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Historic Agreement to Cut Nitrogen by 20-40%

Sewage Treatment Plant courtesy of Portland Water District
Sewage Treatment Plant courtesy of Portland Water District

Imagine if we could remove 500 to 1,000 pounds of excess nitrogen from the Bay each day. An historic effort by Portland Water District may do just that!

After nearly a year of work, the Portland Water District and Friends of Casco Bay developed an agreement aimed at reducing nitrogen pollution from sewage effluent. The collaboration helped the Maine Department of Environmental Protection (DEP) develop a 139-page,
five-year permit for the City of Portland’s East End Wastewater Treatment Facility, which is managed by the Water District, that will better protect water quality. The permit was issued on March 22, 2017.

The $12 million upgrade to the plant’s aeration system may help reduce nitrogen in the plant’s effluent waters by 500 to 1,000 pounds each day!

The aim is to reduce nitrogen loading in the discharges from the plant by 20-40% within five years. This is the first wastewater discharge permit in Maine to address nitrogen levels and is now a model for other communities.

A History of Our Work to Reduce Nitrogen in Casco Bay
In 2007, Friends of Casco Bay helped persuade the Maine Legislature to pass a law requiring the Maine DEP to establish a limit on how much nitrogen may be discharged into coastal waters. Instead of following the Legislature’s lead, DEP has chosen to limit nitrogen permit by permit in Casco Bay. This had led Friends of Casco Bay to work with DEP, municipalities, and businesses, to help set realistic limits on nitrogen in Clean Water Act discharge permits issued to sewage treatment plants and industrial facilities.

We are working with the City of Portland on its Combined Sewer Overflow Remediation Project that will help reduce
nitrogen-laden sewage overflows into the Bay.

Our pumpout boat removes raw sewage—another source of nitrogen—from the holding tanks of recreational boats and transports, for onshore disposal. Contact pumpout@cascobay.org.

Our BayScaping program works with residents and municipalities to help keep fertilizers and pesticides from polluting the Bay. We present BayScaping Socials to help neighbors reduce the use of lawn chemicals. With our support, South Portland passed an ordinance to restrict pesticide use, with an assurance to tackle fertilizers next. Executive Director Cathy Ramsdell served on the Portland Pesticide Task Force as that city considers a similar ordinance.