WASHINGTON – The U.S. Environmental Protection Agency announced Monday that inconsistencies were found in alarming groundwater test results previously submitted by one subcontractor in East Palestine, Ohio, near the 2023 Norfolk Southern train derailment site.
Test results show there was no contamination in fall 2025 and no risk to the public or the environment, according to the EPA.
“EPA does not stand for analysts altering measurements, and we are investigating the actions of this subcontractor to the fullest extent of the law,” EPA Administrator Lee Zeldin said. “My team is working swiftly, transparently and efficiently to redouble all of our efforts to ensure that no one can ever do something like this again.”
The EPA sent a notice to Tetra Tech Inc. that its subcontractor, ALS Houston, failed to meet data quality standards in sampling tests taken in fall 2025. The subcontractor had previously reported to the EPA that 2-butoxyethanol, a colorless solvent used in household cleaners, paints, varnishes and paint strippers was found in groundwater samples from September 2025.
The EPA Region 5 office discovered the data discrepancy and immediately opened an investigation. The EPA found that the results from ALS Houston did not match the results of split sampling testing sent to other labs.
According to a news release, Tetra Tech notified the EPA in February 2026 that ALS Houston had altered the measurements, which resulted in the false sampling data. ALS Houston terminated the two analysts who failed to follow standard operating procedures, according to the release.
The EPA is continuing to monitor groundwater in East Palestine following the fiery train derailment Feb. 3, 2023, which led to chemicals being released into the environment and an extensive cleanup effort.