A new housing development on Route 33 in Greenland, New Hampshire, which borders the southern shore of Great Bay estuary. The town had a population of 3,208 in 2000 and is expected to gain another thousand residents by 2025, a 35 percent increase. PHOTOS: MAUREEN KELLY

Currently, 17 wastewater treatment facilities in the area discharge treated effluent into surface waters, many feeding into Great Bay, New England’s largest inland estuary. Others discharge into the Piscataqua River, which connects Great Bay to the ocean, and into Hampton Harbor, site of the state’s largest salt marsh. To handle increased volumes of waste under stricter federal discharge laws, the facilities will likely need upgrades or other solutions to protect water quality in New Hampshire’s rivers and bays.

The Great Bay Estuary Commission, established in 2004 by the state legislature to investigate options for the long-term management of the region's wastewater, is overseeing a $1 million feasibility study that is inviting Seacoast communities to consider whether they should continue discharging into surface waters or if it is time to examine other possibilities, such as piping treated wastewater into the Gulf of Maine. The state-funded study is being conducted by Metcalf & Eddy, an engineering firm that was the lead designer on Boston's Deer Island treatment facility and the nine-mile outfall pipe that empties into Massachusetts Bay.

The process of finding a solution will be “locally-driven” by public meetings and other community outreach efforts, said Commissioner of the New Hampshire Department of Environmental Services Michael Nolin, a member of the Great Bay Estuary Commission. It is also important, he added, that Maine towns in the watershed participate in the process, which is “important for perpetuating the high quality of the Gulf of Maine.”

In early spring, the study team put 10 options on the table for communities to consider. They included a “business-as-usual” approach, in which facilities would continue to treat and discharge at current locations with upgrades if necessary. Alternatively, facilities could discharge on land to return treated wastewater to aquifers. Communities were also presented with a number of options for managing their waste collectively, which would involve building a regional sewer infra-structure, regional treatment or discharge facilities, and, potentially an ocean outfall pipe.

At a forum held in March to invite public comment on the options, a number of participants asked that the process be guided by legislation that is intended to manage growth in ways that preserve the traditional character of towns, promote settlement patterns that use land and water resources efficiently, and protect open space and quality-of-life.

A number of participants cautioned that some regional waste management scenarios could set the stage for sprawling development. Installing sewers with centralized treatment and discharge is a conventional practice for handling wastewater in densely-settled, urban areas. The systems can reduce contamination from septic systems and offer better control over discharges than in a multiple discharge design. This can result in near-shore improvements to water quality, as seen in Boston Harbor after an ocean outfall pipe went on-line.

However, if towns fail to control their development, extending sewers and water service can motivate unwanted growth into outlying areas. The building of additional roads and parking lots could result in more run-off pollution into waterways. Nonpoint pollution, largely from stormwater run-off, is already the predominant reason for shellfish bed closures in the state's estuaries, according to the New Hampshire Department of Environmental Services.

Consideration of an ocean outfall pipe raised questions about whether releasing wastewater into the Gulf of Maine could alter the hydrology and degrade riverine and estuarine habitat in the Great Bay watershed, as has occurred in metropolitan areas of the Northeast where excessive water withdrawals from rivers and sewers has lowered groundwater tables and displaced water from aquifers. Some participants expressed further concern about possible changes in nutrient and salinity levels in estuaries and around the outfall pipe that could affect habitat for fish, shellfish and benthic life if large quantities of fresh water spill out to sea.

Other stakeholders asked that alternatives be added to the study that would incorporate decentralized approaches and sustainable technologies for managing wastewater rather than large-scale engineering projects. Decentralized systems treat and disperse smaller volumes of wastewater locally and aim to maximize groundwater recharge. On-site septic treatment systems and cluster systems that treat waste from multiple dwellings are examples.

By not considering new sustainable technologies, the study is “un-reasonably narrowing options,” said Doug Bogen of New Hampshire Clean Water Action.

Advanced waste treatment technologies include greenhouse systems like the “Living Machine,” a chemical-free treatment in which sewage is cycled through a series of tanks where bacteria, micro-organisms, algae, plants, snails and fish break down and digest pollutants in the wastewater.

“We are aware that there are many alternative wastewater treatment technologies that are available,” said Bob Scherpf, vice president of Metcalf & Eddy. “For our study, we agreed to look at technologies that have a proven track record” for large-scale waste management in a cold climate.

The forum generated a 95-page summary of public comments and a 25-page report submitted by the Nature Conservancy and the Conservation Law Foundation urging a detailed “consideration of the significant ecological, economic and cultural values of the Great Bay estuary, the Gulf of Maine, and the numerous fish and other species that depend on them, as well as significant growth pressures in the Seacoast region and the sprawling development patterns that have taken root.”

Since then, the study team has narrowed the ten options down to four, which will be studied in greater detail. All four alternatives have the 17 existing wastewater facilities continuing to treat wastewater. The alternatives include continuing discharge into surface waters, discharging treated wastewater to the land, or conveying treated wastewater through a regional pipeline for discharge into the Gulf of Maine. A fourth option - included as a result of public comments received by the study team - incorporates the use of decentralized systems to help manage as much as two-thirds of the Seacoast's future wastewater volume.

A Web site documenting the community outreach efforts and the decision process is at www.coastalclear.org.

© 2006 The Gulf of Maine Times