SFPUC Commission Meeting
May 12, 2026
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
Revised Design - Drilled Piers
7 Requested Cost and Duration
Contingency Increase
• Original award amount: $4,177,936
• Original 10% cost contingency: $417,794
• Approved increase to cost contingency: $1,500,000
• Modified increases to contract amount: $661,632
• Proposed additional cost contingency: $500,000
• Total proposed contract cost limit: $6,595,730
8 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
• Approved increase to duration contingency: 266 calendar days • Modified increase to contract duration: 300 calendar days • Proposed additional duration contingency: 274 consecutive calendar days • Total proposed duration limit: 920 consecutive calendar days Construction Cost and Duration
Contingency Increase
9 Questions?
10 AGENDA ITEM
Public Utilities Commission
City and County of San Francisco
DEPARTMENT: Infrastructure Division
AGENDA NUMBER: 11
MEETING DATE: May 12, 2026
Calendar: Regular Calendar
Project Manager: Kim MacFarlane
Approve Increase to Cost and Duration Contingencies for Contract No. HH-1013, Moccasin Compound Water System Filtration Addition
Summary of Proposed
Commission Action:
Approve an increase of $500,000 to the existing cost contingency and 274 calendar days to the existing duration contingency for Contract No. HH- 1013, Moccasin Compound Water System
Filtration Addition, with Sierra Mountain Construction, Inc. , for a revised cost limit of $6,595,729 and a revised duration limit of 920 calendar days (approximately two years and six months), to address additional costs and schedule impacts resulting from a change in the foundation design, as well as plant design changes.
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 via the
Moccasin Penstocks and produces drinking water for the
employees and r esidents of the town of Moccasin. The MCWS currently uses an ultraviolet light (UV) disinfection system to treat the water prior to 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 (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, the Commission awarded Contract No. HH- 1013, Moccasin Compound Water
System Filtration Addition, to Sierra Mountain Construction, Inc.
The original contract amount was for $ 4,177,936 and the original contract duration was 346 consecutive calendar days.
On June 24, 2025, by Resolution No. 25- 0102, the Commission approved an increase of $1,500,000 to the existing cost contingency and an increase of 266 calendar days to the existing Agenda Title: HH-1013, Moccasin Compound Water System Filtration Addition Commission Meeting Date: May 12, 2026
duration contingency for a revised cost limit of up to $6,095,7 29 and a revised duration limit of 646 calendar days, for additional costs and schedule impacts related to a revised building foundation system due to unforeseen, differing site conditions.
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:
Modifications No. 1 -7: Staff issued Modification Nos. 1 -7, increasing the contract amount by $661,63 3 and increasing the contract duration by 300 calendar days, within the contingencies authorized under Resolution No. 25- 0102, for a total contract amount of $ 4,839,569 and a total contract duration of 646 consecutive calendar days, due to necessary foundation design revision 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, revision to
drainage system and other
adjacent facilities, as well as several design changes resulting in change order work and project delays.
Proposed to Increase Cost and Duration Contingency: Staff recommends the Commission approve an increase of $500,000 to the existing cost contingency and an increase of 274 calendar days to the existing duration contingency, for a revised cost limit of $6,595,729, and a revised duration limit of 920 days. These adjustments are necessary to address additional costs and schedule impacts resulting from a change in the foundation design, as well as plant design changes.
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 Increases to Cost Contingency: $1,500,000
Modified Increases to Contract Amount: $661,633
Total Current Contract Amount: $4,839,569
Current Cost Contingency: $1,256,160
[Proposed] Additional Cost Contingency: $500,000
Total [Proposed] Contract Cost Limit: $6,595,729
Schedule: Notice-to-Proceed Date: September 23, 2024
Original Contract Duration: 346 consecutive calendar days Original 10% Duration Contingency: 34 calendar day
Approved Increase to Duration Contingency: 266 calendar days
Agenda Title: HH-1013, Moccasin Compound Water System Filtration Addition Commission Meeting Date: May 12, 2026
Modified Increases to Contract Duration: 300 calendar days Total Current Contract Duration: 646 consecutive calendar days Current Duration Contingency: 0 calendar days
[Proposed] Additional Duration Contingency: 274 calendar days
Total [Proposed] Contract Duration Limit: 920 calendar days Environmental Review: On February 18, 2021, the Planning Department determined the Project to be categorically exempt from environmental review under the California Environmental Quality Act (CEQA) Guidelines Section 15303, Class 3 (Replacement or Reconstruction) ( Case No. 2020-011950ENV). The modifications are within the scope of the Project authorized under the exemption. View the CEQA exemption determination.
Local Business
Enterprise Utilization
and Non-
Discrimination in
Contracting:
The Contract Monitoring Division (CMD) established a 10% Local Business Enterprise ( LBE) subcontracting requirement for this Contract. The contractor committed to 11.9% LBE subcontractor participation with its bid submittal, and this remains unchanged.
Agenda Title: HH-1013, Moccasin Compound Water System Filtration Addition Commission Meeting Date: May 12, 2026
Location Map
Moccasin Compound Water System Filtration Addition
PUBLIC UTILITIES COMMISSION
City and County of San Francisco
RESOLUTION NO. __________________
WHEREAS, The San Francisco Public Utilities Commission (SFPUC) Water Enterprise is constructing a microfiltration unit necessary to operate and maintain the Moccasin Compound Water System; and
WHEREAS, On May 14, 2024 , by Resolution No. 2 4-0110, this Commission awarded Contract No. HH-1013, Moccasin Compound Water System Filtration Addition, to Sierra Mountain Construction, Inc.; and
WHEREAS, The original contract amount was for $4,177,936 and the original contract duration was 346 consecutive calendar days; and
WHEREAS, The contract Notice-to-Proceed date was September 20, 2024; and
WHEREAS, On June 24, 2025, by Resolution No. 25-0102, the Commission approved an increase of $1,500,000 to the existing cost contingency, and an increase of 266 days to the existing duration contingency, for a revised cost limit of $6,095,729 and a revised duration limit of 646 days, to account for additional costs and schedule impacts related to a revised building foundation system due to unforeseen, differing site conditions; and
WHEREAS, Staff issued Modification Nos. 1-7, increasing the contract amount by $661,633, and increasing the contract duration by 300 calendar days, in accordance with Resolution No. 25- 0102, for a total contract amount of $4,839,569 and a total contract duration of 646 consecutive calendar days, due to necessary foundation design revision to drilled piers and columns arising from 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, revision to drainage system and other adjacent facilities, as well as several design changes resulting in change order work and project delays; and
WHEREAS, Staff recommends this Commission approve an increase of $500,000 to the existing cost contingency, and an increase of 274 calendar days to the existing duration contingency, for a revised cost limit of $6,595,729 and duration limit of 920 days, to address additional costs and schedule impacts resulting from a change in the foundation design, as well as plant design changes; and
WHEREAS, The Contract Monitoring Division established a Local Business Enterprise (LBE) subcontracting participation of 10% for this contract, and the contractor committed to an LBE subcontractor participation of 11.9% with its bid submittal, and this remains unchanged; and
WHEREAS, On February 18 , 202 1, the Planning Department determined the Project to be categorically exempt from environmental review under the C alifornia Environmental Quality Act (CEQA) Guidelines Section 15303, Class 3 (Replacement or Reconstruction) (Case No. 2020-011950ENV) and the modifications are within the scope of the Project authorized under the exemption; and
WHEREAS, Funds are available from Project No. 10014114, Mountain Tunnel Improvements Project; now, therefore, be it,
RESOLVED, That this Commission hereby approves an increase of $500,000 to the existing cost contingency and increase of 274 calendar days to the existing duration contingency, for Contract No. HH- 1013, Moccasin Compound Water System Filtration Addition, with Sierra Mountain Construction, Inc. , for a total cost contingency of $2,417,793, and a total duration contingency of 574 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 modifications to the contract, up to a total cost limit of $6,595,729 and total duration limit of 920 consecutive calendar days.
I hereby certify that the foregoing resolution was adopted by the San Francisco Public Utilities Commission at its meeting of May 12, 2026.
_________________________________
Director of Commission Affairs
San Francisco Public Utilities Commission