03-28-95 SpecialMINUTES
SPECIAL MEETING OF THE BOARD OF DIRECTORS
SOUTH TAHOE PUBLIC UTILITY DISTRICT
MARCH 28~ 1995
The Board of Directors of the South Tahoe Public Utility District
met in Special Session at 3:00 p.m. on March 28, 1995, District
Conference Room, 1275 Meadow Crest Drive.
BOARD OF DIRECTORS:
President Wallace, Directors Strohm, Mason,
Jones, Mosbacher
ROLL CALL
STAFF:
Baer, Solbrig, Hoggatt, Hydrick, Schroeder,
McFarlane, Sharp, Brown, Regan, Attorney
Cherry
GUESTS:
Scott Ferguson/Lahontan; Jack Burnam/John
Carollo Engineers; Jeff Delong/Tahoe Daily
Tribune; C.I. Ross, Ty Baldwin
Construction Manaqer: Jim Hoggatt reported
on the first leak in the B-Line near the
Luther Pass Pump Station:
STAFF REPORTS
The leak resulted from a tear in a 28 year
old flange gasket located in a "Y" reserved
for a future connection to the export line.
Ebright completed the excavation needed to
access the flange in the estimated amount
of $8,000 per day for eight days. At the
moment, Ebright is hauling saturated mat-
erial out of the basin. New AB material
will be required.
Manaqer of Maintenance: Ken Schroeder re-
ported on the second leak in the B-Line
located in a section of the line further
up towards the Luther Pass summit:
This leak was discovered while Inspectors
performed a walking inspection of the export
line. This section of the line has very
limited access. The bottom of the pipe
ruptured as a result of a power surge,
creating a 10" x 10" hole. Burdick Excavat-
ing removed boulders and completed necessary
excavations to access the line. A new piece
ST056488
SPECIAL BOARD MEETING - MARCH 28, 1995 PAGE - 2
of pipe was sectioned in, completing the rePair.
Since runoff washed away all the base material,
concrete was pumped in underneath the line.
STAFF REPORTS
(Continued)
This summer, additional work must be
performed: site restoration, erosion
control work, and curb repair. These items
will be brought before the Board for ap-
proval at a later date and are not included
in the amounts being requested. District
labor and materials are also not included
in the amounts being requested.
Moved Mason/Second Jones/Passed Unanimously
to: A) Authorize declaration of a Great
Emergency.
LUTHER PASS
EXPORT PIPELINE
Hoggatt determined soliciting for bids would
indeed impact progress of needed repairs
because the length of time the bidding pro-
cess would require would delay the project
to the point where the District would fail
to meet its obligation to export treated
wastewater from the Lake Tahoe Basin as
mandated by the Porter-Cologne Act.
Moved Jones/Second Strohm/Passed Unanimously
to: B) Determine substantial evidence has
been presented to authorize an exception be
made to the Public Contract Code Section
22050 that this emergency will not permit a
delay resulting from a competitive for bids
and that this action is necessary to respond
to the emergency.
Hoggatt estimated that two contracts are
necessary to complete the scope-of-work:
CB Ebright - in an amount not to exceed
$70,000 for excavation and work done to
date. This figure includes backfilling
the excavation.
Burdick Excavating - in an amount not to
exceed $50,000 for work done to date.
A discussion was held regarding the pros
and cons of installing a vault around the
flange to provide for easier access. It
was the consensus of the Board that a vault
should not be built.
ST056489
SPECIAL BOARD MEETING - MARCH 28, 1995 PAGE - 3
Moved Strohm/Second Mason/Passed Unanimously
to: C) Authorize agreements be entered into
with contractors to perform repairs in a
total amount not to exceed $120,000. (CB
Ebright in an amount not to exceed $70,000;
and Burdick Excavating contract in an amount
not to exceed $50,000.)
Manager Baer distributed a report written in
November, 1993, by John Carollo Engineers,
detailing recommendations for repairs to the
export system. Even though scheduled repairs
and replacements to the pipeline are
continuously being made, Baer recommended
accelerating this project and making it the
top priority of the District.
The cost of replacing the B-Line alone is
estimated at $13 million, adding the A-Line
brings the total to $30 million. Baer re-
commended staff begin appealing to state
and federal agencies for funding assistance,
in addition to the search for grants
currently underway.
Finance officer, Rhonda McFarlane, reported
an inspector from FEMA will be at the Dis-
trict soon to conduct a preliminary assess-
ment of the damages to the Alpine County
Facilities. Resolution No. 2610, required
by the State of California, office of
Emergency Services, was presented for Board
approval.
An application was received to request E1
Dorado County be designated a disaster area.
This would enable the District to apply
for funding for repairs to the export line.
Resolution No. 2611 was presented for
Board approval.
McFarlane outlined FEMA's conditions if a
grant was given.
Moved Mason/Second Strohm/Passed Unanimously
to adopt Resolution Nos. 2610 and 2611 for
the State of California, office of Emergency
Services.
Manager of Water Operations, Rick Hydrick,
reported on the need to purchase three
LUTHER PASS
EXPORT PIPELINE
(Continued)
MARCH STORM RE-
LATED ACTIVITIES
ST056490
SPECIAL BOARD MEETING - MARCH 28, 1995 PAGE - 4
generators for A1 Tahoe, Tahoe Keys, and
Upper Truckee pump stations. This request
will be presented at a regular Board meet-
ing.
Hydrick also outlined many new procedures
and improvements being considered and
implemented including: new generators,
backup power for autopaging, SCADA program-
ming, consistent manning of Control 1, man-
hole overflow collection system, winter
storm watch mode, identifying manholes for
each pump station to dump into, 24-hour
dispatch, mutual aid listing, pump station
reliability study, computerized preventive
maintenance program, fine tuning communica-
tions, and accelerating the evaluation of
the A1 Tahoe Pump Station's performance.
5:00 p.m.
5:10 p.m.
Director Strohm reported on recent County
Water Agency (CWA) issues:
As a result the STPUD/CWA settlement, a
Roles and Functions Committee was formed
consisting of purveyor managers to make
recommendations regarding the operation of
the CWA. The recommendations that were
recently presented to the Board of the CWA
include: A change of governance (the Board
should include some purveyors); a Five-Year
Plan be prepared and followed; and funding
for Capitol Projects (defined as "works")
be allowed. The CWA Board had mixed reac-
tions and will consider the recommendations
further.
The $117,000 payment for the Texas Hill site
acquisition was also acted on at their meet-
ing. The Board voted to extend the offer to
EID until June 6th to buy the property and
to sell the property if EID does not wish
to purchase it. They also voted to approve
the $117,000 payment.
Moved Jones/Second Mason/Passed Unanimously
to direct staff to prepare a response on
behalf of the District's Board to the E1 Dorado
County Water Agency's Board relaying the
District's concern with their decision.
MARCH STORM RE-
LATED ACTIVITIES
(Continued)
MEETING BREAK
MEETING RESUMED
EL DORADO COUNTY
WATER AGENCY
ST056491
SPECIAL BOARD MEETING - MARCH 28, 1995 PAGE - 5
The comment period for the EIR/EIS ended
March 20. Many comments were received.
Responses are being prepared by District
staff, Jones & Stokes, and EIP.
No Board Action.
5:50 p.m.
FUTURE CONNEC-
TIONS FACILITIES
PLAN
ADJOURNMENT
DUANE WALLACE, PRESIDEN~ OF BOARD
SOUTH TAHOE PUBLIC UTILITY DISTRICT
KATHY 'S~H~, cLERK O~ BOARD
SOUTH TA~K~E PUBLIC UTILITY DISTRICT
ST056492
South Tahoe Public
Utility District
RECOMMENDATIONS FOR
EXPORT SYSTEM REPAIR
John Carollo Engineers
November 1993
ST056493
W.~qG9:REPORT AO0 - Exl~SysRccommcnd. C~.cr
SOUTH TAHOE PUBLIC UTILITY DISTRICT
RECOMMENDATIONS FOR EXPORT SYSTEM REPAIR
TABLE OF CONTENTS
PAGE
NO.
PURPOSE ................................................................................................................
EXISTING TREATMENT AND EXPORT SYSTEM ....................................................
EXPORT PIPELINE REPAIR ALTERNATIVES .........................................................
A-Line .............................................................................................................
B-Line ............................................................................................................
C-Line ............................................................................................................
RECOM1VIENDATIONS
A-Line SEZ .....................................................................................................
A-Line LP ........................................................................................................
B-Line ............................................................................................................
C-Line ............................................................................................................
Project Scheduling ..........................................................................................
2
2
9
9
11
11
11
11
11
JOHN C A~-~OLLO EN~31N~E;~G
w~:~o~^oo-~ ........ ~.~oo ~roc- ~ ST056494
Table
No.
SOUTH TAHOE PUBLIC UTILITY DISTRICT
I:LECOMMENDATIONS FOR EXPORT SYSTEM REPAIR
LIST OF TABLES
Title
Tahoe Regional Planning Agency (TRPA) Land Capability Legend ....
Phased Schedule for the Repair Alternative ....................................
Page
No.
6
13
JOHN C~AROLLO EN(,~IN EEI']'~
W38(59:REPORT AO0-ExpSysRecommcnd-LOT LOT- ~ ST056495
Figure
No.
2
4
SOUTH TAHOE PUBLIC UTILITY DISTRICT
RECOMMENDATIONS FOR EXPORT SYSTEM REPAIR
LIST OF FIGURES
Title
Existing A-Line Wastewater Treatment Plant to Luther Pass Pump
Station .......................................................................................
A-Line SEZ Relocation Options .......................................................
B-Line and C-Line ..........................................................................
C-Line to Harvey Place Reservoir ....................................................
I'atle
No.
7
10
12
JOHN CA;~DLLO ENCIP'-1E(---I:Lr:;
w3sa:r~eom' ^oo - a,s>a ........ a-,,or LOF-1 ST056496
South Tahoe Public Utility District
RECOMMENDATIONS FOR EXPORT SYSTEM REPAIR
PURPOSE
The South Tahoe Public Utility District (District) operates and maintains a complex export
system conveying treated wastewater approximately 25 miles from the treatment plant over
Luther Pass to the Harvey Place Reservoir tn Alpine County. The repair of the District's effluent
export system has been evaluated in three reports: 1) Analysis Of Treatment System Capacity
Expansion, August 1988, 2) Cursory Evaluation Of Export System Alternatives, September
1992, 3) Addendum 1 to the Cursory Evaluation Of Export System Alternatives, September
1993.
The purpose of this report is to: 1) summarize the evaluation of alternatives available for the
repair of the South Tahoe Public Utility District's (District) effluent export system and, 2)
present recommendations for the repair methods and relocation routes to be used. An
additional route for the relocation of the A-line within the Upper Truckee River stream
environment zone (SEZ) that had been identified In the 1988 report is also reconsidered herein.
EXISTING TREATMENT AND EXPORT SYSTEM
The District operates a filtered secondary wastewater treatment plant and effluent export
pumping system that ls currently designed for maximum day flow of 7.7 million gallons per day
(mgd). The District exports its treated effluent from the plant over Luther Pass to the Harvey
Place Reservoir located in Alpine County.
The effluent export system consists of three components.
An export pump station located at the treatment plant and a pressure pipeline
(known as the A-line) that conveys the treated effluent approximately 10.4 miles to
the Luther Pass Pump Station. The export pump statloncontalns two, 450
horsepower pumps which lift the effluent approximately 265 feet from the treatment
plant to the Luther Pass Pump Station.
The Luther Pass Pump Station and the pressure pipeline (known as the B-line)
convey the effluent approximately 1,240 vertical feet through 4.3 miles of pipeline to ·
the summit of Luther Pass. The Luther Pass Station contains two - 700 horsepower
and two - 1,000 horsepower pumps.
The C-line, conveys the treated effluent by gravity approximately 10.7 miles from the
summit of Luther Pass to the Harvey Place reservoir through an estimated vertical
drop of 2,100 feet.
JOHN CAI~tOLLO Er~'GI~EERf3
W38G9:REPORT A00' F. xpSysR ...... ndat,ons 1 ST056497
Loss of any component in the system halts the export of effluent until that component can be
repaired. The shutdown of the export system for an extended period can result In the
discharge of wastewater within the Tahoe Basin. Effluent discharges within the Basin are
forbidden by law and can result In fines of up to ten dollars per gallon discharged leveed by
Lahontan Regional Water Quality Control Board, Thus. the District has a vested interest In
maintaining a xvell run export system.
EXPORT PIPELINE REPAIR ALTERNATIVES
The repair alternatives for each component of the effluent export system are summarized
below,
A-Line
The existing A-line has two distinct sections to be addressed as a part of any export system,
Improvement scenario. The A-line from the W-WTP to the corner of Elks Club Drive and
Highway 50 (approximately 3.9 miles) Is wlthtn the Upper Truckee River SEZ. This section of
the A-line ts deslgnated A-line SEZ, The remalnlng portion of the A-line from the coruer of Elks
Club Drive to the site of the Luther Pass pump station (6.5 miles) follows existing streets and
highways, and ts deslgnated A-line LP. The A-line Is subdivided in this manner to specifically
identify subalternattves for that section of the A-line located within the Upper Truckee River
SEZ versus those subaltematlves viable for the A-line outside the SEZ. Many of the fallurcs
experienced by the A-line appear to be related to the Installation practices utilized tn 1968.
The District has located and repaired many failures of the ex/sting A-line that are believed to be
the result of installation procedures. The A-line from the treatment plant to the Luther Pass
pump station is shown in Figure 1.
Three separate subalternatlves were Identified and evaluated for the porLton of the A-line within
the Upper Truckee River SEZ. Two of the subalternatlves evaluated in-place rehabllltatlon
methods. The third subalternatlve evaluated routes for relocating the existing line outside the
SEZ. The three subalternatlves are presented In the following sections.
In-place Rehabilitation of the A-Line SEZ Using the InsituformTM Process
Rehabilitation of the A-line within the SEZ using an InsltuformTM liner installed inside the
existing pipe was evaluated. The use of the InsituformTM process to rehabilitate the A-line SEZ
would reduce the amount of cut and cover trenching required to rehabilitate the existing
pipeline within the SEZ. However, the use of the InsltuformTM process for the rehabilitation of
the A-line within the SEZ was rejected for the following reasons.
The existing location is inaccessible to District personnel to perform ongoing
inspection and maintenance procedures and the more critical emergency repairs.
This Is especially true during the winter and spring when the snow pack or spring
runoff could: 1) mask the location of line breaks and. 2) prevent District personnel
from accessing the site.
JOi-tlq CA~'IOLLO ['~:.[MGII',I[SEI:li¢
W3869:I~EPORT A00 - ExpSysRecommcndatlorm 2
The liner is designed to be used mainly in gravity pipeline applications and the
manufacturer only recommends their product for use in systems with operating
pressures of 80 psi or less. The pressure In the existing A-line SEZ can reach as
high as 200 psi. Pressures could reach 250 psi following the insertion of the liner
due to the smaller Inside diameter of the liner pipe within the existing pipeline.
If pressures are to be reduced to the required 80 psi, an additional pump station
would need to be constructed at the corner of Elks Club Drive and Highway 50.
This would Increase the mechanical complexity of the export system and reduce the
system's reliability. In addition, this would Increase annual costs for operating and
maintaining the export system.
Excavation and construction would still be required within the SEZ to access the
existing force main for InsituformTM installation. Access pits would have to be
excavated at least every 2000 feet for the installation of the liner. Heavy equipment
(backhoes, trucks, liner installation vehicles, etc.) would have to access each pit
crossing the SEZ In each case.
A temporary surface high pressure by-pass piping system would be required to
continue to export final effluent flows while the lining process was being completed.
The installation and removal of the surface high pressure by-pass system would
disrupt the surface of the SEZ in much the same manner as the trenching that is
not required under this option. The by-pass system would have to be constructed of
materials capable of handling the high operating pressures, the Joints would have to
be restrained to prevent separation, and the temporary line would have to be
anchored using concrete blocks or sandbags to prevent movement during operation.
Heavy equipment would be required to install the temporary pipeline and would
have to transverse the entire length of the SEZ during the completion of the project.
The possibility of a spill occurring during the setup and operation of the high
pressure by-pass system is much greater than under normal 'operations.
The pipeline would still be subject to possible washout due to the two crossings of
the Upper Truckee River.
The cost of the InsltuformTM llner alternative is approximately 62 percent greater
than the chosen alternative for relocating the existing pipeline.
In-place Rehabilitation of the A-Line SF..Z Using High Density Polyethylene (HDPE) Sliplining Pipe
Rehabilitation of the A-line within the SEZ using an HDPE slipliner was evaluated. The
manufacturer's representative recommends the use of an HDPE slipliner with an outside
diameter (O.D.) of no greater than 22 inches to facilitate the installation in the existing 24 inch
pressure line for the A-line SEZ. The annular space between the interior diameter (I.D.) of the
existing pressure line and the O.D. of the HDPE liner Is required to allow the new line to slide
around bends, elbows and imperfections in the existing A-line SEZ without binding. HDPE
pipes are built to withstand pressures of up to 200 psi In the 22 inch s~e range. However, pipe
wall thicknesses also increase as the pressure rating increases, thereby decreasing the I.D. and
ir/creasing flow velocities and resultant headlosses In the system.
JOHN CAROLLO EPJGINL--ERS
W38G9:REPORT AO0 - ExpSysRecommendatlons 4
ST056499
Prelin~tnary hydraulic calculations were completed for HDPE pipe liners with pressure ratings
from 80 to 200 psi in an attempt to balance headlosses versus operating pressures (pipe llimr
wall thickness increases as pressure increases) within the A-line SEZ. In no case could a
combination of HDPE pipe pressure rating and pressures be found that did not require an
intermediate pump station to be located within the SEZ. The construction of an intermediate
pump station' within the SEZ including permanent maintenance access roads and associated
utilities was determined to be unacceptable. In addition, the installation of an HDPE slipliner
would exhibit many of the same problems associated with the installation of an InsituformTM
liner. Therefore, sliplinlng the existing A-line SEZ with HDPE pipe was riot considered further.
Relocation of the A-Line SEZ
A total of six relocation routes were evaluated that would establish a new pipeline outside the
boundaries of the SEZ. Four of these routes were identified in the 1988 Analysis of TreatInent
System Capacity Expansion. The remaining two relocation alternatives were developed and
evaluated in the 1992 Cursory Evaluation of Export System Alternatives. All of tile relocation
alternatives require the installation of a new 36 inch line in the relocated section.
The advantages of relocating the A-line out of the SEZ would be:
The relocated line would be readily accessible for inspection, repair, and
maintenance.
The relocation would respond to the August 29, 1989 agreement between the
District, the State Attorney General, and the League to Save Lake Tahoe to move the
pipeline out of the Upper Truckee River flood plain.
Relocating the A-line SEZ would remove the export force main from an
environmentally undesirable location within the SEZ. The relocation would respond
to concerns raised by the Lahontan Regional Water Quality Control Board and the
Tahoe Regional Planning Agency (TRPA) regarding the problems associated with a
pipeline right next to the Upper Truckee River and within the SEZ.
The relocation would eliminate the concerns of pipeline xvashout at the crossing
locations in the Upper Truckee River.
The old line will be available for use in emergency situations.
The disadvantage to these relocation alternatives is related to the required construction,
(including traffic disruption) work within residential neighborhoods, noise and air pollution
during construction, increased traffic due to construction equipment and required
maintenance of a longer export line.
Both the 1988 and 1992 studies concluded that the best route for the relocation of the A-line
SEZ would be "Route IV". Route IV follows an existing Caltrans right-of-way across forested
lands (along an existing dirt road) from the intersection of Barbara Avenue and Beecher Avenue
to the end of Muskawaki Drive. Route IV then follows the lightly traveled residential streets of
Muskawaki Drive, Onnotioga Street, Washoan Boulevard, Nottaway Drive, Boren Way, Glen
JOHN CAROLLO [~r~olff~r~ERf'~
W3569:REPOI~I' A00 - ExpSysRecommendations 5
ST056500
Eagles Road, Elks Club Drive, Tamoshanter Drive, and Meadow Vale Drive, to Highway 50
where it would tie back into the existing A-line (see Figure 2). The estimated total project cost
for the completion of Route IV is $7.7 million. This cost reflects an increase in the Engineering
News Record (ENR) San Francisco Construction Cost Index from December 1992 (6300) to
June 1993 (6450) and recent increases in material costs. The estimated cost does not include
any purchases of property, easements or right-of-way.
A seventh route (Route VII) was considered briefly in the 1988 report. Route VII follows the
Caltrans right-of-way, as above, to the end of Muskawakl Drive. Then, instead of moving onto
residential streets, remains in the Caltrans right-of-way to an intersection with Elks Club
Drive. From the intersection with Elks Club Drive the new line would be routed down
Tamoshanter Drive and Meadow Vale Drive to Highway 50 to tie back Into the existing A-line,
as shown tn Figure 2. Refer to Table 1 for an explanation of the land capability designations
shown on thls figure.
Table 1 Tahoe Regional Planning Agency (TRPA) Land Capability Legend
Recommendations for Export System Repair
Capability Level Land Coverage
lb 1%
3 5%
4 20%
5 25%
6 30%
7 30%
Route VII was originally rejected in 1988 because: 1) it was believed that this route too closely
infringed on the SEZ area leaving a potential for impacting the Upper Truckee River if a break
should occur and, 2) there would be much the same problem with access for operation,
maintenance and repairs as exhibited on the existing pipeline.
The California Tahoe Conservancy is currently in negotiations with Caltrans to acquire the
right-of-way required under Route VII. Once negotiations are completed, the Conservancy has
indicated that they are considering the installation of a bike path through the right-of-way in
this area. The installation of a bike path along this route could significantly improve the
advantages of this route. The advantages of paralleling the bike path route with a new pipeline
(Route VII) are:
The construction of a bike path would have the same effect on the environment as
the construction of a pipeline, especially ff the Pipeline were installed at the same
time as the bike path. Both items could be considered in a single environmental
impact report (EIR).
A properly constructed bike path would provide the District with year-round access
to the pipeline for operation, maintenance and repairs.
W3869:REPORT A00 - ExpSysRccommcndations
6
JOHN CAROLLO EN~INEEIq.~
ST056501
2:
Z
LdZ
mZO
Replacing the existing A-line with a new pipeline will significantly reduce thc'
possibility of failures. This will require that the new pipeline be properly anchored
and blocked for the hydraulic forces It will experience.
The relocation of the A-line within the Caltrans right-of-way would move the pipeline
further from the Upper Truckee River. The location would eliminate the possibility
of washout because there would be no river crossings.
The construction Impacts on thc residential neighborhoods would be significantly
reduced ff not eliminated.
The length of the new line is approximately 2,000 lineal feet shorter than Route IV
due to the more direct alignment.
Route VII would still exhibit the following disadvantages.
· Parts of the new pipeline would still be In the Upper Truckee River SEZ.
· A pipeline rupture or break could still effect the river.
Based on the above, Route VII would appear to be the preferred route over Route IV. Several
steps must be accomplished in order for Route VII to become the recommended alternative.
First, the Conservancy must obtain the right-of-way from Caltrans. Second. the District would
have to negotiate with the Conservancy to obtain an easement for the plpellne installation
within the right-of-way. This cannot begin until the Conservancy's negotiations with Caltrans
are brought to a successful conclusion. Third, negotiations would have to be completed with
the owners of property because the new pipeline would cross outside the Caltrans right-of-way.
Fourth, an EIR would have to be completed.
The estimated total project cost for the repair of the A-line SEZ using Route VII is $6.1 million
not including the cost of a bike path. The estimated total project cost for a bike path is
$0.9 million. Thus, the total estimated project cost for Route VII including the bike path is
$7.0 million. All estimates assume that the end of the A-line SEZ repair would be at tile
intersection of Meadow Vale Drive and Highway 50. The estimated costs do not include the
purchase of any easements, property or right-of-way for the Installation of the new pipeline.
A-Line LP
The recommended alternative for the repair of the A-line LP is parallel replacement.
Rehabilitation using sliplining techniques and InsituformTM were considered and rejected due
to: 1) increased flow velocities with resultant increased headlosses due to the reduction in I.D. ·
of the lined pipe, 2) thrust blocks on the existing A-line would have to be exposed and
reinforced to handle the Increased pressures on the system and, 3) the need to install a
temporary, high pressure by-pass system during pipe lIner installation. As mentioned earlier,
the chances of a wastewater spill occurring during the setup and operation of a by-pass system
are greatly increased.
JOHN CAROLLO ENGINEERS
^oo. ......... ST056503
Under the recommended parallel pipeline alternative, the A-line LP would be replaced with
another 24 inch pipeline installed in a cut and cover trench paralleling the existing A-line. The
advantages of this repair method are: 1) the existing A-Line LP would be replaced with a new
llne with known installation conditions adding to system reliability, 2) the new lille could be
installed while the existing pipeline is still in service and, 3) the parallel replacement would not
significantly affect residential areas since most of the A-line LP is within high traffic areas such
as Highway 50 or Highway 89. The disadvantage of this repair method would be the potential
for disruption of traffic on heavily used roads during the summer tourist season.
The estimated total project cost for the repair of the A-line LP is $8.6 million. This assumes
that the A-line SEZ repair stops at the intersection of Meadow Vale Drive and Highway 50.
This cost reflects an increase in the Engineering News Record (ENR) San Francisco
Construction Cost Index from December 1992 (6300) to dune 1993 (6450) and recent increases
In material costs. The estimated cost does not Include any easement or right-of-way purchase.
B-Line
As with the A-line, installation procedures for the original B-line may to have accelerated
failures. Operating pressures in the B-line are due predominantly to the static lift existing
between the Luther Pass pump station and the summit of Luther Pass (approximately
1,250 feet). Increasing line size would do little to reduce line pressure regardless of flow
capacity. 'The high static pressures also limit the use of in-place rehabilitation measures.
The recommended alternative for the repair of the B-line is the combination parallel
replacement and relocation of the existing pipeline. The alternative repair methods of sliplinlng
and InsltuformTM were both rejected due to the high pressure In the system and the need to
install a temporary high pressure by-pass system during construction.
The portion of the existing B-line that follows Highway 89 to the summit of Luther Pass would
undergo parallel replacement. The section of the existing B-line that diverts off of Highway 89~
into National Forest Land would be relocated to follow the shoulder of Highway 89 avoiding the
very steep and difficult terrtan encountered in this reach. The relocation would also eliminate
the need for District crews to walk or snowshoe the reach during routine inspection and make
the line accessible to repair equipment ff necessary. The recommended parallel replacement
and relocation route is shown In Figure 3.
The estimated total project cost for the repair of the B-line ls $12.0 million. This cost reflects
an increase in the Engineering News Record (ENR) San Francisco Construction Cost Index from
December 1992 (6300) to June 1993 (6450) and recent increases in material costs.
C-Line
The existing C-line has not had any failures since Its Installation In 1968. The chosen
alternative for the repair of the C-line, if or when it is required, is complete parallel
replacement. Parallel replacement of the existing C-line was selected over the use of In-place
rehabilitation because of the: 1) increased velocities and pressures resulting from the
W3BGg:RlglK)l'x~r AO0 - ExpSysRccommcndatlon8
9
JOHN CAROLLO ENGIN~E'~;:::I-~
ST056504
m
~' 01.1 3NFl. HOIV~I
z ~
~a
installation of a new line within the existing pipeline, 2) required excavation of large installation
access pits to complete rehabilitation and, 3) required excavation and reinforcement of thrust
blocks on the existing pipeline to handle the increased pressures in the system. Further, the
costs for the in-place rehabilitation of existing lines exceed those for parallel replacement. The
alignment for the chosen parallel replacement alternative is shown on Figure 4.
The estimated total project cost for the the repair of the C-line is $18.9 million. This cost
reflects an increase in the Engineering News Record (ENR) San Francisco Construction Cost
Index from December 1992 (6300) to June 1993 (6450) and recent increases in material costs.
The estimated cost does not include any easement or right-of-way purchase.
RECOMMENDATIONS
The recommended methods and routes for the District's export system are presented below.
These recommendations are based on the information contained in this report and the three
reports completed in 1988, 1992 and 1993.
A-Line SEZ
The existing A-line within the Upper Truckee River SEZ should be relocated utilizing either
Routes IV or VII. Route VII would be preferred ff negotiations can be completed with the Tahoe
Conservancy to use the old Caltrans right-of-way and if the alternative can satisfy
environmental concerns. Otherwise, the preferred Route is IV.
A-Line LP
The A-line from the connection with the A-line SEZ to the Luther Pass pump station should be
replaced with a parallel pipeline following the same route as the existing pipeline.
B-Line
The B-line from the Luther Pass pump station to the connection with the C-line at the top of
Luther Pass should be replaced with a parallel pipeline except for that portion of the existing
B-line that is on Forest Service property. The section of the B-line on Forest Service property
should be relocated to follow Highway 89 allowing District personnel easier access for
inspection and routine and emergency repairs.
C-Line
The C-line from the top of Luther Pass to the Harvey Place Reservoir in Alpine County should
be replaced with a parallel pipeline.
Project Scheduling
A scenario for the phased repair of the ex_isLing export pipeline was developed based on a review
of District maintenance records for the last 15 years and meeting with District staff. In
a~tdition, mandates from the Lahontan Regional Water Quality Control Board and District
JOHN CAROLLO ENE~INEEi~IS
11
W38159:REPORT ^00-ExpSysR .... mendaUons ST056506
commitments to other agencies regarding the existing export pipeline were considered in the
scheduling process. The resultant schedule for the completion of repairs to the existing export
pipeline is presented in Table 2. The estimated total project cost for each phase of the
scheduled repair is also presented in Table 2.
Table 2
Phased Schedule for the Repair Alternative(1)
Recommendations for the Export System Repair
Year(2)
Estimated
Cost(3)
A-Line
Route IV
From Beecher Street to Meadow Vale Drive
and Highway 50{4)
(or)
Route VII
From Beecher Street to Meadow Vale Drive
and Highway 50(4)
Bike Path
New ERB or Emergency Power Alternativeis)
From Treatment Plant to Beecher Street
From Meadow Vale Drive and Highway 50 to
Luther Pass Pump Station
B-Line
.From Intersection with Dlstrlct Installed DIP
'to Beginning of C-Line
From Luther Pass Pump Station to Beginning of
· District Installed DIP(o)
Replace District Installed DIP
C-Line
Replace Stage 1
Replace Stage 2
Replace Stage 3
1 $7,688,000 ~
1 $6,093,000
1 $ 864,000
1 $3,955,000
2 $1,751,000
3 $6,869,000 /
5 $4,073,000
15 $7,088,000
40 $1,762,000
25 $6,616,000
26 $6,616,000
27 $5,726,000
(1)
(2)
(3)
(4)
(5)
(6)
Year 1 was considered to be the 1994 construction season for the purpose of this
analysis.
Approximate number o£years until required repairs are completed.
Estimated total project cost includes an ENR adjustment from December 1992
(ENR=6300) to June 1993 (ENR=6450). Estimates do no___j[ include costs for land
aquisition, easement or right-of-way purchase.
Does not include cost for ERB ($3.9 million).
Constr~ction of a new ERB or Alternative Emergency Power Project will be
required to meet agreements with regulatory agencies and meet criteria
established by February 1986 storm and associated events.
Includes $1,164,000 for replacement of pumps and motors in Luther Pass Pump
Station as detailed in 1988 Facilities Plan.
W3869:l~,lgPOI~[' AO0 - ExpSysllccommcndations
13
JOHN (~AROLLO ENGINEE~RS
ST056508
MEETING:
GUEST SIGN-IN SHEET
COMPLETION OF THIS INFORMATION IS VOLUNTARY, NOT MANDATORY,
AND IS NOT A PRECONDITION FOR ATTENDANCE,
IN ACCORDANCE WITH THE BROWN ACT.
ST056509