SFPUC Commission Meeting
June 24, 2025
Approve Increases in Cost and Duration
Contingencies for Contract HH-1013, Moccasin
Compound Water System Filtration Addition
Mountain Tunnel Improvements Project
Presented by: Kim MacFarlane, PM
2 Moccasin Location
Moccasin
3 Project Site
Project Site
Moccasin Penstocks
Moccasin
Powerhouse
Administration
Building
Background
4 Original Design – Retaining Wall
5 Site Conditions – Competent Bedrock
Deeper Than Anticipated
Original Design - Retaining Wall
7 Revised Design - Drilled Piers
8 Requested Cost and Duration
Contingency Increase
• Original award amount: $4,177,936
• Original 10% cost contingency: $417,794
• Modification No. 1: $3,548
• Requested increase to cost contingency: $1,500,000
• Total proposed contract cost limit: $6,095,730
10 Recommended Increase to Cost Contingency
Recommended Increase to Duration Contingency
• Notice-to-Proceed date: September 23, 2024
• Original contract duration: 346 consecutive calendar days • Original 10% duration contingency: 34 calendar days
• Requested additional duration contingency: 266 calendar days • Total proposed duration limit: 646 calendar days
Construction Cost and Duration
Contingency Increase
11 Questions?
12 DEPARTMENT Hetch Hetchy Water and
Power Division
AGENDA NO. 9
MEETING DATE
June 24, 2025
AGENDA ITEM
Public Utilities Commission
City and County of San Francisco
Calendar: Regular Calendar
Project Manager: Kim MacFarlane
Approve Increases in Cost and Duration Contingencies for Contract No. HH-1013, Moccasin Compound Water System Filtration Addition
Summary of Proposed
Commission Action:
Approve an increase of $1,500,000 to the cost contingency and an increase of 266 calendar days to the duration contingency for Contract No. HH -1013, Moccasin Compound Water System Filtration Addition, with Sierra Mountain Construction, Inc., for a revised cost limit of $ 6,095,729, and a revised duration limit of 646 calendar days (approximately one year and nine months), for additional costs and schedule impacts related to a revised building foundation system due to unforeseen, differing site conditions.
Background: The San Francisco Public Utilities Commission ( SFPUC) Water Enterprise Moccasin Compound Water System (MCWS) is located above the town of Moccasin, adjacent to the Moccasin Penstocks. The MCWS is supplied by Hetch Hetchy Reservoir by t he Moccasin Penstocks and produces drinking water for the employees and residents of the town of Moccasin. The MCWS currently uses an ultraviolet light (UV) disinfection system to treat the water before distribution. During Hetch Hetchy system outages and under some water quality conditions , the water supply requires filtering as well as UV treatment. The MCWS is regulated by the State of California, and is essential to provide safe drinking water for the Moccasin community. A microfiltration unit is being constructed to treat raw water with a turbidity of less than 5 Nephelometric Turbidity Unit s
(NTU), and potentially as high as
100 NTU. The installation of a permanent solution for microfiltration relieves the SFPUC of elevated costs associated with renting a temporary unit to support construction outages, and thus this sub- project is funded by the Mountain Tunnel Improvements Project.
On May 14, 2024, by Resolution No. 24-0110 , this Commission awarded Contract No. HH -1013, Moccasin Compound Water System Filtration Addition, to Sierra Mountain Construction, Inc. The original contract amount was $4,177,936 and the original contract duration was 346 consecutive calendar days.
Agenda Title: HH-1013, Moccasin Compound Water System Filtration Addition Commission Meeting Date: June 24, 2025
Scope of Contract: The contract work location is in the town of Moccasin, Tuolumne County, California.
The contract work consists of:
• Construct a permanent microfiltration facility to house filtration operations; and,
• Install, test, and commission an SFPUC-furnished, permanent microfiltration plant.
Modifications to the
Contract:
Modification No. 1: Effective February 11, 2025, Staff issued Modification No. 1, increasing the contract amount by $3,548, within the original 10% contingency, for a total contract amount of $4,181,484, with no change to the contract duration, to install a 6 -inch diameter valve as part of water line relocation work that had not been included in the original scope.
Proposed Increase to Cost and Duration Contingencies: Staff recommends the Commission approve an increas e of $ 1,500,000 to the existing cost contingency, for a revised cost limit of $ 6,095,729, and an increase of 266 calendar days to the existing duration contingency, for a revised duration limit of 646 calendar days (approximately one year and nine months), to account for unforeseen, differing site conditions . These adjustments are necessary to address additional costs and schedule impacts resulting from a change in the foundation design. Specifically, the design was revised from cantilever retaining walls to drilled piers and columns due to the discovery of deeper -than-anticipated bedrock during construction, and constraints that limit the ability
to cut into the slope without affecting the
existing roadway, drainage system, and other facilities located above.
Funding and Costs: Funding Source: Project No. 10014114, Mountain Tunnel Improvements Project
Original Contract Amount: $4,177,936
Original 10% Cost Contingency: $417,793
Approved Increase in Cost Contingency: $0
Modified Increases to Contract Amount: $3,548
Total Current Contract Amount: $4,181,484
Remaining Cost Contingency: $414,245
Recommended Additional Cost Contingency: $1,500,000
Total Proposed Contract Cost Limit: $6,095,729
Schedule: Notice-to-Proceed Date: September 23, 2024
Original Contract Duration: 346 consecutive calendar days Original 10% Duration Contingency: 34 calendar days
Requested Additional Duration Contingency: 266 calendar days Total Proposed Duration Limit: 646 calendar days
Agenda Title: HH-1013, Moccasin Compound Water System Filtration Addition Commission Meeting Date: June 24, 2025
Local Business
Enterprise Utilization
and Non-
Discrimination in
Contracting:
The Contract Monitoring Division established a 10% Local Business Enterprise (LBE) subcontracting requirement for this contract. Sierra Mountain Construction, Inc., committed to 11.9% LBE subcontractor participation with its bid submittal.
Environmental
Review:
On February 18, 2021, the San Francisco Planning Department determined the Project to be categorically exempt from environmental review under the CEQA Guidelines section 15303, Class 3 (New Construction or Conversion of Small Structures ) under Case No. 2020- 011950ENV. The exemption determination can be found here:
https://sfpuc.sharefile.com/public/share/web-
se8fa9e03d35547d5b0f3592973973410
The work under this modification is within the scope of the project authorized under the exemption.
Attachment(s): 1. Contracting Monitoring Division Memorandum Agenda Title: HH-1000R Mountain Tunnel Improvements Project Commission Meeting Date: January 14, 2025
Location Map
Moccasin Compound Water System Filtration Addition
PUBLIC UTILITIES COMMISSION
City and County of San Francisco
RESOLUTION NO.
WHEREAS, On May 14, 2024, by Resolution No. 24-0110, the Commission awarded Contract No. HH -1013, Moccasin Compound Water System Filtration Addition, to Sierra Mountain Construction, Inc.; and
WHEREAS, The construction contract Notice -to-Proceed date was September 2 3, 2024; and
WHEREAS, The original contract amount was for $4,177,936, and the original contract duration was 346 consecutive calendar days; and
WHEREAS, On February 11, 2025, Staff issued Modification No. 1 increasing the contract amount by $3,548, within the original 10% contingency, for a total contract amount of $4,181,484, with no change to the contract duration, to install a 6 -inch diameter valve as part of water line relocation work that had not been included in the original scope; and
WHEREAS, Staff recommends an increase of $1,500,000 to the existing cost contingency, for a revised cost limit of up to $6,095,729, and an increase of 266 calendar days to the existing duration contingency, for a revised duration limit of 646 calendar days , for additional costs and schedule impacts related to a revised foundation system due to deeper bedrock and site constraints, unforeseen, differing site conditions; and
WHEREAS, The Contract Monitoring Division established a 10% Local Business Enterprise (LBE) subcontracting participation requirement for this c ontract and Sierra Mountain Construction, Inc., committed to a n 11.9% LBE subcontractor participation with its bid submittal, and this remains unchanged; and
WHEREAS, Funds for this contract are available from Project No. 10014114, Mountain Tunnel Improvements Project; and
WHEREAS, On February 18, 2021, the San Francisco Planning Department determined the Project to be categorically exempt from environmental review under the California Environmental Quality Act Guidelines section 15303, Class 3 (New Construction or Conversion of Small Structures) under Case No. 2020 -011950ENV, and the work under this m odification is within the scope of the project authorized under the exemption; now, therefore be it
RESOLVED, That this Commission hereby a pproves an increase of $1,500,000 to the existing cost contingency and an increase of 266 calendar days to the existing duration contingency, for Contract No. HH-1013, Moccasin Compound Water System Filtration Addition, for a total cost contingency amount of $1,914,245 and a total duration contingency of 300 calendar days; and be it
FURTHER RESOLVED, That this Commission hereby authorizes the General Manager, or the General Manager’s designee, to consider, and, if appropriate, to approve any future modifications to the contract amount for a total contract amount of up to $6,095,729 and a total contract duration of up to 646 consecutive calendar days.
I hereby certify that the foregoing resolution was adopted by the San Francisco Public Utilities Commission at its meeting of June 24, 2025.
Director of Commission Affairs
San Francisco Public Utilities Commission