ST. LOUIS COUNTY (KMOX) - The achingly slow process of trying to rid a north St. Louis County community of a potentially hazardous chemical from their groundwater supply continues.

The original spill that eventually contaminated groundwater beneath a North County neighborhood didn’t happen last month or even last year.

It happened sometime in the mid-to-late 1980′s, causing some homeowners to express their frustration that they only recently learned about it.

Environmental Protection Agency spokesman Chris Whitley said they have to walk a very fine line when trying to confirm possible health problems reported by several Elmwood Park residents.

“The question is, are those issues in fact linked to any contamination they may have been exposed to in the neighborhood and that’s a very very very difficult thing to say conclusively,” he said.

Whitley said efforts to determine the extent of the problem in an area near Page Avenue and Dielmann Road were recently expanded.

“Drilling at ground water wells, collecting samples from those wells, also doing additional testing from home. We want to, as best as we can, find where the contamination is existing,” Whitley said.

Affected homeowners recently met with EPA officials. They were encouraged to form it’s own community action group to keep on top of the problem.