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Summary
Rising populations and increased development in New Hampshire coastal communities have led to a decline in water quality in the Great Bay Estuary. Responding effectively and affordably to new federal permit requirements for treating and discharging stormwater and wastewater will require innovative solutions from communities in the area. In March 2015, the Water Integration for Squamscott–Exeter (WISE) project completed an integrated planning framework through which the coastal communities of Exeter, Stratham, and Newfields could more affordably manage permits for wastewater and stormwater. However, meeting maximum goals for nitrogen reduction will require collaboration and commitment from all municipalities in the watershed, whether regulated under the Clean Water Act or not.
Introduction
The New Hampshire Great Bay Estuary and portions of the tidal rivers that flow into it have been negatively impacted by human development. The Piscataqua Region Estuaries Partnership has identified cautionary or negative conditions or trends in fifteen of twenty-two indicators of ecosystem health.1 In 2009 many parts of the estuary were listed as “impaired” by the New Hampshire Department of Environmental Services (NHDES) on measures such as nitrogen over-enrichment. Though nitrogen is naturally present in estuarine water, excess amounts support algae growth, decrease oxygen, and ultimately damage aquatic species. Permits now issued by the U.S. Environmental Protection Agency (EPA), which regulates discharges to surface water, require nitrogen controls as low as 3 milligrams per liter (mg/l)—the lowest technically feasible level—on effluent from wastewater treatment plants.2 Municipalities, EPA regulators, and community stakeholders are now discussing strategies that would allow communities flexibility to integrate permit requirements between wastewater and stormwater, and/or combine requirements among multiple permit holders in order to devise control options that might be more cost-effective.
