OMAHA, Neb. (AP) — The Environmental Protection Agency is ordering Nebraska Railcar Cleaning Services to do a better job handling the crude oil, ethanol and other wastes it generates in Omaha.

Regulators said Thursday that the company could face substantial fines of $14,023 per day if it doesn’t comply with the rules for handling waste.

The EPA says the company has been keeping crude oil and ethanol in open, unmarked containers that could lead to fires.

In April 2015, two Nebraska Railcar workers died after an explosion inside a railcar they were cleaning.

Company officials said Thursday that no one was available immediately to comment on the EPA statement.