The tools consisted of models for simulating groundwater flow, groundwater movement, and nitrate loading. These tools were used to map recharge areas for wellfields, calculate nitrate loadings to groundwater, and estimate future nitrate concentrations. Several groundwater quantity and quality challenges were revealed. Groundwater pumping is reducing streamflows in the Plover and Little Plover Rivers. Since the Plover is a larger stream, it might be able to sustain this impact without losing its value for recreation and wildlife.
Additional work needs to be done to quantify stream impacts from groundwater withdrawals.
Nitrate concentrations have been rising in the recharge area for over 30 years. The tools developed in this study were used to estimate what nitrate levels will eventually be reached in individual municipal recharge areas under current land uses and management practices. The tools predict that nitrate concentrations will continue to increase. Most of the nitrate is from agriculture. Even eliminating all nonagricultural nitrate loading to groundwater in general makes only a small improvement in groundwater quality.