The extensive and widespread use of pesticides in the United States over the past several decades has resulted in their frequent detection in groundwater. More than 50 percent of the U.S. population gets its drinking water from groundwater. Current estimates indicate that, on the basis of active ingredient, 970 million pounds of conventional pesticides (i.e., herbicides/plant growth regulators; insecticides/miticides; fungicides; fumigants/nematicides) are used in the United States in a typical year. More than half of this total comes from agricultural application of herbicides and insecticides (e.g., 551 million pounds in 1995). Although groundwater contamination by pesticides is largely attributed to nonpoint sources, a number of studies that have evaluated pesticide contamination of soil and groundwater at pesticide mixing/loading sites indicate that these sites also are significant "point" sources of groundwater contamination. Although the highest pesticide residue levels at mixing/loading sites have been detected in soils where acute spills have occurred, contamination at these sites, most of which are located on the 1.4 million farms that have been estimated to use pesticides, has been shown to be chronic rather than episodic. This indicates that pesticide spillage at mixing/loading sites is an ongoing problem that requires an inexpensive, easily implemented solution that pesticide users can afford and be encouraged to use. The installation of well-designed, chemical mixing centers (CMCs), that include a roofed structure over a concrete pad with associated pumps and tanks, has been proposed to prevent soil and groundwater contamination associated with improper mixing/loading of pesticides. However, most farm families do not possess the financial resources to construct one of these $20,000 to $40,000 facilities. Biobeds represent a cost-effective (approximately $2,500 to $3,000 for installation) alternative to CMCs that are simple in design, easy and inexpensive to maintain, employ inexpensive materials that are readily available to farmers, and are based on the microbial degradation of pesticides. A biobed is a rectangular excavation, larger in area by at least 0.5 m on any side than the mixing equipment and about 60 cm deep. The bed is lined on the bottom with clay or a synthetic material to prevent leaching of pesticides to the underlying soil, filled with a combination of top soil/peat and a lignocellulosic substrate that promotes microbial activity, and covered with a layer of grass to prevent moisture loss. EarthFax proposes, in Phase I, to conduct a laboratory-scale evaluation of pesticide containment and degrading performance of biobeds toward several commonly used U.S. agricultural herbicides. This information will be used in the design of a field-scale technical and economic evaluation of biobeds during Phase II. Supplemental
Keywords: small business, SBIR, pollution prevention, pesticides, agriculture, engineering, nonpoint sources, EPA. , Ecosystem Protection/Environmental Exposure & Risk, RFA, Scientific Discipline, Sustainable Industry/Business, Toxics, Waste, Agricultural Engineering, Agronomy, Analytical Chemistry, Chemical Engineering, Chemical Mixtures - Environmental Exposure & Risk, Chemistry, Chemistry and Materials Science, Ecological Effects - Environmental Exposure & Risk, Ecological Effects - Human Health, Ecological Indicators, Ecosystem Protection, Ecosystem/Assessment/Indicators, Engineering, Environmental Chemistry, Environmental Engineering, chemical mixtures, cleaner production/pollution prevention, exploratory research environmental biology, pesticides, agricultural chemical application, agricultural environments, agricultural mixing/loading , agriculture, agrochemcial, biobeds, pesticide exposure
