January 2023 Update
Prior to July 2022, the U.S. EPA recommended a 70 parts per trillion (ppt) Lifetime Health Advisory (LHA) for PFOA and PFOS in drinking water. The U.S. EPA has since updated their Regional Screening Level Tables, and associated IDEM risk-based tables have been changed accordingly (2022 Table 1 [PDF]). The updated IDEM drinking water levels for PFOA and PFOS are 60 ppt and 40 ppt, respectively. The revisions to the drinking water guidelines reflect that while PFAS are present in many consumer and commercial products, the U.S. EPA has not presently designated those compounds as hazardous, and the greatest long-term public exposures to PFAS are through drinking water ingestion.
In August 2022, IDEM received permission from two additional residents to test their well water. Both properties are located adjacent to Treaty Creek. A drinking water filter system was installed by IDEM in one home where PFAS exceeded IDEM’s published levels.
Based on a review of the collected data, IDEM requested permission to sample 10 additional drinking water wells within 300 feet of stream tributaries in and near the Treaty Creek watershed. Six homeowners agreed to be sampled, which was completed on December 6, 2022. IDEM is awaiting final validation of the results of the samples; however, preliminary results showed PFAS detections in one sample, well below IDEM’s published levels.
Why was PFAS present only in a few wells?
IDEM also conducted area samplings of creek water, field tile, sludge and soil to investigate the PFAS and possible sources. The results showed higher levels of PFAS in limited areas where a type of soil amendment was used to enhance soil nutrient levels. Surface and deeper soil (18 to 24 inches in depth) samples showed PFAS concentrations greatly decreased with depth. The PFAS levels in soil are therefore unlikely to affect usable groundwater at those locations.
The well water results showed that the few wells with PFAS detections are located very close to portions of Treaty Creek with elevated concentrations of PFAS. Because surface water in parts of Treaty Creek interacts with shallow groundwater at varying times throughout the year, these wells appear to be pulling in shallow groundwater mixed with Treaty Creek water.
What does IDEM plan to do protect my drinking water?
IDEM has installed water treatment filters in the few locations where PFAS was present above screening levels, and the drinking water in those homes is protected.
April 2022 Update
IDEM received permission from 44 residents located within 300 feet of Treaty Creek to test the water in their drinking water wells.
What was found?
Laboratory results showed that of the samples collected, water from five wells had detectable levels of PFAS; three of which exceeded the U.S. EPA Lifetime Health Advisory level of 70 parts per trillion (ppt). The laboratory results are located in IDEM’s Virtual File Cabinet.
In the three wells with drinking water results exceeding the U.S. EPA’s 70 ppt health advisory level, water filtration equipment is being installed at no cost to the well owner by an IDEM contractor. Water filtration using activated carbon or reverse osmosis has been shown to be effective at removing PFOA and PFOS from drinking water.
What’s next?
IDEM continues to investigate the source of the PFAS contamination. As part of the investigation, soil testing will be conducted at additional properties where possible PFAS contamination may have occurred due its proximity to Treaty Creek.
Treaty Creek Drinking Water Well Testing Initiative
Wabash County
What is the Treaty Creek Drinking Water Well Testing Initiative?
The Indiana Department of Environmental Management (IDEM), in partnership with the Indiana Department of Health (IDOH) and the local health department, is responding to reports of elevated levels of Perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) in Treaty Creek.
Out of an abundance of caution, IDEM, along with the local health department, is asking approximately 65 property owners located within 300 feet of Treaty Creek for permission to test their private drinking water wells to ensure unsafe levels of PFAS have not entered their wells. The testing will be conducted at no-cost to the property owner.
What is PFOA and PFOS?
Per- and polyfluoroalkyl substances (PFAS) are a class of synthetic, organic chemicals that contain fluorine. Because many PFAS have useful properties, they have been used since the 1940s in products such as textiles, paper, cookware, firefighting foams, and electronics. PFOS and PFOA are among the most widely used PFAS.
What is the concern with these chemicals?
Exposure to PFAS does not mean that you will have health problems now or in the future, and the immediate health risks for most people exposed to PFAS are low. Both PFOA and PFOS are commonly found in people and the environment.
The U.S. EPA has established lifetime drinking water health advisory levels for PFOA and/or PFOS at 70 parts per trillion (one part per trillion is 1 second in 32,000 years or less than one drop of water in an Olympic-sized swimming pool). This health advisory level offers a margin of protection for all Americans throughout their life from adverse health effects resulting from exposure to PFOA and PFOS in drinking water. This level also offers protection to the most sensitive populations, including pregnant women and infants.
Why is this testing necessary?
Indiana American Water (IAW) alerted IDEM to a detection of PFAS in raw water from one of its drinking water wells and in Treaty Creek in July 2021. IAW removed the well from service.
IDEM immediately sampled three additional public water systems’ drinking water wells located adjacent to the creek in August 2021. The water systems sampled were Southwood Elementary School, Southwood High School, and White’s Residential & Family Services. There were no detections of PFAS in any of the drinking water wells.
IDEM conducted additional surface water sampling in Treaty Creek in December 2021 to confirm previous reports of PFAS in the creek and to sample additional locations. Results of this sampling were received by IDEM in January 2022 and showed elevated levels of PFAS in the creek.
PFAS was not detected in the three public water supply wells adjacent to the creek, but out of an abundance of caution, IDEM wants to ensure unsafe levels of PFAS contamination have not affected private drinking water wells near the creek.
What’s next?
In partnership with the local health department, IDEM is sampling drinking water wells located within approximately 300 feet of Treaty Creek to ensure the wells are below U.S. EPA’s lifetime health advisory level for PFAS. Drinking water wells located within this proximity to the creek are more likely to interact with surface water from the creek.
Is my drinking water safe?
Drinking water from a public water system is regulated by IDEM and the U.S. EPA and is tested for many contaminants on a regular basis. The public water systems in your area meet all requirements of the federal Safe Drinking Water Act. Sample results for your water system are available online.
Private drinking water wells are not regulated by IDEM or the U.S. EPA. Properties located in the testing area (within 300 ft of the creek) are more likely to pull in surface water from Treaty Creek into their drinking water wells. Wells located outside this area are not likely to be affected by surface water in the creek.
IDEM has reached out to property owners in the testing area and will be testing the water in their wells, free of charge, as soon as the agency receives permission from the property owner.
What happens if private drinking water wells are confirmed to be above U.S. EPA’s Lifetime Health Advisory Level?
If testing confirms levels above 70 parts per trillion, actions to reduce any potential health effects will be discussed with the property owner. These actions could include bottled water, installation of water filtration equipment, drilling a deeper well, or alternative water sources such as connection to an available public water system.
Water filtration equipment using activated carbon or reverse osmosis have been shown to be effective at removing PFOA and PFOS from drinking water.
Are there any home water filters that are effective at reducing PFAS?
Many home drinking water treatment units are certified by independent accredited third-party organizations against American National Standards Institute (ANSI) standards to verify their contaminant removal claims. NSF International (NSF®) has developed a protocol for NSF/ANSI Standards 53 and 58 that establishes minimum requirements for materials, design and construction, and performance of point-of-use (POU) activated carbon drinking water treatment systems and reverse osmosis systems that are designed to reduce PFOA and PFOS in public water supplies. Carbon filtration and reverse osmosis water systems have been shown to be effective at removing PFAS contamination. Another option is connecting the property to a community water system or consider drilling a deeper well that is not under the influence of surface water. Water softeners and/or boiling the water will not remove PFAS contamination.
What is the source of the PFAS contamination?
IDEM is working to identify the source.
Where can I get more information?
Questions related to drinking water well testing and results:
IDEM Technical Environmental Specialist Lynette Schrowe (800) 541-6027 (toll free), DWtesting@idem.IN.gov. Media may contact media@idem.IN.gov.
Questions related to the human health effects of PFAS:
IDOH Public Health Administrator Grace Bassett (317) 233-9264, eph@isdh.IN.gov. Media may contact media@isdh.IN.gov.