DEPARTMENT
Infrastructure Division
AGENDA NO.
8 MEETING DATE
May 27, 2025
AGENDA ITEM
Public Utilities Commission
City and County of San Francisco
Calendar: Regular Calendar
Contract/Project Manager: Tim Parkan
Approve Increase to Construction Cost and Duration Contingencies for Contract No. DB- 121R2, Moccasin Powerhouse Generator Rehabilitation
Summary of Proposed
Commission Action:
Approve an increase of $1,600,000 to the cost contingency and 331 calendar days to the duration contingency for Contract No. DB-121R2, Moccasin Powerhouse Generator Rehabilitation with General Electric Renewable Energy, for a revised cost limit of $32,648,985, and a revised duration limit of 1,898 consecutive days (approximately five years and three months), to address increased costs and schedule impacts due to shaft alignment issues discovered during reassembly of Generator Unit No. 1.
Background: The San Francisco Public Utilities Commission (SFPUC) operates the Moccasin Powerhouse which was completed in 1969 with the installation of Generator Unit No. 1 and No. 2. T ogether these two units generate a combined maximum output of 110 Megawatts. The average generation from Moccasin Powerhouse is approximately 430 gigawatt hours per year or 25 percent of the total generation from the Hetch Hetchy Water and Power system. The generator units at Moccasin Powerhouse have exceeded their life expectancy by 20 years. The generator units are in critical need of repair to continue operating.
The Hetch Hetchy water system serves 2.7 million people in the Bay Area, with approximately one-third of the delivered water going to retail customers in San Francisco. As the water flows through the Moccasin Powerhouse , its generators also function as flow-regulating facilities. Reliable water delivery depends on both generators being operational . If one generator fails, the SFPUC can continue deliveries using the remaining generator; however, this significantly reduces system redundancy, and places added stress on the remaining unit, increasing the risk of failure. Each generator is equipped with a bypass system design ed to diver t a limited flow of water around the generator. However, these bypasses were not intended for prolonged use and may fail before the generator rehabilitation is completed. If both generators and their bypass systems fail, water deliveries from the Tuolumne River to the Bay Area would cease until the facilities are restored.
On May 11, 2021, by Resolution No. 21- 0078, this Commission awarded Contract No. DB-121R2, Moccasin Powerhouse Generator Rehabilitation, to General Electric Renewable Energy . The original contract amount was Agenda Title: DB-121R2, Moccasin Powerhouse Generator Rehabilitation Commission Meeting Date: May 27, 2025
$26,271,805 and the original contract duration was 1,093 consecutive calendar days.
On June 13, 2023, by Resolution No. 23-0108, the Commission approved an increase to the duration contingency of 365 calendar days, for a total revised duration limit of 1,567 consecutive calendar days , with no change to the contract amount.
On August 13, 2024, by Resolution No. 24-0169, the Commission approved an increase to the cost contingency of $2,150,000, for a total revised cost limit of $31,048,985, with no change to the contract duration.
Scope of Contract: The contract work location is in Moccasin, California.
The contract work consists of designing, manufacturing, and installation of:
• Stator Frame;
• Stator Core;
• Windings;
• Rehabilitation work on the rotor; and
• Relay protection upgrades for two hydro -generation units at the Moccasin Powerhouse.
Modifications to the
Contract:
Design Phase Modifications Nos 1 -3: Staff issued Design Phase Modification Nos. 1- 3 to administratively encumber the full contract value with no changes to the contract amount or contract duration.
Construction Phase Modifications Nos. 1- 17: Staff issued Construction Phase Modification Nos. 1-17, increasing the contract amount by $3,229,612, in accordance with Resolution No. 24- 0169, and increasing the contract duration by 365 consecutive calendar days , in accordance with Resolution No. 23-0108, to replace surface air coolers and bearing oil coolers , re-rating and inspection of gantry crane, changes to the protection and control design, add additional cable to provide proper length for future upcoming project repairs to the turbine shaft collars, perform single unit retardati on testing, design and installation of the new fire suppression system, ensure that the protection engineer be available onsite during the Unit 2 Blackout Outage , Unit 2 alignment and cooling water system , bearing pad rebabbit, lead abatement, and Operations and Maintenance manual modifications, for a total contract amount of $29,501,417, and a total contract duration of 1,458 consecutive calendar days.
Recommended Increase to Cost and Duration Contingenc ies: Staff recommends the Commission approve an increase of $1,600,000 to the cost contingency and 331 days to the duration contingency, for a revised cost limit of $32,648,985, and a revised duration limit of 1,898 consecutive days. The increase to the cost contingency is to include cost for direct field work completed from January 2025 to March 2025 to attempt to address Agenda Title: DB-121R2, Moccasin Powerhouse Generator Rehabilitation Commission Meeting Date: May 27, 2025
unexpected challenges with alignment of Unit No. 1, repairs of Unit No. 1 thrust collar and shims, align unit with repaired collar , contractor compensable delay costs, planning effort by the contractor to review Unit No. 1 shaft repair option, and Contractor effort to complete commissioning after alignment is achieved. The contractor, General Electric Renewable Energy, presented five options to achieve alignment, options varied in duration, cost, and service life. SFPUC staff considered risk and return to service timelines and selected an option deemed in the best interests of the water system . The duration increase request accounts for field iterations to achieve alignment with newly machined parts as well as the availability of water required for commissioning.
Funding and Costs: Funding Source: Hetchy Capital Improvement Program , Project No. 10014086, Moccasin Powerhouse and Generator Step-Up Rehabilitation
Original Contract Amount: $26,271,805
Original 10% Cost Contingency: $2,627,180
Approved Increase in Cost Contingency: $2,150,000
Modified Increases to Contract Amount: $3,229,612
Total Current Contract Amount: $29,501,417
Remaining Cost Contingency: $1,547,568
Recommended Additional Cost Contingency: $1,600,000
Total Proposed Cost Limit: $32,648,985
Schedule: Notice-to-Proceed Date: June 21, 2021
Original Contract Duration: 1,093 consecutive calendar days Original 10% Duration Contingency: 109 calendar days
Approved Increase to Duration Contingency: 365 calendar days Modified Increases to Contract Duration: 365 consecutive calendar days Total Current Contract Duration: 1,458 consecutive calendar days
Remaining Duration Contingency: 109 calendar days
Recommended Additional Duration Contingency: 331 calendar days Total Proposed Duration Limit: 1,898 consecutive calendar days
Environmental
Review:
On August 4, 2014, the San Francisco Planning Department determined the Project to be categorically exempt from environmental review under the CEQA Guidelines section 15301, Class 1 (Existing Facilities) under Case No. 2014.1184E. The exemption determination can be found here:
https://sfpuc.sharefile.com/public/share/web-
sb553b5994d86427e85beb7d537e25184
The work under this modification is within the scope of the project authorized under the exemption.
Agenda Title: DB-121R2, Moccasin Powerhouse Generator Rehabilitation Commission Meeting Date: May 27, 2025
Local Business
Enterprise Utilization
and Non-
Discrimination in
Contracting:
Pursuant to Chapter 14B of the San Francisco Administrative Code, the Contract Monitoring Division has waived subcontracting goals for this construction contract due to the specialized nature of the work.
Agenda Title: DB-121R2, Moccasin Powerhouse Generator Rehabilitation Commission Meeting Date: May 27, 2025
Project Site
PUBLIC UTILITIES COMMISSION
City and County of San Francisco
RESOLUTION NO.
WHEREAS, On May 11, 2021, by Resolution No. 21- 0087, the Commission awarded Contract No. DB-121R2, Moccasin Powerhouse Generator Rehabilitation to General Electric Renewable Energy; and
WHEREAS, The original contract amount was for $26,271,805 and the original contract duration was 1,093 consecutive calendar days; and
WHEREAS, The contract Notice-to-Proceed date was June 21, 2021; and
WHEREAS, On June 13, 2023, by Resolution No. 23-0108, the Commission approved an increase of 365 calendar days to the duration contingency, for a total duration limit of up to 1,567 consecutive calendar days, with no change to the contract amount; and
WHEREAS, August 13, 2024, by Resolution No. 24- 0169, the Commission approved an increase of $2,150,000 to the cost contingency, for a total revised cost limit of $31,048,985, with no change to the contract duration; and
WHEREAS, Staff issued Design Phase Modification Nos. 1 -3 to administratively encumber the full contract value, with no change to the contract amount or contract duration; and
WHEREAS, Staff issued Construction Phase Modification Nos. 1- 17, increasing the contract amount by $3,229,612 and increasing the contract duration by 365 consecutive calendar days, to replace surface air coolers and bearing oil coolers, re-rating and inspection of gantry crane, changes to the protection and control design, add additional cable for future project repairs to the turbine shaft collars, perform single unit retardation testing, design and installation of the new fire suppression system, protection engineer field support, Unit No. 2 alignment and cooling water system, bearing pad rebabbit, lead abatement, and O perational and M aintenance manual modifications for a total contract amount of $29,501,417, and a total contract duration of 1,458 consecutive calendar days; and
WHEREAS, Staff recommends an increase of $1,600,000 to the cost contingency and 331 calendar days to the duration contingency, for additional costs and schedule impacts due to discovery of shaft alignment issues during reassembly of Generator Unit No. 1; and
WHEREAS, The Contract Monitoring Division has waived C hapter 14B of the San Francisco Administrative Code subcontracting goals for this project due to the specialized nature of this work; and
WHEREAS, On August 4, 2014, the San Francisco Planning Department determined the Project to be categorically exempt from environmental review under the CEQA Guidelines section
15301, Class 1 (Existing Facilities ) under Case N o. 2014.1184E, and t he work under this modification is within the scope of the project authorized under the exemption; and
WHEREAS, Funds are available from Hetchy Capital Improvement Program funded Project No. 10014086, Moccasin Powerhouse and Generator Step -Up Rehabilitation ; now, therefore, be it
RESOLVED, That this Commission hereby a pproves an increase of $1,600,000 to the existing cost contingency and an increase of 331 calendar days to the existing duration contingency, for Contract No. DB -121R2, Moccasin Powerhouse Generator Rehabilitation with General Electric Renewable Energy, for a total cost contingency amount of $3,147,568 and a total duration contingency of 440 calendar days; and be it
FURTHER RESOLVED, That this Commission hereby authorizes the General Man ager, or the General Manager’s designee, to consider, and, if appropriate, to approve any future modifications to the contract, for a total contract amount up to $32,648,985 and a total contract duration up to 1,898 consecutive calendar days.
I hereby certify that the foregoing resolution was adopted by the San Francisco Public Utilities Commission at its meeting of May 27, 2025.
Director of Commission Affairs
San Francisco Public Utilities Commission