The New York Department of Environmental Conservation (DEC) has accepted the changes Cornell has made to comply with DEC requirements, following the Dec. 10-11 accidental discharge of nonhazardous treated wastewater from Cornell's alkaline hydrolysis digester.

On Dec. 21, the DEC outlined five key requirements that needed to be made within 30 days in order to maintain compliance with the digester's operating permit. Cornell responded Jan. 18, detailing the changes that have been implemented, which the DEC accepted Jan. 31, agreeing to amend the permit to include the new conditions, said Paul Jennette, the College of Veterinary Medicine's biosafety engineer.

The five changes are:

A detailed investigation concluded that the Dec. 10-11 discharge was caused by programming issues that were traced to the digester's manufacturer.

Investigators found that the amount of hydrolysate effluent -- a brinelike fluid from the chemical digestion of animal remains -- in the digester when the spill occurred was about 1,600 gallons, about half the amount originally reported. This effluent had been diluted with some 90,000 gallons of potable rinse water, and most of the spill ended up in Ithaca's sanitary sewer system. A significant amount of hydrolysate remained in the digester, the investigators believe, and never left the facility.