Title
Report regarding a resolution authorizing a First Amendment to the Services Agreement with Wastewater Solids Management Company for anaerobic digester cleaning services in an amount not to exceed $97,500, increasing the total contract authority to $727,863, extending the term to June 30, 2027, and authorizing the City Manager or designee to execute the agreement on behalf of the City. (Jeff Chou, Senior Civil Engineer and Brian Schumacker, Water Quality Control Plant Superintendent)
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RECOMMENDATION
Recommendation
Staff recommends that the City Council adopt resolution authorizing a First Amendment to the Services Agreement with Wastewater Solids Management Company for anaerobic digester cleaning services in an amount not to exceed $97,500, increasing total contract authority to $727,863, extending the term to June 30, 2027, and authorizing the City Manager or designee to execute the agreement on behalf of the City.
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BACKGROUND/DISCUSSION
The City of South San Francisco Public Works Department’s Water Quality Control Plant (WQCP) Division is responsible for the routine maintenance of digesters and storage tanks. Proper routine maintenance of these assets, including cleaning, solids removal, screening, and on-site dewatering of sludges, is essential to preserving reliability, extending equipment service life, and ensuring the long-term dependability of the City’s vital infrastructure systems.
The City Council previously approved a services agreement with Wastewater Solids Management Company with a total contract authority of $630,363 for routine solids removal and dewatering of five (5) Water Quality Control Plant (WQCP) vessels.
Following initial cleaning operations, staff inspected the interior of Digester No. 1. An unanticipated industrial coating failure existed on the interior roof coating. A separate city-contracted industrial coating company erected scaffolding and performed the critical interior roof industrial recoat. Structural grit blasting, overspray, and debris generation inherent to industrial coating applications subsequently impacted the newly cleaned vessel interior.
To preserve infrastructure integrity and protect downstream process equipment from damage by abrasive debris, the affected digester requires a general recleaning and secondary solids evacuation. Because Wastewater Solids Management Company already holds baseline liability for the vessel handoff sequence, staff negotiated an amendment to extend the term of the original contract and execute this work directly.
Furthermore, Digester No. 5 contained more material build up than estimated during the bidding process. Once cleaning contractors completely dewatered the digester, staff observed a considerable amount of sand and grit buildup.
The First Amendment to the services agreement with Wastewater Solids Management Company covers:
• Remobilization of specialized extraction equipment to the specific digester asset
• Secondary screening and removal of industrial coating debris, industrial coating flakes, and fallen particulates
• Solids dewatering and processing of extra material
• Final high-pressure washdown and structural validation
FISCAL IMPACT
Funding is included in the City of South San Francisco’s Fiscal Year 2026-27 proposed budget. Sufficient revenues exist to cover this routine maintenance. San Bruno shares 26% of these expenses.
RELATIONSHIP TO THE STRATEGIC PLAN
The Public Works Department’s Water Quality Control Plant (WQCP) Division promotes public health and environmental stewardship. Continuing to fund infrastructure capital improvements is in alignment with the quality of life major focus area by protecting public health and safety.
CONCLUSION
Authorizing a First Amendment to the Services Agreement with Wastewater Solids Management Company for Anaerobic Digester cleaning services in an amount not to exceed $97,500, increasing the total contract authority to $727,863, extending the term to June 30, 2027, and authorizing the City Manager or designee to execute the agreement on behalf of the City.
ASSOCIATED DOCUMENTS
1. Visual aid showing Digester No. 1 and No. 5 interiors