SFPUC Southeast Plant Primary & Secondary Clarifier Replacement

Location: San Francisco, CA

Owner: SF Public Utilities Commission

Contract: $25.8 Million

Role: General Contractor

Delivery Method: Design-Bid-Build

Result and Benefit to Client

We performed upgrades while maintaining continuous operation of existing plant. The project was delivered on schedule and under the SFPUC project budget.

Project Description

Constructed in 1952, the aging infrastructure at the San Francisco Southeast Water Pollution Control Plant located in the Bayview Hunters Point Neighborhood required upgrades to the primary and secondary treatment systems, as well as to the odor control system.

Southeast is the city’s primary treatment plant handling approximately 80% of the wastewater from the eastern two-thirds of the city’s residents. The maximum treatment plant capacity is 250 million US gallons (950,000 m3) per day, with the average daily dry weather flow of 60 million US gallons (230,000 m3).

Monterey Mechanical was contracted to replace 8 of the 16 secondary clarifier mechanisms and repair deteriorated concrete. All the primary clarifier mechanisms were replaced as well as the tank covers. Concrete deterioration was also repaired in these tanks. The Odor Control system at the Primary Clarifiers was replaced to eliminate the odor complaints the plant had experienced.

Challenges | Solutions

A key challenge for Monterey Mechanical on the Southeast Plant Primary & Secondary Clarifier Replacement project was maintaining the plant’s ability to meet federal effluent discharge quality requirements, while taking portions of the plant out of service for the repair/replacement work.

We developed a startup, testing and commissioning plan that included forms to document testing and readiness for service of each piece of equipment. We started each system as it became available, and kept existing systems in service until the new system was commissioned and performance-tested for 30 days.