vvEPA
Incident Action Checklist - Harmful Algal Blooms
For on-the-go convenience, the actions in this checklist are divided up into three "rip & run" sections and are examples
of activities that surface water utilities can take to: prepare for, respond to and recover from harmful algal bloom (HAB)
incidents. You can also populate the "My Contacts" sections with critical information that your utility may need during the
HAB incident.
Harmful Algal Bloom Incidents and Water Utilities
Increasingly, utilities face harmful aigal bloom or HAB challenges as they try to ensure the delivery of safe
drinking water to their customers. HABs can create toxins that are difficult to treat, which can lead to prolonged
drinking water outages that can impact both human health and a community's economy. Blue-green algae
HABs or cyanobacteria are single-celled microorganisms that live in fresh, brackish and marine surface
water. Favorable conditions, such as warm water, elevated levels of nutrients (e.g., nitrogen, phosphorus),
slow-moving water and thermal stratification accelerate the growth of cyanobacteria, leading to the creation
of a HAB. Some cyanobacterial blooms are capable of producing highly potent cyanotoxins. Despite their
increasingly common existence, HABs can be difficult to identify. Their shape, size, location, color and
cyanotoxin production can vary bloom by bloom. Tools are available to assist with detecting and monitoring
a bloom. Although blooms tend to form during the late summer, seasonal and year-to-year fluctuations in
cyanobacteria levels can make predicting their occurrence difficult. Cyanobacterial impacts to drinking water
utilities may include, but are not limited to:
	Unpleasant taste and odor, especially earthy and musty
tones;
	Interference with water treatment plant operations such
as floe formation, filtration and chlorination;
	Increased levels of disinfection by-product (DBF)
precursors; and
	Pass through of cyanotoxins into finished drinking water,
if not addressed.
If cyanotoxins occur in tap water over the U.S Environmental Protection Agency's (EPA's) national Health
Advisory level, people are at risk of various adverse health effects including upset stomach, vomiting and
diarrhea as well as liver and kidney damage. The EPA recommends the following Health Advisory levels:
1 Drinking Water Thresholds
Microcystin (pg/L)
Cylindrospermopsin (pg/L) 1
Do Not Drink - children under 6
0.3
0.7
Do Not Drink - children 6 and older and adults	1.6	3.0
Table 1: U.S. EPA Recommended Cyanotoxin Thresholds for Drinking Water
Contact your regulatory agency to determine if your state has additional HAB recommendations, standards,
regulations or monitoring schedules.
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Example of Water System Impacts and Response to a Harmful Algal
Bloom Incident
Carroll Township, Ohio
In September 2013, microcystins concentrations at Carroll Township's intake on Lake Erie increased to >5 pg/L,
the highest concentration observed in four years of monitoring. A finished water sample collected at the same
time had a microcystins concentration of 1.4 pg/L, which exceeded the Ohio Environmental Protection Agency's
(EPA's) microcystins threshold of 1 pg/L. After a repeat finished water sample concentration of 3.6 pg/L, Ohio EPA
recommended that the water system issue a Do Not Dnnk Advisory and transition to an emergency connection
with a neighboring utility. The advisory impacted over 2,200 people and lasted approximately 48 hours. The
water system remained on their emergency connection for several weeks. After the event, the water system
spent approximately $250,000 to upgrade the pre-ozonation portion of their conventional surface water treatment
process with new ozone generators and concentrators to amplify ozone dosages. In subsequent years, the
upgraded and optimized plant was able to effectively treat source water microcystins concentrations of over 50
pg/L, with no finished water detections.
Source: Ohio EPA
Great Lakes Coastal Resilience
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Actions to Prepare to Respond to a Harmful Algal Bloom Incident
Planning	
I I Identify a HAB lead and team of individuals
who would prepare for and respond to a bloom
incident.
I I Identify and coordinate with all water systems
that utilize the same water source. Upstream
systems can be a source of bloom information
and downstream systems should be notified
as they may also become affected. Be sure to
document 24-hour contact information.
~	Develop a list of critical customers who need
a continuous source of potable drinking water
(e.g., hospitals, nursing homes, dialysis clinics,
manufacturers).
~	Review and update all emergency contacts.
I I Develop a cyanotoxin management plan. One
resource to help in the development of the plan
is "Cvanotoxin Management Plan Template and
Example Plans." The plan should consist of the
following:
o Monitoring plan - EPA does not currently
regulate cyanotoxins, so systems are not
required to monitor; however, some states do
require sampling, so please check with your
regulatory agency. Make sure the monitoring
plan includes, but is not limited to:
	When and where to sample (different
intakes or depths);
	Sampling frequency;
	Sample volume;
	What to sample
-	indicators of cyanotoxins such as
chlorophyll a, phycocyanin or qPCR
methods for toxin producing genes;
-	cyanobacterial cells or specific
cyanotoxins or both;
	Which analytical screening test(s) to use
(including field parameters and methods for
indicators described above);
	Cyanotoxin analytical methods;
	Laboratory that can run required analysis
during weekdays or weekends;
	Sampling procedures and safe handling;
and
	Situations when it is necessary to send
sample(s) to an identified laboratory for
confirmation.
Refer to "A Summary of Methods Available for
Cvanotoxin Detection" to identify a sampling
method for your utility.
o Treatment Plan - Identify cyanotoxin
treatment strategies based on your specific
water system's type of treatment. Determine
short-term and long-term treatment strategies.
Refer to "Water Treatment Optimization for
Cyanotoxins"
o Communications Plan - As deemed
appropriate by the utility or per regulatory
agency requirements:
	Identify the required communication steps
and appropriate actions that may be taken
to inform customers and the general public
if cyanotoxins are detected in raw or
finished water;
	Work with local and state officials regarding
public communication requirements -
what cyanotoxin levels, what type of
drinking water sample (e.g., raw, finished,
distribution system) and how many
confirmation samples are needed to trigger
a public notification;
	Develop communication templates for
scenarios for both cyanotoxins and taste
and odor events; and
	Identify appropriate distribution
mechanisms such as reverse 911. Refer
to the "Drinking Water Cvanotoxin Risk
Communication Toolbox"
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Actions to Prepare to Respond to a Harmful Algal Bloom Incident
(continued)
~	Develop an alternate water supply plan that
specifies the following:
o The quantity of water needed to meet
customer demand daily.
o The identification of multiple alternate sources
of water (both raw and finished) such as
bottled water, interconnections, hauling raw
water to the treatment plant or hauling treated
water to a storage tank.
o How the system will obtain and transport
identified alternate sources (including any
treatment requirements).
o Who is responsible for obtaining and
distributing the alternate sources.
This should be done in conjunction with
local response partners such as your local
emergency management agency (EMA) and
local emergency planning committee (LEPC),
as well as your regulatory agency. For more
information, go to "Planning for an Emergency
Drinking Water SuppIv."
~	Meet with your local EMA, health departments
and consecutive systems to share your
cyanotoxin management plan and your alternate
water supply plan.
~	Conduct internal and external (e.g., EMA, health
department, regulatory agency) HAB tabletop
exercises regularly.
r Notes:
I I Participate in Incident Command System (ICS)
and National Incident Management System
(NIMS) training either online or in person with
your local emergency management agency.
I I Join your state's Water and Wastewater Agency
Response Network (WARN) or other local
mutual aid network. In addition, determine if you
are included in a statewide mutual aid law.
Facility	
~	Determine if your utility has the ability to draw
raw water from different intakes or different
depths.
~	Test all interconnections in preparation for
potential use in an emergency and evaluate
potential corrosion control issues.
~	Select distribution sampling sites with 24-hour
access.
I I Identify areas of the distribution system
that could be isolated to limit the number of
customers affected.
I I Implement a comprehensive source water
monitoring program that involves routine raw
water cyanobacteria sampling at multiple depths
and locations.
~	Monitor any operational changes (e.g.,
decreased filter run time, turbidity or pH change,
green sludge or filter backwash) that could
indicate a potential HAB threat.
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Actions to Respond to a Harmful Algal Bloom Incident in Raw Water
Notification
EH Notify the state regulatory agency and local EMA
of your water system's status.
EH Notify utilities that have interconnections with
your utility and those with the same water
source.
~
Notify the local health department.
EH Though not required by federal law, it is
important to keep customers regularly updated
on the situation through local media, social
media, a website or other mechanisms. Updates
should continue until regular operations resume.
-Notes:
Facility	
EH Conduct raw water and finished water sampling
per your established HAB management plan,
including analyzing for intra- and extra-cellular
cyanotoxins, or as directed by the state
regulatory agency. Exercise proper safety
measures when sampling for cyanotoxins to
prevent skin exposure. Wash hands after
sampling.
EH Adjust water treatment processes. Utilities
should confirm the type and concentration of
cyanotoxins present in the source water in
order to determine the most effective treatment
strategy. Applying the wrong treatment process
at a specific treatment stage could rupture the
cyanobacteria cells and result in the release,
rather than removal of, cyanotoxins. Refer to
"Water Treatment Optimization for Cyanotoxins"
EH Implement mitigation measures to control
blooms that have already occurred in the
source water. Remedial measures include
physically removing surface scums and
applying algaecides and other chemicals (e.g.,
permanganate, hydrogen peroxide) to control
blooms. Each bloom is unique and proper
measures need to be considered on a case by
case basis. Refer to "Control and Treatment" for
examples of control and prevention measures.
Control measures must be selected carefully
as they can have unintended consequences
on water quality and negative impacts on the
ecosystem. Refer also to state and primacy
agencies as some control measures and source
water treatment may have specific requirements
or regulations. Disclaimer: EPA has not
conducted an assessment of the effectiveness of
any of the listed control and treatment methods.
Documentation 	
~ Document all events, timeframes, and resulting
impacts, so this information can be used as part
of the post-incident investigation.
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Actions to Respond to a Harmful Algal Bloom Incident in Drinking Water
Notification
EH Notify the state regulatory agency, local
EMA and the local health department of the
cyanotoxin sample detection in finished drinking
water.
EH Notify utilities that have interconnections with
your utility.
EH Determine if any water health advisories need
to be issued. Use pre-identified communication
mediums (e.g., reverse 911, social media) to
notify customers. Refer to the "Drinking Water
Cvanotoxin Risk Communication Toolbox."
o Continue to keep customers updated regularly.
- Notes:
Facility	
EH Activate the alternate water plan, if necessary.
If bottled water is being supplied, provide
information to customers on the distribution
locations.
EH Continue raw water and finished water sampling
as directed by the state regulatory agency.
EH Adjust water treatment processes. Utilities
should confirm the type and concentration of
cyanotoxins present in the source water in
order to determine the most effective treatment
strategy. Applying the wrong treatment process
at a specific treatment stage could rupture the
cyanobacteria cells and result in the release,
rather than removal of, cyanotoxins. Refer to
"Water Treatment Optimization for Cvanotoxins."
EH Implement mitigation measures to control
blooms that have already occurred in the
source water. Remedial measures include
physically removing surface scums and
applying algaecides and other chemicals (e.g.,
permanganate, hydrogen peroxide) to control
blooms. Refer to "Control and Treatment" for
examples of control and prevention measures.
Control measures must be selected carefully
as they can have unintended consequences
on water quality and negative impacts on the
ecosystem. Refer also to state and primacy
agencies as some control measures and source
water treatment may have specific requirements
or regulations. Disclaimer: EPA has not
conducted an assessment of the effectiveness of
any of the listed control and treatment methods.
EH Use WARN for help in obtaining sampling
supplies, additional personnel and HAB technical
assistance as needed.
Documentation 	
~ Document all events, timeframes, and resulting
impacts, so this information can be used as part
of the post-incident investigation.
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Actions to Recover from a Harmful Algal Bloom Incident
EH Lift advisories once you and your state
regulatory agency have deemed the situation
safe.
EH Assign a utility representative to continue
providing updates to customers regarding
current mitigation actions as well as preparation
for future incidents.
EH Complete damage assessments.
EH Work with vendors and internal departments to
return to normal service.
EH Develop a lessons learned document and an
after action report (AAR) to document your
response activities, including what went well and
what did not go well. Create an improvement
plan (IP) based on your AAR and use the
IP to update your vulnerability assessment,
emergency response plan and cyanotoxin
management plan. Share the lessons learned
with water systems you sell water to, if
applicable.
EH Revise budget and asset management plans to
address increased costs from response-related
activities and follow-up actions.
EH Work with your state regulatory agency to
obtain technical assistance to mitigate the
circumstances that led to the HAB incident and
to reduce the likelihood of reoccurrence.
EH Identify mitigation and long-term adaptation
measures with your community that can help
prevent HABs in the future and increase utility
resilience when they do occur. For example,
consider longer-term source water protection
strategies that your community can implement
(such as green infrastructure) to decrease
nutrients in the source watershed. Review
impacts related to HABs when planning for
system upgrades (e.g., treatment changes).
EH Conduct annual utility-specific HAB awareness
training with all employees.
r Notes:
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My Contacts and Resources
CONTACT NAME	UTILITY/ORGANIZATION NAME	PHONE NUMBER

Wholesale system


System with same source water


System with same source water


Local Laboratory


State Primacy Agency


Local EMA


Local Health Department


WARN Chair


State EMA










Resources
	Recommendations for Public Water Systems to Manage Cvanotoxins in Drinking Water (EPA)
	Cvanotoxin Management Plan Template and Example Plans (EPA)
	Cvanobacterial Harmful Algal Blooms (EPA)
	Cyantobacteria Guidelines and Recommendations (EPA and State information)
	Prevention and Mitigation - Control and Treatment (EPA)
	Cyanobacteria State Resources and Laboratories (EPA)
	Drinking Water Cvanotoxin Risk Communication Toolbox (EPA)
	Harmful Algal Blooms: Information for Public Water Systems (Ohio Environmental Protection Agency)
	Technical Assistance in State and Local Response to Harmful Algal Blooms (Centers for Disease
Control and Prevention [CDC])
	Water Treatment Optimization for Cvanotoxins (EPA)
	Drinking Water Health Advisory for the Cvanobacterial Microcvstin Toxins (EPA)
	Drinking Water Health Advisory for the Cvanobacterial Toxin Cvlindrospermopsin (EPA)
	Water/Wastewater Agency Response Network (EPA)
	Planning for an Emergency Drinking Water Supply (AWWA/EPA)
	A Water Utility Manager's Guide to Cyanotoxins (American Water Works Association [AWWA] and
Water Research Foundation [WRF])
Office of Water (4608-T) EPA810-B-17-005 October 2017
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