Marathon County Expands Septic System & Holding Tank Maintenance Requirements to Protect Local Groundwaters

Written by Dale Dimond

The Marathon County Conservation, Planning, and Zoning (CPZ) Department has started the process of adding nearly 7,000 Private Onsite Wastewater Treatment Systems (commonly called “POWTS” or “septic systems”) to its POWTS Maintenance Program. State regulations now require counties to include all septic systems and holding tanks — regardless of age — in the POWTS Maintenance Program. The program currently includes over 14,000 systems installed after July 1, 1980. The 7,000 additions include systems installed before July 1, 1980.


Expanded POWTS Maintenance Program to Improve Groundwater Quality

The expanded maintenance program aims to protect public health and natural resources by reducing the number of holding tank and septic tank systems discharging sewage to the surface of the ground. The maintenance program requires property owners to either have their holding tank pumped when full or have their septic tank system maintained at least once every 3 years, depending which type of POWTS they have. Maintenance includes having a plumber, pumper, or other licensed professional:

  • Visually inspect the condition of the tank (including locks on exposed covers)
  • Check for discharge of sewage onto the ground surface
  • Pump the tank (if necessary)
  • Submit an online report to the CPZ Department

This increase in who must perform routine POWTS maintenance is an important step in meeting Objective 6.3 of the 2018–2022 Marathon County Strategic Plan: “Protect and enhance the quantity and quality of potable groundwater and potable surface water supplies.”

Marathon County Strategic Plan - Page 12
Page 12 of the 2018–2022 Marathon County Strategic Plan.

Announcement Postcard & Official Notice to Watch For

Over a 6-year period, the Marathon County CPZ Department will be mailing owners of septic systems and holding tanks that were installed before 1980 a yellow Maintenance Announcement postcard, followed by a white Official Notice, informing them how to comply with the State’s new maintenance requirements. The yellow announcement postcard has already been mailed to the identified property owners who will be added to the maintenance program in 2020.

Postcards will first be mailed to those who own properties in Marathon County that border surface waters (such as lakes or steams) and will progress to properties located farther from surface waters. This process of gradually expanding the CPZ Department’s POWTS Maintenance Program to include all holding tanks and septic systems in Marathon County is expected to continue until 2025.

CPZ Announcement Postcard for Expanded POWTS Maintenance Program
CPZ Administrative Specialist Toshia Ranallo displays the yellow announcement postcard mailed in May 2020 to inform selected holding tank and septic system owners in Marathon County that beginning in 2020 they will be included in the expanded POWTS Maintenance Program. (Photo courtesy of Dale Dimond.)

MCDEVCO’s POWTS Loan Program

Marathon County has partnered with MCDEVCO to develop a POWTS Loan Program to provide low-interest loans to qualifying low-income property owners who are identified as having to replace a failing holding tank or septic tank system as part of the CPZ Department’s POWTS Maintenance Program. We are pleased to announce that this new community-minded loan program is now available and ready to take applications for those in need.

MCDEVCO-POWTS Loan Program-logos

For more information about the expanded POWTS Maintenance Program or MCDEVCO’s newly created POWTS Loan Program, please visit Marathon County’s dedicated POWTS webpage at

Dale_DimondDale Dimond
Onsite Waste Specialist  |  Marathon County Conservation, Planning, & Zoning Department

Dale Dimond is an Onsite Waste Specialist with the Marathon County Conservation, Planning, & Zoning Department. He has over 40 years of experience with county Private Onsite Wastewater Treatment Systems (POWTS) programs, beginning in 1979 in Adams County and moving to Marathon County in 1993. He has served as chairman of the Wisconsin County Code Administrators POWTS/Sanitation Committee and as a member of Wisconsin’s POWTS Advisory Code Councils. Outside of work, he enjoys spending time in his boat fishing for muskies.  Email Dale Dimond.

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