Settlement Paves Way for Pollution Reductions at Portsmouth Sewage Treatment Plant: Limits on Nitrogen Pollution Key to Protecting Great Bay Estuary - Conservation Law Foundation

Settlement Paves Way for Pollution Reductions at Portsmouth Sewage Treatment Plant: Limits on Nitrogen Pollution Key to Protecting Great Bay Estuary

Brian Barth Brian Barth

Portsmouth, NH (January 18, 2008) A legal settlement signed today by the Conservation Law Foundation (CLF), the City of Portsmouth, and the Environmental Protection Agency (EPA) puts Portsmouth on the path to long awaited reductions in wastewater and nitrogen pollution flowing into the Piscataqua River – an important part of the Great Bay estuary.

“Great Bay now has nitrogen levels similar to those that led to the collapse of the Chesapeake Bay, and critically important eel grass habitat in the Piscataqua River is being decimated,” said CLF Senior Attorney Tom Irwin. “Preventing these problems means reducing nitrogen pollution from multiple sources, including the Peirce Island plant which, with an average wastewater discharge of 4.5 million gallons per day, is the single largest pollution source in the Great Bay estuary.”

Nitrogen pollution levels in the Great Bay estuary have been steadily rising, leading to an increased presence of nuisance algae that causes oxygen depletion and declines in eelgrass habitat. Eelgrass serves as an essential breeding and nursery ground for numerous fish species, and is a cornerstone of the estuary’s ecological health and biodiversity.

EPA confirmed in the settlement that nitrogen pollution poses a mounting problem for the Great Bay Estuary, and put the City on notice that, depending on the final location of the City’s sewage treatment plant, wastewater discharges into the estuary likely will be subject to limits on nitrogen pollution under the Clean Water Act. In the settlement, Portsmouth agreed to include nitrogen removal as a key consideration in its ongoing assessment of future wastewater treatment options. Those options include an upgrade of the Peirce Island plant and re-location of the treatment plant.

Additionally, as part of the settlement, the City must conduct a detailed study, with input from CLF and EPA, of measures it can implement in the short-term – during the course of its three-year, long-term planning study – to reduce nitrogen pollution and total suspended solids, or “TSS.” These interim measures are intended to reduce pollution while long term solutions are being studied and fully developed.

“The Great Bay estuary is one of New Hampshire ’s greatest natural treasures and is threatened by excess nitrogen levels and other harmful pollution,” said Melissa Hoffer , director of CLF’s New Hampshire Advocacy Center . “Cleaning up the nitrogen pollution from Portsmouth ’s wastewater treatment facility is a big step in the right direction toward a better future for the estuary ecosystem, for surrounding communities, and for all who enjoy this remarkable natural resource.”

The settlement announced today comes in response to a legal appeal filed by CLF in May 2007 challenging an EPA-issued wastewater discharge permit for the Peirce Island treatment plant. CLF appealed the permit for its failure to limit harmful nitrogen pollution, and for its omission of a timeline for the City’s adoption of stricter, “secondary” levels of treatment required by the Clean Water Act. To address the permit’s new “secondary treatment” requirement, Portsmouth is already pursuing a multi-year planning process that will result either in the construction of a new sewage treatment plant, or upgrade of the existing Peirce Island facility to secondary treatment. At this time, the Peirce Island plant continues to operate with only enhanced primary treatment.

The Conservation Law Foundation ( works to solve the most significant environmental challenges facing New England . CLF’s advocates use law, economics and science to create innovate strategies to conserve natural resources, protect public health and promote vital communities in our region. Founded, in 1966, CLF is a nonprofit, member-supported organization with offices in Maine , Massachusetts , New Hampshire , Rhode Island and Vermont .