Case Study:
Water and Wastewater Utilities
Planning for Climate Change
MANCHESTER-BY-THE-SEA, MASSACHUSETTS
Background
Manchester-by-the-Sea, Massachusetts provides drinking water and wastewater services to residents, tourists and local
businesses. The wastewater treatment plant (WWTP) is located at Manchester Harbor and is designed for an average
daily flow of 1.2 million gallons per day (MGD), a maximum daily flow of 3 MGD and an instantaneous maximum flow of
5 MGD. The WWTP is permitted to discharge a monthly average of 1.2 MGD from December through May and 0.67
MGD from June through November. The WWTP has an 8,900 foot outfall that discharges outside of the harbor.
Climate Threats
Manchester-by-the-Sea is concerned with flooding from heavy precipitation events, coastal storm surge and sea-level
rise. The sanitary collection system serves about half of the community, but has a high rate of inflow and infiltration
during heavy precipitation events. The WWTP is also not permitted to bypass wastewater treatment, even during heavy
flows. Most of the WWTP is located within the 100- and 500-year flood zones, including the headworks building which is
at a high risk of flooding. The parking lot adjacent to the WWTP has also flooded during especially high tides and storm
surge events in the past.
Planning Process
To better understand the vulnerability of its wastewater infrastructure and operations, Manchester-by-the-Sea assessed
potential climate change impacts using the U.S. Environmental Protection Agency's (EPA) Climate Resilience
Evaluation and Awareness Tool (CREAT). The CREAT assessment brought together individuals from EPA, various
departments within Manchester-by-the-Sea, state agencies and local environmental organizations to think critically
about potential climate impacts, prioritize assets and consider possible adaptation options.
Adaptation Measures
Manchester-by-the-Sea considered the potential consequences of extreme flooding events on its wastewater utility
infrastructure and operations. To assess each of these potential threats, Manchester-by-the-Sea considered how
potential adaptive measures would help lower consequences. See the table below for potential adaptive measures that
were considered.
Manchester-by-the-Sea, Massachusetts Case Study — Page 1
SEPA

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Case Study: Water and Wastewater Utilities Planning for Climate Change
THREAT
POTENTIAL ADAPTIVE MEASURES

Relocate WWTP to higher ground to avoid damage from coastal storm surge
Flooding from
coastal storm
Construct a sea wall on Manchester Harbor to protect the WWTP from coastal storm surge
surges
Green infrastructure at the facility to reduce parking lot flooding

Join the mutual aid network, Massachusetts Water/Wastewater Agency Response Network

Relocate WWTP to higher ground to avoid damage from flooding
Flooding from heavy
Green infrastructure in the community to capture stormwater flows
precipitation events
Future infiltration and inflow reduction activities to complement existing efforts

Incorporate leakage reduction into ongoing utility maintenance
Contact Information
For more information regarding Manchester-by-the-Sea's climate adaptation planning, contact Greg Federspiel
at federspielq@manchester.ma.us.
Manchester-by-the-Sea, Massachusetts Case Study — Page 2
&EPA
Office of Water (4608T)
EPA 800-Q-15-007
December 2015

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