Water Quality Testing

Routine Water Quality Monitoring

WW&LC routinely collects and tests water samples for a variety of biological (bacteria) and chemical contaminants that may be present in drinking water. Samples are collected at Water Utility facilities and representative sample locations within the distribution system. The location and frequency of sampling varies by contaminant. Most, but not all, of this testing is performed to comply with the Safe Drinking Water Act, U.S. Environmental Protection Agency (EPA) and Wisconsin Department of Natural Resources (WDNR). These agencies have regulatory authority over the water quality monitoring performed by the utility. The amount of testing performed by WW&LC as part of its water quality monitoring exceeds the regulatory requirements established by the EPA and WDNR.

Coliform Bacteria

Coliform bacteria are the number one contaminant that WW&LC tests for.  Coliform bacteria are an indicator of potential water contamination. This class of bacteria can be found in soil, on plant vegetation, and in feces of warm-blooded animals such as humans. Most coliform bacteria are harmless soil inhabitants that will not make people sick. However, some types of fecal coliforms (e.g. E. coli), which grow in the intestines of animals, may be pathogenic and can cause diarrhea, intestinal cramps, or nausea. Water samples are collected from wells and representative distribution sample locations each week and tested for coliform bacteria. The absence of coliform bacteria indicates that water is safe for consumption.
A positive total coliform test indicates that the water is potentially unsafe and is further evaluated for the presence of E. coli. If E. coli is present, it indicates that the water has been contaminated with fecal waste. Public notification including a boil water notice is issued until additional tests show that the water supply is free of E. coli. On the other hand, if a coliform-positive sample tests negative for E. coli, the location is resampled to confirm the initial test result. If the results indicate there is a potential that the system has been contaminated, the Water Utility will take immediate corrective action, and the public may be notified to boil their drinking water until additional water sample results confirm the water is free of coliform bacteria.
Routine weekly testing of water samples occurs on chlorinated water collected from wells and distribution sample sites. In addition, on a quarterly basis, the Water Utility collects water from each operating well immediately after it is pumped out of the ground and tests these source water samples for coliform bacteria.
To ensure drinking water safety, 20 samples are collected each month from representative locations and tested for coliform bacteria.

Water Utility Facilities

The Water Works & Lighting Commission’s drinking water system consists of 4 Ranney collectors, 1 16-inch well, 3 water towers, and approximately 160 miles of interconnected transmission and distribution water mains. The Water Utility pumps ground water from a sand aquifer. Wells are 60-70 feet deep and deliver water to the filter plant for final treatment before it is delivered to the city.