HANOVER, Pa. (WHTM) – More than two inches of rain that fell Thursday caused a retention trench at the Miller Chemical and Fertilizer plant to overflow, according to the state Department of Environment Protection.
DEP spokesman John Repetz said contaminated runoff on Friday morning was again entering Slagle’s Run, a tributary of the Conewago Creek. He added that the impact is expected to be minor.
Contaminated runoff had a significant impact to Slagle’s Run and the Conewago’s south branch after a June 8 fire at the plant in Conewago Township, Adams County. Authorities have said the contamination is likely responsible for thousands of dead fish that were seen last week over a 10- to 15-mile span of the creek.
Repetz said samples taken Thursday night indicate contaminants in the contained water are much lower than what was in the firefighting runoff.
He added that while the Conewago Creek is no longer discolored from firefighting runoff, recent rainfall has increased the cloudiness. Authorities have told people not to swim, fish or boat in the creek.
The New Oxford Municipal Authority’s water intake on the Conewago Creek was shut down during the fire and remains closed. New Oxford is receiving water from outside sources and mandatory restrictions remain in place.
East Berlin, located downstream, has taken two of its five wells – those closest to the creek – out of service as a precaution.
Authorities have seen no significant impacts to the Susquehanna River. Samples taken at Wrightsville, the nearest downstream public water system that draws water from the river, show normal background readings and the borough is again pumping water from the Susquehanna.
Lancaster and Columbia also draw water from the Susquehanna River. Both operators have reported no significant changes to their water.
The federal Environmental Protection Agency this week took samples from four private wells considered the most likely to be impacted by contaminated runoff. Repetz said preliminary results of those samples indicated that nitrate and other levels did not exceed the maximum contaminant level.
The cause of the fire is still under investigation. Miller Chemical said preliminary information shows it was likely caused by an electrical circuit malfunction.