Public water and private wells can be contaminated with germs and chemicals from many sources, commercial, industrial, agricultural and naturally occurring substances found in groundwater. The best strategy to minimize pollutants is reduction at the source, but once water is contaminated, monitoring and removal is required to provide safe clean water.
Public water systems are required to test and treat for many germs and chemicals in their drinking water systems by the US Environmental Protection Agency. There are also required to report levels of contaminants to their customers. Private owners must test their own wells, preferably annually.
US EPA water regulations can be found here.
Contaminants that threaten our water
Typical contaminants found in the Chippewa and Eau Claire River watersheds include:
PFOS and PFAS compounds
These are plastic polymers (molecular chains) that incorporate the element fluorine to provide the familiar coating compounds with moisture-, stick-, heat-, stain-, and chemical-resistant properties used in thousands of common products. These widely used products range from raincoats to shaving creams to firefighting foams to fast food containers. The compounds are also used in many industrial manufacturing processes.
The thousands PFAS/PFOS compounds are highly stable and difficult to degrade, but various members of the chemical group are shown risk for cancers, and may affect reproduction, liver and thyroid function, but most of the variants have not been studied for toxicity. Some producers have phased out older generations of PFOS and PFAS and replaced them with new shorter-chain versions which are claimed to be less toxic, though studies proving safety have not been performed on most PFAS/PFOS compounds. (2). As of March 14, 2023, the US Environmental Protection Agency has proposed limiting PFAS contamination to the detection limit of 4 parts per trillion (4 nanograms per liter).
Locally, Eau Claire has found PFAS / PFOS in its municipal well fields, with 6 of its fifteen wells taken offline to prevent contamination of the city water supply. Meeting the new guidelines will be an expensive challenge.
Because of their stability, capturing and degrading PFAS and PFOS compounds is a complex process. Typically a filtration material like activated carbon is required, with filter material being cleaned and contaminant neutralization occurring at special facilities.
Tips for reducing PFAS Exposure, (Sophie Morse, WBUR)
(2) https://www.atsdr.cdc.gov/pfas/health-effects/index.html
https://dnr.wisconsin.gov/topic/PFAS
Volatile Organic Compounds
These are commonly hydrocarbon or chlorocarbon compounds, like benzene and carbon tetrachloride used as fuels, solvents, and cleaners.
Prolonged exposure to VOCs can lead to immune disorders, cancer risk, and liver, kidney and nervous system damage, and cardiovascular disease.
Carbon filtration is effective in removing VOCs from water.
https://www.usgs.gov/mission-areas/water-resources/science/volatile-organic-compounds-vocs
Heavy Metals
Metals such as arsenic, cadmium, chromium, copper, iron, lead, zinc and others may pose problems in the area. Some aquifer contaminants may be naturally occurring such as iron or lead, others may be the result of industrial processes or land waste contamination that seeps into ground water. Water delivery systems (lead pipes or lead solder joints, for example) can contribute heavy metals to water.
Long term heavy metal exposure can be serious, including kidney and liver damage, brain and nervous system harm, anemia, heart arrhythmia and cancer.
Filtration or reverse osmosis systems are effective in removing heavy metals.
https://www.epa.gov/ground-water-and-drinking-water/national-primary-drinking-water-regulations#Inorganic
Fertilizers, Pesticides, Herbicides and Agricultural Chemicals
Agricultural chemicals can contaminate groundwater aquifers through applications onto fields, seepage of contaminated surface water, accidental spills and leaks, and improper disposal. Reduction of
Microbial contaminants
Various bacteria, protozoa and viruses can be present in water, E. coli being the most commonly found. Chemical treatment, typically chlorine, is effective in neutralizing microbial contaminants.
Radon and naturally occurring radioactive minerals
Radon is a common radioactive element found in the bedrock of Wisconsin. While radon is somewhat less prevalent in the Eau Claire area compared to other parts of the state, it is still a potential hazard to homes and water sources. Various treatments can settle out or filter radon and other radioactive minerals in water.
Water Sources
- Municipal systems and shared well systems used by apartment blocks, developments and mobile home parks are required to test for several contaminants and report to the Wisconsin Department of Natural Resources (DNR) per the Environmental Protection Agency’s Safe Drinking Water Act (SDWA). These contaminants include inorganic compounds, synthetic organic compounds, volatile organic compounds, radionuclides, lead and copper on a three-year basis or more frequently if any contaminant is of concern, while bacteria levels are tested at least monthly.
- Municipal water systems typically provide filtering and processing to limit the risks of these contaminants. The City of Eau Claire Water Utility processes its water for manganese and bacterial contamination. The City Water Utility is currently planning for large carbon-filtration systems that will capture the spectrum of contaminants above with replaceable filter modules.
- Private well sources may contain one or more of the contaminants above; well testing is important to understand what may be present and the corrective actions needed. If you depend on well-sourced water, you may be able to receive financial assistance from the WI DNR for testing and remediation. Additionally, free testing for private water supplies serving families with newborn infants is offered for arsenic, fluoride, lead, copper, bacteria, and nitrate through the Eau Claire City-County Health Department.
- Facilities that provide their own water, such as schools, hospitals or factories are regulated similarly to non-municipal sources; for example bacteria are only required to test bacteria quarterly, and radioactive compound tests are not required.
- Small public facilities and non-year-round facilities are regulated by the Wisconsin DNR and are required to test annually for bacteria and nitrates.
Eau Claire County’s report – State of the Groundwater in Eau Claire County, Wisconsin – 2018:
https://www.eauclairecounty.gov/home/showpublisheddocument/25741/636699310364070000
What’s being done and what you can do
The City of Eau Claire Water Department performs over 18,000 tests a year to monitor for the contaminant types above, and treats its water disinfect microbes and filters for the minerals manganese and iron. New standards for PFAS/PFOS chemicals will need new filtration capability to achieve the levels of removal required by EPA guidelines. The Water Department is currently applying for grants to obtain new filtration equipment capable of removing these very low levels of contaminants.
Testing is available for private wells in Eau Claire, and money for treatment or replacement has been made available through ARPA (American Rescue Plan Act) funding.
You may be eligible to participate in an Eau Claire County Private Well Study and receive a free copy of your test results Apply Here
Eau Claire Well Water testing March-April 2023 https://www.eauclairewi.gov/government/our-divisions/health-department/inspections-and-testing/private-wells
There are DNR grants of up to $16,000 available for private well treatment or replacement: https://dnr.wisconsin.gov/aid/WellCompensation.html
You can find the Eau Claire Municipal Waterworks 2021 Quality Report here: https://www.eauclairewi.gov/home/showpublisheddocument/39562/637914168259651602