A government watchdog organization claims to have proof that the U.S. Environmental Protection Agency worked with Norfolk Southern Corporation to remove several chemical compounds from the plan to test soil for pollutants following the Feb. 3, 2023, train derailment in East Palestine, Ohio.

The Government Accountability Project, which defends government whistleblowers, said it has obtained a letter through the Freedom of Information Act dated March 7, 2023, from the EPA to a testing and clean up firm that was aimed at concealing the scope of the contamination from the crash and the burning of rail cars containing vinyl chloride.

The letter removes several chemical compounds from the list of those to be tested for, and directs baseline soil samples to be taken from areas that were in the path of smoke from the rail cars, according to the Government Accountability Project.

The letter is dated one day after a Norfolk Southern contractor issued its initial soil sampling plan, according to the Government Accountability Project. In the letter, the EPA said it received a revised work plan for the first phase of the soil sampling plan from Norfolk Southern and the revisions had been approved.

The revisions removed 2,3,4,6-Tetrachlorophenol, 1,2,4,5-tetrachlorobenzene, pentachlorobenzene, 1,2,3-trichlorobenzene and 1,2,4-trichlorobenzene from the plan.

They also direct baseline samples to be taken farther west of the derailment site than the initial plan called for, according to the Government Accountability Project.

Baseline samples must come from unpolluted areas to accurately measure normal environmental conditions. Baseline samples taken from polluted areas make it impossible to determine if the presence and concentration of chemicals is at, below or above normal levels, according to the Government Accountability Project.