ROCKLAND, MAINE, UPGRADES WASTEWATER TREATMENT FACILITY TO ACCOMMODATE COMBINED SEWER OVERFLOWS AND HIGH-STRENGTH INDUSTRIAL WASTES

In 1998 the City of Rockland, Maine, began a major capital improvement program aimed at its aging wastewater collection and treatment system. The program encompassed the (1) upgrade of its 20-year old wastewater treatment facility (WWTF) and (2) abatement of discharges from the City's combined sewer overflows (CSOs). One of the most important design considerations for both of these functions was to ensure that high-strength industrial wastewaters would be transported, uninterrupted, to the WWTF during overflow events. Other key considerations with the WWTF upgrade included: provisions for high-rate treatment of CSO flows; replacement of inefficient process equipment; improved sludge thickening and dewatering; and addition of an extensive odor control system. The planning and design considerations to accomplish these wastewater treatment and CSO abatement objectives are described herein.