CONCORD, NEW HAMPSHIRE - American Refrigeration Company, Inc., (ARC) pled guilty to one criminal count of causing the Suncook (N.H.) Wastewater Treatment Facility (SWTF) to violate its own environmental permit by discharging ammonia down a sewer drain, rendering the treatment plant inoperable and causing the treatment plant to discharge wastewater into the Merrimack River, announced United States Attorney John P. Kacavas. 
                                                                
ARC, headquartered in Andover, Massachusetts, services industrial refrigeration systems.

ARC acknowledged that on January 24, 2008, an ammonia technician employed by the company began servicing an industrial refrigeration system at a customer’s facility in Pembroke, N.H.  The service job required the technician to remove all of the ammonia from the holding tank.  After transferring most but not all of the ammonia to other parts of the refrigeration system, the technician drained the remaining ammonia to a floor drain, which he knew led to a publicly owned treatment works.  The technician did not obtain permission from any federal, state or local environmental authority before making the discharge.  

After it was discharged down the floor drain, the ammonia was pumped and carried by gravity to the SWTF.  The SWTF has a permit under the National Pollutant Discharge Elimination System allowing it to discharge treated wastewater to the Merrimack River subject to certain conditions, including limits on the discharge’s pH.  On January 25, the ammonia caused the SWTF to violate the pH condition of its NPDES permit.  In addition, the discharged ammonia resulted in toxic shock in the treatment tanks at the SWTF killing much of the organic biomass relied upon for treatment of sewage.  Accordingly, the ammonia discharge resulted not only in an ammonia pass-through but also in the discharge of untreated or significantly under-treated wastewater which, in turn, led to the discharge into the river of undesirable levels of suspended solids and biological oxygen demand.  The plant’s operations returned to normal on January 28.

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