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Sewage Plants Spewing Pollutants Into the Air : Studies Indicate That Scores of Waste Treatment Facilities Can’t Destroy Dangerous Substances

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Times Staff Writer

When Environmental Protection Agency scientists went sleuthing to find out who was pouring hazardous chemicals into the air in the Bridesburg area of Philadelphia, the usual suspects--a maze of chemical plants, plastics makers and other smoky factories--were all in evidence. But the identity of the master villain has proven a most unsettling surprise.

It is the city of Philadelphia’s northeast sewage treatment plant--a plant that, ironically, was mandated by the EPA to rid the Schuylkill River of the same chemical soup that the facility is now apparently spewing into the neighborhood’s air. By one reckoning, the northeast plant was responsible for nearly a fifth of the run-down neighborhood’s total air pollution.

“It was some surprise,” Joseph A. Cannon, the EPA’s top air-quality official, said simply.

It is also some problem.

Tests Under Way

Studies now indicate that the Philadelphia sewage plant--and scores of other big-city sewage facilities across the nation--are major sources of a number of chemical air pollutants that are either known or believed to be health hazards. Tests under way in Santa Clara, Calif., and Baltimore are expected to drive the point home.

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Some experts say that it is virtually impossible to get rid of the dangerous substances--they can be transformed from water pollutants to air pollutants or to solid waste, but destroying them or rendering them harmless is another matter.

The apparent moral of the Philadelphia story, said Robert S. Currie, the EPA’s chief of geographic projects, is that most of the time, you cannot get rid of pollution. All you can do is push it somewhere else.

Even pushing the hazardous wastes somewhere else can be difficult and enormously expensive.

Deputy Philadelphia Water Commissioner Tom Walton said that once the chemicals leave the factory and enter the sewers, “the only solution would be to put a bubble over the sewage treatment plant. And the cost, even if it were feasible, would be incredible.”

The chemical villains in Philadelphia and the sewage plants of dozens of other cities are lumped under the name “volatile organic compounds” and range from industrial solvents to common paint thinners.

Thousands of factories that produce such wastes “pre-treat” them at their sites, then dump the diluted soup into local sewers for final treatment at municipal sewage plants. Thousands of homeowners dump similar, undiluted household chemicals down their own drains.

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But instead of being neutralized at sewage treatment plants, scientists have concluded, virtually all the organic chemicals simply evaporate into the air, where they are inhaled by people living nearby.

“Every manhole you go by is a pollution source,” said the EPA’s Currie, a director of the Philadelphia study. About 25% of the chemicals evaporate in the sewer lines, he said, and another 60% come out at the sewer plant; the rest finally finds its way into the Schuylkill River but evaporates as the river flows through Philadelphia.

It is unclear how great a hazard the emissions pose, partly because the EPA has no data on the health effects of most volatile organic chemicals. Some of the more common ones, such as chloroform and methylene chloride, are suspected cancer agents. Others are known to react in the atmosphere, like auto exhausts, to form the chest-constricting smog that blankets cities in the summer.

Linked to Cancer Cases

Nationally, the EPA estimates, sewage treatment plants are probably responsible for only about 3% of the annual cancer cases that are thought to be caused by toxic air pollutants. The percentage is even lower if cancers caused by partially burned fuels, such as gasoline, are included.

But in neighborhoods close to major treatment plants, the disease rate may well be far higher. A study by Philadelphia’s Fox Chase Cancer Center last year found abnormally high lung cancer rates among men living in or near Bridesburg.

The study’s author, epidemiologist Hari H. Dayal, said that a heavy incidence of smoking in the neighborhood is largely to blame--and that the carcinogens in cigarettes undoubtedly interact with chemical pollutants to redouble the risk for smokers.

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“You cannot deny the fact that, in areas with high lung cancer rates, the air pollution is also high,” he said. “There is clearly a synergistic effect.”

Assessing the hazards of the plants’ pollution will not be easy, Currie said. “What the bottom line is, I can’t tell you. Every time we look at a plant, this stuff seems to be there. But not only are (exposure) standards not available for many of these chemicals, but their toxicity is also unknown.”

The EPA, using computer models, estimated that many urban sewage facilities throw more than 110 tons of volatile organic chemicals into the air each year. The EPA traced only 2.3 cases of cancer each year to a group of sewage treatment plants in 35 counties, but that may not be the whole story.

While acknowledging that this is not a large number, researchers noted that they tested for the effects of only nine of the chemicals that are funneled daily into sewage plants. In north Philadelphia, for example, about 800 chemicals enter the treatment plant every day.

Moreover, the same EPA study indicated that other toxic chemicals may be fouling the air from the burning of sewage-plant sludge--the mud-like residue left over after treatment--in municipal incinerators. The sludge often contains other industrial waste byproducts, such as chromium, which are viewed as potential health hazards.

Resistant to Process

The organic chemicals rising from sewage plants are particularly resistant to biological action, the method used in the United States to treat most sewage.

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The average sewage plant is little more than a sophisticated test tube, filled with bacteria that “eat” human waste and most other organic compounds. The bacteria are aided by a constant stirring and bubbling of the sewage, to provide them with oxygen.

But many volatile organic chemicals are not only impervious to bacterial action but kill the bacteria or dull their appetites. As a result, the sewage treatment process has little effect on the volatile organic chemicals, but the chemicals do have a significant, and negative, impact on the plants.

Sewage facilities receiving large doses of such chemicals often work at less than peak efficiency and discharge substantial quantities of untreated sewage into rivers.

And the bubbling action, designed to favor the bacteria, also helps the organic chemicals evaporate.

For the EPA’s bureaucrats, the sewer plant problem raises troubling questions about the strategy behind a 15-year environmental crusade.

Since the EPA was formed in 1970, the agency’s workers have single-mindedly implemented laws to clean up the air, the water and the landfills containing a mass of buried toxic wastes. Increasingly, however, it appears that officials often have succeeded only in pushing their own pollution problem from one bureaucratic bailiwick to another.

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‘Cross-Media Pollution’

Air emissions from water-cleaning sewage plants are but one instance of what scientists are calling “cross-media pollution.” In other cases, industrial chemicals that were once dumped into rivers or burned in smokestacks are now stored in pits or lagoons, where they seep into groundwater. And hazardous-waste landfills, only recently touted as a final solution for toxic chemicals, were fingered in a September, 1984, EPA report as a growing air pollution problem.

In many cases, the federal government is ill-equipped to stop the pillar-to-post handling of these dangerous wastes.

Air pollution laws, written to set nationwide standards for air quality, are generally useless to address pollution “hot spots” such as sewer plants. The EPA has few rules governing the chemicals rising from those plants because, in general, the plants have been viewed as a local, not a national, problem.

“We have regulations for air emissions from incinerators, but sewage treatment plants were not historically viewed as air pollution sources,” said the EPA’s Cannon. “We don’t have any regulations.”

And even the incinerator regulations do not set limits on the sorts of metallic chemicals that sewage sludge might contain.

New Rules Taking Effect

New rules for pre-treatment of industrial wastes, now going into effect under the Clean Water Act, may well reduce the amount of volatile organic chemicals dumped into the sewers.

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But those rules may only push the air pollution problem from the sewage plants to the factories. Many factories already pre-treat chemical wastes by aerating them--letting them evaporate into the air. The process, called air-stripping, is so far unregulated, and Cannon said that it is uncertain whether the EPA has the legal authority to control air pollution from industrial pre-treatment processes.

Cannon said that the EPA will probably ask Congress this year for authority to tackle sewage-plant emissions and other air pollution “hot spots,” but a few states are not waiting for the federal government to react.

West Virginia, in which the Kanawha Valley chemical complex is a major air pollution source, is already using state law to crack down on air-stripping by Charleston-area factories.

New Jersey recently issued regulations curbing the amount of pre-treated volatile organic chemicals that new industrial sources can send to sewage plants, and it may extend the rules to existing plants. At the same time, the state limits emissions from pre-treatment processes, forcing factories to recycle their chemical wastes instead of simply allowing them to evaporate.

‘Covered at Both Ends’

“We think we’ve got the situation covered at both ends,” said William J. O’Sullivan, chief engineer for the state’s air pollution control program.

In Philadelphia, meanwhile, news of the chemical cloud at the northeast sewage plant has plunged the city’s water department into gloom, and outraged some Bridesburg citizens.

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Having just spent $900 million to upgrade their three major sewage plants, city officials now worry that the EPA will force them to spend millions more on the northeast plant’s air pollution woes.

Walton, the city’s deputy water commissioner, called the furor over the plant “irresponsible” and said that the city disagrees with EPA scientists over some conclusions of the sewer-plant study.

“We don’t think there’s enough data to base a conclusion on,” he said. But, in the meantime, “some people around here are afraid to breathe.”

And a Bridesburg citizens group, armed with the Fox Chase cancer study and the EPA’s own data on the northeast plant, has sued the department over odors that it contends are drifting from the treatment site.

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