As the regional population grows, demand for groundwater will increase. Groundwater is a resource extending beyond municipal boundaries and therefore requires coordination among various partners. Municipalities working together to protect the quality and quantity of our water supply decreases risk of contamination, minimizes draw down, and averts stream baseflow reductions. Regional groundwater planning should incorporate wellhead and source protection efforts. Preventing contamination requires proper management of potential pollutants such as pesticides, herbicides, salt, and petroleum products. Maintaining groundwater quantities necessitates water conservation (reducing overall withdrawals) and stormwater management that promotes infiltration and recharge. This page describes programs in place to protect groundwater.

Photo Courtesy of: Madison Water Utility

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Statewide, there are multiple initiatives for maintaining  groundwater quality and quantity. Wisconsin has groundwater quality standards for a variety of substances. Various state agencies are responsible for ensuring that groundwater contaminant concentrations do not exceed these standards and cause violations. Periodically, the state reviews these concentrations and adds newly identified contaminants. PFAS are an example of currently unregulated substances that are being investigated for future additions to the list.

Multiple agencies carry out actions to meet regulations:

Department of Agriculture, Trade and Consumer Protection - nutrient management planningpetroleum product storage tankspesticide use and storage, fertilizer storageatrazine prohibition areas,  clean sweep, and agrichemical clean-up program and fund

Wisconsin Department of Health Services - enforcement standards

Wisconsin Department of Natural Resource - waste and materials management, industrial and municipal wastewater, wetlands, environmental cleanupdrinking water and groundwater

Public Service Commission - drinking water utilities

Department of Safety and Professional Services - private sewage systems, Wisconsin Fund

Department of Transportation - salt storage, annual winter maintenance report

Review a summary of state regulations here to see regulatory controls of groundwater pollution and withdrawals.


Statewide Coordination

Information Exchange

To ensure that groundwater standards are being met, Wisconsin must coordinate groundwater research and monitoring. The Groundwater Coordinating Council helps state agencies integrate non-regulatory programs and exchange groundwater information. This includes data management, research, and outreach, among other things.

Regional Management

The state also defines groundwater management areas (GMA) where there is significant draw down and coordinated management is especially needed. There are also groundwater attention areas (GAA) where management problems are emerging and, if current trends continue, are likely to become a GMA. Dane County is a GAA.

Water Supply Planning

Municipalities that supply water to more then 10,000 people are required to have an approved water supply service area plan by 2026. These plans help the region prepare for future water demand.

Groundwater Protection Areas are established around new public wells. These zones protect land expected to contribute to a well within five years (or at a minimum, a 1,200 ft radius around a well). Preventing contamination within these recharge areas reduces the risk to public water supplies. Wisconsin Department of Natural Resources coordinates Wellhead Protection and Source Water Protection programs. They also provide a list of funding sources to help municipalities and individuals offset the cost of water and wastewater projects.

The construction and operation of high capacity wells are also regulated by Wisconsin Department of Natural Resources. Permitting helps the state manage the location and quantity of large groundwater withdrawals.

Nutrient Management

Groundwater is also protected by managing the application of agricultural fertilizers and manure. Appropriate nutrient management on farms is one way to reduce the risk of groundwater contamination. UW Extension has developed nutrient application guidelines for Wisconsin crops (available in print or free as a PDF).  The Department of Agriculture, Trade and Consumer Protection (DATCP) also helps farmers meet nutrient management requirements. DATCP tracks the status of nutrient management plans across the state. In 2021, 35% of Dane County's cropland had nutrient management plans. Organizations can apply for grants to help teach farmers how to develop nutrient management plans. There is also a grant that directly supports producer-led watershed protection initiatives. Concentrated Animal Feeding Operations (CAFOs) require discharge permits for wastewater. The Wisconsin Department of Natural Resources issues permits and ensures that CAFOs comply with their nutrient management plans.

Local Initiatives


Dane County ordinance requires new development (both residential and nonresidential) to infiltrate 90% of the rainfall what would have infiltrated before development. Designing stormwater management practices to meet this requirement seeks to maintain similar groundwater recharge rates pre- and post-development. These standards help reduce the impact of increased impermeable areas. Individual municipalities may also have specific infiltration and recharge ordinances that serve to decrease stormwater runoff and replenish groundwater. Some municipal standards are more stringent than the county requirements.

Septic Systems

Public Health Madison and Dane County review and issue permits for septic systems. This oversight promotes proper design and maintenance of these systems, reducing the risk of groundwater contamination.


Public Health is also responsible for ensuring that private wells are located appropriately. Regular maintenance and testing of these wells is also important for confirming private wells remain uncontaminated. Annual testing for well contaminants is recommended. Additional testing is recommended if you observe a change in taste, color, or odor.

Municipal water utilities must annual send consumer confidence reports to their customers. You can generate a report for your water utility here.

Waste Disposal

Household hazardous materials and agricultural chemicals can be disposed through Dane County's Clean Sweep program. Properly disposing these products reduces contamination risks to groundwater.

Leftover and expired medications can be disposed through MedDrop. In addition to reducing the risk of overdose and poisoning, this secure disposal program keeps medication from contaminating surface and groundwater.

Salt Use

Salt used in winter de-icing and in water softening eventually reaches surface and groundwater. Wisconsin Salt Wise works with municipalities, private applicators, and residents to minimize salt use, reducing the amount of chloride reaching groundwater.

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On-Site Wastewater Treatment Systems

In 2013, CARPC published a report on Private On-Site Wastewater Treatment Systems Management. The systems, generally septic, serve about 11% of Dane County households. The primary concern regarding on-site wastewater systems is their effect on groundwater nitrate levels. Both agriculture and on-site wastewater treatment systems can contribute to these concentrations, but since wastewater systems are likely to be in close proximity to shallow private wells, they can pose a unique contamination threat to drinking water. Solutions include improving/replacing individual systems or providing centralized treatment, depending on scale.

On-site systems may fail because of inadequate design, unsuitable site conditions, or lack of proper maintenance. Current siting, design, construction, and maintenance standards, however, achieve minimal environmental impact compared to older systems, built under less stringent standards. A benefit of on-site systems is that they return groundwater to the source, whereas large wastewater treatment plants discharge to surface water. Current regulations and inspection programs generally ensure the level of maintenance and servicing of on-site systems necessary to reduce failures, continue proper functioning, and provide a long system life. Adequate technologies are available for on-site wastewater treatment systems to meet nitrate standards. These should be implemented to address nitrate pollution to groundwater.

Report Recommendations

  • Governmental units responsible for the regulation of private on-site wastewater treatment systems should continue to maintain a rigorous inspection and enforcement program
  • Local management and planning agencies should cooperate in investigating and developing cost-effective solutions for existing rural development experiencing on-site wastewater system problems and/or nitrate contamination issues
    Large on-site wastewater systems and clusters of systems should be planned and evaluated to ensure that wells and water supplies can be protected from excessive nitrate levels
  • Holding tanks should continue to be used for wastewater disposal only in instances when adequate servicing and pumping can be assured, and when suitable disposal methods (well-regulated land disposal sites or wastewater treatment plants) are specifically available for receiving the wastes
    Municipal wastewater treatment plants should include provisions for receiving and treating septage generated within a reasonable service area or distance
  • Explore innovative methods for improving waste disposal and groundwater quality through site design and new technologies
    Land application sites for septage should be carefully located and designed to avoid groundwater contamination and should not be located in areas of extreme groundwater contamination risk or well protection zones. Existing sites located in these area should be monitored and subjected to stringent design and operating requirements
  • Dane County and/or local units of government should assume responsibility for, or participate in, the approval and inspection of land spreading sites for the disposal of septage
  • Local units of government and Public Health Madison & Dane County should encourage all residents with private wells to have their water tested for nitrates, especially those with infants
  • State and local funding for on-site wastewater management and septage disposal programs should be increased to adequate levels

Land use activities affect drinking water quality, and these impacts should be adequately considered in siting decisions. Land uses that could pollute groundwater should be sited strategically away from wells and their recharge areas. Reducing groundwater draw down should also be promoted through recharge and water conservation. By decreasing per capita use and safely handling potential contaminants, we can each do our part to protect Dane County's groundwater resources.