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SCIENCE Wetlands regulations need overhaul, says NRC report A long-awaited report released May 9 by the National Research Council (NRC) concludes that current wetlands regulations are based on scientifically sound principles and that scientific principles should be used to identify and delineate wetlands. However, implementation of current regulations is chaotic and needs to be overhauled, the NRC Committee on Characterization of Wetlands found. "We don't believe the system is off course, arbitrary, or unscientific," says William Lewis, Jr., committee chair. "It doesn't need to be discarded. It needs to be selectively improved." The committee recommended that regulatory agencies use a single, revised manual and that one regulatory agency, rather than the current four federal agencies that share wetlands oversight, take the lead on regulations. It also recommended that wetlands be identified within the context of regional variations. Under current laws, wetlands are federally regulated by EPA, the U.S. Army Corps of Engineers, the U.S. Department of Agriculture's National Resources Conservation Service, and the U.S. Fish and Wildlife Service. These agencies primarily use a wetlands regulation manual developed in 1987 by the Corps of Engineers. Following two failed attempts to revise the 1987 manual—one in 1989 that was criticized for defining too much acreage as wetland, and one in 1991 led by former Vice-President Dan Quayle that was criticized for excluding many wetlands from protection—Congress requested that the NRC study the scientific basis for wetlands. After these revisions failed, says Lewis, many people who are not scientists began to wonder whether wetlands are something that can be identified objectively or whether they are a political construct. A bill recently passed by the House to reauthorize the Clean Water Act (H.R. 961) defines wetlands as land with water at the surface for 21 consecutive days during the "growing season," typi-
Regulators must account for complex relationships of water, soil, and vegetation in identifying wetlands, says a new National Research Council report.
cally the hottest and driest parts of the year. EPA strongly opposes the wetlands provisions of the bill. "This bill mixes the political and the scientific in an unfortunate way," says Lewis. "We don't think the 21-day boundary is a scientifically sound judgment." Under current regulations, wetlands are delineated in part according to a complicated system that determines the percentage of time during the growing season in which the root zone (12 in. below the surface) is inundated or saturated with water. Should the 21-day criterion be implemented, the committee believes a large number of wetlands would be excluded from regulation. The Association of State Wetlands Managers estimates the bill would exclude 60-80% of the nation's wetlands from regulatory protection. The NRC report states that regulators delineating wetlands must account for complex relationships among water, substrate (soil), and vegetation. "If a portion of the landscape has distinctive features of a physical, chemical, or biological nature that are directly explained by sustained, recurrent inundation or saturation near the surface, that is wetland," says Lewis. In addition, current practice emphasizes the existence of hydric soils in wetlands. "We want to be sure that the agencies ac-
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knowledge the existence of wetlands where hydric soils are absent," Lewis explains. This situation occurs in some regions under particular conditions. In addition, hydrophytic (water tolerant) vegetation is usually, but not always, present on wetlands. The report recommends that regulators adopt a hierarchy for evaluating the prevalence of hydrophytic vegetation as evidence of wetland status. Although the NRC committee believes that a single criterion for delineating wetlands oversimplifies the science involved, it did recommend as one identifying factor the use of a measurement over time of 14 consecutive days of water present at the crop root zone. The report also addressed socalled controversial wetlands, including permafrost wetlands. Although their conditions are different from those of wetlands in warmer climates, permafrost wetlands—which are prevalent in Alaska—should be identified as wetlands and not excluded from regulation, states the committee. Federal regulatory agencies are studying the report and have not yet issued a formal response. A source within the Corps of Engineers says the agencies are formulating an interagency response, which will be forwarded to a White House wetlands task force. —ELAINE L. APPLETON
