Municipal Membrane Bioreactor Application in the North East

Epping, New Hampshire's wastewater treatment facility was faced with unusually stringent limits upon receiving a new “National Pollution Discharge Elimination System (NPDES) Permit” for their outfall into the Lamprey River. The Lamprey River, designated a Federal Wild and Scenic River, has traditionally experienced extremely low flows during summer months which provides little dilution for even small quantities of pollution. Also, the river is a drinking water supply to the Town of Newmarket, New Hampshire and potentially to the Town of Durham, New Hampshire. Because of these factors, the new NPDES limits presented to Epping were reduced to nearly drinking water quality standards. The Town retained the engineering firm of Hoyle Tanner & Associates (HTA) to complete a study to look at alternatives, and it quickly became apparent that traditional treatment processes would either not do the trick or would be too costly to build as well as to operate.HTA had recently looked at several new technologies at the national Water Environment Federation Conference. Included among possible solutions to Epping's problem was an ultrafiltration process by ZENON, Inc. of Oakville, Ontario. HTA compared several treatment alternatives for the Town of Epping, and the ZENON Process was determined to be the most promising. Along with the Town's Water & Sewer Commission and a representative of the NH Department of Environmental Services, HTA visited an existing, similar sized facility in Arapahoe County, Colorado and was impressed with the equipment and data provided. Based on their studies, HTA began design of a ZeeWeed Membrane Bioreactor facility for Epping during October of 1999.The plant has been in operation since February 2002. Effluent quality has been excellent, with turbidity values consistently less than 0.1 NTU.