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Drinking Water Safety

In Dane County, water that comes out of the faucet is almost always clean and safe. However, problems occasionally occur with the following: the source of water, in the processing, storage and delivery of drinking water; commercial water products; and internal and external malfunctions in plumbing, sewer and septic systems.

Private Well Users
Since private wells are usually shallow (less than 300 feet) they can be contaminated by nearby use of fertilizers and other agricultural, industrial or household chemicals.  Private wells are especially at risk for contamination by nitrates in fertilizer, which are particularly hazardous to infants and pregnant women.  Animal waste run-off and in-ground septic systems create the potential for bacterial contamination of surface waters and nearby shallow wells.

Public Water Utility Users
Dane County has 34 public water utilities that serve households and businesses in our urban/suburban communities and villages. These utilities, which are regulated by federal and state authorities, have made substantial investments to assure consistent delivery of safe and clean drinking water to their customers. They monitor the water supply for contaminants on a daily basis. However, these are complex systems and problems can occur. High mineral content from, for example iron and manganese, can be a problem and may accumulate in piping systems, affecting some households. Plumbing in older homes often contains lead, a well-known hazard. Newer plumbing contains copper that under certain conditions could dissolve into the water.  Over time, drinking water delivery systems can break down or be damaged during construction or by maintenance errors. These situations could link the home’s water supply to hazards from the surface or from sewage systems.

Is Bottled Water Safe?

In the US, municipal drinking water is regularly tested and reported to the community. On the other hand, bottled water is not rigorously regulated, so we do not know whether it contains contaminates such as chromium 6. There is also the negative impact that bottled water has on the environment, e.g. processing, transportation and disposal of plastic containers. See a more detailed report on tap vs. bottled water (PDF).