Bottlemania - Elizabeth Royte [46]
The EPA says turbidity may never exceed one nephelometric turbidity unit in 95 percent of daily samples in any month, but some researchers think the bar is set too high—that people get sick at even lower values. A study conducted in the early nineties in Philadelphia found that emergency room visits and hospital admissions for children with gastrointestinal illnesses increased by about 10 percent whenever the turbidity of the city’s filtered water supply increased significantly (but was still in compliance with current federal standards). And about ten days after the spikes in turbidity, hospital admissions of the elderly for GI illnesses increased by 9 percent.
To counteract the increased levels of particulate matter, cities have long dumped aluminum sulfate, or alum, into the water. It makes the particles clump together and sink. But alum is no panacea. Heavy use can make water more acidic, and acidic water can corrode pipes. Over the years, so much alum has accumulated on the bottom of New York’s Kensico Reservoir, in Westchester County, that it’s now smothering aquatic life. For many nail-biting months, the city wondered if the EPA would grant the city its next filtration avoidance permit (the previous five-year permit had expired). If the DEP couldn’t get a handle on sediment—perhaps by retrofitting its dams and weirs to give water more time to settle—it would have to build a filtration plant so vast it would cover an area larger than fifteen football fields.
Filtering Catskill-Delaware water would be a blow to New Yorkers’ water pride (the city is currently building a filter plant for its Croton system, which collects water from densely developed watersheds east of the Hudson), but the financial impact, according to James Tierney, the state assistant attorney general charged with enforcing environmental laws within the watershed, would be “like a bomb going off.” The plant would cost more than six billion dollars to build, and the cost of staffing, operation, maintenance, and debt service would reach one billion dollars annually. After examining the city’s watershed protection plan and accepting public comment, the EPA decided to grant the permit. The city’s comptroller, no doubt, said, “Phew.”
After publishing an article on New York’s water system, which mentioned chlorine’s deadly effect on E. coli, I receive a long telephone message from a gentleman in California. The gist of Frank Pecarich’s pitch is that chlorine doesn’t kill all bacteria. He refers me to studies conducted by the U.S. Department of Agriculture’s Agricultural Research service, which found that a particularly virulent strain of E. coli, called 0157:H7, can survive the most stringent wastewater treatment process and then evade standard tests.
“The E. coli has learned to go into an inactive state,” Pecarich says when I call him. Pecarich is a former USDA soil scientist, and he’s apparently devoted his retirement to fighting the use of treated wastewater in agriculture, a common practice in California’s Monterey County. “They form biofilms in pipes. They feed on bacteria in the water, and then they reemerge even stronger.” Bill Costerton, a microbiologist at the University of Southern California who coined the word biofilms, describes them as highly structured communities of bacterial cells living cooperatively and excreting gluey slime that helps them adhere to surfaces—on medical implants, on soil particles, and in water pipes.
It takes as few as ten organisms of 0157:H7, which grow in the rumens of cattle, for an infection, Pecarich says. The strain secretes a powerful poison, called a verotoxin, that can lead to bloody diarrhea, kidney failure, and death. Tertiary sewage treatment gets water 99.7 percent