National Geographic : 1993 Nov 30
runoff. Yet until recently most regulation and enforcement have been aimed at point sources. "Water is in serious jeopardy," says the Natural Resources Defense Council's Robert Adler, "because we're not paying much atten tion to anything except pollution from a pipe." In Cleveland I hiked with a few people under a highway overpass and down a railroad track to a beautiful little waterfall on a creek. The fall was like a piece of natural beauty crouching in the city's underbrush, hiding out from all that technology. But right at the top of the fall was a round door, like a manhole cover. It was part of a combined sewer system, one of the villains in the story of polluted runoff. These systems have large underground pipes that carry sewage, industrial waste, and storm water to treatment plants. During heavy rains the storm water may be more than the plants can handle; overflow carries raw sewage and other pollutants straight into the streams. We stood looking at the big door. Every thing was dry, but in a storm it would open automatically and cough up a gush of polluted runoff and fecal coliform. Curses were spray painted on the door. They seemed appropriate. "People sitting around pointing fingers at in dustry don't realize that most water pollution is runoff," Jerry Schoen, an activist with the Massachusetts Water Watch Partnership, told me at a conference. "America's just waking up to a critical situation. The only way to make progress is to have everybody be part of it." W HEN I FLY from west to east over the northern part of the United States, a curious thing happens. For hours I cross farmland irri gated by canals that move precious water from reservoirs to fields; then suddenly the canals are replaced by ditches with an opposite func tion: to get rid of water. These drainage ditches look like schematic drawings of natural water sheds-the same network of tributaries lead ing to a main channel but all straight lines and angles. To me they are symbolic of agricultural runoff, which, an EPA official said recently, contributes to "about two-thirds of the impair ments in rivers, about half in lakes, and about one-quarter in estuaries." Nutrients from fertilizers and livestock and silt from eroding fields are the leading pollut ants, but others have been at least as deadly. WATER: THE CHALLENGE OF POLLUTION Concentrations of the element selenium-a chemical naturally present in tiny quantities but as poisonous as arsenic in high concentra tions-leached from soil by irrigation have killed thousands of birds in the West. And as William S. Ellis reports in his story on the Mis sissippi (following article), herbicides and pesticides that drain from fields fog even the clearest water with anxiety. Most water looks clean from the air, but everywhere I can see human activities that lead to polluted runoff. Out West the vast clear-cuts in the forests of the U. S. and Canada allow silt to clog mountain streams, hurting both salmon and municipal water systems. In the East the bright emerald checkerboard of lawns means people may be using herbicides and fertilizers as intensively in the cities as on the farms. Even flying through rain, I'm in direct contact with water pollution. This is not just a matter of acid rain, which, though it's now getting less public attention, still kills lakes and trees. Odd pollut ants have been blowing to places that should be pristine. At Lake Laberge, way up in the Yukon Territory, a study of fish flesh turned up a vari ety of chemicals, including the insecticide toxa phene, which has been widely used in Russia. It probably blew east, and rain raked it in. "We thought we were living in a wilderness Shangri-la," a Canadian told me when I landed nearby and asked him about it. "Welcome to the world." If places like Lake Laberge seem insidiously stained, that's nothing compared with the pol lution of groundwater, which is out of sight and, possibly, out of reach. One night I sat in a grade school auditorium on Cape Cod, Massachusetts, with a group of concerned citizens and a panel of experts, who were debating how to deal with plumes of sew age and toxic industrial chemicals that are seeping underground from the Massachusetts Military Reservation. The Department of Defense, responsible for cleanup, and the U. S. Geological Survey have each been studying groundwater pollution here for years, and Denis LeBlanc, a USGS hydrologist, was in an uncomfortable spot: The study goes on and on, and toxic chemicals keep moving toward the towns, despite cleanup efforts just begun. "I've never come across a plume that didn't seem smarter than we are," LeBlanc said. "It's not a simple process."