The Dane County Regional Hydrologic Study

Conceptualized groundwater flow system for Dane County Source: Bradbury and others, 1999.

Recommendations : Alternative pumping strategies Maximizing infiltration Water conservation Analyzing impacts of proposed wells on sensitive resource areas Innovative measures (e.g., treating wastewater as a resource)

Primary Groundwater Quality Problems in Dane County Nitrates and Bacteria Pesticides Volatile Organic Compounds (VOCs)

Zones of Contribution Dane County Proposed 2020 Pumping Rates

Naturally Vulnerable Areas  Locate pollution sources outside these areas  Require special conditions or controls Potential Problem Areas  Existing pollution source areas which threaten drinking water supplies

Elevated Nitrate Levels: Over-fertilization (in excess of crop uptake) Manure Storage Failing Septic Systems Clusters of On-Site Systems (rural subdivisions)

Agriculture: Improved design/construction of manure storage facilities Proper abandonment of manure storage pits Nutrient management planning (to reduce over-fertilization)

Residential On-Site Systems: Triennial inspection and maintenance Evaluate the impact of clusters of on-site systems (rural subdivisions) Replace failing systems Information and Education

Pesticides: Increased monitoring - especially extreme risk areas Promote alternatives to pesticides - such as Integrated Pest Management

Landfills: More monitoring of closed landfills (esp. extreme risk areas and well protection zones) Locate future sites outside these areas Continued support of recycling, waste- reduction and hazardous waste programs

Above Ground Storage Tanks Less of a problem However, information gaps for fuel/chemical tanks (<1,000 gals.) Greater emphasis on proper storage of fuel, pesticides and fertilizers is needed

Land Application of Septage: County oversight/responsibility for approval of land spreading sites Sites should be carefully designed and located outside extreme risk areas and well protection zones More authorized discharge points at municipal treatment plants

Summary: All Significant Land Use and Siting Decisions Should Include an Evaluation of the Potential Groundwater and Hydrologic Impacts:  Locate pollution sources away from high/extreme risk areas  Locate wells where they will be adequately protected  Pursue various management programs to reduce the risk of contaminating drinking water supplies