Frequently Asked Questions about PFAS
Madison Water Utility has received many questions related to low levels of PFAS chemicals detected in water at Well 15 and several other wells. The Wisconsin Department of Health Services has recommended a groundwater standard for two types of PFAS compounds, PFOA and PFOS. The recommended standard of 20 parts-per-trillion for PFOA and PFOS combined is nearly two times higher than the level of those compounds detected at Well 15. While Well 15 water more than meets the recommended standard, Madison Water Utility will continue to operate the city’s water system without Well 15 for the time being as we work with state and local health experts, the Department of Natural Resources and the public to determine next steps for the well.
According to Public Health Madison Dane County, current levels of PFAS detected in Well 15 are not a threat to health. PHMDC information page on PFAS
What are PFAS?
PFAS (or per- and poly-fluoroalkyls), are a widely-used class of chemicals found in non-stick cookware, water-resistant clothing, upholstery, carpeting, food packaging and firefighting foams. Thousands of types of PFAS compounds have been manufactured and many are still being used. Low or trace levels of PFAS have been detected at some city wells. The EPA has established a Lifetime Health Advisory Level for two types (PFOA and PFOS) of 70 parts-per-trillion. High levels of PFAS exposure have been linked to a variety of health concerns, including increased risk of some types of cancer. According to Public Health Madison Dane County, current levels of PFAS detected in Madison wells are not considered a threat to health.
Is my water safe to drink?
According to Public Health Madison Dane County, current levels of PFAS detected in Madison wells are not considered a threat to health. Public Health Madison Dane County does not recommend that residents invest in filtration systems or use bottled water. PFAS levels detected in Madison wells, including Well 15 on East Washington Ave., are well below the EPA Lifetime Health Advisory level.
This guidance also applies to households that include pregnant women, infants and children, and the elderly since the EPA advisory considers these more sensitive populations when it is formulated.
(Information provided by Public Health Madison Dane County's Director of Environmental Health and Environmental Epidemiologist)
Which wells serve my home?
You can enter your address here to see which of Madison's 23 wells serve your home. Many addresses are served by more than one well.
The information is meant to be an estimation of the service areas of the wells, averaging a range of operational conditions over the course of a year. Service areas for any well can change based on season, weather conditions (i.e. drought, heavy rainfall), loss of service at nearby wells, or other unforeseen changes in system operation.
Where are the PFAS chemicals coming from?
Madison Water Utility believes the low levels of PFAS chemicals detected at Well 15 (on East Washington Ave.) have likely traveled in groundwater over several decades from Truax Air Field, where firefighting foams have been used. PFAS chemicals have been found in higher concentrations in groundwater at the base.
Unfortunately, cleaning up known contamination at Truax Air Field will not decrease PFAS detections at Well 15 for years or perhaps decades. It takes 35 to 50 years for PFAS to travel in groundwater from the air base to the well. We believe the chemicals we're seeing in the well now were used at the air base several decades ago.
The sources of PFAS at other city wells are currently unknown.
How much PFAS has been found in Madison water?
Madison Water Utility has been conducting advanced testing of the city’s 23 water wells looking for PFAS compounds. Most wells with PFAS detections show trace amounts of a mixture of several types of the compounds, many of which are at levels too low to accurately measure.
Find detailed results for wells with PFAS detections here.
To be tested summer, 2019 (Seasonal Wells)
Low Level Detection
Well 15 E. Washington Ave.
Well 9 Spaanem Ave.
Well 6 University Ave.
Well 7 N. Sherman Ave.
Well 13 Wheeler Rd.
Well 14 University Ave.
Well 11 Dempsy Rd.
Well 16 Mineral Point Rd.
Well 26 High Point Rd.
Well 29 N. Thompson Dr.
Well 12 S. Whitney Way
Well 18 Park St.
Well 19 Lake Mendota Dr.
Well 20 Prairie Rd.
Well 24 N. Livingston St.
Well 25 Queensbridge Rd.
Well 28 Old Sauk Rd.
Well 30 Moorland Rd.
Well 31 Tradewinds Pkwy.
Well 8 Lakeland Ave.
Well 17 S. Hancock
Well 23 Leo Dr.
Well 27 N. Randall Ave.
Is there a home filter that can be used to reduce the level of PFAS in drinking water?
Public Health Madison Dane County does not recommend that people who get water from Well 15 invest in filters or bottled water at this time. The water is not considered a potential threat to health and is safe to drink.
However, people searching for peace of mind may be interested in the following information about filtration.
The Minnesota Pollution Control Agency and Minnesota Department of Health tested a small, in-home granular activated carbon (GAC) filter for PFAS removal. You can view the results here.
The agencies report that this type of filter was effective at removing PFC or PFAS from drinking water. A filter certified to meet ANSI/NSF P473 will reduce PFOA & PFOS down to the EPA Lifetime Health Advisory Level of 70 parts-per-trillion. However, detections of PFOA & PFOS at Well 15 are 12 parts-per-trillion, already significantly lower than the health advisory level.
As the Minnesota study showed, any filter will lose its effectiveness over time so it is important to install and maintain filters according to the manufacturer instructions. While not specifically rated and/or certified for PFAS removal, some types of activated carbon (charcoal) and reverse osmosis filters might also reduce PFAS levels in water.
The Michigan Department of Environmental Quality has put together a fact sheet detailing in-home PFAS filtration methods.
Can Madison Water Utility take action to ensure there are no longer PFAS chemicals in our water?
Madison Water Utility is calling for the Wisconsin Air National Guard to clean up known contamination at Truax Air Field, the likely source of PFAS found at Well 15 on East Washington Avenue. Unfortunately, cleaning up contamination at Truax will not decrease PFAS detections at Well 15 for years or perhaps decades. It takes 35 to 50 years for PFAS to travel in groundwater from the air base to the well. We believe the chemicals we're seeing in the well now were used at the air base several decades ago.
If levels detected at Well 15 begin to increase dramatically, it would be possible to construct a treatment system to remove PFAS from the well's water. Activated carbon could remove PFAS from Well 15, which already has an air stripper to remove volatile organic compounds (VOC). However, the building footprint may need to be enlarged, and there is no space available on our property for expansion.
Any wellhead treatment ro remove PFAS would cost several million dollars and would take a minimum of two years to design and construct. However, we are investigating those options should PFAS levels rise significantly.
Because the sources of trace levels of PFAS in other city water is unknown, there is currently no remediation action that can be taken. It's unclear if wellhead treatment could successfully remove the very low levels of PFAS found in these wells. Shutting down all wells containing PFAS would leave large parts of the city with no water.
Will Wisconsin set its own drinking water standard for PFAS?
The Wisconsin Department of Health Services has recommended a groundwater standard for two types of PFAS compounds, PFOA and PFOS. The recommended standard of 20 parts-per-trillion for PFOA and PFOS combined is nearly two times higher than the level of those compounds detected at Well 15. This recommendation is not a municipal drinking water standard, but it may guide the Department of Natural Resources as it considers setting a regulation for PFOA and PFOS.
While Well 15 water more than meets the recommendation, Madison Water Utility will continue to operate the city’s water system without Well 15 for the time being as we work with state and local health experts, the Department of Natural Resources and the public to determine next steps for the well.
Nine other states are setting their own standards for PFAS in drinking water. How do PFAS regulations in other states compare with levels found in Madison?
Well 15 levels are currently lower than regulatory levels set in Minnesota, New Jersey, California, Connecticut, Maine, Massachusetts, New Hampshire and North Carolina. They are not lower than the standard set in Vermont. Click here to see PFAS guidance set in other states and look at how levels at Well 15 compare.
All other Madison wells with PFAS detections are below standards or guidelines set in other states for the compounds.
Can Well 15 be shut down?
Yes. It is possible to shut down Well 15 and use other wells to supply water to the area. The well is currently offline for the time being.
Shutting down Well 15 permanently would reduce the overall reliability of the water supply system on the east and north sides of Madison during summer months (the area east of the Yahara River, from the northern city limits to Buckeye Rd). In 2018, Well 15 pumped 370 million gallons of water into the system. Less than one percent of the water pumped is consumed. The rest is used for fire protection capacity, sanitation, cleaning, irrigation, etc.
A shut down of the well would also likely mean more reliance on Well 8 and perhaps Well 23, both of which are used sparingly due to high levels of naturally-occurring iron and manganese
Madison Water Utility looks to Public Health Madison Dane County, the DNR, and Wisconsin Division of Public Health for guidance on this and other issues. None of those agencies has suggested that we should consider shutting down Well 15 due to the levels of PFAS detected in its water. A decision to shut down Well 15 would also end Madison Water Utility’s testing program for PFAS at the well.
Will the WI Air National Guard / Dept. of Defense pay for PFAS removal at Well 15?
National Guard officials have informed us that they will not fund PFAS removal at Well 15 unless levels at the well rise above the EPA's Lifetime Health Advisory Level of 70 parts-per-trillion for PFOA & PFOS. Current levels of PFOA & PFOS at the well are 11-12 parts- per-trillion.