Advice Helped Put San Diego in Sewage Treatment Bind

When San Diego officials traveled to Washington in 1977 to urge that Congress allow coastal cities to sidestep stringent treatment requirements for sewage dumped in the sea, they were aided by some heavyweight members of the local scientific community.

Among them was John D. Isaacs of Scripps Institution of Oceanography. Isaacs, a renowned oceanographer who died in 1980, told legislators that “building pyramids” would make more sense than requiring municipalities to further cleanse sewage before discharging it offshore.

Domestic sewage, he argued, is good for marine life, providing abundant nutrients that many organisms need to live.

Central Question

Isaacs’ views--still espoused by some scientists--represent one response to a question that is central to the heated controversy over sewage treatment standards: Just what effect does waste have on the ocean and its billions of inhabitants?

For years, cities have used the sea as a giant sewage receptacle, but there is still little agreement on the impact the practice has on the marine environment.

Some scientists argue that the ocean’s depth, abundant supply of oxygen and swirling currents make it able to disperse and assimilate most contaminants. “The solution to pollution is dilution” was a popular slogan heard locally and in other cities seeking to skirt tougher treatment requirements ushered in by the Clean Water Act of 1972.

But others are skeptical. Noting the 1986 revelations about contaminated fish in Santa Monica Bay, where Los Angeles has discharged its sewage for years, these critics say that more sophisticated treatment is necessary to better cleanse waste water of ingredients like DDT and other toxics.

Perhaps more compelling is the argument about viruses. Critics of reduced sewage treatment argue that waste-borne viruses, which can cause ailments as mild as diarrhea and as severe as meningitis, are not effectively removed from sewage treated at more rudimentary levels.

While some researchers say the disease-causing agents cannot survive in the harsh saltwater climate, a new study out of the University of Maryland found that they may actually enter a state of hibernation and can become virulent if given the proper medium.

Another published study of a sludge disposal site offshore of Philadelphia found pathogenic viruses in sediment and crab samples more than 17 months after dumping at the site had ceased.

Standard Challenged

Many opponents of reduced treatment levels have also challenged the standard technique used to gauge the presence of viruses in sewage. Research at Johns Hopkins University found that swimmers in New York, Boston and Lake Pontchartrain, La., developed virus-induced illnesses even when fecal coliform bacteria--the indicator of viruses--was not detected.

Dr. John Skinner, an Orange County internist who has fought for improved sewage treatment up and down the California coast, suspects that the chlorine disinfection of sewage practiced by many plants may kill off the indicator bacteria but not harm the viruses.

Brian Melzian, an oceanographer with the Environmental Protection Agency’s regional office in San Francisco, said his agency has recommended use of another bacteria to more accurately assess the presence of viruses.

“For a long time, people argued that there were no definitive answers to these questions and that therefore (a higher treatment standard) wasn’t worth the price,” said David Jones, chief of the EPA’s California branch. “Now, many people say that given the uncertainties, they’re willing to pay whatever it costs.”

On a related front, biologists are troubled by the spillage of raw sewage into the county’s lagoons. On March 5, more than 20 million gallons of sewage spilled from a Sorrento Valley pump station, flooding Los Penasquitos Lagoon.

“After one spill I saw tampon dispensers, prophylactics, oil globules and all kinds of suds in the lagoon,” said Glenn Greenwald, an aquatic ecologist who has studied the inlet for the Los Penasquitos Lagoon Foundation.

Cleansing Action

Still, the impacts of such spills need not be devastating, Greenwald said. If a lagoon is open to the ocean, exchanging its water with the sea on every tide, the pollutants can be swept away before any real damage is done.

But if it is cut off from the sea--as Penasquitos frequently is--the massive load of nutrients in sewage can create clumps of algae blooms that ultimately rot, robbing the water of oxygen needed by fish and other organisms. In October, such a phenomenon killed several thousand fish and invertebrates at Penasquitos, said Greenwald, adding that it was unclear whether a sewage spill or unusual contaminants in local runoff caused the die-off.

“We just don’t know yet what the full effects of these spills are,” said Greig Peters, a biologist with the Regional Water Quality Control Board. “Nutrients tend to get recycled in a system, so we could have problems with algal blooms for years.”

Neighboring residents, meanwhile, worry about the presence of toxic chemicals in the raw sewage spilling from Sorrento Valley. They fear that such materials settle on the lagoon floor, where they may be stirred up by children playing in the warm waters at the mouth of the wetland.

Peters said “it’s a concern, but it hasn’t happened yet.” Testing for pesticides and heavy metals in the lagoon and the creek that feeds it have turned up concentrations well below the hazardous level, he said.