Complying with County Stormwater Regulations


An industrial client facing a complicated stormwater code requirement turned to Farallon for a creative, low-cost retrofit solution.

Farallon offered a range of consulting and engineering services to a client preparing to upgrade an existing stormwater treatment system to obtain building improvement permitting. Farallon evaluated the performance of the existing system and its compliance with county stormwater regulations, and presented various water quality treatment alternatives using county- and state-approved technology, evaluated by treatment effectiveness, ease of maintenance, impact on existing operations, and cost. The client’s priorities for the new water treatment features were that they minimize impact on facility operations and protect recently installed heavy load-bearing pavement.

Farallon provided planning, design, permitting, and construction services for the alternative chosen by the client, which included retrofitting existing stormwater infrastructure for a pumping station and routing conveyance piping to a wet biofiltration swale approximately 500 feet away from the operations area. The approach was simple and saved considerable project costs. Farallon worked closely with the client and the county to optimize the biofiltration swale for treatment effectiveness and aesthetics. Native wetland plants were selected for their treatment characteristics and to create a natural look and feel. The swale now serves as a functional water quality treatment facility that welcomes visitors to the facility with an attractive garden-like natural setting.

“The client was pleased with our creative, low-cost solution that also enhanced the appearance of the entry to the facility.  This successful project resolved a long-standing issue between the client and the county, and facilitated a building permit for a major facility improvement project with lender refinancing requirements” says Farallon Principal Hydrogeologist.