United States
Environmental Protection
\*^l Agency
Office of Water
EPA 823-R-19-001
September 2019
Recommendations for Cyanobacteria and Cyanotoxin
Monitoring in Recreational Waters
Revision 1
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Foreword
The purpose of this document is to provide EPA's recommendations, information and process
steps that a recreational water manager or public health official may choose to follow, or adapt,
to aid in determining if there is a harmful bloom or cyanotoxins posing a risk to humans, pets,
wildlife and livestock in a water body.
This document provides EPA's monitoring recommendations; nonetheless, EPA has provided
general information on these issues on its webpage Monitoring and Responding to Cvanobacteria
and Cyanotoxins in Recreational Waters. For a stepwise conceptual cyanotoxin monitoring
program framework:
• Step 1: Assess vulnerability of the water body to FLABs and prioritize recreational waters
for monitoring;
• Step 2: Observe recreational water body for blooms at the beginning and throughout the
recreational season;
• Step 3: Monitor for cyanotoxins; and,
• Step 4: Follow up cyanotoxin monitoring.
Disclaimer
This document provides the EPA's recommendations for cyanobacteria and cyanotoxin
monitoring in recreational waters. These monitoring recommendations do not impose legally
binding requirements on the U.S. Environmental Protection Agency (EPA), states, tribes, or the
public. These recommendations also do not confer legal rights. These recommendations do not
constitute a regulation, nor do they change or substitute for any Clean Water Act (CWA)
provision or the EPA regulations.
These recommendations may not apply to a particular situation based upon the circumstances.
Interested parties are free to raise questions about the substance of these recommendations and
the appropriateness of their application to a particular situation. The EPA retains the discretion to
recommend approaches on a case-by-case basis that differ from those described in this document
where appropriate. The EPA may revise this document periodically without public notice. The
EPA welcomes public input on these recommendations at any time.
Revision 1 updates
Revision 1 has been updated in September 2019 to include the EPA's final recommended values
for recreational criteria and swimming advisories for microcystins and cylindrospermopsin.
Some of the hyperlinks throughout the document have also been updated to reflect modifications
made to the EPA's website.
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How to Monitor Cyanobacteria/Toxins in Recreational Waters*
!Step 1: Assess vulnerability of the water body to
cyanobacterial blooms arid prioritize recreational
waters for monitoring
Periodically evaluate the vulnerability of recreational
waters to cyanotoxins or harmful algal blooms based
on historical information, remote sensing data, or
environmental conditions duringthe recreational
season.
Is your water body
vulnerable to a
bloom?
Step2: Observe the recreational water body for blooms
Lookfor evidence of a bloom throughoutthe recreational
season, based on visual observations, satellite data, or
phytoplankton (i.e.,algaland cyanobacterial) cell counts.
Step3: Monitorfor cyanotoxins and/or cell densities
Choose amongst several methods based ontesting
logistics and suspected bloom characteristics,
(i.e., algal and cyanobacterial} cell counts.
Step4: Follow up cyanotoxin monitoring
Continue monitoringand notifying public until two
consecutive tests showthe toxin values or cell counts fall
below the/evefe**** used to post the notification and visua
signs of the bloom are gone.
Are there signs of a
bloom?
Are cyanotoxins or
cyanobacterial cell
counts defected
above state or local
advisory levels****'7
Are toxin values
and cells consistently
below levels used to
post the
notification?
Deprioritize
Continue to
Step 2
Continue
Observations
Consider
notifying** &
continue
to Step 3
Continue to
observe during
recreational
*¦ season (Step 2)
Consider modifying
notification*** &
continue to
Step 4
Continue
monitoring &
notification
Lift Notice,
return to Step 2
*Adapted from "Recommendations for Public Water Systems to Manage Cyanotoxins in Drinking Water" June 2015, EPA 815-R-15-010
** This can either be an advisory/warning or a closure.
***If yes, consider modifying notification to indicate dangerous toxin level or cell count. If toxins are present but less than appropriate trigger value,
continue to monitor toxins.
****If the state does not have a HAB program with a value for cyanotoxins or cell counts upon which to base a notification, recreational water managers
may want to consider using the values thatEPA recommends.
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Recommendations for Cyanobacteria and Cyanotoxin Monitoring in Recreational Waters
Step 1: Assess vulnerability of the water body to cyanobacterial blooms and prioritize
recreational waters for monitoring
Protecting public health is the primary objective for a monitoring program. To meet this
objective, recreational water program managers and public health officials should make every
effort to sufficiently characterize the water body to better understand the potential for harmful
blooms, and thus the adverse public health risk that might occur in these waters. Sometimes
phytoplankton (which includes cyanobacteria, microalgae, dinoflagellates and other
microorganisms) can grow to high cell densities and form blooms. These blooms may or may not
be toxic.
This document focuses on cyanobacterial blooms with the potential for harmful cyanotoxins
(also known as harmful algal blooms or HABs). A bloom can have extremely high cell densities
of cyanobacteria (extremely high densities are typically defined as greater than 20,000 to
100,000 cells per mL) (Loftin et al., 2008). Cyanotoxins are produced by some toxic-producing
species and are not always released into the water. Harmful algal blooms could adversely affect
people and animals, regardless of the presence of toxins. Exposure to elevated cyanobacterial
cells densities has been associated to dermal effects such as skin rashes, ear and eye infections
and gastrointestinal distress. Harmful blooms are those that pose a health risk to people, either
due to the presence of toxins or due to elevated densities.
1.1 Assess vulnerability of the water body to cyanobacterial blooms
Some recreational waters are more vulnerable than others based on the water body and water
shed characteristics. Fast flowing, nutrient-poor rivers are less vulnerable than nutrient-rich lakes
and reservoirs. Existing water quality data can help to determine if the water body has had a
history of blooms or bloom indicators such as high cyanobacterial cell counts or chlorophyll-a
levels. Elevated nitrogen and phosphorus levels will be important to consider in a waterbody
evaluation. Waterbody assessments should consider the predominant land use in the watershed
and potential nutrient sources that may lead to cyanobacterial growth for a system-specific
evaluation. Similarly, climate and weather information such as water temperature and intensity
of precipitation events will help to determine if conditions are conducive to increased levels of
site-specific cyanobacterial growth currently and in the future.
A variety of information can be considered to assess the vulnerability of the recreational water to
cyanobacterial blooms including: the type of water body; historical cyanotoxin occurrence;
weather data (increases in temperature, precipitation and light); seasonal patterns of
cyanobacterial blooms; land use patterns; physical and hydrologic factors (e.g., turbidity, pH and
nutrients, and residence time); chlorophyll-a and phycocyanin levels; point and nonpoint sources
of contamination upstream; water quality impairments; and, any other information gathered as
part of source water assessments or sanitary surveys.
EPA recommends that managers, public health officials, tribes and states evaluate available data
on their recreational waters to assess waterbody vulnerability to cyanobacterial blooms.
Specifically, available data can be evaluated against EPA's recommended values or their own
state/s values to determine whether harmful blooms have occurred in the past. As a benchmark
for evaluating the risk to public health in recreational waterbodies, EPA has recommended
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national recreational water quality criteria for cyanotoxins (Recreational AWQC/Swimming
Advisory for Cvanotoxins). See Table 1.
Table 1. EPA Recommended Values for Recreational Criteria and Swimming Advisories for Cyanotoxins
Total
Microcystins
Magnitude
(Hg/L)
Cylindrospermopsin
Magnitude
(fig/L)
Duration
Frequency
8
15
1 in 10-day assessment
period across a recreational
season
Not more than 3 excursions in a
recreational season in more than
one year b
" States and authorized tribes can choose to adopt one or both criteria recommendations.
4 An excursion is defined as a ten-day assessment period with an observed toxin concentration higher than the criteria
magnitude. When more than three excursions occur within a recreational season and that pattern reoccurs in more than one
recreational season (i.e., in more than one year for most areas, although some recreational seasons may straddle two calendar
years), it is an indication the water quality is not supporting its recreational use. States and authorized tribes may choose to
apply either or both toxin recommendations when evaluating excursions within and across recreational seasons. As a risk
management decision, states and authorized tribes which adopt these criteria should include in their WQS an upper-bound
frequency, or recurrence frequency, stating the number of years that pattern can reoccur and still support its recreational use.
Although EPA has recommendations for specific toxins, cell counts and/or biomass, together
with microscopic identification can be informative and an interim step to make public health
decisions and/or prompt toxin analysis. The Global Water Research Coalition, a non-profit
organization for water research, published voluntary guidelines in 2009. The International
Guidance Manual for the Management of Toxic Cvanobacteria provides information on many
topics including cell enumeration, and calculation of biovolume/biomass. The World Health
Organization (WHO) established guidelines for cyanobacterial cells (see Table 1) and several
states (e.g., Connecticut, Indiana, Kentucky, Oklahoma, Utah, Wisconsin) use them for their
swimming advisory level.
Table 2. WHO (2003) Recreational Guidance/Action Levels for Cyanobacteria, Chlorophyll a, and Microcystin
Relative Probability of
Acute Health Effects
Cyanobacteria (cells/mL)
Chlorophyll a (|ig/L)
Estimated Microcystin
Levels (|ig/L)a
Low
< 20,000
< 10
< 10
Moderate
20,000-100,000
10-50
10-20
High
>100,000-10,000,000
50-5,000
20-2,000
Very High
> 10,000,000
> 5,000
> 2,000
aWHO (2003) derived the microcystin concentrations from the cyanobacterial cell density levels.
1.2 Prioritize recreational waters for monitoring
Recreational water managers, public health officials or state water quality staff should develop a
risk-based monitoring plan for recreational waters that are potentially vulnerable to blooms in
order to prioritize their monitoring resources by considering the following information:
• Existing and historical recreational water quality,
• Sampling considerations,
• Analytical methods,
• Sampling/testing logistical considerations,
• Use of predictive tools and satellite data (see Section 2.2), and
Frequency and number of people using the recreational water.
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The prioritization or tiering of monitoring locations and sampling frequency should include an
evaluation of the recreational waters including an assessment of site-specific information and the
potential risk that a bloom at the site would present to human health and the health of animals,
including pets, wildlife and livestock. This step-by-step process may be informed by how the
water body is used by people, whether pets or livestock may enter it, and other relevant factors.
This process will also allow reduction of efforts in locations where blooms are not likely to
occur. For example, the Utah Department of Environmental Quality identified 16 sensitive water
bodies to monitor closely throughout the swim season, based on the designated uses, the
proximity to populated areas, the number of recreational users, and whether cyanobacterial
blooms have occurred in the past.
Two EPA documents National Beach Guidance and Required Performance Criteria for Grants,
2014 Edition (EPA 2014a) and Recommendations for Public Water Systems to Manage
Cvanotoxins in Drinking Water (EPA 2015c) provide valuable information on identifying
sources of risk and prioritizing resources. The National Beach Guidance and Required
Performance Criteria for Grants (EPA 2014a) describes steps to take in prioritizing beach
monitoring sites based on risk to microbial pathogens and use at beaches. Recommendations for
Public Water Systems to Manage Cyanotoxins in Drinking Water (EPA 2015c) describes the
information needed to evaluate drinking water systems' source water vulnerability to HABs.
Step 2: Observe recreational water body for blooms
There are multiple indicators of the potential presence of HABs including visible discoloration of
a water body due to suspended cell filaments or scums (e.g., a red, green, or brown tint); thick,
mat-like accumulations on the shoreline and surface; foul odors and soupy-consistency of the
water; and fish kills. However, toxins can be present at unsafe levels without a visual bloom, and
the presence of cyanotoxins can only be confirmed through testing of the water. Cyanotoxin
production by cyanobacteria is highly variable and strongly influenced by the environmental
conditions as well as the specific cyanobacteria causing the bloom. Microscopic phytoplankton
identification can provide information when blooms are not visually apparent and can determine
the type of bloom.
Public health officials should encourage the general public to notify their state or local
government as soon as they see a bloom. EPA's States HABs Resources site contains an
interactive map with cyanobacteria/cyanotoxins resources for each state. For example, Ohio EPA
encourages individuals reporting potential blooms to fill out a Bloom Report Form on their
website and email the form, with attached digital photographs (if available), to a designated
mailbox (Ohio 2014). Individuals are encouraged to report the bloom location, color, size,
appearance, and location of nearby public beach or drinking water plant intake(s) (if any), as
well as any other available water quality information. The State of New York has a Suspicious
Algae Bloom Report Form and a program for citizens to send in photos of the suspected blooms
(New York, 2015). For examples of state forms for reporting blooms, see Table 3. For a
comprehensive list of HABs programs, please visit the States HABs Monitoring Programs and
Resources website. Managers, public health departments and states may want to consider
creating outreach tools for their community to educate the public on blooms and what to do if
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they see a bloom. In addition, the Cyanobacteria Monitoring Collaborative has an application
(app) to find and study cyanobacteria in waterbodies.
Table 3: Selection of State Forms for the Public to Report Cyanobacterial Blooms
State Organization
Link to Reporting Form for Potential Cyanobacterial
Bloom
California State Water Resources Control Board
Freshwater & Estuarine Harmful Algal Bloom Report
Form
Florida Department of Environmental Protection
Algal Bloom Reporting Form
Illinois Department of Public Health
HAB Human Illness Report Form
HAB Animal Illness Report Form
Indiana State Department of Health
Bloom Report Form
HAB Human Illness Report Form
HAB Animal Illness Report Form
Kansas Department of Health and Environment
Bloom Report Form
HAB Human Illness Report Form
HAB Animal Illness Report Form
New York Department of Environmental Conservation
Suspicious Algal Bloom Report Form
Ohio Environmental Protection Agency
Bloom Report Form
Washington State Department of Health
Bloom Report Website
2.1 Field and Visual Identification
A bloom may be observed or reported by environmental or public health staff or the general
public. Visual inspection can rule out a bloom as cyanobacterial based on the characteristics of
the bloom and by performing the "jar" or "float" test. However, toxins can be present without a
visual bloom on the water surface, and the presence of cyanotoxins can only be confirmed by
testing the water.
The State of Vermont developed a guidance document to help communities within the state
address issues associated with cyanobacteria. The guidance document has helpful tips on
identifying cyanobacterial blooms and conducting jar (or float) or stick tests (Cyanobacteria
Guidance for Vermont Communities) (Vermont 2015).
Microscopic phytoplankton identification can provide information when blooms are not visually
apparent and can determine if species present are toxic- or non-toxic species and the type of
bloom. For more information on identifying blooms and specific cyanobacteria, go to: USGS
Field and laboratory guide. Guidance Document for Harmful Algal Blooms in Colorado, and
Guidelines for safe recreational water environments (WHO 2003). Other States such as Oregon,
California, and New York have also developed guidance materials, including videos on how to
conduct shoreline sampling. In addition, there are academic programs, websites and apps to help
with identification of cyanobacteria and blooms, for example, the New England-based
Cyanobacteria Monitoring Collaborative. BloomWatch is an app which uses crowdsource data to
find and report potential cyanobacterial blooms. Individual citizens who download the
BloomWatch app and use it to submit their photos of the potential bloom to the BloomWatch
project. Users may also send that information to the relevant state or local agency.
In addition to visual inspection for blooms, recreational water managers may want to consider
routine sampling and testing for cyanobacterial cells and/or biomass and cyanotoxins. Testing for
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cyanobacterial cells is less expensive than testing for cyanotoxins using some analytic
methodologies (e.g., mass spectrometric) if taxonomists are already available. Testing can:
Help distinguish green algae and diatom blooms from potentially harmful cyanobacterial
blooms;
Provide information on cyanobacteria that may be present below the surface, and not
visually apparent at the water surface; and,
Detect lower concentrations of cyanobacteria that may not be visually apparent.
Utah DWQ involves citizens in the monitoring and identification process in addition to reporting
blooms. Volunteers are taught how to identify cyanobacteria and in many cases provided with
microscopes for family-level taxonomic identification which can be reported to the National
Oceanic and Atmospheric Association (NOAA) Phytoplankton Monitoring Network. Monitoring
activities are also conducted by local health departments which are often responsible for issuing
the advisories. In addition, many of the monitoring groups use toxin test strips (stick tests) to
detect immediate threats. Broadly, this information acts as an initial screen to notify the Utah
DWQ when to collect phytoplankton/toxin samples for analysis by professional labs.
2.2 Predictive and Remote Monitoring Tools
New technologies are changing the way we monitor pollution in the environment. EPA and other
agencies are studying innovative technologies to support monitoring efforts in assessing water
quality, including cyanobacterial blooms and nutrient pollution using:
Satellites;
Portable and ground remote sensors; and
Measurement and model data which can be used in predictive modeling applications.
NOAA satellite imagery data are being used to predict blooms in western Lake Erie and the Gulf
of Mexico (Florida and Texas). NOAA, EPA, United States Geological Survey (USGS), and
NASA are partnering on the Cyanobacteria Assessment Network (CyAN) project. Once new
satellite sensor data are available, this collaborative will make available nationwide satellite data
which has been processed for cyanobacteria abundance for all large inland lakes. The goal of the
CyAN project is to develop an early warning indicator system using historical and current
satellite data to detect cyanobacteria blooms in U.S. freshwater systems. This project supports
federal, state, and local partners in their monitoring efforts to assess water quality to protect
aquatic life and human health. Satellite imagery may not be appropriate for all waterbodies
because most satellites support resolutions (e.g., 30 m - 1 km) that are adequate only for
moderate- to larger-sized lakes and usually at a frequency of no more than once a week.
Environmental monitoring of physical, chemical and biological indicators of bloom formation
potential is important but can be resource intensive if data are not already available from other
sources. Key indicators include cyanobacterial cell counts, biovolumes (the volume of cells in a
unit amount of water, mm3/L), chlorophyll a and phycocyanin concentrations, presence of
cyanotoxin production genes in the water body, nutrient concentrations (nitrogen and
phosphorus), changes in hydrophysical conditions and new weather patterns (such as increased
temperature and rain) (Izydorczyk et al., 2005; Ohio 2014). EPA encourages recreational water
managers to use all available data, as discussed in Step 1, as part of a weight of evidence
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approach to determine if recent changes have occurred, possibly indicating bloom occurrence.
Bloom indicators can be used to inform a decision whether toxin analysis should proceed.
As previously noted, although EPA has national recommendations for specific cyanotoxins (see
Table 1), cyanobacterial cell counts can be informative and serve as an interim step before toxin
analysis. WHO established guidelines (see Table 2) and several states (such as Connecticut,
Indiana, Kentucky, Oklahoma, Utah, and Wisconsin) use cyanobacterial cell levels for their
respective swimming advisory levels.
2.3 Continued assessment of waterbodies for potential blooms
Properly trained staff might conduct field inspections of those recreational waters that are likely
to be vulnerable to blooms (as determined in Step 1) focusing on specific seasons the water was
previously determined to be vulnerable. For those recreational waters that the state or locality has
determined not to be vulnerable to cyanotoxins or blooms, the manager may still want to
consider periodically reassessing as watershed characteristics may change over time.
For vulnerable waters, even if there is no indication that a bloom has occurred, EPA encourages
the program to continue observing for possible blooms throughout the vulnerable season
(determined previously as part of this Step). If any of the observations indicates a bloom is
occurring, the manager may want to notify the public by posting cautionary warning signage and
begin monitoring for toxins.
2.4 Notification of risk from bloom and potential cyanotoxins
When a bloom and/or the presence of cyanotoxins are confirmed, the manager usually issues a
notification (which could either be an advisory or a closure) to raise awareness of the potential
risks associated with swimming and other water contact activities. Water body or beach
advisories are recommendations to limit swimming or other recreational activities, due to an
increased health risk due to contact with or ingestion of the cyanobacteria and/or cyanotoxins.
An advisory notification does not, however, officially close the recreational area to the public.
Advisories can be based on the simple presence of a bloom even though the predominant species
of phytoplankton or presence of cyanotoxins has not yet been confirmed. Alternatively, the
advisory may also be posted only after confirmation of the presence of cyanotoxins. Permanent
advisories may be used to notify the public of a continuing potential human health risk
associated with use of the water. In contrast, a closure notification or posting typically means
that the water body is officially closed to the public. Closing a water body or a beach is a local
decision. Templates for communication materials are available at Communicating about
Cyanobacterial Blooms and Toxins in Recreational Waters.
Several States have risk communication tools to assist during a cyanobacterial bloom event. For
example, California has a voluntary guidance system of thresholds, decision tree, and signage
used to notify the public regarding freshwater HABs. These materials are posted on the
California HA.BS Portal. California has proposed a 3-tiered approach to notifying the public. If a
bloom is suspected based on visual elements (e.g., water appears soupy) or if there is an increase
or change in pH or nutrient loading, or other characteristics that historically have predicted
blooms, then a "warning" sign is posted. If human or animal illness is suspected, then a
"caution" sign is posted. "Danger" is posted once a human illness, or animal illness or death has
been confirmed due to cyanotoxin exposure.
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Oregon Department of Environmental Quality has developed a harmful bloom strategy (Oregon
HAB Strategy) with the goal of preventing and controlling HABs. The voluntary strategy focuses
on identifying waters that experience HABs, issuing health advisories and educating the public
about their risks. If a bloom is present, the strategy recommends collecting samples for algal
identification and cell counts and/or analysis of toxins.
If there is no indication of a bloom, EPA encourages the continued observation of vulnerable
waters for possible blooms throughout the season as determined previously as part of this Step
(see discussion under section 2.3). If a bloom occurs near where people, pets, or livestock could
be exposed, the recreational water manager may want to begin monitoring that water for toxins
(Step 3).
Step 3: Monitor for cyanotoxins
3.1 Methods
There is a diverse range of rapid screen tests and laboratory methods used to detect and identify
cyanobacteria cells and cyanotoxins in water. Types of methods include:
Enzyme-linked immunosorbent assays (ELISA);
Reversed-phase high performance liquid chromatographic methods (HPLC) combined
with mass spectrometric (MS, MS/MS) or ultraviolet/photodiode array detectors
(UV/PDA);
Protein phosphatase inhibition assay (PPIA);
Liquid chromatography/mass spectrometry (LC/MS);
Quantitative Polymerase Chain Reaction (qPCR) and microarrays/DNA chips; and
Cyanobacteria cell counts through microscopy.
For more information about these methods, see this EPA website A. Summary of the Methods
Available for Cyanotoxin Detection and USGS Analytical Methods for Cyanotoxin Detection,
and Impacts on. Data Interpretation. (USGS 2010). In addition, see a list of specific methods in
Table 4, below.
The decision to use a monitoring method should be made based on the needs and resources of the
waterbodies to be monitored. Methods vary widely in sensitivity, rapidity, cost and level of
expertise required to perform the method. The potential risk from cyanotoxins can be estimated
by directly measuring the toxin (bioassays- HPLC, MS, LC/MS), by measuring antibodies raised
against the toxin (bioassays by chromatography - ELISA, PSI, PPIA) or by estimating the
potential for toxin production by measuring a gene that can produce the toxin in cyanobacteria
(PCR). As demonstrated in studies comparing these methods (Gaget 2017; Loftin 2008) there is
no single, best method. Each method has its strengths and weaknesses. For example, some
chromatographic methods are very accurate but are limited to one or a few cyanotoxin congeners
of a toxin; such methods may underestimate the total risk. PCR methods can be rapid and
reliable measures of potential risk; however, if the cyanobacteria are not producing or releasing
the toxin, the risk may be overestimated. Managers may also combine methods by adding a
confirmation test. Commercially available Enzyme-Linked Immunosorbent Assay (ELISA) test
kits are one of the more commonly utilized cyanotoxin testing methods, since they do not require
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expensive equipment or extensive training to run. Semi-quantitative field screening ELISA kits
are available for the presence or absence of cyanotoxins. If cyanotoxins are detected by a field
screening kit, repeat analysis is recommended using either a quantitative ELISA test or one of
the other analytical methods identified above.
More precise, more quantitative ELISA test kits are available for microcystin-LR,
microcystins/nodularins (ADDA), saxitoxin, and cylindrospermopsin. In addition, a rapid
receptor-binding assay kit is available for the detection of anatoxin-a. Although they provide
rapid results, ELISA kits generally have limitations in specificity and are not congener specific.
In addition, some cross-reactivity may occur. The microcystins/nodularins (ADDA) kit is based
on the ADDA structure within the microcystin molecule and is designed to detect over 100
microcystin congeners identified to date; however, it cannot distinguish between congeners).
Methods that utilize liquid chromatography combined with mass spectrometry (LC/MS) can
precisely and accurately identify specific microcystin congeners for which standards are
available; LC/MS methods have also been designed to minimize matrix interference. At this time
there are only standards for a limited number of the known microcystin congeners. If congener-
specific information is needed, an LC/MS method should be considered. HPLC-PDA methods
are less specific than LC/MS methods, and the quantitation is more problematic due to less
specificity and sample matrix interference. However, when analytical toxin standards are
available for confirmation, they provide a measure of resolution of the congeners present.
For detection of cyanotoxins in drinking water, EPA developed Method 544. a liquid
chromatography/tandem mass spectrometry (LC/MS/MS) method for microcystins and nodularin
(combined intracellular and extracellular), and Method 545. a liquid chromatography
electrospray ionization tandem mass spectrometry (LC-ESI/MS/MS) method for the
determination of cylindrospermopsin and anatoxin-a. EPA also developed Method 546, an
ELISA Method for ambient and drinking water. Standard operating procedures for this method
developed by Ohio EPA provide additional advice for quality-control and sample-handling
measures for ambient waters (Inland i
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Table 4: Analytical methods of Microcystin and Cylindrospermopsin detection and non-toxins in ambient water1
TEST/ METHOD
Analytical Target
APPROX. LIMIT OF
QUANTIFICATION
LOCATION OF
TEST
TIME TO
RESULT
SCREENING
ONLY TOOL
EPA Method
546
Adda-EUSA
Intracellular and
Extracellular
Microcystins
0.10-5.0 ng/L
Lab
~ 1 day
No
EUSA-DM
Laboratory Test
Total Microcystins
0.010 ng/L
Lab
3 hours or
less
No
ELISA
Laboratory Test
SAES (Abraxis)
Total Microcystin in
marine/brackish
water
0.016 ng/L
Lab
3 hours or
less
No
ELISA
Laboratory Test
(Abraxis)
Total
Cylindrospermopsin
0.05 - 2.0 ng/L
Lab
3 hours or
less
No
ELISA
Laboratory Test
(Beacon)
Total
Cylindrospermopsin
0.1-2.0 Mg/L
Lab
~2 hours
No
HPLC-UV (PDA)
Total Microcystins-
limited specificity
~0.3 Mg/L
Lab
~ 1 day
No
Protein
Phosphatase
Inhibition Assay
Total Microcystins
0.02 Mg/L
Lab
N/A
No
Microcystin
Tube Kit
(Abraxis)
Total Microcystins
0.1-5.0 Mg/L
Lab
~45 minutes
No
Microcystin
Tube Kit
(Beacon)
Total Microcystins
0.3-5.0 Mg/L
Lab
~1hour
No
Abraxis Test
Strip
Total Microcystins
1-10 Mg/L
Field
~45 minutes
Yes
Total
Cylindrospermopsin
0.5-10 Mg/L
Field
~45 minutes
Yes
Non-Toxins Methods
Phycocyanin
Continuous
Monitoring
Cells/ Biomass
0.04 Mg/L
Field
N/A
Yes
qPCR
Cells/Biomass
Lab
~30 minutes
Yes
DNA Chip
Cells/Biomass
Presence/Absence
Lab
~4 hours
Yes
Microscopic
Techniques
Cells/Biomass
N/A
Lab
N/A
Yes
In the case of public waterways and drinking water sources, many state environmental agencies
operate monitoring, sampling, and testing programs. Several of these states perform the analysis
on samples taken from potential blooms in state-run laboratories; however, other states with
HAB programs, in addition to municipalities, private utilities, and other stakeholders of
freshwater systems send their samples to commercial and public laboratories. States should
1 EPA does not endorse any particular brand or method in this table, and there may be other similar
services that have been inadvertently left out of the table or have been developed after the release of this
document. Other than EPA Method 546, EPA has not approved or verified these methods.
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consider providing training to lab personnel to ensure consistent results. For a non-
comprehensive list of laboratories that accept samples for cyanobacteria and cyanotoxin analysis,
please visit the State Resources page on this website (States Resources).
If cyanotoxins are confirmed, EPA encourages contacting appropriate partners that use the same
water body and alert them to the potential threat as well as contacting managers of downstream
recreational areas. EPA recommends that state water recreation managers or appropriate state
partners report suspected and confirmed harmful blooms and/or human and animal illnesses
associated with HABs to the One Health Harmful Algal Bloom System (OHHABS). The Centers
for Disease Control and Prevention (CDC) developed OHHABS as a voluntary reporting system
available to state and territorial public health departments and their designated environmental
health or animal health partners. For guidance about defining a bloom and how to report health
and environmental data, see OHHABS.
3.2 Sampling Logistics
Select monitoring sites to ensure that the main public access locations are included, as well as
those areas prone to scum build-up due to prevailing winds (e.g., shorelines). Samples should be
handled properly to ensure reliable results, whether analyzing the samples using a field kit or
shipping them to a laboratory. EPA recommends that a manager follow sample collection and
handling procedures required by the method or laboratory performing the analysis. For
laboratory analysis, EPA encourages the use of laboratory-provided sample containers to collect
water samples. Laboratories may not accept containers from other sources, or they may
invalidate results. Amber glass containers are typically used to avoid potential cyanotoxin
adsorption associated with some plastic containers and to minimize exposure to sunlight (U.S.
EPA, 2014a). Samples should be cooled immediately after collection, during shipping, and
pending analysis at the laboratory. Ideally, samples should be shipped on the same day they are
collected. Samples generally should be analyzed within five days from the time of collection.
EPA encourages systems to contact the laboratory prior to shipping samples for additional
sample handling instructions. More information is available from (USGS 2008) Guidelines for
Design and Sampling for Cyanobactedal Toxin and Taste-and-Odor Studies in Lakes and
Reservoirs.
3.3 Safety and handling
Because the water body may contain toxins, samplers should take the following safety
precautions. Wear appropriate safety equipment, for example gloves, eye protection (such as
goggles), and waders/boots during sampling. Do not ingest water or allow the water to come into
contact with exposed skin. Avoid inhaling spray caused by boats, wind or other water surface
disturbances. If these conditions are present, wear a mask to avoid inhalation of water spray.
Hands should be washed thoroughly after sampling before eating or drinking. Waders/boots
should be rinsed before storage. It is important that sampling crews also watch for and report any
symptoms of exposure to cyanotoxins, which can occur immediately to several days following
exposure. In addition to personal protection, rinsing equipment between uses will help avoid any
potential cross-contamination of waterbodies if multiple waterbodies are sampled using the same
equipment. See Recommended Standard Procedures for Phytoplankton Collection to Detect
Harmful Algal Blooms (Utah 2016), Chapter 9 of the USGS 2014 National Field Manual for the
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Collection of Water-Quality Data, and EPA's Sampling Guidance for Unknown Contaminants in
Drinking Water (EPA 2017) for further information.
Step 4: Follow up cyanotoxin monitoring
In cases where monitoring (Step 3) is triggered by visual confirmation of blooms, EPA
encourages the recreational water manager to continue monitoring and to take notification
action(s) until the toxin level is no longer measurable or consistently below the trigger value.
EPA recommends, at a minimum, continuing notification actions until at least two consecutive
tests show that the toxin level is below the trigger value as was described on page 25 of
Recommendations for Public Water Systems to Manage Cvanotoxins in. Drinking Water (EPA
2015).
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References
EPA. 2012a National Lakes Assessment Field Operations Manual Version 1.0, May 15, 2012,
EPA 841-B-l 1-003. Available online.
EPA. 2012b. National Lakes Assessment Laboratory Operations Manual Version 1.1 October 9,
2012. EPA 841-B-l 1-004. Available online.
EPA. 2014a. National Beach Guidance and Required Performance Criteria for Grants, EPA-823-
B-14-001.
EPA. 2014b. Drinking Water Science and Regulatory Support. Available online
EPA. 2015a. Drinking Water Health Advisory for the Cyanobacterial Toxin Microcystin. EPA
820R15100.
EPA. 2015b. Drinking Water Health Advisory for the Cyanobacterial Toxin
Cylindrospermopsin. EPA 820R15101.
EPA. 2015c. Recommendations for Public Water Systems to Manage Cyanotoxins in Drinking
Water, EPA 815-R-15-010.
EPA. 2017. Sampling Guidance for Unknown Contaminants in Drinking Water, EPA-817-R-08-
003. Available online.
Gaget, V., M. Lau, B. Sendall, S. Froscio, A. Humpage, 2017. Cyanotoxins: Which detection
technique for an optimum risk assessment? Water Research 118(2017) 227-238.
International Guidance Manual for the Management of Toxic Cyanobacteria. 2009. Available
online.
Izydorczyk, K. Tarczynska, M., Jurczak, T., Mrowczynski, J., Zalewski, M. 2005. Measurement
of Phycocyanin Fluorescence as an Online Early Warning System for Cyanobacteria in Reservoir
Intake Water. Environmental Toxicology 20(4): 425-430.
Loftin, K. A., Ziegler, A. C., and Meyer, M. T. 2008. Guidelines for design and sampling for
cyanobacterial toxin and taste-and-odor studies in lakes and reservoirs. U.S. Department of the
Interior, U.S. Geological Survey.
New York. 2015. Algae Bloom Report Form. Available online.
Ohio 2012. Inland Lakes Sampling Procedure Manual. Available online.
Ohio. 2014. Public Water System Harmful Algal Bloom Response Strategy. Available online.
USGS. 2008. Guidelines for Design and Sampling for Cyanobacterial Toxin and Taste-and-Odor
Studies in Lakes and Reservoirs. Technical Report 2008-5083. Available online
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USGS. 2010. Analytical Methods for Cyanotoxin Detection and Impacts on Data Interpretation.
Powerpoint presentation from April 26, 2010. Available online.
USGS. 2014. National Field Manual for the Collection of Water-Quality Data, Book 9. Available
online.
Utah. 2016 Recommended Standard procedures for phytoplankton collection to detect harmful
algal blooms. Available online.
Vermont. 2015. Cyanobacteria (Blue-green Algae): Guidance for Vermont Communities.
Available online. Vermont Department of Health.
WHO. 2003. Guidelines for Safe Recreational Water Environments: Volume 1: Coastal and
Fresh Waters. World Health Organization.
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