A previous statewide survey showed that 14% of rural wells in Iowa contained detectable concentrations of pesticides.
To determine if improved private well construction regulations should be included in Iowa's State Pesticide Management Plan, a two-year study was undertaken to determine : the effects of well construction on pesticide, nitrate-nitrogen, and bacterial contamination of wells ; and the possible role of point sources of contamination.
Eighty-eight rural water supply wells in nine Iowa counties were sampled daily for five weeks during late spring and summer of 1993, and 20% of these were resampled in 1994.
Short-term variation in nitrate-nitrogen concentrations was examined as a possible indicator of rapid inflow of shallow groundwater associated with well construction defects.
Mean total coliform bacteria, nitrate-nitrogen, chloride, atrazine, alachlor, and metolachlor concentrations were statistically analyzed to determine if they were correlated, and t-tests also were used to determine if these water quality parameters were affected significantly by physical well parameters such as depth, type of casing, grouting, location within frost pits, and proximity to various potential sources of contamination. (...)
Mots-clés Pascal : Caractéristique construction, Contamination biologique, Contamination chimique, Distribution concentration, Qualité eau, Secteur privé, Source ponctuelle, Variation court terme, Puits eau, Zone rurale, Bactérie, Coliforme, Alachlor, Atrazine, Azote, Chlorure, Eau souterraine, Nitrate, Iowa, Etats Unis, Amérique du Nord, Amérique, Etude statistique, Etude sur terrain, Approvisionnement eau, Environnement, Gestion ressource eau, Pollution eau, Amide organique, Anion minéral, Herbicide, Pesticide, Polluant, Produit agrochimique, Triazine dérivé, Metolachlor, CONSTRUCTION DE PUITS
Mots-clés Pascal anglais : Construction parameter, Biological contamination, Chemical contamination, Concentration distribution, Water quality, Private sector, Point source, Short term variation, Water well, Rural area, Bacteria, Coliforms, Alachlor, Atrazine, Nitrogen, Chlorides, Ground water, Nitrates, Iowa, United States, North America, America, Statistical study, Field study, Water supply, Environment, Water resource management, Water pollution, Organic amide, Inorganic anion, Herbicide, Pesticides, Pollutant, Agricultural chemical product, Triazine derivatives, WELL CONSTRUCTION
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 97-0390649
Code Inist : 001D16A04B. Création : 12/09/1997.