San Diego Union-Tribune (Sunday)
MODIFIED SEAWATER INTAKES OK’D FOR DESAL FACILITY IN CARLSBAD
A permit approved Thursday by the California Coastal Commission will allow the Carlsbad desalination plant to modify its seawater intakes and discharge structures to better protect marine life and create a “stand-alone” system.
The desalination plant takes ocean water from the Agua Hedionda Lagoon through intakes formerly used for the cooling system at the now demolished Encina power plant, built by San Diego Gas & Electric Co. in the 1950s. The old power plant was replaced by a more efficient plant that does not use seawater for cooling.
However, the desalination plant, which began production in 2015, still uses parts of the power plant’s intakes and now needs additional upgrades to conform to state environmental requirements, according to a Coastal Commission staff report.
The changes include installing improved screens with a 1-millimeter mesh that would continually rotate through the incoming water, the report states. Debris would be routed to a sorting area where trash is removed prior to discharge. The intakes also have bars to prevent marine mammals from getting close to the screens and a floating boom to stop f loating debris.
The Coastal Commission approved Poseidon’s upgrades to the system unanimously and without comment, although two speakers advised the agency to be cautious about the system’s effects on the environment. The plant pulls in about 300 million gallons of seawater per day, and kills any marine life drawn into the intakes. The plant also increases the salinity of seawater near the discharge by releasing a concentrated brine into the ocean.
Poseidon remains in violation of the Coastal Commission’s requirement for wetlands mitigation to offset marine life killed by the system, one speaker said. The commission’s deadline to start that work was last year. Poseidon has said it will begin this fall.
“They really haven’t lived up to their promises, and I hope you will keep an eye on them,” said Nancy Okada of the Sierra Club at Thursday’s meeting.
The Carlsbad plant provides about 10 percent of the drinking water consumed in San Diego County.