Officials said the spill resulted from water used to put out a fire at the J&J chemical plant.
The runoff which flowed into nearby Trail Creek, they say, was unfortunate but could not be avoided.
At a meeting this week EPD regulators assured the Board of Natural Resources they are actively monitoring the site.
According to the Morris News Service EPD director Allen Barnes told the board his department should have responded more quickly with cleanup efforts.
So far tests show chemical levels are decreasing in the creek.