The U.S. Environmental Protection Agency says it is investigating dead fish found in Sulphur Run during routine restoration efforts at the site of the February 3, 2023, derailment in East Palestine.

According to a news release, response staff members discovered the fish on Friday during routine monitoring of the stream.

Investigators believe that more than 4 inches of rainfall in late March and early April caused floodwater to flow from State Line Lake and the derailment site’s Freshwater Bypass Pond.

Fish from State Line Lake migrated to the bypass pond and were pulled into pump intakes, pouring into Sulphur Run.

Crews began picking up deceased fish along Sulphur Run, starting downstream at the Park Drive Bridge to the outlet of the bypass system feeding Sulphur Run. Approximately 1,000 dead fish were collected.

The ODNR, Division of Wildlife, has joined the investigation.

Although the EPA anticipates that no more fish will be pulled into the intakes as flooding has receded, controls to prevent this from happening in the future are being considered by the agency.

Norfolk Southern is expected to resume cleaning up sediment in Sulphur Run this week.  The EPA recently suspended the cleanup to evaluate how to more effectively contain and recover sheen from sediments.