The E.P.A. and Mr. Wright’s team at Dow reached an agreement to clean waterways near Midland, Mich., in 2010. River decontamination is progressing, and officials cannot yet say when it will be complete. Credit: Sammy Jo Hester/Mlive

The lawyer nominated to run the Superfund toxic cleanup program is steeped in the complexities of restoring polluted rivers and chemical dumps. He spent more than a decade on one of the nation’s most extensive cleanups, one involving Dow Chemical’s sprawling headquarters in Midland, Mich.

But while he led Dow’s legal strategy there, the chemical giant was accused by regulators, and in one case a Dow engineer, of submitting disputed data, misrepresenting scientific evidence and delaying cleanup, according to internal documents and court records as well as interviews with more than a dozen people involved in the project.

The lawyer, Peter C. Wright, was nominated in March by President Trump to be assistant administrator at the Environmental Protection Agency overseeing the Superfund program, which was created decades ago to clean up […]