Investments in infrastructure and strong partnerships key to health of Casco Bay


Today the Portland Water District held a ribbon cutting at its East End Wastewater Treatment Facility to celebrate the completion of the $12 million upgrade to the plant.  Both DEP Commissioner Paul Mercer and Efficiency Maine's Deputy Director Peter Eglinton were there to applaud the project and praise the plant's operational efficiency and positive impact on the environment. Also on site were project partners and stakeholders.

The $12 million aeration system upgrade delivers significant benefits to Casco Bay and the community.  By replacing the 36-year old system, the plant was able to increase operational performance and efficiencies, particularly during wet weather events, continue compliance with permit conditions, and reduce odors associated with the process.  

The Portland Water District recognizes concerns over nutrients and the modernization of the plant has also allowed PWD to proactively optimize processes and set a goal to reduce total nitrogen by 20-40% in the effluent entering Casco Bay. Nitrogen, which is found in sewage, stormwater, fertilizers, and the air, can contribute to harmful algal blooms. Early water quality monitoring results have been promising.  Last year we were able to meet the goal for a period, and we are excited to continue our efforts to manage nitrogen from this facility.

“We are pleased to continue working with various stakeholders, including the Department of Environmental Protection, the city of Portland, Casco Bay Estuary Project and Friends of Casco Bay, to understand the issues affecting Casco Bay and make positive contributions towards collaborative solutions,” stated PWD’s General Manager Carrie Lewis.   

The aeration project replaced mechanical surface aerators with a modern process that diffuses air more efficiently from the bottom of the tanks. The aeration process now uses 10,000, 9-inch diffusers and holds 4.2 million gallons of wastewater. Efficiency Maine has recognized the project’s energy efficiency with a $200,000 grant.

Clean Water Week is June 3-9: In 1983 the Maine Legislature made provisions to designate the first full week of June as Maine Clean Water Week.  Maine Clean Water Week was created to increase the public’s awareness of the improvements made in the quality of Maine’s waterways. 

The East End Wastewater Treatment Facility was constructed in 1979.  It processes 20 million gallons of wastewater a day and prevents 8,700,000 pounds of pollution from entering the bay per a year. 

Project engineers: Hazen and Sawyer and Woodard and Curran

Project contractor: Penta Corp.



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