ST. PAUL, Minn. (AP) - A Minnesota Pollution Control Agency staff member involved in the environmental review of the Sandpiper oil pipeline won't be disciplined for emails containing a disparaging tone about the project.

In a letter Saturday, MPCA Commissioner John Linc Stine said a state investigation "did not produce any cause for disciplinary action."

The investigation began after January reports on 2014 emails from MPCA environmental specialist Scott Lucas to activists fighting the pipeline that would bring North Dakota oil across northern Minnesota to Wisconsin.

The commissioner's letter reportedly said that an independent investigation of several hundred emails concluded Lucas did not oppose the pipeline, but instead had sent two emails with "poorly chosen words."

Lucas is based in the agency's Brainerd office.