Officials with the AMP-Ohio plant say they recently got notice of a violation investigation from the US EPA concerning its Gorsuch Plant in Marietta.

The investigation is regarding modifications completed at the facility in connection with the Clean Air Act.

AMP-Ohio officials say some of the modifications go back to 1981, pre-dating the company's ownership, to Elkem Metals.

The investigation stems from a boiler replacement performed at the facility in the 1981 to 1986 time frame and an upgrade project performed in the 1988-1991 time frame.

The upgrade project was performed to decouple the electric generation from the process steam production at the plant.

AMP-Ohio legal counsel and staff are reviewing the documentation received from US EPA.