South County Coast Hit by Discharge of Sewage

For about 10 days in June, a malfunction in a San Clemente sewage treatment plant led to the dumping of inadequately treated sewage into the ocean off Dana Point.

The discharge never posed a health hazard to bathers or to those who used the San Clemente municipal golf course, which is irrigated with reclaimed sewer water, said Michael P. Wehner, water quality program chief for the Orange County Health Care Agency.

But the San Clemente plant’s problems caused a regional sewage treatment facility--which collects the city’s treated waste water, then pumps it into the ocean along with its own treated effluent--to violate federal discharge limits.

Limits Set on Discharge

Discharges from the regional plant, operated by the South East Reclamation Authority (SERRA), are limited to 50 milligrams per liter per day of suspended solids--particles that can carry health-threatening bacteria or viruses. But during the malfunction, the outfall pipe discharged from 60 to 88 milligrams per liter of solids a day, SERRA general manager William Becker said.

Such violations could lead to fines of up to $10,000 a day for each day that the SERRA plant was out of compliance. But because repairs were made quickly, no fines are expected, said Dave Barker, a senior engineer for the state Regional Water Quality Control Board in San Diego, which monitors SERRA’s discharge.

According to city and county officials, in early June, the microorganisms that feed on waste material in San Clemente’s sewage treatment plant somehow got “out of balance” and were unable to treat suspended solids.

San Clemente regularly sends about 3.6 million gallons of treated effluent a day to a SERRA outfall pipe that extends about two miles south and 115 feet deep into the ocean off Dana Point. The pipe also carries 1.5 million gallons of sewage each day from the small Capistrano Beach Sanitary District, plus 8 million gallons of sewage a day from SERRA, which treats sewage for Dana Point, the Moulton Niguel Water District, the city of San Juan Capistrano and the Santa Margarita Water District.

San Clemente City Engineer William Cameron said the problem in the city’s treatment plant was caused by a faulty adjustment, which allowed the wrong kind of bacteria to become dominant and resulted in “suspended solids . . . floating over the weirs” and into the outfall pipe.

That sewage went through the outfall and into the ocean, Cameron said, and another 400,000 gallons of partially treated sewage were routed each day through a holding pond, and the reclaimed effluent was used to water the city golf course. Although coliform counts in that water were high, Cameron said that the golf course was watered at night and that no golfer risked contamination.

Cameron noted that even though suspended solids were not adequately removed from the city’s sewage, other biologic treatments at the plant were working, including a process that removes hydrogen sulfide and methane gas from sewage. “Raw sewage was never being discharged through our plant,” he said.

Cameron said the San Clemente plant first slipped out of compliance on June 4 when it discharged waste water containing 53 milligrams per liter of suspended solids. According to city tests made off and on through the end of the month, the city recorded levels that fluctuated below 50 milligrams and gradually reached a high of 129.5 milligrams per liter on June 18. The overall discharge from the SERRA outfall measured considerably less, however--recorded at a maximum of 88 milligrams per liter a day--because San Clemente’s sewage was diluted by SERRA’s larger effluent flow.

After June 18, solids from the San Clemente plant began to decrease to permissible levels, Cameron said. By Sunday, “we were producing an extremely fine effluent, down to 10.6 milligrams,” he said.

San Clemente is not the only city with treatment problems. According to SERRA general manger Becker, the small Capistrano Bay Sanitary District has violated discharge limits for suspended solids for about six months, releasing effluent that averages 60 to 70 milligrams per liter per day.

But because Capistrano’s 1.5 million gallons of daily effluent is usually diluted with much greater quantities of better-treated waste water from the San Clemente and SERRA agencies, the total ocean discharge remained within allowable limits, Becker said.

But when San Clemente’s plant went awry, too, SERRA’s effluent could not sufficiently dilute the inadequately treated discharges, and the total level of suspended solids from SERRA’s outfall exceeded the terms of its National Pollution Discharge Elimination Permit, Becker said.

The San Clemente Taxpayers Assn. has complained that the city plant regularly operates over capacity, processing up to 400,000 gallons of sewage each day over its 4-million-gallon capacity.

But Cameron said the plant is operating properly now, and he did not believe that the problem would recur. He added that although the sewage plant has operated above capacity on some days this month, its average for June is expected to measure under 4 million gallons a day.