Contamination in Ontario farmstead domestic wells and its association with agriculture: 3. Results from multilevel monitoring Well installations

摘要

Mltilevel monitoring wells(MLWs)were installed at 144 farms which were part of a province-wide survey of farm drinking water wells conducted in 1991-1992 in Ontario, Canada. The multilevel sites were selected in areas characterized by coarse-textured soils, on farms Typifying local agricultural enterprises. The MLWs were installed in cultivated fields adjacent to The location of the drinking water wells on each farm(within 200 m). On 16 of these farms, MLWs were also installed in a woodlot adjacent to the field site. Water samples were collected on Two occasions(winter and summer)and analyses were conducted for nitrate(NP~-_3), typical Bacteria and a selected suite of common pesticides.