3223.1 - Meeting drinking water quality standards of the Safe Drinking Water Act: Assessing transient non-community water systems in south central Wisconsin

Program: One Health

Session: One Health Poster Session 2b: Various One Health Topics

Presenter: Kei Kohmoto

Abstract

Transient non-community (TN) systems are public water systems that serve more than 25 people for 60 or more days a year, including restaurants, gas stations, and campgrounds. These systems must meet drinking water quality standards under the Safe Drinking Water Act, complicated by seasonal operations and varying maintenance practices. These standards are set by the Wisconsin Department of Natural Resources, which has primacy from the EPA to do so. This work examined compliance and water quality issues in south central Wisconsin, a region with nitrate contamination concerns linked to agricultural land use practices.
We conducted inspections of over 80 TN systems in south central Wisconsin from June through August of 2025. Inspections evaluated physical infrastructure, including well casings, conduits, treatment systems, and pressure tanks for quality status and potential cross-contamination sources. Combined with assessing nitrate concentrations and total coliform presence (which can be an indicator of e. coli), we evaluated compliance with the SDWA.

Though violations were not common, when found, the most common are damaged conduits (often from lawn maintenance equipment), corroded well casings, and cross connections in drainage spaces. These can make the system more vulnerable to contamination. Though nitrate is often present, the maximum contaminant level is rarely exceeded. As of July, no assessed systems tested positive for total coliform. Numbers will be finalized in August upon completion of work.

These findings highlight water quality considerations relevant to TN water systems that can pose public health risks, including infantile methemoglobinemia from high nitrate exposure and sickness from total coliform/e coli exposure. Improved compliance can help increase confidence in drinking water quality and strengthen collaborative relationships between regulatory agencies and businesses. Proactive maintenance protocols and proper education can reduce contamination risks, while fostering cooperative rather than punitive regulatory approaches that facilitate effective and trustworthy partnerships.