Advanced treatment will reduce discharges to ocean, provide sustainable water source
The U.S. Environmental Protection Agency (EPA) and the San Diego Regional Water Quality Control Board finalized a City of San Diego wastewater discharge permit to protect ocean water quality and increase water reuse. The Clean Water Act National Pollutant Discharge Elimination System five-year permit for the City’s Point Loma Wastewater Treatment Plant establishes discharge limits to meet federal and state water quality standards.
“The permit will protect coastal waters through its stringent terms and by reducing discharges to the ocean,” said Alexis Strauss, EPA acting regional administrator for the Pacific Southwest. “In addition, this permit goes beyond what is necessary to meet federal and state discharge permit requirements and will require the facility to implement a water reuse program to provide a safe, reliable water supply for San Diego.”
“The approval of the joint permit and the variance are an important milestone in the protection of both coastal water quality and improvement of local water supply reliability,” said David Gibson, executive officer for the San Diego Regional Water Quality Control Board. “The collaborative efforts of the state and regional water boards, EPA, and environmental advocates have resulted in a permit and variance that advances the restoration of coastal water quality and augments municipal water supplies with high quality, safe water for the benefit of present and future generations.”
The city will rely in part on its Pure Water San Diego program to achieve the standards outlined in the permit. The program will use advanced water purification technology to filter recycled water to produce a reliable source of potable water. Eventually the system will divert up to 83 million gal of Point Loma wastewater per day from ocean discharges to local reservoirs. By 2035, the Pure Water program is expected to generate one-third of the potable water supply needed for San Diego and surrounding communities.
To accompany the permit, EPA has renewed its Clean Water Act section 301(h) variance for the Point Loma facility, thereby allowing it to forego some wastewater treatment requirements based upon Clean Water Act criteria and the plant’s performance. The Clean Water Act section 301(h) variance also requires the facility to monitor water quality to ensure coastal waters are protected.
The City of San Diego must apply for a permit renewal every five years and is required to meet secondary treatment levels. EPA may grant a modification of these standards for ocean discharges if federal and state water quality standards are met. The Point Loma plant has been operating under such a modification since 1995, consistently meeting or exceeding federal and state discharge requirements.