Chemicals found in Dayton water prompt new letters to customers

DAYTON, Ohio -- A potentially dangerous substance once used as a firefighting foam at Wright-Patterson Air Force Base that infiltrated groundwater and prompted the shutdown of several Dayton water wells has now been detected in drinking water bound for customers.

The system operators, however, say the level of polyfluoralkyl substances (PFAS) is well below allowable limits.

Both the city of Dayton and Montgomery County are sending customers notices with the results of recent testing of treated water leaving the city's Ottawa Water Treatment Plant. The results of March testing show PFAS detected at a level of 7-13 parts per trillion.

Officials stress that level is significantly below the EPA health advisory limit of 70 ppt for lifetime exposure, but it marks the first time PFAS have been detected in water after the treatment process.

"The city's water remains safe, with readings well below the EPA health advisory limit," wrote Michael Powell, Dayton's Department of Water director, 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."

Dayton's well fields supply water for 400,000 residents in multiple jurisdictions. In addition to Dayton they include those in Centerville, Harrison Twp., Kettering, Miami Twp., Washington Twp., and others.

Joe Tuss, Montgomery County administrator, said the county, in coordination with the city, 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?"

Seven drinking water production wells were turned off last year at Dayton's Huffman Dam well field as a precaution, officials said earlier. Monitoring wells detected polyfluroalkyl substances on site. In the last six months, Dayton has installed 77 of 150 additional monitoring wells to help isolate the sources of PFAS and to optimize pumping, according to the city.

At certain levels, the substances can cause major health concerns. 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, according to the U.S. EPA.

Story Filed By Cox Newspapers

For Use By Clients of the New York Times News Service