Water utilities need to assess which potential waste sources may have the greatest potential adverse impact on source water quality, and prioritize protection activities and measures for action in their source water area. Assessment and consideration for prioritization should include all potential waste sources, not just those from the agricultural sector or CAFO facilities alone. For the agricultural sector, water utilities should be concerned not just about AFOs and CAFOs, but about poorly managed farms of any type. Periodic reassessment of the action priorities and the success of approaches taken will help ensure the program is achieving the optimal benefits.
All source waters should have had a Source Water Assessment Program (SWAP) report prepared under requirements of the 1996 SDWA. If a water utility is concerned that the SWAP for their source water was not thorough enough in identifying potential contaminant sources and prioritizing their potential impact, then they are encouraged to conduct additional study and monitoring. Advanced studies use hydraulic and contaminant transport modeling of watersheds or groundwater to more fully potential impacts from priority contaminant sources. Modeling can also be used to assess the anticipated general effect of possible BMPs and to prioritize actions. Many utilities have conducted this type of thorough analyses of the potential impact of the actual and potential priority pollution sources in their source water area (e.g., Tulsa, Oklahoma and Philadelphia,
A sound source water assessment that analyzes the relative contributions of potential pollutant sources in a source water area can go a long way toward providing the scientific evidence necessary to effectuate change in land use practices. Utilities can help themselves by bringing in the right experts and expertise to perform sound scientific assessments. Data and sound science showing agricultural impacts on source water quality should be locally and regionally based in order to be more convincing to local and regional agricultural interests.