Groundwater Quality

• What is a Groundwater Plan?

  A groundwater plan identifies the condition of groundwater resources, concerns and considerations for future management of groundwater quality and quantity, and strategies that should be pursued for future management.

• Why do we need a Groundwater Plan?

  Groundwater is the major source of all water consumed in Marathon County. Understanding the condition and quantity of our groundwater resources, and identifying concerns and strategies to address those concerns, is critical to maintaining quality of life and economic well-being for all of Marathon County. Most, if not all, counties in our region of the state are attempting to understand the same things and for many of the same reasons.

• Who is overseeing the Groundwater Plan Update?

  The Groundwater Plan Update is a collaborative effort. While staff at the Marathon County Conservation, Planning, and Zoning and Health Department will oversee testing and planning efforts, a Marathon County Groundwater Workgroup will also provide guidance to the update process.

  This group includes regional partners, technical advisors, and major stakeholders. The goals of this group are to provide a dynamic framework to the plan that can adjust over time, to gather input from all stakeholders, to support the efforts necessary to achieve the plan’s objectives, and to create a collaborative atmosphere. A collaborative approach (a “aqua-shed coalition”) is required to effectively define and address our groundwater concerns in the county because no one organization or group has the level of expertise to accomplish this work on its own.

• What is included in the Groundwater Plan Update?

  • Sample collection and testing of up to 1,000 private wells.
  • Gathering of existing data from municipal water sources.
  • Collaborating with the Wisconsin DNR on additional sampling.
  • Community outreach and engagement to identify groundwater concerns, strategies for protecting it, and policies that may be considered.
  • Development of actions and strategies the region and stakeholders should pursue to protect groundwater into the future.

• How is the Groundwater Plan Update being funded?

  As of May 2023, the Marathon County Board has contributed $275,000 from Environmental Impact Funds to support this update. Marathon County is also working with state and local partners to collaborate on certain efforts via in-kind services.

• How will well sampling locations be determined?

  Marathon County is working with the University of Wisconsin-Stevens Point Water and Environmental Analysis Lab (WEAL) and the Health Department to develop a sampling approach, distribute bottles, and conduct testing. Wells will be selected from those that have been assigned a Wisconsin Unique Well Number and locatable well construction information (i.e. well depth, casing depth, static water level). Selection criteria will include spatial, geologic, and land-use characteristics to ensure that wells are representative of the diversity of factors in the county that might influence well water quality. Initially a grid sampling approach will be used to ensure sampling is spatially and geologically distributed across the county. Using GIS data and mapping, Marathon County will identify and reach out to landowners within each grid to obtain samples within each area.

• What will well sampling test for?

  At minimum, all samples would be tested for nitrates,  dissolved minerals, atrazine and possibly select forms of bacteria. Further, sampling for atrazine in our atrazine prohibition areas will be conducted.

• Will wells be tested for PFAS?

  Per and polyfluoroalkyl substances (known as PFAs) are not being tested for in this groundwater plan update. Currently, the ability to test private wells for PFAs on a broad scale remains cost prohibitive.

  If you are interested in testing a well for PFAs, Northern Lakes Laboratories (715-478-2777) and the Wisconsin State Lab of Hygiene (608-224-6203) are resources to obtain kits and more specific analysis costs.

• Will sampling for this effort be mandatory?

  No, all testing will be voluntary and only conducted with the landowner’s consent. Landowner eligibility will be based on the sampling approach, but if they do not wish to participate in the study by testing their well, they will not be required to do so.

• Who will do the testing?

  The University of Wisconsin-Stevens Point Water and Environmental Analysis Lab (WEAL) and the Marathon County Health Department will be responsible for processing the well water tests. The testing is being funded by Marathon County. Wisconsin Department of Natural Resources will also assist with testing in atrazine prohibition areas.

• How will my data from well testing be used?

  Marathon County will only be summarizing well data trends at a county or regional level. Landowners who opt to have their well tested will need to sign an agreement acknowledging  their data will be summarized within the plan, but individual data records are subject to Wisconsin public records law requests.

• If I don't want my well tested through the Groundwater Study, what other options are available?

  The Marathon County Health Department is State certified to conduct testing for nitrates and coliform/E. coli bacteria.  A listing of other Labs certified in bacterial and chemical testing may be found at https://dnr.wisconsin.gov/topic/DrinkingWater/laboratories.html

• What if my well was not selected for testing, and I want it tested?

  Initially, those who wish to volunteer their well for sampling  will be added to a waitlist and may be selected for sampling in either the 2023 or 2024 sampling rounds.  If you are not selected, or do not want to wait for selection, there are other options to have your well tested:

  • AgSource – 715-898-1402
  • Marathon County Health Department Laboratory – 715-261-1908
  • U.S.Water, LLC – 715-842-2215
  • UW Stevens Point WEAL – 715-346-4490

  A full listing of other Labs certified in bacterial and chemical testing may be found at: https://dnr.wisconsin.gov/topic/DrinkingWater/laboratories.html

  Wisconsin State Lab of Hygiene offers additional water testing information and locations for testing: https://www.slh.wisc.edu/environmental/water/

• What happens if a landowner gets test results indicating there is a problem with their water?

  Marathon County staff and Groundwater Workgroup members would work with landowners to connect them with resources from state and federal programs (this might be  funding and/or technical assistance) to treat or repair their wells. Currently, there are a few programs available to landowners to mitigate or repair well water issues, but first they need the well testing data to identify if an issue exists. All funding must be applied for by the landowner. The awarding of funding is subject to eligibility requirements of individual programs.

• Why should I have my well tested?

  The CDC recommends checking the mechanical status of a well¹ every spring and testing the water at least annually.  The DNR recommends testing be performed if there is a change in appearance, odor, or taste of your water. According to the National Groundwater Association, testing should be done more frequently under special circumstances, such as a newborn living in the household or family members being diagnosed with certain gastrointestinal illnesses. Owners should also consider potential environmental factors, such as nearby septic system failures or fertilizer applications when evaluating the frequency of testing their water.

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  ¹ Mechanical status means, checking the well visually to make sure the "well cap is tight on the well casing, the well conduit is seated firmly in the cap, and the well casing does not show damage. Additional information on well construction can be found at: https://www3.uwsp.edu/cnr-ap/watershed/Documents/wiwellwater101_ver2.pdf.

   

• How do contaminants get in my water?

  Naturally occurring minerals and chemicals, such as arsenic and uranium, can contaminate groundwater, according to the EPA. In agricultural areas, groundwater can become contaminated by livestock and feeding operations, as well as by the application of fertilizers, pesticides, and biosolids from municipal or industrial waste treatment facilities. In industrial and urban areas, volatile organic compounds (VOCs) such as gasoline or solvents, may seep into groundwater. Sewer overflows and malfunctioning water treatment systems can also release contaminants into groundwater.

• How do I get more information?

  We encourage interested stakeholders to reach out to Marathon County’s Conservation, Planning, & Zoning Department at 715-261-6046 or by emailing groundwater@co.marathon.wi.us.