Staff Writer

AYER — An allegedly unreported oil spill from a railway locomotive in the rail yard two years ago has led to Grand Jury indictments against Pan Am Railways Inc. and three of its subsidiaries, Attorney General Martha Coakley’s office and the Massachusetts Department of Environmental Protection (DEP) have announced.

Pan Am Railways, Springfield Terminal Railway Co., Maine Central Railroad Co. (MEC), and Boston and Maine Corp. were arraigned in Middlesex Superior Court May 27, entering pleas of not guilty. The next scheduled court date is July 9, according to the attorney general’s office.

The firms were charged with two counts each of violating the Massachusetts Oil and Hazardous Materials Release Prevention Act, which requires any owner or operator of a site to immediately notify DEP of a release or threat of oil or hazardous materials. Each failure to report is punishable by a criminal fine up to $100,000.

DEP was notified of a fuel spill on Aug. 9, 2006, by a caller who wished to remain anonymous out of concern for retribution from the railroad, according to the attorney general’s office. The caller said the railroad was alleging the spill was less than the minimum reportable quantity of 10 gallons and might be trying to hide it under fresh track ballast.

An investigation by the Massachusetts Environmental Crimes Strike Force (ECSF) determined that on the evening of Aug. 8, 2006, a locomotive owned by MEC left idling in Pan Am’s Ayer rail yard spilled hundreds of gallons of diesel fuel onto the ground.

The spill was not reported within the two-hour time limit for spills of 10 gallons or more, and remained unreported, reports claim.

Responders from the Ayer Fire Department, a DEP emergency-response team and the Federal Railroad Administration concluded Aug. 9, 2006, that more than 900 gallons of diesel fuel had leaked from the locomotive.

A Middlesex Grand Jury returned indictments on April 1.

Neither Pan Am staff attorney Michael Geary or Ayer fire Chief Robert Pedrazzi were available for comment by press time.

Privately owned Pan AM Railways — previously Guilford Rail Systems — transports freight throughout northern New England from Maine to New York. MEC owns the locomotive in question, Boston and Maine Corp. owns the Ayer rail yard, and Springfield Terminal Railway Co. operates the locomotive and the yard.

ECSF is an inter-agency organization that includes prosecutors from the attorney general’s office, environmental police, and investigators, engineers and lawyers from DEP. Overseen by the attorney general, DEP Commissioner Laurie Burt, and Energy and Environmental Affairs Secretary Ian Bowles, it investigates and prosecutes crimes that harm water and air and pose significant threats to human health.