What types of pollutants are at issue?
Pollutants of concern vary from watershed to watershed. In much of rural Idaho, water quality concerns center around excess sedimentation, elevated temperatures and nutrient overloading. In developed areas, concerns may focus on fecal coliform, oil and grease or dissolved oxygen. In industrial areas, heavy metals such as lead, zinc and copper or organic chemicals such as benzene, napthelene or chloroform may be at the top of the list. In general, watersheds are subject to two broad categories of pollution: Point Source and Non-point Source. Point Source Pollution is typically associated with industrial discharges, municipal waste treatment facilities and animal feedlots. The effects can be directly traced to a particular source or facility. Point source pollution can often be measured at an outfall or pipe. Non-point Pollution, on the other hand, is more difficult to identify. It includes, among other things, the cumulative effects of fertilizers and pesticides that farmers and homeown
