Earthquake Resilience Guide for Water and Wastewater Utilities


EARTHQUAKE RESILIENCE GUIDE
for Water and Wastewater Utilities
Select a menu option below.
Introduction
and Video
Step 1.
Understand the
Earthquake Threat
Step 2.
Identify Vulnerable
Assets and Determine
Consequences
Disclaimer: This guide is not intended to serve as regulatory guidance. Mention of trade names, products or services does not convey
official United States Environmental Protection Agency (EPA) approval, endorsement or recommendation for use.
Step 3.
Pursue Mitigation and
Funding Options
SEPA
EPA Office of Water (4608T) | EPA 810-B-18-001 | March 2018
Next ~

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oEPA
Introduction and Video
Introduction
and Video
Step 1
Understand the
Earthquake Threat
Step 2
Identify Vulnerable
Assets and Determine
Consequences
Step 3
Pursue Mitigation
and Funding
Options
An earthquake is a sudden and violent shaking of the ground caused by movement within the earth's crust or by volcanic
activity. While certain regions are more prone to seismic activity, earthquakes can occur anywhere in the country.
Earthquakes are difficult to predict and they may result in large-scale social and
economic impacts.
The water sector is particularly vulnerable to earthquake damage and service
disruptions. As stated in Resilience by Design from the Los Angeles Mayoral Seismic
Safety Task Force, "the water system is the utility most vulnerable to earthquake
damage, and that damage could be the largest cause of economic disruption
following an earthquake."
Estimated Annualized Earthquake Losses for
the United States, Losses are increasing due
to more development in earthquake-prone
areas, vulnerability of older infrastructure
and increased public and private sector
interdependences. Estimated losses are $6.1
billion per year with the largest in California
(61%), Oregon and Washington (12%) and
the central states (8%).
By understanding the threat of earthquakes and the potential impacts to both
the water infrastructure and the community, water utility owners and operators can make more informed decisions
on earthquake mitigation options. While requiring financial investment, earthquake mitigation can significantly reduce
or even prevent much costlier damages and economic impacts from future earthquakes. Also, the faster a water or
wastewater utility recovers from an earthquake, the faster the community it serves can recover.
This guide helps water and wastewater utilities to be more resilient to earthquakes. It contains best practices from
utilities that have used mitigation measures to address the earthquake threat. However, utilities should be cautious
about proposing major seismic upgrades based solely on the information in this guide - a more detailed analysis is
recommended. The guide is primarily meant to help:
• Utilities that know they are in earthquake-prone areas, but have not taken steps to address the hazard.
• Small and medium-sized utilities that need to better understand their seismic hazards.
There are three steps in this guide:
Step 1 - Understand the Earthquake Threat.
Step 2 - Identify Vulnerable Assets and Determine Consequences.
Step 3 - Pursue Mitigation and Funding Options.
Click the Surviving the Quake icon to watch a video about potential earthquake impacts to
water systems.
Earthquake Resilience Video

-------
oEPA
Introduction
and Video
Step 1
Understand the
Earthquake Threat
Step 2
Identify Vulnerable
Assets and Determine
Consequences
Step 3
Pursue Mitigation
and Funding
Options
Step 1. Understand the Earthquake Threat
More than 143 million Americans, almost half the population of the United States, live in areas that
are vulnerable to earthquakes.
•	The western United States is particularly vulnerable due to a large number of faults or fractures in the earth's crust.
•	In the central United States, the New Madrid Seismic Zone is a significant threat to at least eight states.
•	In the eastern United States, earthquakes are smaller in magnitude; however, South Carolina has a significant seismic
hazard.
•	Both Alaska and Hawaii are prone to major earthquakes.
With thousands located across the country, many
water and wastewater utilities are in earthquake
hazard areas.
Is your Utility in an Earthquake Hazard Area?
•	First, determine the earthquake threat to your
utility. Use EPA's Earthquake Interactive Maps to
locate your utility on the hazard maps.
•	Then, contact your state hazard mitigation officer
and work with your local mitigation planner. They
may have already assessed and characterized
your local earthquake hazard.
Click "Next" to learn about types of earthquakes.
Click for Earthquake Interactive Maps
page 1 of 3
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oEPA
Introduction
and Video
Step 1
Understand the
Earthquake Threat
Step 2
Identify Vulnerable
Assets and Determine
Consequences
Step 3
Pursue Mitigation
and Funding
Options
Step 1. Understand the Earthquake Threat
Types of Earthquakes
• Natural Earthquakes. Earthquakes occur on fault lines when rock bodies slip relative to each other. Seismic activity can
happen deep in the earth or closer to the surface. The deepest earthquakes occur at subduction zones,
where dense oceanic crust will sink, or subduct, under the lighter continental crust. Because of the large
amount of seismic energy released at subduction zones, such earthquakes can shake the ground over
many hundreds of miles. In contrast, crustal earthquakes are generally shallower. They can still cause
intense shaking in more localized areas and are more likely to have fault displacement that ruptures the
ground surface.
I DETOUR
Learn about
earthquake severity,
or intensity scales
• Induced Earthquakes. Induced earthquakes are caused
by human activity and may be triggered by such actions
as impoundment of reservoirs, surface and underground
mining, withdrawal of fluids and gas from the subsurface and
injection of fluids into underground formations. For example,
when injected fluid finds its way to a stressed earthquake
fault, the fluid can prompt fault movement and induce
earthquakes. In the central United States, the number of
earthquakes has increased dramatically since 2009 based on
United States Geological Survey data. Typically, the seismic
intensity of induced earthquakes is relatively small and
not likely to cause much damage to water and wastewater
utilities. However, larger and potentially damaging induced
earthquakes have occurred in the past.
Click "Next" to learn about the types of ground movement that
affect utilities.
1200
Central United
States Earthquakes
1973-2016
200
855 M > 3 Earthquakes 1973 - 2008
2897 M > 3 Earthquakes 2009 - 2016
1975 1980 1985 1990 1995 2000 2005 2010 2015
Natural and Induced Earthquakes > 3 Magnitude (USGS. 2016 data)
page 2 of 3

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oEPA
Introduction
and Video
Step 1. Understand the Earthquake Threat
Types of Ground Movement
• Shaking and Ground Displacement. Earthquakes are characterized by shaking that can damage structures. Shaking
may be increased or amplified by the type of topography. For instance, ground shaking is worse in basins with soft
sediments (e.g., Seattle) than in mountainous regions. If you know your utility is located on soft soils, damage may
be worse than expected. The ground can also displace horizontally or vertically at the faults. This can cause surface
ruptures and breaks in piping and other utility assets that cross these ground displacements.
• Liquefaction. When earthquakes occur in areas that are saturated and have loose, sandy
soils (e.g., by rivers, lakes), the shaking can turn the ground to liquid. This phenomenon,
called liquefaction, can be very destructive to your utility because buildings can sink
into the liquefied ground. Buried drinking water pipes also will sink, however sewer
pipes, manholes and pump stations (assets partially filled with air) may float to the
surface. After the earthquake, the liquefied soil will re-solidify, locking tilted buildings
and broken connections into place. To help identify potential liquefaction areas, use the
liquefaction maps in EPA's Earthquake Interactive Maps or contact your state geological
survey office.
• Lateral Spreading. Lateral spreading is the sideways movement of liquefied soils on gentle slopes. This happens when
liquefaction occurs in the subsurface layer, the movement of which can result in the opening of large fissures in the
ground which can reach distances of several hundred feet. It can damage pipes, treatment facilities, wells, tanks and
other water and wastewater assets. If the liquefied material is located far below the surface and there is a significant
slope, the liquefied material and the ground surface can undergo significant down slope movement. This flow can
particularly damage buried pipes and tanks.
• Settling. Earthquakes can cause the ground to change elevation and eventually settle. This is called
ground subsistence and it can have serious impacts on water and wastewater systems, especially in
locations dependent upon gravity flow. For example, in Christchurch, New Zealand, severe ground
settlement of pipes prevented the proper flow of sewage.
M!l^
Learn about other
earthquake hazards
page 3 of 3
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Introduction
and Video
Step 1
Understand the
Earthquake Threat
Step 2
Identify Vulnerable
Assets and Determine
Consequences
Step 3
Pursue Mitigation
and Funding
Options
£EPA
Step 2. Identify Vulnerable Assets and Determine Consequences
Water arid wastewater utilities are particularly vulnerable to earthquakes
because of the extensive network of above and below ground pipelines, pump
stations, tanks, administrative and laboratory buildings, reservoirs, chemical
storage and treatment facilities.
For a drinking water system, an earthquake can cause hundreds ... even
thousands ... of breaks in water pipelines, ruptures in storage and process tanks
and the collapse of buildings. This can cause a loss of water system pressure,
contamination and drinking water service disruptions for your customers.
A wastewater system can also expect infrastructure damage from an
earthquake, including breaks in the collection system. Sewers and wastewater treatment plants tend to be built on ground
which is subject to liquefaction. Damage can lead to sewage backups in homes and potential releases of untreated sewage
into the environment.
To protect your utility, you will need to assess the potential damage to buildings and key assets. This step is broken into
three actions:
• Action 1 - Inventory critical assets and plot them on hazard maps.
• Action 2 - Characterize critical assets, types of failures and consequences to your utility.
• Action 3 - Summarize results and prioritize mitigation.
Click "Next" to learn more about these three actions.
Ultimately, these actions will help you determine the types of mitigation measures and strategies that are worth
considering. However, you still may require technical expertise and analysis from other professionals. State agencies,
other utilities, consultants and free assessment tools may be helpful.

Learn about
assessment tools
page 1 of 5
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Poiaslc VAilcr Tank
_ Vfetar Mans IS" aid
Lager
_ Active FauhZone
Qjjndiy
|wip| /fee'T"salT;enIPBr1
|WTP|
Assets on Hazard Map
Click "Next" to see how to characterize the vulnerability of your buildings and pipelines and then click "Next" again for
tanks and reservoirs, pumps, lift stations and wells, treatment facilities and power assets.
page 2 of 5

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oEPA
Step 2. Identify Vulnerable Assets and Determine Consequences
Action 2 - (continued)
2a) Characterize Buildings. Characterize the
age and construction type of your buildings to
determine their vulnerability to earthquakes.
Note that building failure and collapse are
critical dangers to your personnel. See the table
to the right for summary information relating
anticipated earthquake damage to building
construction type (see Association of Bay
Area Governments Resilience Program). Also,
consult the American Society of Civil Engineers
(ASCE) Standard 41-06 Seismic Rehabilitation of
Existing Buildings (2007). In general, buildings
older than 1995 are more vulnerable to earthquake damage.
2b) Characterize Pipelines. Characterize pipelines to determine vulnerability to earthquakes. Consider
factors including pipe location, age, compatibility with soils, construction materials and number of joints.
From ground shaking, pipes often crack at brittle joints or are crushed at the bell or pipe barrel. From
liquefaction or lateral spreading, pipes often break or separate at the joints. For example, in the Kobe,
Japan earthquake, more than half of the drinking water pipe failures were from joints pulling apart.
Drinking water pipes are commonly made with ductile iron (Dl) (historically cast iron), welded steel,
polyvinyl chloride (PVC), pre-stressed concrete or asbestos cement. Cast iron pipes have the highest break
rate in both liquefaction and non-liquefaction areas. Asbestos cement pipes are known to have moderate
to high vulnerability, especially in liquefaction areas.
Building Structure
Anticipated Damage
Unreinforced masonry
Severely cracked or collapsed walls. Separation
between floors and walls jeopardize vertical support
of roof and floor systems, leading to collapse
Unreinforced brick
Substantial damage
Tilt up concrete
Connection between the roof and walls can fail
causing roof collapse
Non-ductile concrete frame
Lateral movement can strain frame with
catastrophic consequences
Non-Structural elements (cladding)
Detach from building injuring people and impeding
evacuation or access
Learn more about
pipe vulnerability
Wastewater pipes are more prone to damage than drinking water pipes, however in terms of function, damaged sewer
pipes may still be operational with some leakage. Wastewater pipes are typically made of reinforced concrete, PVC,
vitreous clay and fiberglass. Such pipes and manholes may buoyantly float in liquefied soils, causing severe problems.
In general, pipelines are prone to failure at connections to aboveground structures, such as reservoirs, treatment plants,
pump stations and at bridge or fault crossings.
page 3 of 5

-------
oEPA
Introduction
and Video
Step 1
Understand the
Earthquake Threat
Step 2
Identify Vulnerable
Assets and Determine
Consequences
Step 3
Pursue Mitigation
and Funding
Options
Step 2. Identify Vulnerable Assets and Determine Consequences
Action 2 - (continued)
2c) Characterize Tanks and Reservoirs. Damage to storage tanks can occur
from the actual shaking as well as the permanent ground deformation caused
from liquefaction, landslides, etc. Types of damage include sliding on the
foundation, elephant foot buckling for steel tanks, stretching of bars for wood
tanks or cracking or shearing of walls for concrete tanks. Also, liquids in tanks or
reservoirs can slosh and create forces on tank walls beyond the design capacity.
In the 1994 Northridge earthquake, movement of a water tank caused the
piping to sever. A steel tank at a utility in Los Angeles suffered elephant foot
buckling from sloshing.
2d) Characterize Pumps, Lift Stations and Wells. Pay particular attention to wastewater pump stations and booster pumps
in liquefiable soils as they often float, which severs connecting piping. An inoperable lift station can cause wastewater to
overflow and backup into residences and commercial buildings. Manholes may also float. For wells, ground movement,
including liquefaction-induced lateral spreading, can bend casings, distort vertical shafts and disable well pumps.
2e) Characterize Treatment Facilities. Treatment structures at water and wastewater utilities
have a wide variety of equipment, processes and chemicals. Wastewater treatment buildings
tend to be near rivers in areas subject to liquefaction. Also (as in the 1989 Loma Prieta
earthquake in California), clarifiers can be heavily damaged due to sloshing wastewater. In
another example, an earthquake created a chemical spill that entered the collection system
of a wastewater utility, which then caused the biological treatment process to fail. Coupled
with the loss of power to the blowers, the secondary treatment system was inoperable for
several weeks.
2f) Characterize Power Assets. Maintaining electric power is key for both water and wastewater operations. Earthquake
damage to power lines, transformers, generators and feeds will disrupt equipment functionality. Assets from both the
power utility and the water and wastewater utility need to be assessed for possible failure and restoration.
page 4 of 5
Damaged clarifier
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oEPA
Step 2. Identify Vulnerable Assets and Determine Consequences
Action 3 - Summarize results and prioritize mitigation
After completing Actions 1 and 2, summarize your asset vulnerability and consequences in a simple table such as the one
below. Then, determine the "Priority for Mitigation" (last column) based on your best professional judgment and advice
from government or private sector experts.

Sample Evaluation Factors
Priority for
Mitigation
Critical Asset
or Resource
Subject to liquefaction
Not seismically protected
May endanger employees
Close to earthquake fault
In earthquake hazard zone
Reliant on grid power
Materials, design or age make asset
vulnerable
Impacts firefighting ability
Critical for clean water and sewage
treatment
Enhances response and/or recovery
Failure may endanger public
Consequence
s
O
	1
Medium
sz
CD
in
Pump #5

Y

y
~
y





Pump is the backup for Pump #6. Loss of
pump could be handled by...

y

Cast iron
pipe near
treatment
facility
Y
Y


Y

Y
Y
Y


Cast iron pipes fail at joints to above-
ground buildings. Result in loss of system
pressurization. No drinking water for weeks
and limited water available for firefighting.


Y
Occupied
building #1

y
y

y
y


y


Building could collapse and endanger
workforce.


Y
page 5 of 5
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-------
oEPA
Introduction
and Video
Step 1
Understand the
Earthquake Threat
Step 2
Identify Vulnerable
Assets and Determine
Consequences
Step 3
Pursue Mitigation
and Funding
Options
Step 3. Pursue Mitigation and Funding Options
Consider mitigation actions and projects to help your utility better withstand an earthquake, minimize damage and rapidly
recover from disruptions to service. An example is to replace vulnerable buried pipe with seismic resistant pipe. Such
efforts can be part of a long term capital improvement and asset management plan. As one strategy, when you replace
aging equipment after its design life, install seismic upgrades, which are typically not major added costs.
Mitigation Options
Fortunately, many utilities have evaluated the threat of earthquakes and taken actions to mitigate damage. Explore some
of these mitigation approaches, including several low cost options.
Mitigation for Immediate
Life Safety
Mitigation for Key Systems
in Hazard Areas
Mitigation through
Emergency Response
Mitigation by Specific
Asset

^etourJ

Learn more about mitigation
from other sources
I DETOUR
Learn more about
seismic building codes
Funding Options
Utilities have many options to implement and fund earthquake mitigation projects. Click Funding Options:
Funding Options
page 1 of 14
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-------
oEPA
Introduction
and Video
Step 1
Understand the
Earthquake Threat
Step 2
Identify Vulnerable
Assets and Determine
Consequences
Step 3
Pursue Mitigation
and Funding
Options
Step 3. Pursue Mitigation and Funding Options
Mitigation for Immediate Life Safety
s
Mitigation Options
Cost
1. Protect your employees


a. Make sure employees know your emergency response plans and practice emergency action drills.
$

b. Maintain emergency generators (seismically certified) at employee locations to help mitigate widespread power outages.
$$

c. Prevent collapse of occupied buildings. For seismic protection of new buildings, follow ASCE 7 Standard Minimum Design Loads for
Buildings. To retrofit buildings (e.g., bracing or shear walls), follow ASCE 41-06 Seismic Rehabilitation of Existing Buildings.
$$$

d. Anchor equipment (e.g., computers, bookshelves) as well as laboratory equipment and chemical and fuel tanks.
$

e. Identify people who can perform post-earthquake building inspections for safety.
$
2. Protect the public from catastrophic failures of vulnerable storage tanks or reservoirs

a. Seismically retrofit water tanks (e.g., anchoring to foundations).
$$$

b. Strengthen concrete tank walls, replace non-flexible connections and improve roof structures over large reservoirs.
$$$

c. For new tank installations in high risk seismic zones, determine If liquefaction or other permanent ground movements are possible. If
so, stabilize the foundation to minimize movement. Design the tank height to safely account for sloshing forces during an earthquake.
$$$
3. Plan for emergency public health and firefighting

a. Work with your community and state on an emergency plan for drinking water and sewage treatment (e.g., improvised chemical toilets).
$

b. Develop a plan for emergency sewage capability, including portable or improvised chemical toilets.
$

c. Plan for use of temporary bypasses to move wastewater flow away from the public following ground movement.
$$

d. Address high consequence sewers like those that are difficult to repair (e.g., under rivers, highways or buildings).
$$$

e. Coordinate with firefighters on a plan to obtain alternate water supplies like swimming pools, reclaimed water and seawater.
$
Cost Key (Ranks relative costs of mitigation measures - actuai costs may differ for your utility)
$ - Little to no cost. Some internal level of effort required, but no contractor support needed.
$$ - Moderate cost and complexity. Likely involves contractual costs
$$$ - High cost and complexity. Will require one or more contractors to implement this option.
page 2 of 14
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Mitigation Options
Cost
1. Reinforce "backbone" of your utility (e.g., treatment facilities, transmission lines, large diameter pipelines and storage tanks)

a. For a water system, consider installing isolation valves on main transmission lines. For pipes in areas with a moderate to high
liquefaction hazard or that traverse active faults, replace with pipes designed to the specifications in Seismic Guidelines for Water
Pipelines (ALA, 2005). In general, use steel with welded joints, high-density polyethylene (HDPE) pipes with fused joints, ductile iron
with seismic joints and molecularly oriented PVC (PVCO) with restrained joints (American Water Works Association C909 PVCO
Pressure Pipe, 4 In. through 24 In., for Water, Wastewater, and Reclaimed Water Service; 2010).
$$$

b. Design the backbone of your utility to supply water to critical facilities (e.g., hospitals and fire suppression points). This strategy might
require special points of distribution or other ways to deliver water from the backbone. Also, consider quick fixes (e.g., temporary piping
to maintain capability) in the short term as you wait for completion of expensive mitigation projects that may take years to implement.
$$-
$$$

c. For a wastewater system, seismically harden major trunk lines and pump stations.
$$$
2. Address liquefaction areas and fault lines

a. Consider options to protect fixed water system assets, including improving soils with soil mixing, cement grouting, stone columns,
piles, compaction or movement of assets into non-liquefaction areas. Consult geotechnical engineers and engineering geologists
experienced in liquefaction hazard mitigation.
$$$

b. Position drinking water wells outside of seismic hazard zones if possible.
$$$
c. Require mitigation for key pipelines that cross known and active fault lines. Consider installing a bypass or temporary emergency
pumping systems as well as replacing hard (inflexible) tank joints with soft (flexible) or ball joints to limit breakage.
$$$
Cost Key (Ranks relative costs of mitigation measures ¦¦ actual costs may differ for your utility)
$ ¦ Little to no cost. Some internal level of effort required, but no contractor support needed.
$$ - Moderate cost and complexity. Likely involves contractual costs.
$$.$ -¦ High cost and complexity. Will require one or more contractors to implement this option.
page 3 of 14
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a. Develop an emergency response plan (ERP) that includes procedures for earthquakes. $-$$

b. Ensure that employees are trained on the ERP and periodically exercise its procedures to maintain an acceptable level of readiness.
Also, train workers in the incident command svstem so that utilitv resDonders can better coordinate with other local and state
responaers. Participate in community-wide earthquake preparedness training and exercises.
$

c. Consider back-up locations for your Emergency Operations Center and back-up systems for emergency communications (e.g., 800
MHz radios)
$$

d. Consider preparing emergency "Go Kits" for employees and their families.
$

e. Establish and maintain a current list of key contacts and phone numbers for local agencies, contractor services support, material supply
vendors and Interdependent services within the community.
$

f. Coordinate earthquake preparedness activities with interdependent services within the community, such as power providers, and with
critical customers, such as hospitals and major commercial entities.
$
2. Maintain Assets for Response

a. Have adequate spare parts (e.g., temporary piping, pre-made hose bibs and hydrant cable connections), equipment and certified,
trained staff to rapidly fix damage after an earthquake.
$$

b. Address how power will be restored to pump stations (e.g., permanent or portable generators, portable pump connections and whether
to own, share or contract fuel trucks for generators).
$$-
$$$

c. Join a mutual aid network like the Water and Wastewater Agency Response Network (WARN). During the Napa earthquake, the Napa
water utility used the California WARN to request seven teams from other utilities to help repair pipelines.
$

d. If appropriate, maintain a fleet of small water tanker trucks or water buffaloes and the fuel needed to operate them.
$$
Cost Key (Ranks relative costs of mitigation measures - actual costs may differ for your utility)
$Little to no cost. Some internal level of effort required, but no contractor support needed.
% - Moderate cost and complexity. Likely involves contractual costs.
$$$ - High cost and complexity. Will require one or more contractors to implement this option.
page 4 of 14
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Introduction
and Video
£EPA
Step 3. Pursue Mitigation and Funding Options
Mitigation by Specific Asset
Click a photograph below and get information on specific earthquake mitigation options for that asset.
Return ^ Previous Next ~
page 5 of 14
Basins, Reservoirs and
Impoundments
Above Ground Storage
Tanks
Power Supply and
Electrical Components
Treatment Facilities,
Pumps, Lift Stations and
Sewers
Wells, Source Water and
Dams

-------
oEPA
Introduction
and Video
Step 1
Understand the
Earthquake Threat
Step 2
Identify Vulnerable
Assets and Determine
Consequences
Step 3
Pursue Mitigation
and Funding
Options
Step 3. Pursue Mitigation and Funding Options
Mitigation for Pipes
Cost Key (Ranks relative costs of mitigation measures - actual costs may differ for your utility)
$ - Littie to no cost. Some internal level of effort required, but no contractor support needed.
'|| - Moderate cost and complexity. Likely involves contractual costs.
$$$ - High cost and complexity. Will require one or more contractors to implement this option.

Mitigation Options
Cost
1. Above Ground Pipes

a. Brace pipes with ties or other methods; provide flexibility arid connections to hard points.
$$
2. Underground Pipes - Non Liquefaction Areas

a. Use modern pipe (e.g., Dl, PVC) which is typically adequate for areas with small to moderate ground motions and no
permanent ground deformation.
$$

b. Replace vulnerable transmission and backbone piping first before distribution piping. For vulnerable pipelines, consider
installing redundant pipes in locations with less seismic activity.
$$$
3. Underground Pipes - Liquefaction Areas

a. Use seismic resistant pipe such as steel with welded joints, HDRE with fused joints, Dl with seismic joints or molecularly
oriented PVC with restrained joints (AWWA C909) for transmission pipelines subject to ground deformation from liquefaction
and landslides.
$$

b. Slip line existing pipe with HDPE to decrease the pipe's vulnerability.
$$

c. Replace pipes In accordance with Seismic Guidelines for Water Pipelines (ALA, 2005) in areas with moderate to high
liquefaction or that traverse active faults.
$$$

d. Consider changing pipe alignment to avoid liquefiable areas or replace with new pipe. Intake pipes are often susceptible to
liquefaction. Stabilization of soils (e.g., deep soil mixing and stone columns) is possible, but expensive.
$$$

e. install portable facilities (e.g., hoses, pumps) to allow pipelines to bypass areas of liquefaction.
$$
page 6 of 14
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-------
oEPA
Introduction
and Video
Step 1
Understand the
Earthquake Threat
Step 2
Identify Vulnerable
Assets and Determine
Consequences
Step 3
Pursue Mitigation
and Funding
Options
Step 3. Pursue Mitigation and Funding Options
Mitigation for Buildings
Follow ASCE 7 for new buildings and ASCE 41-06 for retrofitting of buildings. Retrofits could be accomplished by adding
new seismic bracing or shear walls. Do not forget to anchor equipment within buildings (e. g., computers, bookshelves
and vending machines). You can find additional suggestions in the Association of Bay Area Governments Resilience
Program or ASCE 41-06.
y
Mitigation Options
Cost
1. Unreinforced Masonry Buildings

a. Tie walls to floor and ceiling elements or anchor unsupported masonry walls, install bracing or apply wall overlays to add
strength.
$$$
2. Non-Ductile Concrete Frame Buildings

a. Add interior walls or jacketing or wrap concrete structural columns for strength and ductility.
$$$
3. Tilt-up Concrete Building

a. Bracket the walls to the roof.
$$
Cost Key (Ranks relative costs of mitigation measures - actual costs may differ for your utility)
$ ¦ Little to no cost. Some internal level of effort required, but no contractor support needed.
$.$ - Moderate cost and complexity. Likely involves contractual costs.
$.$$ - High cost and complexity. Will require one or more contractors to implement this option.
page 7 of 14
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-------
oEPA
Introduction
and Video
Step 1
Understand the
Earthquake Threat
Step 2
Identify Vulnerable
Assets and Determine
Consequences
Step 3
Pursue Mitigation
and Funding
Options
Step 3. Pursue Mitigation and Funding Options
Mitigation for Treatment Facilities, Pumps, Lift Stations and Sewers
/
Mitigation Options
Cost
1. For Both Liquefaction and Non Liquefaction Areas

a. Anchor or brace pumps, process and lab equipment.
$

b. Maintain seismicaily certified (see the international Building Code) emergency generators at key facilities to help mitigate
widespread power outages.
$$
2. For Liquefaction Areas

a. Consider mitigation approaches, including improving soils with soil mixing, cement grouting, stone columns, compaction and
piles for treatment facilities. Piping associated with treatment faciiities may also benefit from these strategies.
$$$

b. Provide flexible connections for pipeline connections to pump stations.
$-$$

c. Consider what design might be best for new sewers in liquefiable soils, as sewers and manholes will float during an
earthquake. HDPE with tie downs Is one alternative, another is adding concrete to manholes to reduce their buoyancy.
$$
Cost Key (Ranks relative costs of mitigation measures -¦ actual costs may differ for your utility)
$ - Little to no cost. Some internal level of effort required, but no contractor support needed.
$$ - Moderate cost and complexity Likely involves contractual costs.
$$$ - High cost and complexity. Will require one or more contractors to implement this option.
page 8 of 14
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-------
oEPA
Introduction
and Video
Step 1
Understand the
Earthquake Threat
Step 2
Identify Vulnerable
Assets and Determine
Consequences
Step 3
Pursue Mitigation
and Funding
Options
Step 3. Pursue Mitigation and Funding Options
Mitigation for Basins, Reservoirs and Impoundments
/
Mitigation Options
Cost
1. For Both Liquefaction and Non Liquefaction Areas

a. Reinforce concrete structures, strengthen concrete tank walls, use flexible connections to pipes (e.g., ball joints) and improve
roof structures over large reservoirs.
$$$

b. Strengthen reservoirs by buttressing basin walls.
$$$

c. Increase capacity for buried, seismically-protected drinking water storage. Consider redundancy of these assets for the short
term, but you will need to evaluate cost effectiveness.
$$$

d. Replace hard (inflexible) tank joints with soft (flexible) joints to limit breakage especially where tank wall uplift is anticipated
(e.g., unanchored tanks).
$$

e. Anchor older pre-stressed concrete tanks with seismic cables.
$$

f. Use AWWA Standards D100-10 (Welded Carbon Steel Tanks for Water Storage, 2010) D110-13 (Wire and Strand Wound,
Circular, Prestressed Concrete Water Tanks, 2013) and D115-06 (Tendon Prestressed Concrete Water Tanks, 2006). For
concrete tanks and basins, use ACI 350-06 (Code Requirements for Environmental Engineering Concrete Structures, 2006).
$
Cost Key (Ranks relative costs of mitigation measures - actual costs may differ for your utility)
$ - Little to no cost. Some internal level of effort required, but no contractor support needed.
.$$ - Moderate cost and complexity. Likely involves contractual costs.
.$$$ - High cost and complexity. Will require one or more contractors to implement this option.
page 9 of 14
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a. Conduct site-specific subsurface investigations for new tank installations in high seismic zones to determine the potential for
permanent ground movements. If the site has a moderate to high potential for movement, use steel tanks rather than concrete
unless the hazard is mitigated.
$$$

b. Reinforce the foundation on large horizontal tanks. Some unanchored tanks will sustain damage where they connect to fixed
piping.
$$$

c. Consider automatic shutoff valves on tanks. Use only on tanks in pressure zones with multiple reservoirs and feeds.
$$

d. Seismically retrofit water tanks, which can include anchoring to foundations, strengthening concrete tank walls, replacing non-
flexible pipe connections and improving roof structures over large reservoirs.
$$$
2. Chemical Tanks

a. Anchor or restrain chlorine containers and chemical tanks.
$
Cost Key (Ranks relative costs of mitigation measures - actual costs may differ for your utility)
$ ¦ Little to no cost. Some internal level of effort required, but no contractor support needed.
$.$ - Moderate cost and complexity. Likely involves contractual costs.
$.$$ - High cost and complexity. Will require one or more contractors to implement this option.
page 10 of 14
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-------
oEPA
Introduction
and Video
Step 1
Understand the
Earthquake Threat
Step 2
Identify Vulnerable
Assets and Determine
Consequences
Step 3
Pursue Mitigation
and Funding
Options
Step 3. Pursue Mitigation and Funding Options
Mitigation for Power Supply and Electrical Components*
/
Mitigation Options
Cost
1. Power Supply

a. Consider purchasing or renting seismically-certified backup power generators. Fixed generators and associated systems must
be anchored.
$$

b. Have portable generators available to dispatch with capacities determined and plug-ins designed for specific facilities.
$$

c. Test emergency power options regularly.
$

d. Communicate with your power company to prioritize electricity restoration to water and wastewater utilities.
$
2. Electrical Components

a. Add electrical redundancy at treatment plants. Note that multiple feeds may come from the same high voltage substation,
which may itself be vulnerable to earthquakes.
$

b. Install new anchorages for transformers and reroute electrical boxes.
$$
"Refer to Power Resilience Guide for Water and Wastewater Utilities for additional suggestions.
Cost Key (Ranks relative costs of mitigation measures - actual costs may differ for your utility)
$ - Little to no cost. Some internal level of effort required, but no contractor support needed
$$ * Moderate cost and complexity. Likely involves contractual costs.
$$$« High cost and complexity. Will require one or more contractors to implement this option.
page 11 of 14
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a. Consider locating wells outside of seismic hazard zones. Wells are vulnerable if exposed to ground deformation from
liquefaction, fault activity and landslides.
ip Cp-vP vpvp
b. Design the upper casing (approximately 40 feet) to resist all imposed loads due to liquefaction and/or lateral spread.
$$
c. Use stainless steel screens rather than slotted casings to avoid corrosion failures that can result in a loss of capacity or water
quality issues.
$$
d. Provide well discharge piping with the ability to accommodate differential settlement between the well head and buried pipe.
$$
2. Source Water

a. Explore a diversity of water sources (e.g., river, groundwater or reservoir) and associated supporting facilities. Certain water
sources may be more vulnerable to earthquakes.
vP vp-vP VpxP
3. Dams

a. Assess dam vulnerability with an expert. The consequence of dam failure can be very high in terms of public safety.
$$$
Cost Key (Ranks relative costs of mitigation measures - actual costs may differ for your utility)
$ - Little to no cost. Some internal level of effort required, but no contractor support needed.
.$$ - Moderate cost and complexity. Likely involves contractual costs.
.$$$ - High cost and complexity. Will require one or more contractors to implement this option.
page 12 of 14
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-------
oEPA
Introduction
and Video
Step 3. Pursue Mitigation and Funding Options
Funding Options
Step 1
Understand the
Earthquake Threat
Step 2
Identify Vulnerable
Assets and Determine
Consequences
Step 3
Pursue Mitigation
and Funding
Options
Federal Funding for Mitigation Projects. Receiving federal funding for an earthquake
mitigation project often requires diligence, good connections with local mitigation
planners and a strong application. To help utilities understand and obtain federal
disaster and mitigation funds, EPA developed Fed FUNDS. Fed FUNDS can help you
quickly screen for applicable funding programs from FEMA, EPA, the United States
Department of Housing and Urban Development (HUD), the United States Department
of Agriculture (USDA) and the Small Business Administration (SBA). It also provides
examples of successful utility applications and tips to get funding.
FEMA has three individual programs to fund mitigation projects for earthquake resilience:
• Public Assistance (PA) Grant Program.
• Hazard Mitigation Grant Program (HMGP).
• Pre-Disaster Mitigation (PDM) Program.
Each program has specific project eligibility and funding requirements. Typically,
the proposed mitigation projects must go through a benefit-cost analysis and show
clear benefits. See the FEMA STAPLEE Method for a formal benefit-cost review used
for FEMA funded projects.
Utilities in Utah became involved in
their local hazard mitigation process
and ended up receiving significant
FEMA and Bureau of Reclamation
funds for earthquake mitigation.
When evaluating the mitigation
approaches, consider:
• Effectiveness in mitigating asset damage.
• Practicality in implementing mitigation
options.
• Costs, including capital, operations and
maintenance.
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Become Eligible for Funding by Joining Local Mitigation Efforts. Local governments
are required to develop hazard mitigation plans and have strategies in place to
mitigate the effects of natural disasters, including earthquakes. Be sure that local
mitigation plans include language about mitigating earthquakes at your utility so that proposed mitigation projects
become eligible for federal funding. Also, adopt seismic design standards for new facilities, so that if the facility is
damaged in an earthquake, the Federal Emergency Management Agency (FEMA) will reimburse you to the adopted
standard. How can you partner with your local mitigation planner? Check out EPA's Hazard Mitigation Guide for Natural
Disasters.

-------
oEPA
Introduction
and Video
Step 1
Understand the
Earthquake Threat
Step 2
Identify Vulnerable
Assets and Determine
Consequences
Step 3
Pursue Mitigation
and Funding
Options
Step 3. Pursue Mitigation and Funding Options
Funding Options
Develop a Plan to Implement Earthquake Mitigation Projects. The plan should identify the actions to implement the
project, the time to complete the project, the lead person or agency responsible for taking the actions and the costs
and funding sources (e.g., grant funds or capital expenditures). The plan should reflect a long-term commitment to
the project. Depending on the size, cost and complexity, some mitigation actions may be completed through internal
work orders, capital improvement planning or supplemental funding. The use of multiple funding sources is an effective
strategy. See a sample mitigation project plan below.
Mitigation Project
Actions to Implement Mitigation Project
Time to
Complete
Lead Individual or
Agency
Funding Source
Seismic Retrofit of Water
Tanks
* Develop proposal that outlines basic engineering plans and a
benefit-cost analysis to retrofit tanks (2 months).
»Incorporate project into local hazard mitigation plan and capital
improvement budget (3 to 10 months).
«Take proposal to town manager for preliminary approval (4 months).
• Work with local mitigation official and pursue FEMA mitigation funds
(4 months to 1 year).
1 year
Operations and
Financing
Capital
improvement
funding and
FEMAHMGP
Seismic Emergency
Power Generator
• Develop proposal that outlines basic engineering plans and a
benefit-cost analysis for a seismic generator (note benefits for other
disasters); include costs for operations, maintenance and fuel (2
months).
• Talk to power utility about priority restoration of electricity as well as
possibility of a generator (2 to 3 months).
• Talk to fuel vendors to establish agreements (within 2-3 months).
• Take proposal to town manager for preliminary approval (4 months).
• Work with local mitigation official and explore idea of getting
FEMA mitigation funds for generator, perhaps bundled with other
measures (4 months to 1 year).
1 year
Operations and
Financing
Capital
improvement
funding and
FEMAHMGP
page 14 of 14
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oEPA
Measuring Earthquake Severity
Introduction
and Video
Step 1
Understand the
Earthquake Threat
Step 2
Identify Vulnerable
Assets and Determine
Consequences
Step 3
Pursue Mitigation
and Funding
Options

Modified Mercalli Intensity Scale
Scale ranging from I to XII based on damage at a particular location. The more the damage, the higher the number.

Intensity
Shaking
Description and Damage
I
Not felt
Not felt.
II
Weak
Felt only by people sitting or those on upper floors of buildings.
III
Weak
Felt by almost all persons indoors. Hanging objects swing. Vibrations felt similar to the passing of a
truck. May not be recognized as an earthquake.
IV
Light
Felt by all indoors and a few outdoors. Some awakened at night. Stopped cars rock. Windows, dishes
and doors rattle. Glasses clink. In the upper range of IV, wooden walls and frames creak.
V
Moderate
Felt by nearly everyone; many awakened. Some dishes and windows broken. Unstable objects
overturned. Pendulum clocks may stop.
VI
Strong
Felt by all. People walk unsteadily. Windows crack. Dishes, glassware, knickknacks and books fall off
shelves. Pictures fall off walls. Furniture moved or overturned. Weak plaster, adobe buildings and some
poorly built masonry buildings crack. Trees and bushes shake visibly.
VII
Very
strong
Difficult to stand or walk. Noticed by drivers in cars. Damage to poorly built masonry buildings. Weak
chimneys broken at roof line. Plaster, loose bricks, stones, tiles, cornices, unbraced parapets and
porches fall. Some masonry buildings crack. Waves on ponds.
VIII
Severe
Steering of cars affected. Extensive damage to unreinforced masonry buildings, including partial
collapse. Some masonry walls collapse. Chimneys twist and fall. Wood-frame houses moved on
foundations if not bolted; loose partition walls thrown out. Tree branches broken.
IX
Violent
General panic. Damage to masonry buildings ranges from collapse to serious damage unless modern
design. Wood-frame structures rock and, if not bolted, shift off foundations. Underground pipes broken.
It is also likely that pipes are broken at lower intensities.

Extreme
Some well-built wooden structures and bridges destroyed; most masonry and frame structures
destroyed with their foundations. Rails bent. Poorly built structures destroyed with their foundations.
¦

Rails bent greatly. Underground pipelines completely out of service.
m

Damage nearly total. Large rock masses displaced. Lines of sight and level distorted. Objects thrown
into the air.
Richter Scale*
Magnitude
Strength of

Earthquake
3-3.9
minor
4-4.9
light
5-5.9
moderate
6-6.9
strong
7-7.9
major
8+
great
"Logarithmic measure of total
energy (magnitude) released
at epicenter (point on earth's
surface directly above where
earthquake starts). Scale does
not relate to damage.
Moment Magnitude
logarithmic measure of
energy release.
function of the length, width
and fault offset,
replacing Richter Scale.
Return

-------
oEPA
Introduction
and Video
Step 1
Understand the
Earthquake Threat
Step 2
Identify Vulnerable
Assets and Determine
Consequences
Step 3
Pursue Mitigation
and Funding
Options
Learn More about Earthquake Hazards
Below are other hazards that can accompany earthquakes. Also, the United States Geological Survey
has a wealth of information on earthquakes.
Tsunamis. In the ocean, an earthquake may generate significant tsunamis (huge waves of
water) that can severely damage your coastal infrastructure. Tsunamis can be generated from
displacement of faults under the ocean or from generation of large landslides. For example, an
earthquake at the Cascadia subduction zone could cause a tsunami off the coasts of Oregon,
Washington and northern California. One study looked at flood inundation and evacuation
maps for two small coastal towns in Oregon. Tsunamis can also strike coastal states even
though they may be generated by earthquakes in other states and countries.
Landslides and Rockfalls. Shaking can trigger landslides and rockfalls. Both can damage
aboveground utility structures as well as buried pipelines.
Flooding. Earthquakes can damage dams and reservoirs that can potentially release floods that
can threaten populations and damage infrastructure.
Fires. Outbreaks of fires often accompany earthquakes. This presents a potential challenge
when fires are near utility assets as well as an added responsibility of the utility to maintain „ . ,
' Computer modeling
water availability for firefighting. ofa tsunamj aftera
hypothetical magnitude
7.8 earthquake on the
Cascadia subduction zone.
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Introduction
and Video
Step 1
Understand the
Earthquake Threat
Step 2
Identify Vulnerable
Assets and Determine
Consequences
Step 3
Pursue Mitigation
and Funding
Options
£EPA
Tools to Assess Your Specific Structures
If you want to perform a seismic analysis of your specific structures (e.g., treatment buildings,
biosolids building, administration building, electrical controls), there are free tools to help, but it may
take some time and experience to use them.
FEMA Hazus - Contains models for estimating potential losses from earthquakes, floods and hurricanes. Hazus uses
Geographic information Systems (GIS) technology to estimate physical, economic and social impacts of disasters.
Chapter 8 of the Technical Manual for Earthquakes Model focuses on direct damage to water utilities and wastewater
utilities as well as estimated restoration time.
ROVER - Rapid Observation of Vulnerability and Estimation of Risk, is FEMA's free mobile software to inventory buildings
(including location) and help building managers prioritize evaluation and rehabilitation after an earthquake.
ShakeCast and ShakeMaps - During earthquake response, these free USGS software products predict damage to your
buildings from actual earthquakes and notify you so that you can take quick actions to ensure safety and restore your
utility. For earthquake planning, ShakeMaps has earthquake scenarios that you can use to determine the potential
damage to your buildings.
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Introduction
and Video
Step 1
Understand the
Earthquake Threat
Step 2
Identify Vulnerable
Assets and Determine
Consequences
Step 3
Pursue Mitigation
and Funding
Options
Pipe Vulnerability
oEPA
Pipe Material Type and Diameter
AWWA Standard
Joint Type*
Low Vulnerability
Ductile Iron
C1xx Series
B&S, RG, R
Polyethylene
C906
Fused
Steel
C2xx Series
Arc Welded
Molecularly Oriented PVC
C909
B&S, RG, R
Ductile Iron Seismic Joint
C1xx Series
Pb&S, RG, R
Low to Medium Vulnerability
Concrete Cylinder
C300, C303
B&S, R
Ductile Iron
C1xx Series
B&S, RG, UR
PVC
C900, C905
B&S, R
Steel
C2xx
B&S, RG, UR
Moderate Vulnerability
AC > 8" D
C4xx Series
Coupled
Cast Iron > 8" D
None
B&S, RG
PVC
C900, C905
B&S, UR
Concrete Cylinder
C300, C303
B&S, UR
Moderate to High Vulnerability
AC <= 8" D
C4xx Series
Coupled
Cast Iron <= 8" D
None
B&S, RG
Steel
None
Gas Welded
High Vulnerability
Cast Iron
None
B&S, Rigid
Utilities can use empirical
relationships developed by the
American Lifelines Alliance (ALA,
2005) to predict the number of
breaks and leaks in your pipeline
system. Estimate the time
required to both repair the breaks
and leaks and restore system
functionality based on historical
crew productivity data.
*B&S - bell and spigot; RG - rubber gasket; R-restrained; UR - unrestrained
Vulnerability was based on consideration of ruggedness, bending, joint flexibility and joint restraint.
Source: Overview of Piping Systems and their Seismic Vulnerability; Donald Ballantyne, Ballantyne Consulting LLC; National Water and Wastewater Association meeting (2014).
Return

-------
oEPA
Introduction
and Video
Step 1
Understand the
Earthquake Threat
Step 2
Identify Vulnerable
Assets and Determine
Consequences
Step 3
Pursue Mitigation
and Funding
Options
Standards and Building Codes for Utility Earthquake Resilience
Newly built utility structures should conform to seismic building codes. Existing assets should conform to various
standards. The International Building Code (IBC) specifically addresses seismicity in both "design" and "installation"
of building systems. Check your local and state building codes.
Title
Code
Standard
Guideline
IBC Internationa! Building Code (2015) or applicable jurisdictional building code
X


ASCE-7, Minimum Design Loads for Buildings and Other Structures (2016)

X

ALA* Seismic Design and Retrofit of Piping Systems (2002) (primarily above ground pipe)


X
ALA Seismic Fragility Formulations for Water Systems (2001) (used to estimate system pipeline damage)


X
ALA Seismic Guidelines for Water Pipelines (2005)


X
ALA Guidelines for Implementing Performance Assessments of Water Systems (2005)


X
ALA Wastewater System Performance Assessment Guideline (2004)


X
ASCE 41-06 Seismic Rehabilitation of Existing Buildings (2007)

X

ACI 350-06 Code Requirements for Environmental Engineering Concrete Structures (2006)

X

AWWA D100-11 Welded Carbon Steel Tanks for Water Storage (2011)

X

AWWA D110-13 Wire and Strand Wound, Circular, Prestressed Concrete Water Tanks (2013)

X

AWWA D115-06 Tendon Prestressed Concrete Water Tanks (2006)

X

*Note: The American Lifelines Alliance (ALA) is no longer in existence, but some of the guidelines they developed are useful for assessing and designing pipelines.
For underground pipelines in water and wastewater systems, there are no earthquake design standards, only guides.
Often, the Chief Engineer of a utility is responsible for establishing its design practices and criteria. For example, the
San Francisco Public Utilities Commission developed its own internal standard, called General Seismic Requirements
for Design of New Facilities and Upgrade of Existing Facilities.
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oEPA
Introduction
and Video
Additional Earthquake Mitigation Resources
There are many publications and resources for identifying cost effective mitigation measures for earthquakes. These
include:
Step 1
Understand the
Earthquake Threat
Step 2
Identify Vulnerable
Assets and Determine
Consequences
Step 3
Pursue Mitigation
and Funding
Options
Resource
Description
Recent Earthauakes: Imoiications for United States
Water Utilities
Potential impacts of earthquakes on water utilities and effectiveness of seismic upgrades to
tanks, buildings, equipment and pipes. (Water Research Foundation)
Oreaon Earthauake Resiliency Plan
Mitigation measures for the anticipated Cascadia Earthquake. Chapter 8 addresses water and
wastewater systems. (Oregon Seismic Safety Policy Advisory Commission)
Seismic Guidelines for Water Pipelines
Overview of how to design and install pipelines to mitigate damage from earthquakes. (FEMA,
National Institute of Building Sciences, and American Lifelines Alliance)
Earthauake Hazard Mitiaation for Utilitv Lifeline
Systems
An overview of strategies for mitigation and response planning for utilities. (FEMA)
Incident Action Checklist - Earthauake
Checklist of activities that water and wastewater utilities can take to prepare for, respond to and
recover from earthquakes. (EPA)
Power Resilience Guide
Guide promotes coordination and communication between water sector utilities and their electric
utilities; and provides strategies to increase water utilities' resilience to power loss. (EPA)
Water Utilities Fact Sheet
Factsheets of best practices for utilities in earthquake areas. (East Bay Municipal Utilities
District)
Is vour Water or Wastewater System Prepared? What
vou need to know about Generators.
An explanation of how to integrate generators into a utility's emergency response operation.
Includes an explanation of different types of generators. (EPA)
Seismic Options for New and Old Reservoirs
Presentation of building codes, seismic options and associated costs for water reservoir storage
tanks. (Pacific Northwest States AWWA)
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