San Diego Secondary Treatment Waiver

The City of San Diego submitted a consistency certification to the California Coastal Commission for the reissuance of its secondary treatment waiver for the municipal discharges from its Point Loma Wastewater Treatment Plant (WWTP). The waiver reissuance would be needed to allow San Diego to continue to discharge effluent receiving less than full secondary treatment in terms of total suspended solids (TSS) and biochemical oxygen demand (BOD). If no waiver were granted, the City would be required under the Clean Water Act to implement upgrades meeting secondary treatment requirements, which would mean removal of 85% of both TSS and BOD. With a waiver, CWA Section 301(h) and (j) require, among other things, removal of 80% of TSS and 58% of BOD.

Other coastal municipalities that had sought past waivers have now upgraded to secondary treatment. San Diego is pursuing a different approach: as an alternative to upgrading to secondary treatment, they propose to reduce wastewater flows to the plant, through water recycling, which then reduces flows (and pollutant loads) into the ocean.

On December 9, 2014, the City of San Diego expanded and updated its commitments to water reuse, in a Cooperative Agreement with San Diego Coastkeeper, the San Diego Chapter of Surfrider Foundation, the Coastal Environmental Rights Foundation, and the San Diego Audubon Society. This agreement commits San Diego to a compliance schedule for initially implementing at least 15 million gallons per day (MGD)of potable water reuse by end of 2023, at least 30 MGD by the end of 2027, and ultimately achieving at least 83 MGD of wastewater reuse by the end of 2035. The Regional Water Quality Control Board’s Order incorporates the City’s commitments to continue to pursue and implement its recycled water program, converting wastewater into potable water, under a program called “Pure Water San Diego.” The US EPA, San Diego Chamber of Commerce, Surfrider Foundation, San Diego Coastkeeper and Coast Law Group all testified in favor of the waiver.

A representative from the US EPA testified pointing out that the associated discharge empties into federal waters – thus prompting this agenda item. The EPA has the sole responsibility of acting on the waiver. They pointed out that the City has already met very stringent requirements that do not adversely effect the ocean environment. The performance of the facility has improved over the past 20 year and meets permitting authority requirements by a wide margin.

The waiver concurrence was approved unanimously.