Boston Raises Wastewater Facility to Avoid Inundation

*©¦ epa.gov/arc-x/boston-raises-wastewater-facility-avoid-inundation

In the late 1980's, Boston's Deer Island Wastewater
Treatment Plant needed an upgrade. The
Massachusetts Water Resources Authority (MWRA)
determined facility vulnerability to sea level rise and
decided to raise key portions of the plant by 1.9 feet.
The redesign and construction covered a ten year
period (1989-1998) and was part of a $3.8 billion
upgrade to add secondary treatment and consolidate
regional treatment capacity by increasing Deer Island
capacity from 250 to 350 million gallons for day.
MWRA's decision to raise portions of the plant avoided
extensive costs associated with building a seawall and
covered the projected vulnerability over the planned life
of the facility (through 2050). MWRA considers the
vulnerability of its facilities on an on-going basis using
current information to assess the effectiveness of its
climate adaptation actions. The Deer Island adaptation
action has been re-evaluated for effectiveness within
the city's Comprehensive Adaptation Plan ("Climate
Ready Boston", 2013). This review used a community
non-profit's sea level rise study and concluded that
MWRA's decision to raise Deer Island is likely to be
sufficient to avoid inundation of the facility over the next
century.

Applicable

How Did They Do It?	EPA Tools

MWRA identified facility
vulnerability

• MWRA assessed its Deer
Island wastewater facility's
vulnerability to sea-level rise
in accordance with the best
available science at the
time.

The Climate
Resilience
Evaluation
and

Awareness
Tool (CREAT)
helps

understand

expected

utility facility

vulnerabilities

from a

changing

climate.

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Applicable

How Did They Do It?	EPA Tools

MWRA adapted to future

EPA's Climate

conditions

Ready Water



Utilities

• When confronted with

Adaptation

needing to modernize the

Strategies

Deer Island facility, MWRA

Guide, assists

took the opportunity to

utilities

redesign it keeping

identify

vulnerability over its

potential

projected operating life in

facility

mind (i.e., raising key

adaptation

portions by 1.9 feet).

strategies



based upon



expected



climate



vulnerabilities.

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How Did They Do It?

Applicable
EPA Tools

As science improves, MWRA re-
evaluates risk and
vulnerabilities to ensure
effective adaptation

•	In recent years, MWRA
analyzed its entire system's
projected vulnerabilities to
storm surge (using a proxy
measurement equivalent to
Superstorm Sandy), the 100
and 500 year storm events
and low and high sea level
rise scenarios. The analysis
identified the facilities most
at risk due to anticipated sea
level rise. Deer Island, due
to the adaptation measures
already adopted, was
among the least vulnerable
facilities.

•	MWRA also continues to
monitor best available
science to determine
performance, including of
the Boston Harbour
Association's sea level rise
analysis (used within
Climate Ready Boston:
Municipal Vulnerability
Report). This report further
supports previous analyses
that suggest Deer island is
among the least vulnerable
facilities.

o Climate Ready
Boston: Municipal
Vulnerability Report
(PDF)(29 pp, 7.17
MB)

The EPA
Coastal
Inundation
Toolkit can
assist utilities
in better
understanding
facility
vulnerability
by illustrating
a range of
potential sea
level rise and
storm surge
scenarios.

Similar Cases and More Information

Sea-level rise is only one impact from climate change. Climate projections are typically best considered as a range of likely
impacts based on best available science. To see how a community conducted their own vulnerability analysis to sea-level rise,
not relying on external analyses, view Manchester-by-the-Sea. Retrofitting is not the only adaptation strategy for utilities

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dealing with projected increased flooding, two other strategies utilities can consider are building a wall to protect facilities from
higher water levels (DC Blue Plains) and decommissioning flood-prone facilities (Iowa City, IA) decommissioned a highly flood-
prone wastewater facility. For more on how Boston is adapting to climate change, view Climate Ready Boston.

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