Itm 4_South Y PCE_Jun19_TAC_KJ-061819AGENDA ITEM 4.
FEASIBILITY STUDY
Infrastructure Needs
Life-Cycle Costs
Initial Study Checklists
FEASIBILITY STUDY
INFRASTRUCTURE NEEDS
CONSIDERATIONS
•Sizing Based on Demands
•Pipe Sizing to Convey Range
of Estimated Pumping
•Treatment Sizing to Meet Demands
•Storage?
•Location of New Facilities
•Length of New Piping
•Tie Into Distribution System
•Other New Infrastructure
•Raw/Treated Water Pump
Stations
•Electrical and Facility Piping
•Structures/Building
Tahoe Keys
Well No. 1
STPUD – LBWC Intertie
CONVERSION OF MODEL FLOWS TO
INFRASTRUCTURE NEEDS
•Model Pumping Based on Pumping Data
•Monthly Total System Pumping 2005 – 2018
•Annual Pumping by Well 2009 – 2018
•Infrastructure Sizing Process:
•Identify Max Monthly Production per season
•Summer = May through September
•Winter = October through April
•Calculate ADD, MDD, PHD Based on California Waterworks Standards
•Distribute Pumping According to Portion of Historical Annual Pumping By Well
•Fire Flow not Included – Assume Supplied by STPUD Intertie
FEASIBILITY STUDY INFRASTRUCTURE NEEDS
BASE FLOW ASSUMPTIONS
Summer ADD (MGD) MDD (MGD) PHD (MG/Hr) Max Month (MG)
LBWC 1.0 1.4 0.09 28.5 (Sept 2010)
TKWC 1.9 2.9 0.18 59.6 (July 2018)
STPUD 11.0 16.5 1.03 329.5 (June 2009)
Winter ADD (MGD) MDD (MGD) PHD (MG/Hr) Max Month (MG)
LBWC 0.35 0.52 0.03 10.8 (Oct 2013)
TKWC 0.90 1.35 0.08 28.0 (Oct 2011)
STPUD 5.76 8.64 0.54 178.5 (Oct 2009)
•Summer and Winter Base Flow Assumptions calculated using the method described in California
Waterworks Standards, Chapter 16 §64554. New and Existing Source Capacity.
•Assumed Peaking Factors:
•MDD = 1.5 x ADD
•PHD = 1.5 x MDD
•ADD Based on 2014-2018 LBWC and 2009-2018 TKWC and STPUD South Y Pumping Data
•Alternative 1 – Base Treatment
•No new infrastructure
•Alternative 2 – Targeted Pumping
•New Piping Needed for
increased pumping at TKWC 2
(with GAC)
•Option 1 Install New 12” at
TKWC 2/Abandon Existing 8”
•Option 2 Install Parallel New 4”
at TKWC 2
•Piping at LBWC 5 (with GAC)
adequate
Tahoe Keys
Well No. 1
Upsize
Piping
for
TKWC 2
FEASIBILITY STUDY INFRASTRUCTURE NEEDS
ALTERNATIVES 1 AND 2
Alternative 2
STPUD – LBWC Intertie
FEASIBILITY STUDY INFRASTRUCTURE NEEDS
ALTERNATIVE 3
CONVERSION TO SURFACE WATER TREATMENT
•Intake Structure on Lake
Tahoe
•Centralized Membrane
Water Treatment Facility
•New Raw Water/Treated
Water Pipelines and
Pump Stations
•Electrical and Facility
Piping
•Storage?
Tahoe
Keys Well
No. 1
STPUD – LBWC Intertie
Potential WTP Locations
Potential Lake Intake Location
STPUD – LBWC Intertie
FEASIBILITY STUDY LIFE-CYCLE COSTS –
ALTERNATIVE 1
•Base Treatment
•Existing GAC Change Out
•Existing Chlorine
•Existing Energy
•Well Pumping
•Associated Facilities
•Existing Labor
•Other Existing O&M
•Cost of Water Purchased from STPUD
FEASIBILITY STUDY LIFE-CYCLE COSTS –
ALTERNATIVE 2
•Targeted Pumping
•Additional GAC Change Out
•Chlorine
•Additional Energy
•Well Pumping
•Associated Facilities
•Additional Labor
•Other Additional O&M
•Cost of Water Purchased from STPUD
FEASIBILITY STUDY LIFE-CYCLE COSTS –
ALTERNATIVE 3
•Conversion to Surface Water Treatment
•Permitting
•Energy
•Treatment Process
•Associated Facilities
•Treatment
•Chemicals/Membrane change out
•Labor
•Maintenance
•Disposal
•Other Additional O&M
FEASIBILITY STUDY LIFE-CYCLE COSTS – REQUEST
FOR INFORMATION
•On an annual basis:
•What is the existing cost for GAC change out at TKWC 2?
•What is the existing cost for GAC backwash at TKWC 2?
•What is the existing cost for chlorine?
•What is the existing cost of labor?
•What is the cost of energy for each well in 2018?
•What is the miscellaneous cost of energy? (e.g. Buildings, etc.)
•What is the cost of water purchased from STPUD?
•What are the other costs for O&M?
INITIAL STUDY CHECKLISTS
•CEQA Initial Study Checklist and TRPA Initial Environmental
Checklist (TRPA-IEC)
•Air Quality
•GHG Emissions
•Hazards and Hazardous Materials
•Hydrology and Water Quality
•Noise
•Utilities and Service Systems
•Estimated Cost of Mitigation
TAC DISCUSSION RE FEASIBILITY STUDY