A nitrate groundwater standard for the 1990 farm bill

Abstract

Overuse of fertilizer and/or animal wastes has been cited as the reason for elevated nitrate concentrations in groundwater in agricultural areas. In coastal plain regions of the United States and in other areas where farming practices are conducted over aquifers in unconsolidated sediments, nitrate contamination may occur primarily as a result of climactic abnormalities even when the nutrients are used according to recommended practices. Water quality standards are often cited as a way to protect to protect groundwater quality. Research suggests that current best management practices are not capable of allowing producers in coastal plain regions to always comply with a nitrate standard for groundwater of 10mg/l of nitrate. Research indicates that some agricultural activities may affect the quality of groundwater in rural areas (7, 16). Groundwater quality is but one aspect of the public's heightened interest in environmental issues. The public now is demanding that agriculture be accountable for its effects of the environment, just as other industries have been held accountable (3, 6). Thus, water quality components likely will be included in 1990 farm legislation, and nitrogen (N) management will be a probable target (4). Water quality goals or standards are among the options available to policymakers for inclusion in the 1990 farm bill, despite the difficulties (12) that might be encountered in their application. The national health standard for nitrate in public drinking water, 10mg/l of nitrate nitrogen (NO3-N) is a reference gauge against which to compare groundwater and surface water quality. This standard would be among those most likely to be included in water quality components of new national legislation. The four studies reported here illustrate that a 10mg/l limit for NO3-N in groundwater beneath some agricultural systems probably cannot be met consistently using currently accepted farming practices.