In most cases, the water produced by a groundwater well is safe to drink. If properly sited and constructed, well water is free of the microbiological contamination which can make one quickly and, potentially, seriously ill. However, groundwater may contain substances which make the water unhealthy or, more frequently, either unpalatable or aesthetically disagreeable.

Health-related contaminants found in Wisconsin groundwater include radionuclides, arsenic, nitrates, pesticides and herbicides, and volatile organic compounds. Some of these contaminants, such as arsenic, occur naturally in the aquifer. Others, such as pesticides, are man-made.

Aesthetic-related contaminants include iron, manganese, odor, and total dissolved solids. Of these, iron is the most common. High iron concentrations can cause the water to be cloudy, have a yellow or reddish tint, or have a noticeable taste.

Different treatment methods are used to treat different contaminants. In most cases, the goal of treatment is to remove all or most of the subject contaminant. In the case of treating for iron, chemicals can be added which delay the onset of discoloration and fixture staining caused by iron. The chemicals do not remove the iron. If the treated water remains in the distribution system too long, the effectiveness of the chemicals breaks down.

Lead contamination has been in the news ever since the acute problem occurred in Flint, Michigan. While lead normally is not found in groundwater, systems supplied by wells may need to treat for lead. In the case of Flint and most other water systems where lead contamination has occurred, it is because the water is corrosive. If the service lateral through which water is conveyed from the water main in the street to a customer’s home is made of lead, corrosive water can dissolve the lead and cause high concentrations of lead in the water delivered to the customer. Various chemicals can be added to the water to either make it less corrosive or to apply a coating to the pipe so that the lead is not in contact with the water.

For most municipal water systems supplied by groundwater, chlorine is added to help reduce the potential for microbiological contamination in case an event, such as a water main break, occurs which could allow soil or other materials to enter the distribution system.

For assistance with groundwater treatment, contact an expert at R/M today.

About the Author

Daniel R. Butler, P.E.

Daniel R. Butler, P.E. 
Senior Project Manager

Dan has been with Ruekert & Mielke, Inc. (R/M) since 1978. Dan’s expertise in water supply projects is based upon many years of experience involving nearly every community in southeastern Wisconsin. He has worked as a design engineer and a project engineer on a wide variety of water supply projects, including planning studies, well siting studies, well construction, pumping stations, storage facilities, control systems, distribution system modeling and water treatment facilities.

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