Case Study:
Water and Wastewater Utilities
Planning for Climate Change
CITY OF BREMERTON UTILITIES, WASHINGTON
Background
The city of Bremerton provides drinking water and wastewater services to a population of approximately 56,000 residential
customers and various large water users in Bremerton, Washington. In addition to its 56,000 customers, the city also sells
water to the Puget Sound Naval Shipyard and Intermediate Maintenance Facility. This customer accounts for 20% of the
city's overall average daily demand of 6.2 million gallons per day (MGD). The city of Bremerton's water system is one of
the few unfiltered surface water supplies in the country and is served by one surface water source: the Union River
Reservoir. The Union River Reservoir provides 60% of the city of Bremerton's water while the other 40% is supplied by 13
groundwater wells.
Climate Threats
The city of Bremerton has focused on a worst case scenario of climate change driven threats including ecosystem
changes within the watershed that could compromise the water quality of the Union River Reservoir, such as wildfires and
tree damage from species like the bark beetle. Although the city has not experienced severe tree damage from pests in
the watershed and has not had a wildfire since the 1930s, their primary concern is that significant water quality changes in
the Union River Reservoir would require a large investment to enhance treatment capabilities.
Planning Process
The city of Bremerton engaged with the U.S. Environmental Protection Agency (EPA) in a series of webinars and an in-
person meeting to conduct a climate change risk assessment using EPA's Climate Resilience Evaluation and Awareness
Tool (CREAT). The city has conducted climate change planning for their utility in the past to better understand local
climate impacts, and is currently using their CREAT assessment to build on and complement those existing efforts.
Adaptation Measures
For this assessment, the city of Bremerton assessed the consequences of a wildfire and ecosystem changes on the Union
River Reservoir. The city developed three adaptation plans in CREAT, including an existing adaptation measures plan
and two other adaptation plans—the Filtration Avoidance Plan and the Filtration Plan—that contain adaptation measures
that would provide additional protection to the city of Bremerton's assets from climate change threats in the future.
Following refinement of CREAT inputs, the city of Bremerton plans to use CREAT to screen the cost effectiveness and
overarching benefits of potential adaptation measures to inform which of those measures can be incorporated into current
and future climate change adaptation planning efforts. See the table below for details regarding potential adaptive
measures that were considered.
City of Bremerton Utilities Case Study — Page 1
*>EPA

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Case Study: Water and Wastewater Utilities Planning for Climate Change
TYPE
POTENTIAL ADAPTIVE MEASURES
Filtration Plan
Construction and maintenance of a water filtration plant

Forest monitoring - tracking of forest health and presence/incidence of
pests/disease
Filtration Avoidance
Improvement of existing water quality monitoring of the Union River Reservoir to
reduce the consequences from water quality degradation and ecosystem
changes

Improvement of current fire management practices and patrols to reduce the
consequences from water quality degradation and ecosystem changes
Contact Information
For more information regarding the city of Bremerton's climate adaptation planning, contact Kathleen Cahall at
Kathleen. Cahall@ci.bremerton.wa. us.
City of Bremerton Utilities Case Study — Page 2
c/EPA
Office of Water (4608T)
EPA 810-S-16-007
January 2017

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