Efforts to remove a toxic substance polluting the city’s only source of drinking water are entering the final stages after a nearly five-year hiatus.

The water underground surrounding the former AEP Flexo site, located at 1300 Hook Drive in Middletown, is polluted, according to the Ohio Environmental Protection Agency.

The building’s current owners, however, are claiming a nearly six-year remediation process by the Ohio EPA was botched, and that levels of the volatile chemical, trichloroethylene — a carcinogen prevalently used in the dry cleaning and printing industry — are present again because of a lack of attention by the company charged with removing the substance.

Regardless, a recent decision by the Ohio Attorney General’s Office is putting the remediation of the site on the fast track, and efforts to remove the pollutant will be under way again in the next four to six weeks, according to the Ohio EPA.