seismic loads shall be provided by the following: friction between foundation mat or footing.
A5
1.7 SEISMIC DESIGN REQUIREMENTS FOR NON-STRUCTURAL
COMPONENTS
Architectural, mechanical, and electrical components shall be designed for seismic loads as required by ASCE 7,
Chapter 13, for Seismic Design Category D, as a minimum.
1.8 ANCHORING TO CONCRETE
Cast-in anchors and post-installed anchors shall be designed to meet the requirements of ACI 318, Chapter 17,
except for special anchor types not covered by ACI 318.
1.9 STRUCTURAL SPECIAL INSPECTIONS REQUIREMENTS
Provide special inspections, structural testing, structural observations and written statements per the 2016 CBC.
Special Inspection requirements are listed on the GS sheets of the Contract Documents
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 96
SANTA CLARA VALLEY WATER DISTRICT RINCONADA WTP -
JDH/STANTEC CONDITION ASSESSMENT
This section includes the Santa Clara
Valley Water District (SCVWD) Rinconada
WTP Gravity Thickener No. 1 and No. 2
Condition Assessment Draft Report developed
by subconsultant JDH for Stantec.
SCVWD Rinconada WTP, Los Gatos, CA
1100 Willow Pass Court, Concord, CA 94520
Tel. No. 925.927.6630 Fax No. 925.927.6634
STANTEC, INC.
SCVWD - RINCONADA WATER
TREATMENT PLANT
GRAVITY THICKENER NO. 1 AND NO. 2
Protecting the infrastructure
through innovative
Corrosion Engineering Solutions
Santa Clara Valley Water District
Rinconada Water Treatment Plant
Gravity Thickener No. 1 and No. 2 Condition
Assessment Draft Report
For
Stantec Consulting Services, Inc.
1340 Treat Blvd. #300
Walnut Creek, CA 94597
Gravity Thickener No. 1 and No. 2 Condition Assessment
Rinconada Water Treatment Plant, Los Gatos, CA
JDH Corrosion Consultants, Inc.
2
Respectfully submitted,
J. Darby Howard, Jr., P.E.
JDH CORROSION CONSULTANTS, INC.
Principal
Sergio Maciel, P.E.
JDH CORROSION CONSULTANTS, INC.
Project Engineer
Sean Carey
JDH CORROSION CONSULTANTS, INC.
Operations Manager
2 6/17/2019 Review SM JDH JDH JDH
1 5/28/2019 Review SM JDH JDH JDH
0 5/17/2019 Review SM JDH JDH JDH
Rev. Date Issued for By Checked By PE PM
Gravity Thickener No. 1 and No. 2 Condition Assessment
Rinconada Water Treatment Plant, Los Gatos, CA
JDH Corrosion Consultants, Inc.
3
June 17, 2019
Stantec Consulting Services, Inc.
1340 Treat Blvd. #300
Walnut Creek, CA 94597
Attention: Steve Tidwell, PMP
Senior Project Manager, Water
Subject: Gravity Thickener No. 1 and No. 2 Inspection
Rinconada Water Treatment Plant
Los Gatos, CA
Dear Steve,
Per your request, JDH Corrosion Consultants, Inc. (JDH), with support from Stantec, Voss
Laboratories (Voss Labs), CEL Consulting, and Santa Clara Valley Water District (District), has
completed a condition assessment of Gravity Thickener No. 1 (GT No. 1) and Gravity Thickener
No. 2 (GT No. 2) at the Rinconada Water Treatment Plant (RWTP). The results from this
condition assessment are included herein for your consideration.
BACKGROUND
The RWTP is located in Los Gatos, California and the treats and delivers up to 80 million
gallons of water each day for retailers who supply residential and commercial users in the West
Valley, including the cities of Santa Clara, Campbell, Sunnyvale, Cupertino, Mountain View,
Monte Sereno, Saratoga and Los Altos and the towns of Los Gatos and Los Altos Hills.
The District completed construction of two gravity thickener concrete tanks at the RWTP during
the spring of 2016. The District identified softening of the interior concrete surfaces and some
cracking in both thickener tanks almost immediately after construction. District operation staff
conducted a subsequent shutdown and an initial qualitative inspection that provided indications
that areas of concrete inside the tanks may not satisfy performance specifications as identified
in the project construction documents.
PURPOSE
JDH was asked to conduct a confined space entry inside GT No. 1 and GT No. 2 in order to
provide information on their condition, including any recommendations for needed remediation.
JDH performed a condition assessment of GT No. 1 and No. 2 that consisted of a visual
inspection, delamination tests, surface scratching, and dry film thickness (DFT) tests and
ultrasonic thickness (UT) tests on metallic elements.
Gravity Thickener No. 1 and No. 2 Condition Assessment
Rinconada Water Treatment Plant, Los Gatos, CA
JDH Corrosion Consultants, Inc.
4
EXECUTIVE SUMMARY
In general, the concrete in Gravity Thickener No. 1 (GT No. 1) and Gravity Thickener No. 2 (GT
No. 2) is in good condition with respect to deterioration. GT No. 1 and GT No. 2 have surface
mortar loss up to ¼’’ and surface air voids and bug holes are present. The estimated water to
cement ratio for both thickeners was found to be 0.40 and the depth of carb onation for both
thickeners was found to be 0.1 inches. Voss Laboratories conducted concrete and concrete
core analysis and CEL Consulting conducted a petrographic study for GT No. 1 and GT No. 2
and their results are attached at the end of this report. In general, Voss Laboratories concluded
that the compressive strength of the core samples for both tanks exceeds the specified design
compressive strength for the tanks and CEL Consulting, Inc. concluded that the cores that they
examined were sound and of good quality and that both samples were consistent with the
concrete mix design that was approved for the tanks.
In general, most metallic elements inside GT No. 1 and GT No. 2 Thickener No. 1 were found to
be in excellent to moderate condition with respect to corrosion. The coating on the rake arm
members inside both thickeners has failed at the corners and edges due to an inadequate stripe
coat application. Several areas on the rake arm where metal was exposed at the corners and
edges have experienced significant corrosion and metal loss. The coating on the center
column, center cage, and influent well was in good condition with no significant signs of coating
deterioration or steel corrosion.
JDH recommends recoating the rake arms inside GT No. 1 and GT No. 2 with an NSF 61
approved coating and adding supplemental galvanic anodes within two years. Inspect GT No. 1
and GT No. 2 two to five years after the rake arm coating application is complete to ensure
proper coatings performance. JDH also recommends reassessing GT No. 1 and GT No. 2 at
five-year intervals as part of an ongoing asset management program.
Gravity Thickener No. 1 and No. 2 Condition Assessment
Rinconada Water Treatment Plant, Los Gatos, CA
JDH Corrosion Consultants, Inc.
5
SITE PLAN
Santa Clara Valley Water District
Rinconada Water Treatment Plant
Gravity Thickener
No. 2
Gravity Thickener
No. 1
Gravity Thickener No. 1 and No. 2 Condition Assessment
Rinconada Water Treatment Plant, Los Gatos, CA
JDH Corrosion Consultants, Inc.
6
DISCUSSION
GENERAL
JDH Corrosion Consultants, Inc. (JDH), with operational support from Santa Clara Valley water
District (District), assessed GT No. 2 at the RWTP on April 9th, 2019 and assessed GT No. 1 at
the RWTP on April 16th, 2019. District personnel isolated the structures and JDH mobilized for
entry into the structure before it was returned to service. JDH conducted the condition
assessment with a focus on the metallic elements inside Thickener No. 1 while Tom Voss with
Voss Laboratories, Inc. (Voss Labs) focused on the concrete components. CEL Consulting
conducted a petrographic study of concrete cores from both tanks. JDH has included photo
documentation for GT No. 1 and GT No. 2 in Appendix A.
GT No. 1 and GT No. 2 are both a 50’-diameter by 21’ high concrete tanks. The interior and
exterior concrete walls are uncoated and steel surfaces inside both thickeners are coated.
In general, the concrete inside GT No. 1 and GT No. 2 is in good condition with no major voids or
exposed reinforcing steel. No major signs of cracking were observed on the interior and exterior
tank walls and no major leakage sites were observed on the exterior of the tank walls.
In general, the metallic structures and coatings inside GT No. 1 and GT No. 2 are in excellent to
moderate condition. The coating on the center column and center cage is in good condition with
no significant cracks or disbondment. The coating on the rake arms has failed at corners and
edges of rake arm members. Areas of exposed steel at the rake arms have experienced
significant corrosion and metal loss.
Table 1 below indicates the scoring method developed for identifying conditions for concrete
structures and Table 2 indicates the scoring method developed for identifying conditions for
metallic structures. Table 3 presents a summary of findings and recommendations for GT No. 1
and Table 4 GT No. 2 concrete and metallic components.
Gravity Thickener No. 1 and No. 2 Condition Assessment
Rinconada Water Treatment Plant, Los Gatos, CA
JDH Corrosion Consultants, Inc.
7
Table 1 – Concrete Condition Scoring Key
Condition
Score Description
1 Excellent – No noticeable or noteworthy deficiencies. Surface of concrete is smooth and
free of exposed aggregate, cracks and spalls.
2 Good – Minor cracking less than 1/32” wide with some exposed aggregate but no spalling
evident
3 Fair – The surface has cracks greater than 1/16” wide with large areas of exposed
aggregate and carbonation up to ¼” deep and up to 10% of the surface with spalling
evident
4 Poor – Carbonation up to ½” deep, large areas of exposed aggregate and evidence of loss
of aggregate due to loss of cement paste from chemical attack, cracks greater than 1/16”
and large areas of spalling evident and some exposed reinforcing steel evident on the first
layer of reinforcing steel with minor amounts of corrosion on the steel rebar. Spalled
concrete and corroded rebar reasonably easily repairable.
5 Serious – Major areas of spalling and exposed reinforcing steel evident. Repairs will
require replacement of reinforcing steel and significant amounts of spalled concrete.
Structural analysis may be necessary to determine if the structure can continue to function
as designed without immediate repair.
Table 2 – Metallic Equipment Condition Scoring Key
Condition
Score Description
1 Excellent – No noticeable or noteworthy deficiencies. Corrosion metal loss, material
cracking, delamination, are negligible.
2 Good – Minor corrosion metal loss, material cracking, and delamination damage. No
immediate action is necessary.
3 Fair – Moderate corrosion metal loss, material cracking, and delamination damage.
4 Poor – Moderate corrosion metal loss, material cracking, and delamination damage.
Should address within 2 to 5 years.
5 Serious – Major deficiencies evident. Equipment has reached the end of its useful life,
and requires immediate replacement.
Gravity Thickener No. 1 and No. 2 Condition Assessment
Rinconada Water Treatment Plant, Los Gatos, CA
JDH Corrosion Consultants, Inc.
8
Table 3– Summary of Findings and Recommendations for GT No. 1
Structure/Asset Observed Condition
Score
Observed Issues/remarks Recommendations
Concrete
Interior Walls 2
Interior surface mortar loss up to
¼’’. Surface air voids and bug
holes present.
No action required at
this time.
Floors 1 No major voids or exposed
reinforcing steel was observed.
No action required at
this time.
Exterior walls 1 No major voids or exposed steel
was observed.
No action required at
this time.
Rake arms 3
Coating on most corners and
edges of rake arm members has
failed. Significant corrosion on
exposed steel has occurred in
some areas.
Remove and replace
coating on rake arms
within two years.
Ensure proper stripe
coat is installed.
Supplement coatings
with galvanic anodes.
Center column 1 Coating is in good condition. No
significant signs of corrosion.
No action required at
this time.
Center cage 1
Coating is in good condition. No
significant signs of corrosion.
Threaded bolts and nuts
connecting center cage and rake
arms are significantly corroded.
Replace threaded bolts
and nuts with stainless
steel material within 2
years.
Influent well 1
Coating is in good condition. No
significant signs of corrosion.
Moderate corrosion on nuts and
bolts on influent well.
Replace nuts and bolts
with stainless steel
material.
Table 4 - Summary of Findings and Recommendations for GT No. 2
Structure/Asset Observed Condition
Score
Observed Issues/remarks Recommendations
Concrete
Interior Walls 2
Interior surface mortar loss up to
¼’’. Surface air voids and
bugholes present.
No action required at
this time.
Floors 1 No major voids or exposed
reinforcing steel was observed.
No action required at
this time.
Exterior walls 1 No major voids or exposed steel
was observed.
No action required at
this time.
Rake arms 3
Coating on most corners and
edges of rake arm members has
failed. Significant corrosion on
exposed steel has occurred in
some areas.
Remove and replace
coating on rake arms
within two years.
Ensure proper stripe
coat is installed.
Supplement coatings
with galvanic anodes.
Center column 1 Coating is in good condition. No
significant signs of corrosion.
No action required at
this time.
Center cage 1 Coating is in good condition. No Replace threaded bolts
Gravity Thickener No. 1 and No. 2 Condition Assessment
Rinconada Water Treatment Plant, Los Gatos, CA
JDH Corrosion Consultants, Inc.
9
significant signs of corrosion.
Threaded bolts and nuts
connecting center cage and rake
arms are significantly corroded.
and nuts with stainless
steel material within 2
years.
Influent well 1
Coating is in good condition. No
significant signs of corrosion.
Moderate corrosion on nuts and
bolts on influent well.
Replace nuts and bolts
with stainless steel
material.
Gravity Thickener No. 1 Condition Assessment
Sounding on interior and exterior concrete surfaces revealed that the concrete was sound and in
good condition with no indications of delamination or voids. Interior walls had surface mortar loss
up to ¼’’ and surface air voids and bug holes were present. Additional concrete and concrete core
analysis for GT No. 1 is provided by Voss Labs and CEL Consulting and is attached at the end of
this report. This lab analysis includes but is not limited to depth to reinforcing steel, chloride profile
and depth of carbonation, concrete compressive strength, Schmidt Hammer rebound strength
tests, and a petrographic analysis.
Carbonation of concrete is a process by which the environment around the concrete reacts with
cement paste, with the effect that pH in the cement paste is reduced. When this reduction in
alkalinity approaches approximately pH 10, passivation of the reinforcing steel is impaired, and
onset of corrosion of any embedded steel in this environment may commence. The process of
carbonation typically occurs relatively uniformly through the concrete structure from one of the
surfaces. It is common, therefore, to perform tests to determine location of the carbonation front, or
the extent (depth) of the leading edge of carbonation in concrete structures. This data, when
compared with depth of reinforcing steel cover, provides an understanding of whether the
embedded reinforcing steel is at risk of corrosion due to reduced pH.
The coating on the GT No. 1 rake arm members has failed at corner and edges. The coating
failure at these locations is likely due to an inadequate stripe coat application. Several areas on
the rake arm where metal was exposed at corners and edges have experienced significant
corrosion and metal loss. The coating on the center column, center cage, and influent well was in
good condition with no significant signs of coating deterioration or metal corrosion.
Thickener No. 2 Condition Assessment
Sounding on interior and exterior concrete surfaces revealed that the concrete was sound and in
good condition with no indications of delamination or voids. Interior walls had surface mortar loss
up to ¼’’ and surface air voids and bug holes were present. Additional concrete and concrete core
analysis for GT No. 2 is provided by Voss Labs and CEL Consulting and is attached at the end of
this report. This lab analysis includes but is not limited to depth to reinforcing steel, chloride profile
and depth of carbonation, concrete compressive strength, Schmidt Hammer rebound strength
tests, and a petrographic analysis.
The coating on the GT No. 2 rake arm members has failed at corner and edges. The coating
failure at these locations is likely due to an inadequate stripe coat application. Several areas on
the rake arm where metal was exposed at corners and edges have experienced significant
corrosion and metal loss. The coating on the center column, center cage, and influent well are is in
good condition with no significant signs of coating deterioration or metal corrosion.
Gravity Thickener No. 1 and No. 2 Condition Assessment
Rinconada Water Treatment Plant, Los Gatos, CA
JDH Corrosion Consultants, Inc.
10
RECOMMENDATIONS
JDH recommends that District conduct the following remediation for GT No. 1 and GT No. 2:
General
1. Inspect GT No. 1 and No. 2 five years from the date of this report to ensure proper coatings
performance after the rake arms have been recoated.
Gravity Thickener No. 1:
1. Remove and replace coating on rake arms with an NSF 61 approved coating. Acceptable
coating systems include:
a. Sherwin Williams Tank Clad HS
b. PPG Amerlock 2
c. Carboline 891 VOC
2. Install galvanic anodes on metallic structures inside GT No. 1 to supplement coating
system. A sample galvanic anode protection system for gravity thickener metallic
components is shown in Appendix D.
3. Remove and replace all four rake arm/center cage threaded rods and nuts with stainless
steel material.
4. Replace sample pipe with stainless steel material within 5 years for longevity.
Gravity Thickener No. 2
1. Remove and replace coating on rake arms with an NSF 61 approved coating. Acceptable
coating systems include:
a. Sherwin Williams Tank Clad HS
b. PPG Amerlock 2
c. Carboline 891 VOC
2. Install galvanic anodes on metallic structures inside GT No. 2 to supplement coating
system. A sample galvanic anode protection system for gravity thickener metallic
components is shown in Appendix D.
3. Remove and replace all four rake arm/center cage threaded rods and nuts with stainless
steel material.
4. Replace sample pipe with stainless steel material within 5 years for longevity.
We appreciate the opportunity to assist Stantec on this project. If you have any questions, or if
we can be of any additional assistance at this time, please contact our office at (925) 927-6630.
Gravity Thickener No. 1 and No. 2 Condition Assessment
Rinconada Water Treatment Plant, Los Gatos, CA
JDH Corrosion Consultants, Inc.
11
Appendix A
Photographs
Gravity Thickener No. 1 and No. 2 Condition Assessment
Rinconada Water Treatment Plant, Los Gatos, CA
JDH Corrosion Consultants, Inc.
12
Gravity Thickener No. 1 Assessment Photos
Photo 1.Concrete on outside of GT No. 1 in good
condition with no major signs of
Photo 2.Influent well in good conditoin. Moderate
corrosion on nuts and bolts on influent well.
Photo 3.Overall view of rake arms.Photo 4.Galvanized fasteners on rake arm
members in good condition.
Photo 5.Coating failure at edges of rake arm picket.
Significant corrosion on
Photo 6. Coating on rake arm component edges and
corners has failed.
Gravity Thickener No. 1 and No. 2 Condition Assessment
Rinconada Water Treatment Plant, Los Gatos, CA
JDH Corrosion Consultants, Inc.
13
Photo 7.Center column and center cage in good
condition with no major signs of corrosion.
Photo 8.Bottom of center column. No significant
corrosion on rake arms, center column, or center
cage
Photo 9.Corroded nuts/bolts on lower junction of
rake arms and center cage.
Photo 10.Significant corrosion on threads of bolt
connecting center cage to rake arms.
Photo 11.1/8’’ pit on nut that is part of the center
cage/rake arm fastener system.
Photo 12.Leaks underneath thickener launder.
Gravity Thickener No. 1 and No. 2 Condition Assessment
Rinconada Water Treatment Plant, Los Gatos, CA
JDH Corrosion Consultants, Inc.
14
Photo 13.Sample pipes are in good condition with no
significant corrosion.
Photo 14.Sample pipe brackets are in good
condition with no significant corrosion.
Gravity Thickener No. 1 and No. 2 Condition Assessment
Rinconada Water Treatment Plant, Los Gatos, CA
JDH Corrosion Consultants, Inc.
15
Gravity Thickener No.2 Assessment Photos
Photo 15.Overall view of GT No. 2. Exterior
concrete is in good condition with no significant
deterioration.
Photo 16.Overall GT No. 1 feed well view.
Photo 17.Overall view of GT No. 2 rake arms.Photo 18.Center cage and center column in good
condition with no major signs of corrosion.
Photo 19.Coating failure rake arm members due to
inadequate stripe coat. Corrosion product is
present on steel substrate.
Photo 20.Coating failure on underside of rake arm
members and corrosion product on steel substrate.
Gravity Thickener No. 1 and No. 2 Condition Assessment
Rinconada Water Treatment Plant, Los Gatos, CA
JDH Corrosion Consultants, Inc.
16
Photo 21. Galvanized rake arm nuts and bolts in
good condition. Coating failure on edges and
corners of rake arm components.
Photo 22. Coating failure on edges and corners of
rake arm members due to inadequate stripe coat.
Corrosion product is present on steel substrate.
Photo 23.Significant corrosion on all four bolts
connecting rake arms to center cage.
Photo 24.Coating failure on underside of rake arm
members due to inadequate stripe coat. Corrosion
product is present on steel substrate.
Photo 25.1/8’’ pit on nut connecting rake arm to
center cage.
Photo 26.Close up of corrosion on threaded bolt.
Gravity Thickener No. 1 and No. 2 Condition Assessment
Rinconada Water Treatment Plant, Los Gatos, CA
JDH Corrosion Consultants, Inc.
17
Photo 27.Feel well coating in good condition. Feed
well nuts and bolts are moderately corroded.
Photo 28. Coating on feed well pipe in good
condition. No significant corrosion is present.
Gravity Thickener No. 1 and No. 2 Condition Assessment
Rinconada Water Treatment Plant, Los Gatos, CA
JDH Corrosion Consultants, Inc.
18
Appendix B
Raw Data
Table 5. Dry Film Thickness Tests at Various Gravity Thickener
No. 1 Locations
Structure/Area Dry film thickness (mils)
Rake arms 13.3 –18.3
Center cage 14.6 –28.8
Center column 19.7 –26.7
Catwalk (East end)5.4 –13.8
Catwalk (West end)10.1 –23.6
Table 6. Ultrasonic Thickness Test Measurements for Gravity
Thickener No. 1
Structure/Area Ultrasonic
thickness
tests
(inches)
Rake arms (truss arm)0.300
Rake arms (all other members)0.245 –0.280
Rake arm (scraper)0.240 –0.245
Center column 0.365
Center cage (truss arm)0.380 –0.385
Center cage (angle member)0.250
Center cage (vertical member)0.375
Table 7. Dry Film Thickness Tests at Various Gravity Thickener
No. 2 Locations
Structure/Area Dry film thickness (mils)
Rake arms 13.3 –18.3
Center cage 14.6 –28.8
Center column 19.7 –26.7
Catwalk (East end)8.9 –16.1
Catwalk (West end)10.0 –18.4
Gravity Thickener No. 1 and No. 2 Condition Assessment
Rinconada Water Treatment Plant, Los Gatos, CA
JDH Corrosion Consultants, Inc.
19
Table 8. Ultrasonic Thickness Test Measurements for Gravity
Thickener No. 1
Structure/Area Ultrasonic
thickness
tests
(inches)
Rake arms (truss arm)0.300
Rake arms (all other members)0.245 –0.280
Rake arm (scraper)0.240 –0.245
Center column 0.365
Center cage (truss arm)0.380 –0.385
Center cage (angle member)0.250
Center cage (vertical member)0.375
Gravity Thickener No. 1 and No. 2 Condition Assessment
Rinconada Water Treatment Plant, Los Gatos, CA
JDH Corrosion Consultants, Inc.
22
Appendix E
Gravity Thickener No. 1 and No. 2 Drawings
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 118
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 119
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 120
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 121
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 122
APPENDIX B - RESUMES9
STEVEN BECK, PE
PRINCIPAL-IN-CHARGE/PROJECT MANAGER
Steve is a recognized leader in wastewater treatment design. With more
than 34 years of experience, he has managed all phases of wastewater
treatment projects (conceptual planning, feasibility studies, design, and
construction management). Steve served as principal-in-charge and/or
project manager for the City of Lincoln WWTRF, City of Merced WWTF,
City of Rio Vista Northwest WWTF, and the Donner Summit Public Utility
District WWTP Upgrade and Expansion, to name a few.
Select Project Experience:
City of Madera WWTP Phase 1 Rehabilitation Project, Madera, CA
(Principal-in-Charge) | This $6 million project included a condition
assessment of the City’s WWTP to determine the cause and associated
risks of reported structure and equipment failures. Stantec designed
the Phase I Rehabilitation project to restore operation to three primary
clarifiers (included concrete repair, new protective coatings, new
sludge and scum collectors, and replacement of primary sludge and
scum pumps), overhaul three anaerobic digesters (new sludge mixing
systems, new sludge and gas valves, coating the tanks and roofs, and
refurbishing a heat exchanger), repair corroded centrate drain line with a
new cured in place pipe (CIPP), construct a new primary effluent pump
station, and install a new plant water well with hydropneumatic tank.
City of Los Banos New Headworks Project, Los Banos, CA (Principal-
in-Charge and Project Manager) | This $7 million project included
improvements to the City’s WWTP to increase the plant capacity
from 4.0 MGD to 4.9 MGD. The project included construction of new
headworks and influent pump station, new electrical building, and
modifications to the existing recirculation pump station, yard piping, and
new sampling docks for the treatment ponds. Stantec services included
design, bidding support, engineering services during construction,
and construction inspection. Supporting services including surveying,
structural design, and permitting were also performed by Stantec.
City Dixon WWTF Improvements Project, Dixon, CA (Principal-in-
Charge) | This $25 million project included conversion of a facultative
pond plant into an extended aeration activated sludge plant with a new
self-cleaning pump station, headworks with mechanical screening, dual
train oxidation ditch, secondary clarifiers, RAS pump station, blower
building, sludge stabilization ponds, vactor truck receiving station,
operations and laboratory building, and 12,000 lineal feet of 12-inch-
diameter potable water pipeline from the City to the WWTF.
Education: MS and BS, Civil
Engineering, California State
University, Fresno, CA | BS,
Construction Management,
California State University,
Fresno, CA
Registrations/Certifications:
Professional Civil Engineer
#43799, CA (NV)
Years of Experience:
34+
Availability:
60%
Total Commitment Level of All
Other Projects for the Duration
of the District’s Project:
40%
Location: Rocklin, CA
9. APPENDIX B - RESUMES
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 123
Mid-Western Placer Regional Sewer Project, Placer
County, CA (Principal-in-Charge) | This $77 million
regional project consolidated wastewater treatment
for the City of Lincoln and northern Placer County.
The project included a new sewage lift station with
emergency storage basins, 15 miles of pipeline,
and expansion of the City of Lincoln Wastewater
Treatment and Reclamation Facility (WWTRF). The
WWTRF expansion included new influent pumps, new
headworks screen, oxidation ditch, secondary clarifier,
RAS/WAS pump station, tertiary filters, chemical feed
facilities, odor control, and effluent pumps.
Donner Summit Public Utility District Wastewater
Facilities Upgrade and Expansion, Soda Springs,
CA (Principal-in-Charge and Project Manager)
| This $21 million project included equalization
storage, headworks, a membrane bioreactor system
with advanced biological nitrogen removal facilities,
disinfection, and effluent storage and spray irrigation
disposal facilities. The project implemented biomass
augmentation through ammonia addition during low
load periods to enhance nitrification, carbon addition
to enhance denitrification and on demand reactor
heating during extremely cold temperatures.
City of Merced WWTF Phase V Solids Handling
Upgrade, Merced, CA (Principal-in-Charge and
Project Manager) | This $33 million expansion and
upgrade included significant modifications to the
existing solids handling system at the WWTF to
comply with updated WDRs by abandoning existing
earthen lined solids drying beds and installing
mechanical dewatering systems; including the addition
of centrifuges and active solar driers to produce Class
A biosolids. This project also included a centrate pump
station and equalization tank, rehabilitation of two
anaerobic digesters, digester gas holder, two natural
gas hot water boilers that can run on digester gas,
bolted steel solids holding tank, a new primary clarifier
with a coupled scum and sludge pump station and a
new septage receiving station.
City of Merced WWTF Phase IV Upgrade &
Expansion Project, Merced, CA (Principal-In-Charge
and Project Manager) | This $34 million upgrade
and expansion to the existing WWTF included new
headworks with influent pumps, screens and grit
removal equipment, secondary treatment process
improvements for simultaneous nitrification/
denitrification, new blower for aeration basins,
rehabilitation of primary and secondary clarifiers,
primary effluent equalization basin, tertiary pump
station, tertiary flocculation basins and filters,
UV disinfection system, outfall with cascading
aerator, chemical building and storage facility,
standby generator, plant water pump station, and
improvements to existing operations building.
City of Rio Vista Wastewater System Master Plan,
WWTP Expansion, and Northwest WWTP Design
Development, Rio Vista, CA (Project Manager) | This
$30 million new membrane bioreactor (MBR)plant
included an influent pump station, headworks, standby
generator, emergency storage basin, MBR process,
blower building, ultraviolet (UV) disinfection, effluent
pump station, outfall pipeline, and diffuser into the
Sacramento River. Solids handling included belt filter
presses and active solar drying.
City of Lincoln Wastewater Treatment and
Reclamation Project, Lincoln, CA (Project Manager)
| This $56 million Title 22 tertiary treatment plant
included an influent pump station and headworks,
oxidation ditches with anoxic basins, secondary
clarifiers, return active sludge pump station,
maturation/filter feed pump station, and maturation
ponds. The tertiary treatment facilities included
dissolved air flotation system, chemical coagulation,
flocculation, filtration, ultraviolet (UV) disinfection,
effluent re-aeration for surface water discharge, and
effluent pump station. The project also included solids
handling facilities with solids holding tank, solids pump
station, and dewatering facility with centrifuges.
City of Woodlake WWTF Upgrade and Expansion,
Woodlake, CA (Principal-In-Charge and Project
Manager) | This $15 million WWTF project replaced
an existing pond plant. The new facilities included
headworks screening, influent pump station, two
oxidation ditches with anoxic basins for nitrogen
removal, two secondary clarifiers, return activated
sludge and scum pump stations, solids stabilization
lagoons, percolation ponds, standby generator, and an
operations building.
City of Dinuba Wastewater Reclamation Facility
(WWRF) Phase 1 Improvements Project, Dinuba,
CA (Principal-in-Charge and Project Manager)
| This $7 million improvement project involved
design of upgraded facilities including headworks
screens, influent pumps, primary clarifier and primary
sludge pump station rehabilitation, aeration basin
improvements, new aerobic digester, and solids
dewatering facility with screw press.
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 124
AKRAM BOTROUS,
PH.D., PE, BCEE
PROCESS MECHANICAL LEAD
Akram has 27 years of wastewater treatment research and design
experience. His areas of expertise include secondary treatment process
design, biological nutrient removal, and membrane bioreactors (MBR).
He has hands-on experience with BioWin process modeling, hydraulic
profiles, water CAD modeling, process optimization, troubleshooting,
capacity assessment, and pilot studies. He also has experience with
detailed design of WWTPs, specification writing, and engineering
services during construction. Akram has published several papers
and spoke in conferences on latest development in wastewater
engineering. He is the primary author of the sixth edition of the
primary treatment chapter of the Manual of Practice No. 8 (MOP8).
Select Project Experience:
City of Merced, Wastewater Simultaneous Nitrification Denitrification
and Aeration System Upgrade, Merced, CA (Project Engineer)
| Akram provided engineering to upgrade the 12-MGD treatment
plant to reliably meet a nitrate level of 10 MG/L without demolishing
the existing diffusers or baffles. The aerobic reactors were
modified to promote simultaneous nitrification and denitrification
(SND) using the SymBio® process. A dissolved oxygen meter,
air flow meter and air flow control valve were provided to each
aeration zone to allow independent dissolved oxygen control.
City of Lincoln, Wastewater Treatment and Reclamation Facility
(WWTRF) Expansion Plan, Lincoln, CA (Lead Process Engineer) |
Akram was the lead process engineer for planning, design, and support
during construction of the expansion of this treatment facility for
the City of Lincoln. This $90 million regional project will consolidate
wastewater treatment for the City of Lincoln and Placer County SMD-
1 service areas, as encouraged by Regional Board policy. The project
includes a new local lift station, 15-miles of pipeline, and expansion of
the Lincoln treatment plant with new headworks screening, oxidation
ditches, secondary clarifiers, RAS/WAS pump station, deep bed sand
filters, chemical facilities, odor control, effluent disposal pumps, and
reclamation piping and pumps. Akram prepared contract drawings,
specifications, and cost estimates for the secondary treatment including
the oxidation ditch, the secondary clarifier, and the RAS pump station.
City of Dixon, WWTP Expansion Projects, Dixon, CA (Process and
Design Engineer) | Akram provided planning, process, and detailed
design; and services during construction for the secondary treatment
process. This $25 million project included converting a pond plant
into an extended aeration activated sludge plant with a new self-
cleaning pump station, headworks, dual train oxidation ditch and
clarifiers, percolation pond improvements, screw press mechanical
Education: Ph.D.,
Environmental Engineering,
University of Nebraska, Lincoln,
NE | MS, Sanitary Engineering,
IHE, Delft, Netherlands |
BS, Civil Engineering, Cairo
University, Egypt
Registrations/Certifications:
Professional Civil Engineer
#68781, CA
Years of Experience:
27
Availability:
30%
Total Commitment Level of All
Other Projects for the Duration
of the District’s Project:
70%
Location: Rocklin, CA
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 125
solids dewatering facilities, operations and laboratory
building, and miscellaneous site appurtenances.
City of Dinuba, Wastewater Reclamation Facility
(WWRF) Phase 1 Improvements Project, Dinuba,
CA (Design Engineer) | Akram provided design
services for this $10 million improvement project
that modified an existing facility. Improvements
were made to the headworks, influent pump
station, and primary and secondary treatment;
and a new aerobic digester was added.
Donner Summit Public Utility District, Wastewater
Facilities Upgrade and Expansion, Soda Springs,
CA (Process and Design Engineer) | Akram provided
process and design engineering for improvement
and expansion of the membrane bioreactor system
with a four-stage reactor configuration for advanced
biological nitrogen removal. Nitrogen removal is a
challenge for this resort community in particular
because of highly variable flows and loads and
cold temperatures. The project included biomass
augmentation through ammonia addition during low
load periods to enhance nitrification, carbon addition
to enhance denitrification, and reactor heating when
needed because of extreme cold temperatures.
City of Merced, WWTF Phase V Solids Handling
Upgrade, Merced, CA (Design Engineer) | Akram
designed the primary treatment upgrades and
decant equalization for the $33 million expansion
and upgrade project. Improvements included
significant modifications to the existing solids
handling system to comply with updated WDRs
by abandoning existing earthen lined solids
drying beds and installing centrifuges and active
solar driers to produce Class A biosolids.
San Andreas Sanitary District, WWTP Upgrade
Project, San Andreas, CA (Design Engineer) | Akram
was responsible for process and detailed design for
secondary treatment as part of the 0.35-MGD activated
sludge system, designed to reliably achieve nitrification
downstream of the existing trickling filter plant.
City of Los Banos, WWTP Expansion and Upgrade -
Phase II, Los Banos, CA (Project Engineer) | Akram
performed the hydraulic calculations and prepared
contract drawings and specifications for the pump
station. The project included new headworks and
influent pump station design and miscellaneous
improvements to the existing pond treatment system.
City of Woodlake, WWTF Upgrade and Expansion,
Quad Knopf, Woodlake, CA (Design Engineer) |
Akram was responsible for process design and
detailed design of secondary treatment facilities
(ditches, clarifiers, RAS pump station, and scum pump
station) for a 1.3 MGD activated sludge process. This
$15 million WWTF replaced an existing pond plant
with new facilities including headworks screening,
influent pump station, two oxidation ditches with
anoxic basins for nitrogen removal, two secondary
clarifiers, return activated sludge and scum pump
stations, solids stabilization lagoons, percolation
ponds, standby generator, and operations building.
City of Williams, WWTP Improvements (2009),
Williams, CA (Design Engineer) | Akram was
responsible for process design and preparation of
contract drawings, specifications, and cost estimates
for the secondary treatment processes. The 0.5-MGD
activated sludge process was part of the overall
$9 million project that upgraded an existing pond
treatment system to an extended aeration, activated
sludge treatment plant with cloth media filtration, UV
disinfection, reaeration, and other supporting facilities.
City of Live Oak WWTP Improvements Project, Live
Oak, CA (Design Engineer) | Akram was responsible
for process design, preparation of contract drawings,
specifications, and cost estimates for the secondary
treatment including a selector, two oxidation ditches,
two secondary clarifiers, and a RAS/WAS pump
station. The $17 million project upgraded an existing
pond treatment system to a 1.4 MGD activated sludge
treatment plant with cloth media filtration and UV
disinfection.
City of Lathrop Consolidated Treatment Facility
Phase I, Lathrop, CA (Process and Design Engineer)
| Akram conducted a capacity assessment for the
City’s existing MBR plant and concluded that the
membranes are the bottleneck that restricts the
capacity of the plant, and that the MBR plant can
be expanded from 0.75 MGD to 1.0-MGD without
building more reactor basins. The resulting project
includes upgrades to the headworks screens and grit
removal as well as biological process and membrane
basins modifications, which complies with Title 22
unrestricted recycled water reuse requirements.
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 126
DAVID PALMER, PE, SE
SEISMIC REVIEW
David has extensive experience with structural design in high
seismic applications – for both hydraulic and non-hydraulic
applications, in water and wastewater conveyance, treatment,
containment, and storage facilities, and in industrial and institutional
buildings. He is also experienced with seismic evaluation, retrofit
and rehabilitation of existing structures and facilities. David is
fluent in concrete design, masonry design, steel design, and wood
design, using the California Building Code (CBC), and seismic
evaluation and retrofit using the CBC and the American Society
of Civil Engineers Standard 41 (ASCE 41). He also has extensive
experience in providing engineering services during construction.
Over the past twenty years, David has been the Lead Structural
Engineer on multiple projects ranging in size from small to very
large. These have included water and WWTPs, intakes and pump
stations; intakes and pump stations for irrigation purposes;
program designs of deep well extraction, pumping, conveyance,
and storage systems; reservoirs; control houses and other
support facilities for hydropower, dam, and lock operations; and
structural evaluations, rehabilitations, and seismic retrofits.
Select Project Experience:
Orange County Sanitation District, Seal Beach Pump Station and
Force Main Upgrade and Rehabilitation, Seal Beach, CA (Lead
Structural Engineer) | David is the lead structural engineer and project
technical lead for this project, which includes the seismic evaluation,
retrofit, and modification of the existing pump station; a new electrical
building, generator building, odor control building, diversion structure,
and force main outlet structure; miscellaneous minor civil structures;
evaluation and modifications for the force main crossing at the Bolsa
Chica Channel Bridge; as well as hydraulic modeling, modification, and
rehabilitation of the force main.
The project site is in Southern California and requires designing
for high seismic loads at a site subject to high groundwater and
liquefaction. Below grade structures and structural components will
be reinforced concrete, and above grade structures and structural
component will be reinforced CMU with steel roof systems. The key
structural element of this project is the seismic evaluation, retrofit
and modification of the existing pump station. The existing structure
has been evaluated by David using an ASCE 41 Tier 3 Systematic
Evaluation to assess the viability of retrofitting the below grade
portion of the structure as needed to allow complete demolition of the
superstructure, replacement of all mechanical and electrical equipment,
and construction of a new superstructure designed to provide a Spanish
Mission-style structure resembling the contemporary architecture
Education: MS, Civil and
Environmental Engineering,
University of California, Davis,
CA | BS, Civil Engineering,
University of the Pacific,
Northern California
Registrations/Certifications:
Professional Structural
Engineer #5353, CA (AK) |
Professional Civil Engineer
#65089, CA (AK)
Years of Experience:
21
Availability:
25%
Total Commitment Level of All
Other Projects for the Duration
of the District’s Project:
75%
Location: Sacramento, CA
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 127
of the surrounding neighborhood. The structural
demolition and construction will be designed and
detailed to allow continued operation of the pump
station throughout the construction process.
City of Sacramento Department of Utilities,
Condition Assessment of Water Storage Facilities,
Sacramento, CA (Lead Structural Engineer)
| David conducted an ASCE 41 Tier 1 seismic
evaluation of the elevated steel Freeport Reservoir
as part of a project focused on evaluating the
condition of the City’s water storage assets.
United Stated Coast Guard, Base Kodiak WTP,
Kodiak, AK (Lead Structural Engineer) | David was
the lead structural engineer for this project, which
include evaluation, rehabilitation, and expansion of
the Base Kodiak WTP and the Buskin Lake Pump
House. Structural tasks for the project included
an ASCE 41 Tier 1 seismic evaluation of the Pump
House to assess the viability of adding an additional
story to the existing structure to allow elevation
of equipment above flood levels; and design of an
enclosure for the existing Filters at the WTP.
San Francisco Public Utilities Commission (SFPUC)
Sunol Valley WTP Repair and Rehabilitation Project,
Sunol, CA (Lead Structural Engineer) | David was the
lead structural engineer for this project, which included
conducting a condition assessment and developing
rehabilitation alternatives for the existing Flocculation
and Sedimentation Basins and other ancillary facilities.
City of Sacramento, WTPs Improvements Project,
Sacramento, CA (Lead Structural Engineer) | David
was the lead structural engineer for this extensive
expansion of the Sacramento River WTP and E.A.
Fairbairn WTP. Work at the SRWTP included the
addition of new flocculation-sedimentation basins,
filters, high service pump station, electrical building,
and mechanical dewatering and solids handling
facilities; and condition assessment of the historical
pump station, filters, and head house. Work at
the EAFWTP included the addition of mechanical
dewatering and solids handling facilities at the E.A.
Fairbairn WTP. Challenges associated with this project
included moderate seismic loads, liquefiable soils, high
groundwater, and coordination with existing facilities.
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 128
LLOYD SOOHOO, PE, SE
MECHANISM STRUCTURAL LEAD
Lloyd has more than 20 years of experience in the structural design
of reservoirs, industrial buildings, pump stations, and WWTP/WTPs.
A licensed structural and civil engineer, he has also seismically
evaluated and designed strengthening for existing structures. Lloyd
has been certified as a California Safety Assessment Program (SAP)
Evaluator to assess the safety of facilities deemed essential to
emergency management efforts and to perform rapid evaluations of
structures in accordance with ATC-20 following a seismic event.
Select Project Experience:
Marin Municipal Water District (MMWD) SGWTP Clarifier Seismic
Upgrades, Woodacre, CA (Structural Engineer) | The client’s seismic
performance goal was that the WTP be capable of producing water
within 24 hours for the purpose of fire suppression. The plant’s
clarifiers are integral to the plant’s treatment process and must
function with minimal repairs following an earthquake. The existing
clarifier structures were evaluated to current code level seismic forces.
However, the existing clarifier mechanisms and their anchorages
were deemed incapable of resisting the design seismic forces, so
Lloyd worked with clarifier manufacturers to develop seismic criteria
consistent with the client’s criteria. Seven-foot-thick clarifier foundations
were also designed to resist the seismic overturning forces.
SFPUC, Harry Tracy WTP Long Term Improvements Project*, San
Bruno, CA (Structural Engineer) | The project’s seismic performance
goal was established such that the plant would sustain only limited
damage following an Mw = 7.9 earthquake, and would be able to deliver
140 MGD within 24 hours after such an earthquake. Lloyd performed the
ASCE 41-based seismic strengthening of the ozonated water channel
that delivers water from the ozone contactors to the flocculation basins.
Strengthening techniques involved thickening of channel walls and
slabs, and the addition of collectors to transfer loads to shear walls.
Central Contra Costa Sanitary District (CCCSD), Filter Plant
Improvements, Martinez, CA (Structural Engineer) | The client’s
recycled water facilities were constructed in the mid-1970s and modified
over time under several subsequent projects. The project is intended to
repair, rehabilitate, and upgrade the facilities for near-term and potential
long-term recycled water demands. Lloyd led the efforts to perform
concrete condition assessments and seismic evaluations of existing
concrete water structures that included the Filters, Filter Forebay,
Clearwell dividing wall, and pile-supported Filter Effluent Pipeline.
The findings have helped to develop planning level cost estimates
of required structural improvements to facilitate future projects.
Education: MS, Structural
Engineering, University of
California, Berkeley, CA | BS,
Civil Engineering, University of
California, Berkeley, CA
Registrations/Certifications:
Licensed Structural Engineer
#S5063, CA (HI and OR) |
Registered Civil Engineer
#C63251, CA (OR and NV)
Years of Experience:
22
Availability:
25%
Total Commitment Level of All
Other Projects for the Duration
of the District’s Project:
75%
Location: Walnut Creek, CA
* denotes projects completed
with other firm
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 129
Contra Costa Water District (CCCWD), Bollman WTP
Seismic Improvements*, Concord, CA (Structural
Engineer) | Lloyd led the design effort for the seismic
evaluation and strengthening of the plant’s 40+ year
old sedimentation basin launders and 10 MG cast-
in-place buried rectangular clearwell. The structures
were evaluated and strengthened in accordance with
District-specific seismic design criteria. Concrete
brace beams were designed to strengthen the
sedimentation basin launders against seismically-
induced hydrodynamic forces. Reinforced shotcrete
was applied to clearwell walls to increase flexural
capacity. All strengthening was closely developed
with input from District staff to minimize plant outage
duration and reduce impact on operations staff.
Santa Clara Valley Water District, Santa Teresa
and Rinconada WTPs*, CA (Project Structural
Engineer) | Lloyd designed seismic improvements
to both the Santa Teresa and Rinconada WTPs.
The overall construction cost of this project was
$125 million. These improvements for regulatory
compliance and treatment capacity include oxygen
fed ozone systems, filter modifications, washwater
clarification, new chemical systems, new 20-MGD
clarifier, and a variety of additional seismic upgrades
to the reinforced concrete. Lloyd designed the new
clarifier and filter structures, in addition to seismic
retrofit schemes as necessary. He assisted in
the QA/QC of the contactor structure as well.
Honolulu Board of Water Supply, Water Master
Plan*, Honolulu, HI (Project Engineer) | Lloyd
performed structural and seismic evaluations of
select circular concrete reservoirs throughout the
island of Oahu. The island’s 170+ reservoirs are of
varying construction type (cast-in-place, wire wound,
internal post-tensioned, external post-tensioned,
etc.) and of varying age (some constructed in
1920s). Seismic strengthening conceptual details
and estimated construction costs were developed
based on desktop analyses of 17 reservoirs and
extrapolated to the remaining reservoirs based on
age, construction type, and capacity. In addition to
the reservoir evaluations, Lloyd directed the structural
condition assessments of buildings at six corporation
yards across the island. These buildings were of
concrete, masonry, and/or steel construction. The
findings from these preliminary analyses will be used
to help prioritize the order in which reservoirs and
structures are repaired, strengthened, or replaced
as part of the Honolulu’s Water Master Plan.
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 130
JIM LOUCKS, PMP, CCE
COST ESTIMATING LEAD
Jim has more than 40 years of construction cost estimating
and scheduling experience for numerous water supply projects
and has prepared the construction cost estimates and detailed
execution schedules for water infrastructure projects designed by
Stantec, in Northern California and the West region in the past 15
years. Serving as National Estimating Practice Leader, he has over
three decades of experience in civil and mechanical construction
estimating and project management, with an emphasis in large
civil works, water treatment, conveyance, and industrial process
facilities. He is experienced in several diverse project delivery
methods, including design-build, engineer-procure-construct, and
traditional design-bid-build or hard-dollar contracting. Jim has
organized and managed numerous design-build bidding efforts,
from the conceptual planning stage through detailed design, and
provides estimating support. He has served in a lead estimator
capacity on projects exceeding $1 billion in construction costs.
Select Project Experience:
City of Roseville WTP Expansion, Roseville, CA (Lead Estimator) |
Jim was the lead estimator for the City of Roseville WTP Expansion
Project. This $32 million treatment plant expansion increased the
rated capacity to 100 MGD and, in addition to other work, included
two additional horizontal flocculation and sedimentation basins. Jim
prepared interim cost estimates at the 30, 60, and 95% design stages
and also the final engineer’s opinion of probable construction cost.
SFPUC, Sunol Valley WTP, Sunol, CA (Estimating Manager)
| Jim oversaw lead QC resource for the plant upgrades. The
process plant expansion was a key project under the Hetch
Hetchy Water System Improvement Program (WSIP).
Green River Filtration Facility, Tacoma Water, Tacoma, WA (Lead
Estimator) | For this $180 million plant expansion project, Jim and his
team successfully submitted cost estimates at the preliminary design
report, 30 and 60% design stages that have correlated to within 2% of
the GM/GC’s GMP proposals. The project is to expand an existing WTP.
Waterman WTP, City of Fairfield, CA (Lead Estimator) | Jim was
the principal estimator for plant expansion work and submitted
cost opinions at the PDR and 30, 60, and 90% design stages. The
project involved a doubling in capacity of an existing convention
filtration process including flocculation and sedimentation facilities
at a working WTP. Phasing constraints and inclusion of costs to
keep the existing plant operational during the construction period
were analyzed and included in the various estimate iterations.
Education: BS, Construction
Engineering, Arizona State
University, Tempe, AZ
Registrations/Certifications:
Certified Cost Professional
#06226 | Project Management
Professional (PMP)® #534386
Years of Experience:
41
Availability:
15%
Total Commitment Level of All
Other Projects for the Duration
of the District’s Project:
85%
Location: Walnut Creek, CA
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 131
Willamette WTP, City of Wilsonville,, OR (Project
Support) | For the 40-MGD plant expansion, Jim
developed and negotiated the original design-
build proposal and played a key role in resolving
cost issues during the two-year project.
Vineyard WTP, Sacramento County Water Agency,
Sacramento, CA (Cost Estimator) | Jim developed
the 30, 60, and 90 percent design stage cost
estimates for the $75 million Greenfields plant.
Sacramento River Water Reliability Study,
Sacramento County Regional Water District, CA
(Principal Estimator) | Jim served as principal
estimator for this $775 million program that
involved river intake and water conveyance pipeline
upgrades for four major water districts in northeast
Sacramento, covering a multi-year build out program.
Sewer System Master Plan Cost Estimate Review,
SFPUC, San Francisco, CA (Principal Estimator)
| Jim lead a cost review of the SFPUC’s planned
$4 billion program to upgrade the combined sewer
system over the next 10-15 years. Stantec was asked
to review consultant cost opinions for all program
features including several WWTP expansion options,
conveyance tunnel options and the new Biosolids
Facility. Stantec was also asked to comment on
forward cost escalation trends, comment on the
cost of construction in San Francisco compared
to other parts of the country, and to develop a new
cost estimate for the Greenfields digester facility
to be located at the existing Southeast Plant Site.
Big Creek Expansion Project, Southern California
Edison, Shaver Lake, CA (Senior Estimator)
| Jim delivered appraisal level Class IV cost
estimates to support project feasibility studies
for various water chain management systems
associated with a 700MW, $1 billion hydropower
expansion project. Facilities included dams, tunnels,
reservoirs, penstocks, and powerhouses.
Upper San Joaquin River Basin Storage
Investigation, US Bureau of Reclamation,
Millerton Lake, Fresno, CA (Principal Estimator)
| As part of the California Association for Local
Economic Development (CALFED) Bay-Delta
program, the feasibility study evaluated several
Class IV alternatives to develop water supplies
from the San Joaquin River. Jim developed
conceptual and detailed level costs for several dam
raise options at Friant Dam including associated
outlet works and power generating features.
Shasta Dam Water Resources Investigation, US
Bureau of Reclamation, Redding, CA (Principal
Estimator) | Jim developed appraisal level Class
IV cost estimates were to support feasibility level
designs of dam raise alternatives including main
dam and wing dam (embankment) modifications,
spillway improvements, river outlet upgrades,
temperature control device (TCD) installation, and
miscellaneous civil infrastructure improvements.
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 132
BETH COHEN, PE, ENV SP
CONCRETE REHAB LEAD
Beth has more than 15 years of design and planning experience
in a wide-range of water and wastewater projects. Her expertise
includes wastewater treatment and conveyance system master
planning and detailed wastewater treatment process design.
Beth specializes in developing condition assessment, water and
wastewater infrastructure evaluations, preparing construction
cost estimates and life cycle analyses, securing financing,
preparing static and dynamic hydraulic models, and facilitating
a coordinated effort between project team members.
Select Project Experience:
City of Madera WWTP Rehabilitation Project, Madera, CA (Project
Manager) | Depressed economic conditions of the City’s rate
payers began impacting reliability and performance of the WWTP.
Beth provided a condition assessment of the City’s wastewater
and water infrastructure, preparing a risk ranking list used to
determine the highest priority items needing improvement for
the five-year Capital Improvement Projects (CIP) list. Beth further
designed the Phase I Rehabilitation project to restore operation to
three primary clarifiers, overhaul the anaerobic digesters, repairing
the corroded centrate drain line with a new cured in place pipe
(CIPP), constructing a new primary effluent pump station, and
installing a new plant water well with hydropneumatic tank.
City of Lincoln Phase I Reclamation Project, Lincoln, CA (Design
Manager) | Increased flow rates associated with a regionalization
project necessitated modification to the off-site reclamation
facilities for Title 22 certified effluent disposal. Beth assessed the
condition of several miles of sewer piping for suitability to convert
to the reclaimed force mains. She further designed upgrades to the
reclaimed water booster pump station, 7,000 feet of new 18-inch-
diameter pressurized distribution piping, and conversion of several
miles of existing sewer piping into reclaimed water force mains.
Discovery Bay Wastewater Master Plan, Town of Discovery Bay
CSD, CA (Design Manager) | The Town owns and operates two
treatment plants, each providing treatment through oxidation ditches
and clarifiers before co-mingled secondary effluent is treated at Plant
No. 2’s tertiary facilities (filters and UV disinfection) and discharging to
surface waters. Beth evaluated operational concerns and assessed the
condition of the existing wastewater treatment and pipeline conveyance
facilities (stormwater, water, and wastewater). She prepared a matrix
of recommended upgrades, associated costs, and a 10-year CIP.
Education: BS, Environmental
Engineering, Oregon State
University, Corvallis, OR
Registrations/Certifications:
Professional Civil Engineer
#70184, CA (NV) | LEED
Accredited Professional
#10368466
Years of Experience:
16
Availability:
25%
Total Commitment Level of All
Other Projects for the Duration
of the District’s Project:
75%
Location: Rocklin, CA
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 133
City of Merced WWTF Phase I-V Projects, Merced,
CA (Design Manager) | These $85 million expansion
projects increased capacity to 12 MGD, added a
new influent pump station and headworks complex,
new Title 22 certified tertiary treatment and UV
disinfection facilities, new mechanical dewatering
facilities (centrifuges and active solar driers). Beth
developed master plan, CIP list, and detailed design
for the 30-MGD capacity headworks, mechanical
septage receiving and stormwater acceptance
plants, tertiary facilities, solids drying infrastructure,
100-year levee improvements, reclaimed water
pumping stations, and reuse discharge piping.
Miscellaneous Master Planning Projects | SASD (5.4
cfs), City of Auburn (9.5 cfs), City of Live Oak (6.7 cfs),
Jackson (5.4 cfs), City of Rio Vista (9.5 cfs), City of
Colusa (4.3 cfs), City of Williams (3.6 cfs), City of Dixon
(4.5 cfs), City of Reno Stead (3.1 cfs), Lemmon Valley
(2.8 cfs), Woodlake (2.9 cfs), Donner Summit PUD (2.6
cfs), and City of Dinuba (7.44 cfs).
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 134
MATT CARPENTER, PE
CIVIL DESIGN LEAD
Matt has 18 years of design and construction experience and currently
serves as a senior associate in Stantec’s water group. His extensive
experience includes planning, design, coordination, construction
support, and construction management on treatment facilities, large
diameter pipelines, canals, pump stations, reservoirs, fish screen intake
facilities, and wells across California. His specific focus has been on
wet infrastructure and water resource design and construction projects
that have required close coordination with a number of federal, state,
and local agencies. Throughout his career, Matt has served as a project
engineer and technical lead of large design teams, served as lead civil
engineer of record, and performed construction management duties as
resident engineer onsite during construction.
Select Project Experience:
City of Sacramento Department of Utilities, WTPs Rehabilitation
Project, Sacramento, CA (Resident Engineer) | Matt served as the
resident engineer during the construction, final design, and procurement
phases of the City of Sacramento WTPs Rehabilitation Projects. The
$113 million project involved the construction at two City WTPs,
Sacramento River WTP and E.A. Fairbairn WTP. The construction work
included a new high service pump station, electrical substation building
(4,160V Power), a new filter complex and flocculation sedimentation
basin, and new solids handling facilities for the processing of residual
sludge. Matt reviewed 90% design documents and provided detailed
review of the plans and specifications.
Sacramento County Water Agency, Vineyard Surface WTP (VSWTP),
Sacramento, CA (Project Engineer/Lead Civil Engineer) | Matt served
as the full-time project engineer and ESDC coordinator during the three-
year construction period of the $207 million facility. During the design
phase of this project, Matt’s duties included site layout analysis and
selection, utility coordination, site grading and earthwork, large diameter
pipeline design, and detailed civil design of the 80-acre, 50-MGD
conventional WTP. During construction, Matt focused on day-to-day
construction support services and leading the Stantec construction
support team. The site’s facilities comprise over 20 structures, including
a potassium permanganate building, a flow distribution structure,
flocculation/sedimentation basins and filter waste washwater clarifiers,
filters, a chemical building, an 8,000-hp treated water pump station, a
24-MG CT tank/clearwell, five-megawatt generators, and solids handling
facilities. The construction of the VSWTP was completed on schedule
and on budget.
Education: BS, Civil
Engineering, California State
University, Sacramento, CA
Registrations/Certifications:
Professional Civil Engineer
#66888, CA
Years of Experience:
20
Availability:
15%
Total Commitment Level of All
Other Projects for the Duration
of the District’s Project:
85%
Location: Sacramento, CA
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 135
Sacramento County Water Agency, Wildhawk
Groundwater Treatment and Storage Facilities
Project, Sacramento, CA (Project Engineer) |
Matt was the full-time project engineer and ESDC
coordinator during the two-year construction period
of this $14 million facility. Throughout construction,
he worked hand-in-hand with the Sacramento County
Construction Management and Inspection Division
(CMID), providing technical support and guidance,
attending weekly progress meetings, submittal review,
RFI review, design revisions, and leading the Stantec
construction support team. The project featured a
7.7-MGD (10.3-MGD ultimate) greensand and pressure
filter system for removal of iron and manganese from
groundwater. The design included a pressure filter
treatment system, two 1.5-MG treated water storage
tanks with pump station, backwash water supply
pumps, filter backwash water equalization and reclaim
tanks and reclaimed water pump station, chemical
storage and feed systems, and operations building. In
addition to the treatment facility, the project included
equipping two remote groundwater production wells to
supply raw water to the treatment facility. The facility
was located in an existing residential area that required
all decisions to consider aesthetics and impact on
the public. Matt played a key role in the success of
this project, which was an important factor in SCWA’s
decision to select Stantec for the much larger Vineyard
Surface WTP project.
City of Fairfield, South Cordelia Zone 1 Reservoir
Project, Fairfield, CA (Project Engineer) | Matt
served as project engineer and was responsible for the
civil and mechanical design of 3,500 feet of 30-inch-
diameter steel water pipeline, a pump station, and
a 5-million-gallon buried concrete reservoir. He also
coordinated between the utility and project team.
AKT Development and Sacramento County
Water Agency, SunRidge Phase 1 Water Supply
Facilities, Anatolia Groundwater Treatment and
Storage Facilities Project, Sacramento, California
(Project Engineer) | Matt served as the full-time
project engineer and engineering support during
construction (ESDC) coordinator during the two-
year construction period of this $12 million facility.
Throughout construction he worked hand in hand
with the Sacramento County CMID staff, providing
technical support and guidance, attending weekly
progress meetings, submittal review, RFI review,
design revisions, and leading the Stantec construction
support team. The project features a 6.5-MGD (13.0-
MGD ultimate) greensand and pressure filter system
for removal of iron and manganese from groundwater.
The design included a pressure filter treatment
system, two 2-MG treated water storage tanks with
pump station, backwash water supply pumps, filter
backwash water equalization and reclaim tanks and
reclaimed water pump station, and chemical storage
and feed systems, and operations building. In addition
to the treatment facility, the project included equipping
three remote groundwater production wells to supply
raw water to the treatment facility.
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 136
PHIL ATKINSON, PE, CENG.
I&C LEAD
Phil has successfully managed dozens of instrumentation and control
systems projects. With more than 36 years of experience, he has
provided specialized expertise during the design, implementation,
construction and commissioning phases in the fields of
instrumentation, SCADA, DCS, telemetry, and PLC/PC-based systems
for wastewater and WTPs. He has a proven track record of success in
delivering projects on schedule and on budget. Phil also has extensive
knowledge of turnkey projects for the wastewater/water industry. He
proficient in the application of design processes and tools to establish
integrated designs. Phil is also an expert in hazard analysis, design
and implementation of safety instrumented systems to satisfy safety
class and safety significant controls (ANSI S84/IEC 61508/61511).
Select Project Experience:
City of San Mateo Basins 2 and 3 Project, San Mateo, CA
(Principal I&C Engineer) | Phil is overseeing the I&C design of
three wastewater system projects for the City of San Mateo, CA.
Firstly, the wastewater conveyancing system is being modified to
include new diversion structures and the addition of an underground
storage facility. Secondly, the addition of two new lift stations and
thirdly the refurbishment of a major large pump station. For all three
projects, the Stantec design team is working in conjunction with
the program management team to supplement the development
client standards that will apply to concurrent and future projects.
City of Buckeye Water Supply and Treatment Project, AZ
(Principal I&C Engineer) | Phil is currently responsible for the
Instrumentation and Control design of a new water treatment
campus for the City of Buckeye, Arizona. The new treatment plant
includes both arsenic removal and reverse osmosis processes.
The plant is fed from six new wells, two of which are already under
construction with the remaining four to be completed soon.
North Slope Borough WTP/WWTP I&C Design and SCADA/
PLC System Integration, Prudhoe Bay, AK (Lead Electrical and
Controls Engineer) | Phil oversaw the I&C design of the WWTP,
WTP, and hot water delivery plant. All three plants service the remote
facilities and workers’ camps that support Oil industry operations
on the North Slope of Alaska. A team led by Phil also successfully
integrated the PLC/SCADA systems for the three facilities with
commissioning and startup finishing in December of 2015.
South Fork WTP I&C Design and SCADA/PLC System Integration,
City of Nanaimo, British Columbia, Canada (Lead Controls Engineer)
| Phil designed the instrumentation and control systems on the design
of a mem-brane process and instrumentation systems for a new
Education: BE/BEng, Electrical
and Electronic Engineering,
University of Exeter, Devon,
UK | BTEC, Industrial
Measurement and Control,
University of Bolton, Greater
Manchester, UK
Registrations/Certifications:
Professional Control Systems
Engineer #7375, CA (AK, AZ, ID,
and NV) | Arctic Engineering
Certification
Years of Experience:
35
Availability:
15%
Total Commitment Level of All
Other Projects for the Duration
of the District’s Project:
85%
Location: Sacramento, CA
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 137
WTP located on the outskirts of Nanaimo, British
Columbia, a medium sized town located on Vancouver
Island. He also acted as the system integrator of
the PLC/SCADA systems for the entire facility.
The plant went operational in January of 2016.
City of Las Vegas WWTP, Odor Control Project,
NV (Principal I&C Engineer) | Phil is overseeing
ongoing design of the I&C systems for multiple
projects with the City of Las Vegas. In particular, he
was responsible for odor control systems, upgrades
to RAS/WAS systems and Flare system design.
Girdwood Waste WTP New Influent Pump Station,
Girdwood, AK (Principal Controls Engineer) | Phil
designed the I&C systems for a new inlet pump station
and associated electrical facilities at the Anchorage
Water and Wastewater Utilities (AWWU) Girdwood
WWTP in Alaska. Phil provided PLC/SCADA software
services for this client on a previous project at the
Ship Creek WTP in Anchorage and by client request
also self-performed the software implementation
for the new Girdwood inlet pump station. The inlet
pump station feeds the existing adjacent wastewater
facility utilizing six variable frequency drives on
both 450 and 800-GPM pumps. The Girdwood
WWTP services the small town of Girdwood and the
extremely popular Alyeska Ski & Mountain resort.
AWWU utilize iFIX exclusively for their SCADA
and also utilize the GE Proficy Historian to collect,
manage and protect data from multiple facilities.
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 138
STEVE CHAVEZ, PE, CE/ME, CCM
CONSTRUCTION SEQUENCING LEAD
Steve has more than 18 years of experience in engineering and more
than 30 years in construction for a variety of commercial, industrial
and municipal projects, including engineering design, delivery order
contracting, inspections, program management and construction
management administration. His program management experience
includes coordination and support for multiple interproject elements. His
construction management experience includes a variety of municipal
projects including pump station, treatment plants, pipeline and levee
projects, with both Stantec designed projects and third party CMS.
His construction management experience also includes a variety of
duties such as construction manager, resident engineer, delivery order/
project manager, office engineer and field inspector. He has detailed
engineering design experience involving civil design of water treatment
facilities and mechanical design for HVAC design/build projects.
Steve has special inspection experience, owning licenses in reinforced
concrete, structural masonry and the Uniform Mechanical Code.
Select Project Experience:
City of Sacramento Department of Utilities, WTPs Rehabilitation
Project, Sacramento, CA (Resident Engineer) | Steve served as
the resident engineer for the City of Sacramento for the final design,
procurement and construction phases. The $120 million project at
the two City WTPs (Sacramento River WTP and E.A. Fairbairn WTP)
involved construction work for a new high service pump station,
electrical substation building (4,160V Power), a new filter complex
and flocculation sedimentation basin, and new solids handling
facilities for the processing of residual sludge. Steve reviewed 90%
design documents and provided detailed review of the plans and
specifications, including the construction sequencing, milestones and
constraints. He reviewed final bid documents during the procurement
and bid phase and provided review and comments for Owner prepared
addenda. During the construction phase, Steve conducted and
documenting weekly progress meetings, control and review of the CM
quality control and testing program, review and recommendations for
monthly progress payments and overall management of field staff.
Patterson Irrigation District, Main Canal Rehabilitation Project
Schedule A, Patterson, CA (Construction Manager) | Steve
currently serves as the construction manager for the $11 million
Main Canal Rehab (Schedule A) project, managing construction of
a one mile of 90-inch diameter welded steel pipe, a new 180 cfs
pump station, and electrical and instrumentation control building.
The Project replaces aging infrastructure including a segment of
concrete lined open flow channel and two 80-year old pumping
stations. Steve led the bid phase coordinating and responding to bid
questions and recommending award of contract. As construction
Education: BS, Mechanical
Engineering, California State
University, Sacramento, CA
Registrations/Certifications:
Professional Mechanical
Engineer #33265, CA |
Professional Civil Engineer
#74517, CA
Years of Experience:
24+
Availability:
30%
Total Commitment Level of All
Other Projects for the Duration
of the District’s Project:
70%
Location: Sacramento, CA
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 139
manager, he leads the CM team in project meetings,
change issues, submittal and RFI coordination
and responses, coordination with Agencies and
overall management of the project Team.
City of Sacramento Department of Utilities, 9th
Street Sewer Improvements, Sacramento, CA
(Construction Manager) | Steve managed the
construction of the $6 million 9th Street Sewer
Improvements project involving five blocks of 60-inch-
diameter combined sewer pipeline in downtown
Sacramento, including three tunneling drives
ranging from 400 to 500 feet in length. The project
involves extensive bypass pumping of the existing
CSS flows in busy downtown areas of Sacramento
along 9th Street. Steve was involved in project
meetings, change issues, coordination with agencies
and overall management of the project team.
Santa Clara Valley Water District, Rinconada WTP
Residuals Remediation Project, Los Gatos, CA
(Constructability Reviewer) | Steve performed
condition assessment services to evaluate the
condition of the mechanical thickener mechanisms
for two sludge gravity thickeners. Steve also serves
as a constructability reviewer for pre-design drawings
and scheduler for the pre-design project schedule.
South County Regional Wastewater Authority,
Plant Capacity Expansion Project, Gilroy, CA
(Constructability Reviewer) | Steve served as a
constructability reviewer for civil, structural and
mechanical design drawings for an estimated
$70 million MBR treatment plant expansion
project. Steve identified constructability
issues and inter-discipline conflicts.
City of Sacramento Department of Utilities,
McKinley Park CSS Storage Facility, Phase 1
Pre-Design, Sacramento, CA (Constructability
Reviewer) | Steve served as an assistant project
manager and constructability review lead for the
City of Sacramento for the pre design phase for an
estimated $30 million buried 7.0 MG CSS storage
tank facility. Steve managed contract negotiations,
and project scoping, setup, and implementation.
Steve served as the lead constructability reviewer
to analyze project impacts to the City’s McKinley
Park, including evaluating truck traffic and routes.
U.S. Army Corps of Engineers, Sanitary Sewer
Condition Assessment, Sierra Army Depot,
Herlong, CA (Project Technical Lead) | Steve
served as the project lead in conducting a sewer
system cleaning and condition assessment of the
Sierra Army Depot Garrison and Mission area sewer
pipes. The work involved coordination with Depot
staff and USACE staff to prepare safety plans,
quality plans, conduct meetings and coordinate
subconsultants for inspection of the sewer pipe
system. Steve reviewed and prepared draft and
final reports and negotiated changes to the work.
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 140
ERIC SNYDER, PLS
SURVEY LEAD
Eric is a licensed professional land surveyor in the States of Arizona,
Nevada, and Utah. He manages the geomatics team in Stantec’s
Reno, Nevada office. He began his surveying career right out of high
school and has continued to add to his knowledge and experience
in every aspect of the surveying field over the past 39 years. With
Eric’s vast surveying experience, he provides the knowledge and
leadership required to accomplish all survey projects. Some of the
projects Eric has been involved with include residential and commercial
subdivisions, electric and gas transmission lines and facilities, military
installation upgrades and improvements, ALTA/NSPS Land Title
Surveys, geodetic control, mining claims, and construction staking.
Select Project Experience:
City of Reno, Reno-Stead Water Reclamation Facility, Expansion
Improvements - Reno, NV (Survey Manager) | On this water
reclamation expansion project located in the Stead area north of
Reno, Eric coordinated the field survey for this 50+ acre site. The
survey included aerial photography and field surveys. He coordinated
the field survey for aerial target placement, ties to benchmarks
& existing monuments and the supplemental field surveys for
more detailed information in the areas of the proposed expansion.
He reviewed the field survey data and approved the AutoCAD
drawing file created for the design group’s use. Additionally, he
coordinated the layout and printing of the orthophotograph of the
project site for the City of Reno’s Public Works Department.
NV Energy. Gas Pipeline Improvements, Sparks, NV (Survey Manager)
| On this proposed pipeline project located on the portion of Sparks
Boulevard between Prater Way and Baring Boulevard Eric coordinated
the field surveys, aerial subconsultant and base map preparation. To
keep the project ahead of schedule he led the survey crew to establish
aerial panels and have the site flown within two days after notice to
proceed. He researched and drafted recorded maps and documents
to determine the centerline and right-of-way for Sparks Boulevard. Eric
prepared the topographic base map, compiling all the record data, aerial
mapping and field surveys into an AutoCAD base map drawing file.
Kennedy/Jenks Consultants, Antelope Valley East Kern Water District
Water Distribution Project*, Palmdale & Los Angeles County, CA
(Director of Surveys) | Eric’s responsibilities included a GPS control
survey of existing section and right-of-way monuments to determine
site boundary and street right-of-way and a topographic survey of the
existing roadway improvements, a WTP facility, and ground topography
on adjacent vacant parcels. He provided research on right-of-way
information, recorded maps and provided the topographic mapping
along 116th Street East from East Avenue U to the existing facility ¾
Registrations/Certifications:
Professional Land Surveyor
#11194, NV (AZ and UT)
| 5000-23 Surface Metal/
Nonmetal, Mining Safety
and Health Administration |
34-003205024, Occupational
Safety and Health Administration
Years of Experience:
39
Availability:
40%
Total Commitment Level of All
Other Projects for the Duration
of the District’s Project:
60%
Location: Reno, NV
* denotes projects completed
with other firm
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 141
of a mile to the south, as well as along East Avenue
U from 96th Street West to 116th Street West.
Pacific Gas & Electric, California ALTA/NSPS
Land Title Surveys, Various Cities and Counties,
CA (Project Manager) | As the survey manager
on this multiple location ALTA/NSPS Land Title
survey project Eric coordinated all the survey and
mapping for each site. The project consisted of
eight separate sites located from Watsonville to
Rocklin, California. He provided research on recorded
maps, benchmarks and GPS control surveys. Eric
coordinated the survey crews from various offices
to perform the field surveys. Each survey was
to establish aerial panels, located and measure
established control points, existing parcel corner,
street and section corner monuments. He reduced
the field ties, analyzed the boundary against the
measured monuments and provided the ALTA/
NSPS plat for review, stamp and signature by our
California Licensed Professional Land Surveyor.
Warm Springs Holdings, LLC, Whiskey Springs
Development, Washoe County, NV (Project Manager)
| As the project manager on this 1200-acre project
Eric coordinated the GPS control survey to establish
aerial panels, located and measure Washoe County
control points, existing parcel corner and section
corner monuments. He reduced the field ties, analyzed
the boundary against the measured monuments
and provided a topographic and boundary map for
the 1,200 acres consisting of 10 separate parcels.
California Department of General Services –
Topographic Surveys, Various Counties, CA (Survey
Manager) | Eric coordinated all the survey and
mapping for each site. The project consisted of four
remote locations located in Northern California. He
provided research on recorded maps, bench marks
and GPS control surveys. Eric coordinated the survey
crew to perform the field surveys. Each survey required
establishing horizontal and vertical control points,
locating and measuring existing bench marks and
section or parcel corner monuments, if available.
He reduced the field ties, analyzed the boundary
against the measured monuments and provided the
topographic survey to the design team for their use.
Stantec | Engineering Services for Secondary Clarifier Rehabilitation 142
SEAN CAREY
CORROSION LEAD (JDH)
Sean brings more than 11 years of experience in corrosion projects
including design and testing of both galvanic and impressed
current cathodic protection systems. He has experience in
performing drawing checks, and preparing AutoCAD documents.
Performed corrosion evaluation assessments, and produced
corrosion evaluation and soil corrosivity reports. Sean conducted
numerous corrosion inspections of storage tank exteriors for the
chemical industry. He is also experienced in conducting continuity
testing and locating of underground piping, in-situ soil resistivity
testing, and preparing project schedules and progress reports.
Select Project Experience:
Central Contra Costa Sanitary District, Martinez, CA | Sean
supervised district-wide survey of cathodic protection systems including
the main treatment plant, collections systems, pumping stations and
force mains, and recycled water treatment facilities and transmission
pipelines. His work included generating project schedules, progress
reports, directing and conducting surveys, developing an Access
database, and sub-meter locating of cathodic protection components.
Sonoma County Water Agency, Santa Rosa, CA | Sean supervised
district-wide survey of cathodic protection systems on numerous
large diameter transmission pipelines within SCWA’s jurisdiction. His
work included sub-meter locating of cathodic protection components,
collection of relevant corrosion-related data, troubleshooting, and
inspection and oversight of impressed current cathodic protection
system installations. Sean responded to RFIs, and coordinated with
third party entities, including property owners, during the course of
cathodic protection surveys and district improvement projects.
Slough, Redwood City, CA | Sean investigated corrosion of reinforced
concrete piles and recommended remediation for corrosion protection.
The investigation included concrete sounding, collection of concrete and
soil samples for chemical analysis, and remediation recommendations.
Stanford Linear Accelerator Center (SLAC), Palo Alto,
CA | Sean helped investigate corrosion related failure of piping
penetrations and manhole access to Stanford’s linear accelerator
tunnel. He also helped with soil and metal sample collection,
visual inspection, and analyzed construction drawings.
Romic Environmental, East Palo Alto, CA | Sean conducted
corrosion loss inspection using ultrasonic thickness testing for
storage tanks throughout facility and reported on findings.
Education: BA, Architecture,
University of California,
Berkeley, CA
Registrations/Certifications:
Level 1 NACE Cathodic
Protection Tester | Level 2
NACE Cathodic Protection
Technician | Level 1 NACE CIP
Years of Experience:
11+
Availability:
10%
Total Commitment Level of All
Other Projects for the Duration
of the District’s Project:
90%
Location: Concord, CA
DESIGN WITH
COMMUNITY IN MIND
STANTEC
3875 Atherton Road,
Rocklin, CA 95765
3301 C Street
Suite 1900
Sacramento, CA 95816
stantec.com
Cover Image: Onsite,
South Lake Tahoe, CA