Bottlemania - Elizabeth Royte [45]
In Washington, D.C., the switch to chloramines exposed tens of thousands of residents to lead at three hundred parts per billion. The EPA “action level,” above which utilities must take mitigating steps, is 15 ppb. As of mid-2007, the city had replaced about a third of its lead service lines, which connect mains to individual water meters. Whenever I speak to water experts in the capital region, whether in government, in academia, or at advocacy groups, I ask what they drink. Always it’s tap; always, they run it through either a pour-through or on-tap filter.
Seattle, San Francisco, and Portland, Oregon, own their entire watersheds, which means they’re generally protected from developers and industry. But coliform bacteria—from animals and from humans—still make their way into the water. That’s life. New York City controls less than 50 percent of its watershed (Boston slightly more than 50 percent), and roughly one hundred wastewater treatment plants dump their effluent into streams that lead to reservoirs. The practice is more common than one might think: more than two hundred municipalities, including Las Vegas, discharge billions of gallons of sewage into the Colorado River, which supplies drinking water to San Diego and other cities. All down the Missouri and the Mississippi, towns drink from, and discharge back into, the river. New Orleans, at the bottom of the Mighty Miss, drinks the effluent of nearly half the U.S. urban population. But those discharges are first filtered and disinfected at wastewater treatment plants, then diluted in the river before they’re sucked up by drinking-water plants, which treat the water again before sending it out to taps.
New York City is trying to upgrade all the sewage plants in its watershed to state-of-the-art “tertiary” treatment, but more than two dozen of them still use suboptimal “secondary” cleaning. Of the effluent from the more advanced plants, Steven Schindler says, “I’ve heard of plant operators drinking it on a tour.”
This information lifts the eyebrows of the NRDC’s Eric Goldstein. “It’s very clean for sewage water,” Goldstein says, practically hidden behind towers of reports, legal pads, newspaper clippings, and memos on his desk in Manhattan, “but you’d have to be a nut to do that.” Goldstein reminds me—and I really do want to believe him—that the city’s water settles for months, and it’s enormously diluted. He hops up to grab a thick book. “Here we go,” he says, flipping through the pages. “Ten point five million gallons of sewage a day goes into the system.” That sounds like a lot (it would fill nearly sixteen Olympic-size swimming pools), but the reservoirs hold about 550 billion gallons of water, of which the city takes 1.2 billion gallons (1,817 swimming pools) a day. The ratio of sewage to nonsewage, in other words, is sub-homeopathic.
The thing is, chlorine is supposed to take care of that effluent, the bad stuff that makes it out the discharge pipe. But creeping levels of sediment in the reservoirs can block disinfection. Sediment can also serve as food for disease-causing organisms. In general, the higher the turbidity, the higher the risk that water drinkers will develop gastrointestinal diseases. In New York, the problem