First PFAS testing results of 2019 are in

Tuesday, February 26, 2019 - 11:44am

Madison Water Utility has received results from its 2/4/19 PFAS testing at municipal Well 15 on East Washington Avenue. The utility sent samples from the well to two national laboratories looking for 30 different types of PFAS compounds, up from the 18 types it tested for in October.

“PFAS chemicals are widely used. You find them in firefighting foam, nonstick cookware, stain-resistant clothing, and some food packaging” says Madison Water Utility water quality manager Joe Grande, who oversees the utility’s testing program. “The PFAS chemicals we’ve detected at Well 15 likely came from firefighting foam used at Truax Air Field that traveled in groundwater over several decades to reach the well.”

PFOA + PFOS Results

PFOA and PFOS are two of the most well-known and prevalent types of PFAS chemicals. The EPA has set a drinking water Health Advisory Level for these two compounds of 70 parts per trillion.
The two labs reported slightly different results for the combined concentration of PFOA and PFOS: 11.2 and 11.6 parts per trillion, for an average result of 11.4 ppt.

In October 2018 sampling, the utility found a PFOA and PFOS combined concentration of 10.5 ppt. While this might appear to be an increase of 0.9 ppt, there is usually some variability in results when testing for chemicals at such low levels.
The utility also used different testing labs to analyze the 2/4/19 samples compared to earlier tests.

“Variability among labs is not uncommon, and it also reflects the absence of a standard method for PFAS testing,” Grande explains. “We expect directly comparable results in the coming months because of consistency in the types PFAS compounds we’re testing for and the lab method used. Any trends will become more clear as monthly testing continues this year.”

Total PFAS Results

Beginning with the 2/4/19 sample, Madison Water Utility expanded testing to include 30 types of PFAS compounds – 12 more than it tested for in 2018. Expanded testing revealed trace amounts of four additional types of PFAS, all just above the detection limit, which in most cases is 2 parts per trillion. These new detections bring the total concentration of PFAS at Well 15 to about 56 parts per trillion, with 10 of 30 types of PFAS found.
Grande says the results are not a surprise.

“Because firefighting foams contain a mixture of PFAS compounds, we did expect to find some additional PFAS chemicals at low levels when testing was expanded,” he says.

What’s next?

  • Madison Water Utility will continue monthly testing at Well 15 using similar methods and the same lab(s) used for the 2/4/19 analysis.
  • Madison Water Utility will conduct a simple study to see how much PFAS can be removed from Well 15 water using a pitcher with an activated carbon filter. The study will also look at how any removal might change over the recommended life of the filter. We expect results of this study later this year.
  • At the Water Utility Board Meeting tonight, MWU staff will present a contingency plan for shutting down Well 15 should PFAS levels rise substantially. A shut down of the well would likely mean more reliance on Well 8 and Well 23, both of which are used sparingly due to high levels of naturally-occurring iron and manganese
  • Madison Water Utility and Public Health Madison Dane County are holding joint community meetings with the Eken Park Neighborhood Association, Emerson East Neighborhood Association, and Friends of Starkweather Creek and attending the Carpenter-Ridgeway Neighborhood Association meeting.
  • Madison Water Utility and Public Health Madison Dane County will hold a meeting at the East Madison Community Center on March 16th. Hmong and Spanish interpreters will be on hand, as will a representative from the Wisconsin Department of Health Services.
  • Staff from Madison Water Utility and City of Madison Engineering plan to serve on the DNR’s new PFAS Technical Advisory Group. According to the DNR, the goal of the group is to examine the “what, where, when, and how” of PFAS investigation and remediation by sharing concerns, identifying current and proposed practices, and strategizing on issues requiring solutions.
  • Madison Water Utility is recommending that DNR make a formal request to the Department of Health Services that it expand the PFAS it’s evaluating for a potential state groundwater standard to include additional types of PFAS chemicals beyond PFOA and PFOS.

Contacts


Agency: 
Water Utility
Area: 
East