Maine environmental regulators have asked a railroad cleaning up a freight train derailment site to repair forest management roads and culverts damaged by heavy equipment and that led to the discharge of sediment into area waters.

State Department of Environmental Protection Commissioner Melanie Loyzim in a letter Thursday to Canadian Pacific Kansas City said the equipment used to reach the derailment site in a rural area of Somerset County "crushed culverts and displaced soil in and adjacent to several streams," and no attempts have been made to correct the damage.

"CPKC must immediately take measures to stabilize the access roads leading to the derailment site, stabilize all stream and culvert crossings, and prevent further discharges of sediment to waters of the state of Maine," the letter said.

A CPKC spokesperson said in an email Saturday that the railroad is committed to a full restoration and cleanup in cooperation with the Department of Environmental Protection and other agencies.

"The remote forested nature of the area combined with the spring thaw has made cleanup efforts challenging, including for the ingress and egress of people and equipment," the statement said. "Throughout this response, the safety of personnel at the site and restoration of the environment remains our priority."

Three railroad employees were hurt when three locomotive engines and six train cars carrying lumber and electrical wiring went off the tracks on April 15 and started a small fire in the woods. Two cars carrying hazardous materials were also being hauled but they did not derail, spill or catch fire.

The derailment occurred near Rockwood, a town of about 300 people on Moosehead Lake, a prime recreational fishing area about 90 miles (140 kilometers) northwest of Bangor.

The Department of Environmental Protection earlier criticized CPKC for failing to meet the agency's expectations with regards to response and timing "to effectively mitigate impacts to the environment and public health."

Derailments and railroad safety have been a growing concern nationwide since the fiery Feb. 3 Norfolk Southern derailment outside East Palestine, Ohio, released chemicals that forced evacuations and created lingering health concerns.