Officials still believe an herbicide or pesticide is responsible.

By: KDKA-TV News Staff

UPPER ST. CLAIR, Pa. (KDKA) — There is an update this weekend on the thousands of dead fish found rotting in Chartiers Creek.

The Department of Environmental Protection (DEP) will now wait for lab results after wrapping up its investigation this week.

The DEP still believes an herbicide or pesticide is to blame.

READ MORE: DEP Suspects Pesticides Or Herbicides Killed Thousands Of Fish In Chartiers Creek

However, they are waiting on more test results before giving a final ruling.

They are also urging the public to report all fish kills and suspected pollution immediately.

Anyone can do so by calling the DEP Southwest Regional Office.