Officials say the level of polyfluroalkyl substances (PFAS) detected in the treated water is well below allowable limits, constituting only 7-13 parts per trillion.
That level is well below the EPA health advisory limit of 70 ppt for lifetime exposure. Still, it was the first time PFAS was detected in water after the treatment process.
“The city’s water remains safe, with readings well below the EPA health advisory limit,” Michael Powell, Dayton’s Department of Water director, said in an email sent to customers. “Additionally, the city will continue to use the latest available technology to proactively monitor and safeguard our drinking water in coordination with the Ohio EPA and U.S. EPA.”
A problem before
This isn’t the first time the substance has caused concern in the area.
Last year, several wells in Dayton’s Huffman Dam well field were turned off as a precaution when the substance was detected. The levels of PFAS were below the lifetime exposure limit then as well.
At the time, officials said PFAS had not been detected in drinking water.
In the last six months, Dayton has installed 77 of 150 additional monitoring wells to help isolate the sources of PFAS and to improve pumping, according to the city.
The substance has been used in firefighting chemicals at Wright-Patterson Air Force Base and at Dayton’s firefighting training center, this news organization previously reported.
According to the U.S. EPA, studies indicate high-level exposure to the contaminant may lead to testicular and liver cancer; changes in cholesterol; low birth weight in newborns; liver tissue damage; and effects on the immune system and thyroid.
Wright-Patterson has been combating water contamination for years, shutting down wells temporarily and building a new water treatment facility to ensure water safety, as well as tracking ways tainted groundwater makes it on and off the base.
Officials said more testing needs to be done to determine how the contaminant distributes throughout the water distribution system.
Montgomery County Administrator Joe Tuss said the county, in coordination with Dayton, will begin testing water within the distribution system for PFAS.
“We want to understand what that means if the treated water coming out of the plant is 7-13 parts per trillion, which is extremely low,” Tuss said. “What does that mean as it moves through the distribution system?”