The Illinois Environmental Protection Agency announced Friday that it recently tested about 20 private wells in unincorporated southern Naperville for chemical solvents.
The tests are being done as a precaution and not because of any known contaminants in the wells, state officials said. Results are due in 30 days.
The volatile organic compound TCE, or tricholorethylene, has been found in wells northwest of the city near an old Nike missile site and in unincorporated Lisle, Downers Grove and Woodridge.
“With the discovery of the contamination in residential wells in the Downers Grove area, the IEPA reviewed files on other closed public wells and decided as a precaution to sample select private wells in the Naperville area,” said Renee Cirpiano, director of the Illinois EPA.
The wells tested Wednesday and Thursday are within a 2-mile radius of one of the city’s former wells at 75th and Washington Streets. The city closed the well in 1986.
A recent review by the IEPA of a July 1985 test of the former well showed TCE at levels three times the federal standard of 5 parts per billion.
The review was prompted by the recent revelation that in 1994 high amounts of TCE were detected in a public well in the former Belmont Highwood Water Service District in unincorporated Downers Grove.
The well was closed and the district’s customers connected to Downers Grove’s system. But neither the agency nor the district had investigated the source of the contamination, which angered Downers Grove residents whose wells are testing positive for TCE. The IEPA has yet to determine the source.
