People tend to associate herbicides and pesticides with agriculture, and indeed these compounds are important pollutants in rural areas. Since each kit is specific for one individual compound, it's essential to know which is likely to be present in the sample. Information on which herbicides and pesticides may have been used in a particular watershed should be available from state or county natural resource or agricultural agencies. They are mainly useful for testing soil and sediment, since water concentrations of PCBs are generally too low to be detected by the kits. Although PCBs have been banned since 1976, they still persist in the environment and are important pollutants because of their toxicity and carcinogenicity.
Kit suppliers are generally quite cooperative about supplying literature, advice, and even training.
The Volunteer Monitor is aware of only one volunteer monitoring group that has used EIA kits. Friends of the North Fork Shenandoah River, in Virginia, used Ohmicron kits to test 24 wells for two herbicides, metolachlor and atrazine. They found that 22 wells had detectable levels of at least one of the herbicides.