Sadly this been an ongoing issue throughout the history of Guilford / Pan Am, and it has happened at all of their majority facilities, including Rigby and East Deerfield.
According to news reports, the Maine Department of Environmental Protection documented 22 oil spills at Rigby Yard between 1983 and 2008. Those spills released a combined 12,000 gallons of petroleum products.
At least two of those spills resulted in diesel fuel and lube flowing into a nearby creek and ending up in the pond at Calvary Cemetery. The railroad didn't report the spills to the authorities; the spills were discovered by mourners at Calvary Cemetery who were paying their respects to deceased loved ones. To say the community was outraged would be an understatement.
Pan Am Railways — Boston & Maine/Maine Central — Delaware & Hudson
Central Maine & Quebec/Montreal, Maine & Atlantic/Bangor & Aroostook
Providence & Worcester — New England — GE Locomotives