Water Board To Adopt Ocean Desalination Rules and Regulations
The long awaited amendments to the California Ocean Plan relating to ocean desalination are set for an adoption hearing on May 6, 2015. After four years of multiple public workshops, several expert panels and studies a new rigorous 21st Century set of rules will apply to ocean desalination intakes and brine disposal in order to protect the marine environment off of the California Coast.
The proposed new rules for intakes and mitigation still find subsurface intakes the best available technology but leave the door open for open ocean intakes under certain conditions. If subsurface intakes are shown to be infeasible, open ocean intakes could be utilized with a passive intake screen (“wedge wire screen”) that must be sized at 1 millimeter or smaller, the intake velocity must not exceed one half foot per second, and the screened ocean intake would require mitigation. As for Brine Disposal, mixing brine concentrate with wastewater is still viewed as the best available technology, but diffusers may be used under specified circumstances. Discharges shall not exceed a daily maximum of 2.0 parts per thousand (ppt) above natural background salinity measured no further than 100 meters horizontally from the discharge.