ON SEPTEMBER 24, 2007, APPROXIMATELY 150 GALLONS OF HEAT TRANSFER OIL WAS DISCHARGED FROM THE COOLING HEAT EXCHANGER, AND MADE ITS WAY TO THE MERRIMACK RIVER. THE SPILL ORIGINATED FROM A LEAK OR SEVERAL LEAKS IN THE TUBE BUNDLE IN THE COOLING HEAT EXCHANGER WHICH SEEPED INTO THE RIVER WATER COOLING SYSTEM. THERE WERE NO REPORTS OF ENVIRONMENTAL HARM AS A RESULT OF THE DISCHARGE.