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St. Croix SWCDA - Towns of Hudson and Warren

Special Well Casing Depth Area

Many drinking water wells in the towns of Warren and Hudson, situated in St. Croix County, are contaminated with trichloroethylene (TCE), a volatile organic compound (VOC). A Special Well Casing Depth Area (St. Croix SWCDA - Towns of Hudson and Warren) was established in July 1991 to protect residents from exposure to the contaminated water. New drinking water wells constructed in the area must be drilled below the contaminated aquifer and include certain well construction methods that prevent the contamination from entering the well. The DNR reviews variance requests to well construction requirements within the SWCDA on a case-by-case basis.

The DNR will engage with interested stakeholders, including elected officials, well drillers, property owners and developers as it navigates the path forward.

SUBSCRIBE to updates about the SWCDA and private well contamination in the towns of Hudson and Warren.

SUBMIT a question, comment or concern about the SWCDA or private well contamination in the towns of Hudson and Warren.

Public Meetings

Upcoming Meetings

None currently scheduled.

Past Meetings

Public MeetingDateTimeLocationInformation
Informational Meeting #2Wed., March 8, 20235:30 p.m.This meeting was held in person at Hudson High School and was also held remotely via Zoom
Informational Meeting #1Wed., Oct. 27, 20216-7:30 p.m.This meeting was held remotely via Zoom

St. Croix SWCDA Background

Maps

Map of the original extent of the St. Croix Special Well Casing Depth Area

Map of the current extent of the St. Croix Special Well Casing Depth Area

Interactive map for well drillers to check special casing depth area requirements

Source of Contamination

Comingled plumes of contamination from three sites caused drinking water wells in the towns of Warren and Hudson (St. Croix County) to become contaminated with trichloroethylene (TCE). The sites are:

  • Junkers Landfill (02-56-000088) - The Junkers Landfill TCE plume is situated in the central portion of the SWCDA. Parties responsible for the cleanup (the Junker Landfill Remediation Trust (LRT) entered into a consent decree with the state of Wisconsin in 1997. The consent decree established funding for 25 years, which ceased at the end of 2022. The DNR has been overseeing investigation and mitigation activities at this site since 1984.
  • Nor-Lake (02-56-000089) - Nor-Lake Inc. is the responsible party for the TCE plume that exists on the western end of the SWCDA. The DNR began overseeing the site investigation and cleanup at this facility in 1984; the case was closed in 2023.
  • Town of Warren TCE (02-56-373815) - The town of Warren TCE plume is situated on the eastern end of the SWCDA; the responsible party is unknown. The DNR has been overseeing investigation and cleanup of this area since 1999.

The groundwater plume encompasses approximately six square miles (4,000 acres). Approximately 600 private drinking water wells are located within this area; 121 of the private drinking water wells currently or historically have contained TCE above the current groundwater enforcement standard established in ch. NR 140, Wis. Adm. Code.

Trichloroethylene (TCE)

The contaminant of concern in the SWCDA is trichloroethylene (TCE). TCE is a solvent often used in industrial processes and may also be discharged to the environment from unintentional releases or improper disposal of industrial wastes at landfills. TCE can migrate through soil and groundwater. People who drink water from wells near TCE discharge sites may be exposed. Additional information regarding the health risks associated with TCE are available on the Wisconsin Department of Health Services website.

Ch. NR 140, Wis. Adm. Code contains groundwater standards for TCE, including an enforcement standard (ES) of 5 µg/L (micrograms per liter) and a preventive action limit (PAL) of 0.5 µg/L. In 2019, the Wisconsin Department of Health Services (DHS) reviewed the existing groundwater standards for TCE. Based on recent scientific information from the U.S. Environmental Protection Agency (EPA) on the health impacts of TCE, DHS recommended a TCE of 0.5 µg/L and a PAL of 0.05 µg/L; the DHS recommendation has not yet been adopted in Wisconsin Administrative Code. Additional information regarding the DHS recommended ES and PAL may be found on the DHS Groundwater Standard Recommendations webpage.

Cleanup Funding Affecting Costs In Junkers Landfill Portion of SWCDA

Funding for the Junkers Landfill portion of the SWCDA, established under consent decrees in the 1990s, ceased at the end of 2022. This resulted in two financial impacts to stakeholders:

  • Well construction costs increased significantly. The DNR previously issued variances for well construction under s. NR 812.43, Wis. Adm. Code, knowing that the Junkers Landfill RP group would pay for installation and maintenance of Point of Entry Treatment (POET) systems for wells within the Junkers Landfill area of the plume. Due to the ending of funding for the Granular Activated Carbon (GAC) filtration systems, the DNR is no longer able to issue variances that rely on this funding for new well construction. The DNR will continue to evaluate variance applications for new wells on a case-by-case basis.
  • Well owners within the Junkers Landfill portion of the SWCDA wanting to maintain existing filtration systems are financially responsible for ongoing maintenance and water sampling requirements. Costs to sample well water and maintain filtration systems within the Junkers Landfill area of the plume were previously covered by the Junkers Landfill RP group, the Junker Landfill Remediation Trust (LRT). Homeowners may choose to keep the filtration system, or have the system removed at the expense of the LRT.

Information For Homeowners

SWCDA Well Requirements

New drinking water wells constructed in the SWCDA must be drilled below the contaminated aquifer and include certain well construction methods that prevent contaminated groundwater from entering the well.

To determine if the proposed well is located within the SWCDA, check to see if the proposed location is within the current SWCDA boundaries.

My Property Is In The SWCDA - What Does This Mean For Me?

  • If your well was constructed after 1991, your property and existing well should have been granted a variance to the SWCDA well construction requirements. All variances include conditions of which well owners must be aware.
    • To determine the age of your well and other well construction information, utilize the online Well Records Search.
    • To determine if a variance was recorded for your property and obtain a copy, contact the St. Croix County Register of Deeds at 715-386-4652.
  • If your property was added to the SWCDA in July 2021 and your well was drilled before July 2021, your well does not have a variance to the SWCDA requirements and there are no continuing obligations for your existing well. More information about existing water test results from your well or sampling your well is provided below.
  • If you will be constructing a new well on property within the SWCDA, the well should be constructed to the SWCDA requirements as detailed in “Information for Well Drillers - SWCDA Well Requirements” below.

How Can I Find Out If My Well Has Been Tested?

Your well may have been tested for trichloroethylene (TCE) in the past. To request previous testing information from the DNR, send an email to DNRStCroixSWCDA@wisconsin.gov with your property address.

Should I Get My Well Water Tested?

If your well is located within the SWCDA and was not tested for TCE within the last several years, you may choose to test your well water. You can request a drinking water sample kit for volatile organic chemicals (VOCs) using the Safe Drinking Water Act (SDWA) method 524.2 which will include TCE from any of the following Wisconsin accredited laboratories. The cost of sampling private wells is the obligation of the homeowner.

Lab nameCity, StatePhone
CT LaboratoriesBaraboo, WI608-356-2760
Davy LaboratoriesLa Crosse, WI608-782-3130
Eau Claire City-County Health DepartmentEau Claire, WI715-839-4734
National Testing Laboratories, Inc.Ypsilanti, MI734-483-8333
Northern Lake Service Inc.Crandon, WI715-478-2777
Pace Analytical Services, LLCMinneapolis, MN612-607-1700
Pace Analytical Services, LLCOrmond Beach, FL386-672-5668
Suburban Laboratories, Inc.Geneva, IL708-544-3260
Wisconsin State Laboratory of HygieneMadison, WI608-224-6203

Read the Wisconsin State Laboratory of Hygiene (WSLH) instructions for collecting a sample. The cost for a drinking water sample kit for volatile organic chemicals (VOCs) using method 524.2 from the WSLH is approximately $180.

Treatment System Maintenance

Costs to sample well water and maintain granular activated carbon (GAC) filtration systems within the Junkers Landfill area of the plume were covered by the Junkers Landfill RP group through 2022. Starting in September 2023, well owners within the Junkers Landfill portion of the SWCDA who want to maintain existing filtration systems are financially responsible for ongoing maintenance and water sampling requirements.

The annual cost of maintaining an existing filtration system can vary from approximately $337 to $1,000 or more depending on the necessary change out frequency of the filters which is a direct result of how much water your household uses. Some filters may only need to be changed every other year, while others will require annual or semiannual change outs. Each filter costs approximately $337 to $585 per change out. Each filtration system has two filters per home with the first filter being changed out while the second is moved to the first position and a new filter is installed in the second or "polish position."

Real Estate Transfers

Prior to selling a property with contamination, you may be required to make a real estate condition report disclosure under ch. 709, Wis. Stats. Additional information about contamination and real estate is available in Environmental Contamination & Your Real Estate.

Information for Well Drillers

SWCDA Well Requirements

New drinking water wells constructed in the SWCDA must be drilled below the contaminated aquifer and include certain well construction methods that prevent contaminated groundwater from entering the well.

To determine if the proposed well is located within the SWCDA, check to see if the proposed location is within the SWCDA boundaries in the Well Driller Viewer.

If the proposed well is located within the SWCDA:

  • A much deeper well is needed (compared to wells located outside of the SWCDA).
  • Construction of the well needs to include enough steel casing and neat cement grout to ensure the upper contaminated aquifer is sealed off from entering the new well and the lower aquifer.
  • Water samples must be collected and tested for volatile organic compounds (VOCs), including TCE, after the well is constructed and annually until it is determined that sampling is no longer needed.

Read additional information on well construction requirements for the SWCDA.

Variance Requests

The DNR will continue to evaluate variance applications for new wells on a case-by-case basis. To request a variance for a new well, submit a detailed and complete Application for Variance (Form 3300-210) to Private Water Supply Specialist John Bowen at john.bowen@wisconsin.gov.

Health Information and Resources

The Wisconsin Department of Health Services (DHS) is supporting the DNR by assessing human health risks associated with the TCE contamination in the St. Croix SWCDA - towns of Hudson and Warren, including recommendations to reduce those risks.

For health-related questions, please email DHS at DHSEnvHealth@dhs.wisconsin.gov.

Learn more about the health effects of various TCE on the following websites.