James M. O’Neill/Northjersey.com The movement of a toxic chemical plume under the streets of central Hockessin is the likely cause of spiking concentrations of the pollutant PCE at wells that supply drinking water to the area, according to the Delaware Department of Natural Resources and Environmental Control.
"The state did not have the financial resources to move forward with investigating it.” Last week, federal regulators responded, announcing that the EPA has proposed adding the central Hockessin area to its National Priorities List – a designation that would free up federal Superfund dollars to pay for further investigation and cleanup of the underground aquifer.
Those who use a private well within a half-mile of the contaminant plume under the core of Hockessin, and do not have a water treatment system, should contact DNREC’s Hockessin Groundwater Site Project Manager Robert Asreen at Robert.Asreen@state.de.us.
Regulators initially considered nine companies as potential sources of the contamination – four gas stations, four dry cleaners, and an auto mechanic’s garage.
"Right now we have not identified any other sources, but that’s part of the investigation," he said.
"At this time all we know is that there are two sources.
The state of Delaware’s maximum allowable contaminant level for PCE in drinking water is one part per billion.
"It could be that the last part of the contamination finally got to the wells," he said.
Though water from one well recently tested 1.1 parts per billion, DiNunzio said.
Tests in 2001 after the chemical first was found in Hockessin showed PCE levels surpassed federal limits at two wells.