The Gulf of Maine is an international watershed in the North Atlantic stretching north from Provincetown at the tip of Massachusetts Bay in the Commonwealth of Massachusetts to Cape Sable on the Bay of Fundy in the province of Nova Scotia in Canada. For over 13,000 years, the Gulf has been developed around access to the coast for fishing, trading, and recreation. Today, these coastal development patterns put the cultural landscapes, economies, communities, and aging infrastructure systems along the Gulf at risk.
Climate Futures on the Gulf of Maine uses place-based scenario planning to illustrate the risks, vulnerabilities, and plausible futures for ten infrastructure systems along the rim of the Gulf. Place-based scenario planning is a method of long-term strategic planning that creates representations of multiple, plausible futures that are used to inform decision-making in the present. While complementary to probabilistic models used to forecast future vulnerabilities, scenario-based planning shifts emphasis from statistical probability to ways of thinking about the future. The goal of place-based scenario planning is not to predict the most likely outcome, but to reveal biases and blind spots in complex and non-linear situations.
Climate Futures uses the medium of landscape representation to surface the cultural value systems embedded in existing infrastructural systems, and position landscape as a driver when evaluating design from individual infrastructures to the Gulf of Maine watershed.
Infrastructure > Wastewater
GLOUCESTER WASTEWATER TREATMENT PLANT
50 Essex Avenue
Gloucester, MA 01930
The Gloucester Wastewater Treatment Plant 1 treats sewage from the City of Gloucester, as well as limited wastewater from the Towns of Rockport and Essex on Cape Ann on the unceded land of the Agawam and Pawtucket Peoples. 2 3
The plant was built in 1984 on filled salt marsh along the Annisquam River in West Gloucester. 4 The low-lying Treatment Plant is located within the FEMA AE and X Flood Zones, at risk of flooding during 100 and 500-year storms. 5 Essex Avenue, the access road to the facility, currently floods during high and king tides. 6 7
The Plant is managed by a public-private partnership between the City of Gloucester and Veolia Water North America Northeast, and is the only plant in New England that treats sewage with only primary treatment. 8 9 The plant discharges 5.15 million gallons of effluent per day, which flows a quarter mile out through an outfall pipe into Gloucester Harbor, an active working waterfront and fishing port. 10
In addition to the outfall pipe, there are four active combined sewer overflow (CSO) outflows in Gloucester Harbor. During storms and periods of heavy rainfall, when the capacity of Gloucester’s sewer system is exceeded, a mixture of stormwater and domestic sewage waste flow out of these outfalls into Gloucester Harbor. 11 As a result, the shellfishing flats adjacent to the Wastewater Treatment Plant and in the Harbor are permanently closed. 12 These two issues: an outdated primary treatment system and contaminated CSO outflow during storm events, contribute to ongoing sanitation and water quality issues along the Annisquam River and in the Harbor that extend beyond the footprint of the Wastewater Treatment Plant into the surrounding waterways.
The primary treatment issue is currently being addressed. In 2022, the U.S. Environmental Protection Agency (EPA) denied a request for a variance that would allow the City of Gloucester to continue violating the Clean Water Act by pumping effluent without secondary treatment into Massachusetts Bay. 13 14 In response, in 2023, the City of Gloucester and the EPA signed a consent decree, stating that the City agreed to finish construction on a secondary treatment system at the existing facility by 2028. 15
This secondary treatment system will be the second major improvement to the facility after a series of automatic floodgates were installed around the perimeter of the Plant in 2023. 16 These gates allow pedestrian and vehicle access without relying on people or power during storms. However, the project is limited to the Treatment Plant site, and does not address flooding or sea level rise concerns along Essex Avenue, the access road to the facility.
The mandated secondary treatment system and uncertainty around continued access to the plant provides an opportunity to re-evaluate the piecemeal resilience solutions that are being implemented, and consider other potential future scenarios, including investment in an updated facility in a less vulnerable area, introducing new technology, such as a waste-to-energy plant, and proactively restoring the ecosystem. 17
Scenario 0: Storm of the Century 2030
After power goes out at the plant, the facilities manager fails to complete the emergency generator’s on-site manual startup. Electrical equipment is submerged in corrosive seawater while effluent and solid waste spills out into the Annisquam River, leaving the City without wastewater treatment for two weeks before repairs are completed. Shellfishing grounds, previously closed for two days after rain events, remain permanently closed after the storm.
Scenario 1: Fortified Systems
The City of Gloucester invests in an earthen berm to protect the upgraded secondary treatment system plant from flooding. Simultaneously, Essex Avenue is elevated on pylons salt marsh along the banks of the Annisquam River, which is transitioning to open water. The plant’s operations continue to be interrupted by flooding at sewer pump stations around the larger Cape Ann region.
Scenario 2: Catchment Commons
After a waste-to-energy facility serving the Cape Ann region opens, the wastewater treatment plant is gradually decommissioned, decontaminated, and removed. While the site remains inaccessible during the long process of phytoremediation, visitors can observe the process as they walk the boardwalk over restored saltmarsh grasses planted along the former path of Essex Avenue.
International Watershed | Gulf of Maine | Hydrologic Unit Code |
Region | New England | HUC 01 |
Subregion | Massachusetts-Rhode Island Coastal | HUC 0109 |
Basin | Massachusetts-Rhode Island Coastal | HUC 010900 |
Subbasin | Charles | HUC 01090001 |
Watershed | Boston Harbor – Massachusetts Bay | HUC 0109000110 |
Subwatershed | Annisquam River – Gloucester Harbor | HUC 010900011002 |
The treatment plant is officially named the Gloucester Water Pollution Control Facility.
On Cape Ann, the late Mary Ellen Lepionka is an independent scholar whose research centers the Indigenous history of Essex County. She researched and wrote about the evidence of indigenous settlements on Cape Ann. Mary Ellen Lepionka, “Where were the Indigenous settlements in Essex County?” Indigenous History of Essex County, Massachusetts, 2024, www.capeannhistory.org
The plant treats sewers in the City of Gloucester and a limited amount of wastewater from the Town of Essex as well as trucked waste from commercial and residential holding tanks. The Plant serves a total of 26,250 people. Deborah Szaro and United States Environmental Protection Agency, “FINAL DECISION OF THE REGIONAL ADMINISTRATOR UNDER 40 CFR PART 125, SUBPART G (NPDES Permit No. MA 0100625)” (Boston, MA: United States Environmental Protection Agency, July 2, 2022).
Until the Clean Water Act was passed, Gloucester discharged untreated sewage from its municipal system into its harbor. In 1979, the City agreed to build a wastewater treatment plant in Gloucester that would bring coastal neighborhoods into the central treatment system to eliminate failing septic systems. This agreement was the result of a consent decree to settle lawsuits brought by the United States Environmental Protection Agency (EPA) and Massachusetts State Department of Environmental Protection (DEP). Bruce Tobey and United States Environmental Protection Agency Local Government Advisory Committee, “Gaining Public Support for Water Infrastructure Costs: Gloucester Massachusetts,” Interviews with Local Government Officials (Gloucester, MA: United States Environmental Protection Agency, August 2006).
The FEMA AE Flood Zone notes areas that have a 1-percent change of being inundated by a flood event in any given year. The 1-percent annual chance flood is also referred to as the 100-year flood. The FEMA AE Flood Zone notes areas that have a 0.2-percent change of being inundated by a flood event in any given year. The 0.2-percent annual chance flood is also referred to as the 500-year flood. See “Glossary,” Federal Emergency Management Agency, www.fema.gov/about/glossary
The City of Gloucester commissioned a report on low-lying roads vulnerable to inundation and sea level rise. Essex Avenue is a state-owned road, and determined to be “likely to experience flooding now and in the future.” See Woods Hole Group, “Technical Memo: Low Lying Roads Assessment” (Gloucester, MA: City of Gloucester, June 17, 2024).
Metropolitan Area Planning Council, “City of Gloucester Hazard Mitigation Plan” (Gloucester, MA: City of Gloucester, 2020).
According to the United States Environmental Protection Agency, primary wastewater treatment is the process of “allowing solids to settle and be removed from wastewater.” At the treatment plant, solid waste flows through a screen, which removes large floating objects. Next, sewage passes through a grit chamber where smaller particles settle out into the bottom. Additional particles are settled out in a sedimentation tank, where the speed of flow is reduced, allowing solids that are suspended in water to settle to the bottom, where they form a mass of biosolids. These biosolids are removed from the tanks and can be further treated. United States Environmental Protection Agency, How Wastewater Treatment Works` The Basics (Washington, D.C.: United States Environmental Protection Agency, 1998).
The City of Gloucester has operated its Wastewater Treatment Plant with only primary treatment plant through a variance waiver from the Environmental Protection Agency. The EPA granted a variance from secondary treatment requirements for the plant in 1985, renewed it in 2001, and denied in 2022. Deborah Szaro and United States Environmental Protection Agency, “FINAL DECISION OF THE REGIONAL ADMINISTRATOR UNDER 40 CFR PART 125, SUBPART G (NPDES Permit No. MA 0100625)” (Boston, MA: United States Environmental Protection Agency, July 2, 2022).
Effluent from the Gloucester Wastewater Treatment Plant is released into the ocean through a 14,869’ outfall pipe that discharges approximately one mile southwest of the Dog Bar Breakwater Lighthouse. See United States Environmental Protection Agency, NPDES Permit No. MA0100625 Fact Sheet Draft National Pollutant Discharge Elimination System Permit to Discharge to Waters of the United States (Boston, MA: United States Environmental Protection Agency, 2010).
See “Terms & Acronyms,” United States Environmental Protection Agency, accessed June 5, 2025, www.sor.epa.gov/sor_internet/registry/termreg/searchandretrieve/termsandacronyms/search.do
The Massachusetts Department of Marine Fisheries issues growing area classifications for shellfish based on sanitary surveys, which determine whether shellfish can be harvested for human consumption. The area around the Wastewater Treatment Plant and in Gloucester Harbor are classified as Prohibited: Closed to the harvest of shellfish under all conditions, except the gathering of seeds for municipal propagation programs. See Massachusetts Division of Marine Fisheries, Shellfish Sanitation and Management Annisquam River & Gloucester Harbor Growing Area Code N9, Shellfish Sanitation and Management (Boston, MA: Massachusetts Division of Marine Fisheries, June 2, 2025), www.mass.gov/info-details/shellfish-classification-areas.
Deborah Szaro and United States Environmental Protection Agency, “FINAL DECISION OF THE REGIONAL ADMINISTRATOR UNDER 40 CFR PART 125, SUBPART G (NPDES Permit No. MA 0100625)” (Boston, MA: United States Environmental Protection Agency, July 2, 2022).
Secondary treatment removes additional organic matter in sewage using bacteria. In secondary treatment, effluent that leaves the primary treatment stage trickles over beds of rock or plastic where bacteria gather to consume organic matter. Cleaner water then trickles through pipes into a sedimentation tank to remove additional bacteria. Finally, the effluent is disinfected with chlorine before the water is discharged. United States Environmental Protection Agency, How Wastewater Treatment Works` The Basics (Washington, D.C.: United States Environmental Protection Agency, 1998).
Tom Zuppa and City of Gloucester, “City of Gloucester Enters Consent Decree for Improvements at Water Treatment Plant,” March 3, 2023.
“Passive Automatic Floodgates installed in Coastal Resilience Improvements at Gloucester Water Pollution Control Facility,” Floodbreak, accessed May 30, 2025, www.floodbreak.com/projects/passive-automatic-floodgates-installed-in-coastal-resilience-improvements-at-gloucester-water-pollution-control-facility/
In 2025, the Massachusetts Solid Waste Management Section determined that a site on Kondelin Road is suitable for a proposed solid waste management facility. This location has previously been discussed as a potential location for a solid waste-to-energy plant. Commonwealth of Massachusetts Department of Environmental Protection to Paul Hardiman, “Positive Determination of Suitability,” April 3, 2025.
