draw the line at this point in their policy is on mandatory steps that would effectively implement die Kyoto agreement before the agreement is ratified by the government," said Tom Curtis, director of NGA's natural resources group. Strategies that the state commissioners may consider next year include a voluntary state registry program to track a company's emissions reductions and a voluntary emissions trading profor gases covered by the Kyoto agreement, including carbon dioxide nitrous oxide and sulfur hexafluoride said Jackie Chanudet special assistant to the commissioner for the New Jersey
Department of Environmental Protection. A trading program would deny a company the right to emit greenhouse gases unless it had a permit to do so. Programs created by ECOS could lead to interstate emissions trading by taking into account greenhouse gases that move across state lines, said Jodi Perres an ECOS spokesperson. More than half the states already have taken two steps leading toward voluntarily reducing gases: they have evaluated greenhouse gas emissions within their boundaries, based on 1990 data, and are creating projections for emissions 2012, Chanudet said.
"The third step to reducing greenhouse gas emissions would be to determine how to reduce our emissions," she said. Industry representatives like die sound of voluntary compliance. "We support die idea that the more information you have about global warming and greenhouse gas emissions the sooner you will be able to come up with a rational policy," said Mike Shanahan, a spokesperson for the American Petroleum Institute (API). Like many in industry, API opposes the Kyoto protocol because it does not include reduction requirements for developing nations. DEBRA A. SCHWARTZ
Wastewater reuse: Water shortage solution or long-term nightmare? Disinfection byproducts resulting from the tertiary treatment process of municipal wastewater, as well as pharmaceutically active chemicals that survive the treatment process, may be creating long-term problems, according to a new study from the U.S. Department of Agriculture (USDA). These chemicals, along witii salts, nitrogen, heavy metals, and certain organic compounds found in wastewater could be slowly leaching to groundwater sources from which many communities draw their drinking water, according to the report Irrigation With Municipal Wastewater How Safe Is It? from die USDA's Water Conservation Lab Until now, EPA water reuse guidelines have focused on pathogens, linking die level of treatment to me degree of likely human contact. For example, effluent used for landscaping purposes in a residential area or schoolyard must be virtually padiogen free, as does effluent used to irrigate food crops eaten said Herman Bouwer, who coauthored the report. So far, no groundwater problems associated witii effluent irrigation have been observed. In some cases, reclaimed water can even be of higher quality than actual stream water, noted Bob Bastian, a senior EPA scientist. "Compared to water from the Colorado River, reclaimed water
California and Florida have wholeheartedly embraced the practice of irrigating crops and public areas with treated municipal wastewater as a way of extending and conserving available water supplies. (Courtesy USDA Agricultural Research Service)
might be better because it tends to have far lower levels of salts, boron, and other things that could eventually lead to problems with long-term irrigation well before the effluent would," Bastian said. Areas in Nebraska and further west, which have not irrigated witii wastewater effluent, are finding elevated levels of nitrate and certain pesticides in their groundwater as a result of normal agricul-
tural practices, he added. And in many ways, the benefits of using wastewater to irrigate outweigh the potential risks, at least for now. California's Irvine Ranch Water District (IRWD), a municipal water utility, has reduced its water supply demands by 20% using recycled water, said Ron Young, IRWD's general manager. All of the recycled water the IRWD uses is applied at rates that allow it to be used up in the upper soil mantie or evaporated, Young said, keeping the water from infiltrating to lower groundwater depths hundreds of feet underground. Likewise, heavy metals and organics tend to get tied up in the soil where they absorbed and subsequently degraded or held for a certain period of time Testing for excess salt content, microbe constituents, heavy metals, and other elements that tend to bioaccumulate in soil, leaves, and turf has shown no measurable buildup or change from normal levels, Young said. "We've also tested in areas where we irrigate with drinking water and compared the results to areas where we irrigate with reclaimed water and haven't found any differences." Almost all proponents of wastewater reuse agree, however, that more monitoring must be done to ensure groundwater viability in the coming decades. —KRIS CHRISTEN
OCT. 1, 1998 / ENVIRONMENTAL SCIENCE & TECHNOLOGY / NEWS • 4 4 7 A
