Thursday, December 7, 2017 - 9:24am

Madison Water Utility will be drilling two small monitoring wells in Spring Harbor Park (5218 Lake Mendota Dr.) today as part of our efforts to understand and potentially mitigate road salt infiltration at nearby municipal Well #14. Media is invited to the site between 10:30 and 11:30. 

It appears that a major storm sewer outlet could be impacting water quality at the well. The storm sewer collects and carries runoff from as far away as West Towne Mall and empties into Lake Mendota across the street from the park, about .3 miles from Well 14 (see attached map). In the winter and spring months, the storm water likely carries large amounts of chloride from road salt.

We are hoping the test wells will show us how much chloride, if any, is being pulled from the storm water outlet area toward the well through groundwater. When Well 14 is in operation, it pumps about 2,000 gallons of groundwater every minute. Once the monitoring wells are in place, we will begin collecting groundwater samples on a monthly basis and testing for chloride.

Madison Water Utility would like to thank the Spring Harbor Neighborhood, City of Madison Parks Division and the Parks Commission for allowing us to install the temporary wells in Spring Harbor Park.


  • Well 14 on University Ave. and Flambeau Rd. pumps 750 million gallons of water a year to homes and businesses along the University Avenue corridor.
  • The well’s water has been showing increasing amounts of sodium and chloride, the chemicals that make up salt.
  • While it’s not a health threat for most people, road salt in the water can have a big impact on taste.
  • Madison Water Utility expects that levels will surpass the EPA-recommended threshold for taste in the next 12 to 15 years.
  • In 2018, Madison Water Utility will spend $125,000 studying ways to mitigate road salt infiltration at Well 14. Options include costly wellhead treatment, well reconstruction, or abandoning the facility entirely. It could be ten years before a solution is in place.
  • Road salt is a city-wide environmental issue, impacting the health of our lakes, streams and groundwater.
  • In October, the city launched the state’s first Winter Salt Certification Program, open to all in Dane County. The program teaches snow removal contractors how to reduce salt use on parking lots, sidewalks, driveways and roads while maintaining safety.
  • Salt spread on parking lots and sidewalks alone makes up about half of the total winter salt use in the city.


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