Bottlemania - Elizabeth Royte [42]
In reservoirs and rivers across the country, these excess nutrients encourage the growth of algae. When algae die, bacteria feed on the dead plants and consume the oxygen in the water. These anaerobic conditions strangle aquatic life in reservoirs and have created a nearly 8,000-square-mile “dead zone” in the Gulf of Mexico, into which the Mississippi River drains. Low-oxygen conditions also release iron and manganese previously bound to bottom sediments. Water taste, odor, and color quickly go downhill (the technical term is skunked). It gets worse: dead algae and bacteria, along with other organic material, combine with chlorine in treated water to form a polysyllabic array of potential carcinogens in drinking water. These disinfection by-products—trihalomethanes and haloacetic acids—have been linked to an increased risk of bladder cancer and miscarriage. In cities such as New York, levels of disinfection by-products typically increase by as much as 1.5 to 2 times during summer months, when there’s more organic material in the water and plant operators dispense more chlorine.
Klender doesn’t worry about nitrogen—there’s so much water in the Missouri that by the time he takes his cut, levels are fairly dilute. “Got it covered” is his general attitude: with enough chemicals and technology, it seems, he can handle anything. Other cities aren’t so lucky. Des Moines, which drinks from the Raccoon and Des Moines Rivers, was forced to build a $4.5 million de-nitrification plant (which costs three grand a day to run) to comply with federal requirements. Iowa communities that drink from shallow wells, and that lack funds for fancy ion-exchange systems, have a tougher time of it. When nitrates spike, they issue “blue baby” alerts. (Nitrates in water bind to hemoglobin in babies’ blood, hindering its ability to deliver oxygen to the brain. In adults, high nitrate levels have been linked with increased risk of hyperthyroidism, birth defects, and spontaneous abortions.)
Ethanol plants themselves, the destination for about a fifth of the corn crop in 2007, will affect both water quantity and quality. Producing one gallon of the alternative fuel requires about four gallons of water: a facility making 100 million gallons a year, then, would need about 400 million gallons of water. Iowa water managers worry that most of the state’s twenty-seven ethanol plants will be pulling that water from deep aquifers that provide drinking water to the state. So worried are water managers in Nebraska, the nation’s number three corn producer, that some workers spend their days whacking phragmites and other water-sucking plants from wetlands to save water for other uses.
The ethanol industry says that more than half the water it uses either evaporates or is treated and released to streams. But the plants’ wastewater, Susan Heathcote, water program director of the Iowa Environmental Council, says, “can be more like brine. They use reverse osmosis to purify their water”—forcing water at high pressure through a semipermeable membrane—“and they end up with high concentrations of sulfides, chloride, and iron.” Diluted sufficiently in big streams, the contaminants are harmless, but many plants discharge into creeks that contain little water.
Ethanol worries Klender only if it means more atrazine will be washing from cornfields. It’s his job to lower levels, sometimes as high as 35 ppb, to less than 3. It costs him thirty-six thousand dollars to fill an empty silo with carbon (which also removes oil and pesticides from water), and he goes through as many as five silo loads a year.