Yet, without a practical method to quantify nonpoint impacts and estimate the potential water quality impact of management practices, municipalities face serious obstacles to effective control of nonpoint pollution. The level of control needed is difficult to identify. Local officials must be convinced that nonpoint inputs are affecting or have the potential to seriously impair valuable water resources before adopting more stringent controls. The effectiveness of nonpoint management practices is not well understood. Local officials need information on the relative benefits of management options to select appropriate controls, to generate public support for adoption of controls, and to establish defensible land use regulations.
Tight budgets limit local capability to adopt, monitor and maintain nonpoint management practices.
When the price tag for sewers or stormwater improvements is high, municipalities are likely to gain public support for new pollution control projects only when the cost of inaction exceeds the control cost. It has been developed specifically for use in Rhode Island and the New England region to assess the effects of current land use, future development alternatives, and pollution management practices on valuable water resources. Calculate nitrogen and phosphorus loading to surface waters, and nitrogen loading to groundwater under present land use. Compare the change in pollution potential and nutrient loading with build-out under present zoning or other development scenario. Compare nutrient inputs with critical freshwater eutrophication levels and drinking water quality standards.