Backflow Laws: Wisconsin
Wisconsin Backflow Prevention Laws, Regulations, and Compliance Requirements
Wisconsin is nationally recognized as one of the three highest-regulation states for cross-connection control alongside California and Michigan. Wisconsin Administrative Code Chapter NR 810.15, updated in 2010, requires every municipal water supplier to develop and implement a comprehensive cross-connection control program, with mandatory surveys of ALL service connections — commercial and industrial every 2 years, residential at minimum every 10 years. Annual testing of testable assemblies is required statewide. Testers must be certified by the Wisconsin Department of Safety and Professional Services (DSPS). Test results must be submitted to both the Wisconsin Department of Commerce (now DSPS) and the local water utility. This guide covers NR 810.15 in detail and major utilities including Milwaukee Water Works, Madison Water Utility, La Crosse, and others.
Wisconsin State Regulatory Framework
Wisconsin’s cross-connection control requirements are established in Wisconsin Administrative Code Chapter NR 810.15 — Cross-Connection Control, administered by the Wisconsin Department of Natural Resources (DNR) for water system oversight, with plumbing code (SPS 382/SPS 383) administered by the Wisconsin Department of Safety and Professional Services (DSPS). Wisconsin holds EPA primacy under the federal Safe Drinking Water Act.
NR 810.15 requires every municipal water supplier to develop and implement a comprehensive cross-connection control program. The required program elements include: (a) a local ordinance establishing the CCC program; (b) a list of methods, devices, and assemblies used to protect the potable water supply; (c) a time schedule for public education materials and surveys; (d) a complete description of protection methods, devices, and assemblies (compliant assemblies listed in SPS 382.41); (e) provisions for denial or discontinuance of service for unprotected cross-connections; and (f) submission to DNR of a copy of the CCC ordinance, an annual report including total service connections by category, and a report indicating the number of surveys completed in each category for that year.
Wisconsin's Tiered Survey Schedule — The Most Distinctive Feature
Wisconsin’s NR 810.15 establishes a tiered mandatory survey schedule that is unique among U.S. states:
Industrial, commercial, and public authority services: a minimum of once every 2 years. (Madison Water Utility operates on a 2-3 year cycle for commercial/industrial high-hazard facilities.)
Residential services: a minimum of once every 10 years, or on a schedule matching meter replacement. Public education materials must be provided to the customer no less than every 3 years and with every cross-connection survey.
This comprehensive residential survey requirement — even if only decennial — distinguishes Wisconsin from most U.S. states that exempt residential properties from mandatory survey programs. Wisconsin utilities often coordinate residential CCC surveys with water meter replacement programs to minimize cost and customer disruption.
Wisconsin DSPS Tester Certification — SPS 382
Backflow assembly testers in Wisconsin must be certified by the Wisconsin Department of Safety and Professional Services (DSPS). The Wisconsin Uniform Plumbing Code Section SPS 382 establishes minimum standards for backflow prevention throughout Wisconsin. Pressure and reduced pressure type backflow preventers must be registered with the Wisconsin Department of Commerce (now DSPS). All backflow preventers must be tested by a licensed tester and results reported to both the Wisconsin DSPS and the local water utility. Test kit calibration must be current — Wisconsin regulations require calibration within the previous 12 months.
Annual DNR Report Required
Wisconsin municipalities must submit to the DNR an annual report documenting their CCC program activities — including total service connections by category and the number of surveys completed in each category for that year. This mandatory annual reporting to DNR is one of the elements that places Wisconsin in the top tier of national CCC regulation alongside California and Michigan.
Wisconsin's Two-Year Commercial Survey Is One of the Shortest Mandatory Cycles Nationally
While many states survey commercial properties every 3-5 years (or not at all), Wisconsin’s NR 810.15 requires commercial, industrial, and public authority service connections to be surveyed at minimum once every 2 years. This means a Wisconsin property manager can expect a cross-connection survey visit from their water utility every 2 years — and the utility can deny or discontinue water service if access is refused. Commercial property managers should be prepared to facilitate these biennial surveys by providing access to mechanical rooms and water infrastructure areas.
Major Water Purveyors in Wisconsin
Milwaukee Water Works
Milwaukee Water Works serves Wisconsin’s largest city and surrounding communities, making it one of the largest municipal water utilities in the Midwest. Milwaukee Water Works requires annual backflow preventer testing for commercial and industrial facilities. Test reports must be submitted to Milwaukee Water Works within specific timeframes with records maintained on-site for at least three years. Testing must be performed by individuals certified by the Wisconsin DSPS, with credentials verified through the DSPS state database.
Madison Water Utility
Madison Water Utility serves Wisconsin’s capital city. Madison’s CCC program has been active since 1994 (commercial/industrial) and was expanded to residential surveys coordinated with the Project H2O water meter upgrade from 2012-2014. Current survey frequencies: Commercial (High Hazard) and Industrial — 2-3 year cycle; Residential — coordinated with meter replacement. Annual testing of testable backflow devices is required. Madison’s program is fully documented on the city’s website and serves as a model program for Wisconsin utilities.
La Crosse Water Utility
La Crosse Water Utility has contracted with HydroCorp Inc. to manage its CCC program. HydroCorp has been performing CCC inspections for La Crosse commercial and industrial facilities since 2006, with residential inspections added to the program. La Crosse’s residential CCC inspection cycle is approximately 20 years, coordinated with the Public Service Commission of Wisconsin’s mandatory meter replacement program. Annual testing of testable assemblies is required.
Green Bay Water Utility and Northeast Wisconsin
Green Bay Water Utility and other northeastern Wisconsin water systems operate comprehensive NR 810.15-compliant programs. Annual testing is required for all testable assemblies.
Other Major Wisconsin Utilities
Weston, Prescott, Eau Claire, Appleton, Oshkosh, Racine, Kenosha, and other Wisconsin municipalities each implement NR 810.15-compliant programs with biennial commercial surveys, decennial residential surveys, and annual testing requirements. Many have contracted with HydroCorp or other specialized CCC program administrators.
Wisconsin DNR Annual Report Failure Consequences
Water systems that fail to submit the required annual CCC report to Wisconsin DNR — including the total service connections by category and number of surveys completed — are in violation of NR 810.15 and subject to DNR enforcement action. Wisconsin DNR conducts sanitary surveys of water systems that may include review of CCC program records. A water system without the required ordinance, annual reports, or survey documentation may face formal enforcement including orders to comply and potential service quality impacts.
Property Owner Compliance Summary for Wisconsin
DSPS-certified tester: All backflow assembly testing by Wisconsin DSPS-certified tester with current (within 12 months) calibrated test kit.
Annual testing: All testable backflow prevention assemblies must be tested annually.
Dual filing: Test reports must be submitted to both Wisconsin DSPS and the local water utility.
Biennial commercial surveys: Expect your water utility or their contractor to conduct a cross-connection survey of your premises every 2 years (commercial/industrial).
Assembly registration: Pressure and reduced pressure assemblies must be registered with Wisconsin DSPS.
Find a Certified Backflow Tester in Wisconsin
Find Wisconsin DSPS-certified backflow testers at getyourbackflowtested.com/backflow-testing-near-me/wisconsin-backflow-testing — covering Milwaukee, Madison, Green Bay, Kenosha, Racine, La Crosse, and all major Wisconsin communities.
Wisconsin Regulatory Reference Links
| Resource / Agency | URL / Link Target |
|---|---|
Wisconsin DNR — NR 810.15 (Cross-Connection Control) | |
Wisconsin Legislature — NR 810.15 Full Text | |
Wisconsin SPS 382 — Plumbing Code Backflow Standards | |
Madison Water Utility — Cross-Connection Control Program | |
Milwaukee Water Works — Customer Backflow Information | |
La Crosse Water Utility — Cross-Connection Control Program | |
Wisconsin DSPS — Plumber Licensing and Backflow Certification |