Wisconsin Department of Natural Resources Regulations (NR 811.09) recommends that all industrial, commercial, and institutional facilities be surveyed for cross connections regularly (every two to six years depending on the degree of hazard within the facility).
The survey is a walk-through of the water-system piping in a building or property, starting at the water meter and ending at the last free-flowing tap. Survey time varies depending upon the facility being surveyed. Large, complex facilities will be required to prove that they have an internal program to protect the potable water system. At the end of the survey HDI will produce a report describing any violations of discrepancies found, as well as a time frame for compliance.
Surveys of existing facilities will be scheduled based on the degree of hazard that they present to the water system. The first round of inspections will include city-owned buildings, public school facilities, hospitals/medical facilities, car washes, industrial/manufacturing facilities, and mortuaries. Inspections notices will be mailed to water customers approximately two weeks before the scheduled inspection date. A building representative should be available during the inspections to answer questions and provide access to areas within the facility.