Encina Sewage Plant to Put a Lid on Odor Problems

Times Staff Writer

Carlsbad residents downwind from the Encina sewage plant will have to hold their noses a while longer while workers hustle to solve the odor problem, but they shouldn’t have to worry about the quality of the ocean water during the summer sunbathing months.

The 12-member Joint Advisory Committee of the Encina Water Pollution Control Facility voted Wednesday to move as fast as possible to cover the stench that has been affecting nearby residents since the plant increased its treatment of the sewage to the secondary level last October. At the same time, the committee members unanimously rejected the idea of reverting to advanced primary treatment to lessen the smell, to the great relief of local environmentalists.

Happy With Decision

“We’re elated that the board has decided to do the right thing here,” said Richard MacManus, spokesman for People for a Clean Ocean. “We have empathy for the local residents that have to deal with the odor issue, and hopefully there will be a quick solution to that problem, but you can’t jeopardize the public health.


“Hopefully, the days of lower sewage treatment are gone forever.”

People for a Clean Ocean lobbied extensively for a switch to secondary treatment, which more effectively removes toxins, bacteria and viruses from the effluent before it is dumped from the plant’s ocean outfall 1 1/2 miles offshore. But, when the new system was kicked into gear last fall, it soon became obvious that more intensive treatment resulted in a more intense smell.

A recently completed study, done jointly by the John Carollo engineering firm and TRC Environmental Consultants, concluded that most of the odor was coming from the plant’s uncovered aeration basins, where the sewage settles, and from the channels running between the basins.

Engineer Dennis Wood told the committee Wednesday that simply covering the open basins and channels would virtually wipe out the problem.


The study’s recommendations, which were unanimously approved by the committee, called for the the basins and channels to be covered as soon as possible with plywood. The makeshift plywood covers will be replaced with interim covers designed to last about three years--which could be in place before the end of 1989, “with a little bit of hard work and a lot of luck,” Encina General Manager Rick Graff said.

Permanent Covers Are Goal

Meanwhile, the facility will seek a contract to build permanent fiberglass or aluminum basin covers, which could be removed for occasional maintenance. If work proceeds quickly, the permanent covers could be in place by July, 1990, the study said.

The committee also explored the possibility of reverting to less-intensive treatment until the end of the year to mitigate the smell, but Graff recommended against it.


Such a switch would have negligible financial benefits and could actually cause more odor because of the complexities of switching systems, Graff said. Furthermore, the plant would have to go back to secondary treatment in November or December, when the federal Environmental Protection Agency issues its new five-year license, which will provide for secondary treatment only.

After hearing the presentation, the entire board seemed to agree with the remarks of Carlsbad Councilman Eric Larson, who said that reverting to advanced primary treatment is “not even a viable alternative.”