Harmful Algal Blooms (HAB)

Cyanobacteria (also known as blue-green algae) are microscopic organisms found naturally in surface water that can sometimes multiply to form harmful algal blooms (HABs). HABs can potentially produce toxins capable of causing illness or irritation, sometimes even death, in pets, livestock and humans.

In addition to producing toxins, cyanobacteria can pose other treatment challenges for public water systems, including taste and odor and shortened filter run times. The information below is provided to assist public water system operators with preventing, identifying and responding to HABs.

Prevention and Treatment

• AWWA White Paper on Cyanotoxin Treatment (2016)
• Algaecide Application Fact Sheet
• Developing a Harmful Algal Bloom Treatment Optimization Protocol — Guidance for Public Water Systems
• Fillable form for HAB Treatment Optimization Protocol
• Developing a Harmful Algal Bloom (HAB) General Plan — Guidance For Public Water Systems

HAB Maps and Strategy

• Public Water System and Other Surface Water Monitoring Data — Cyanotoxin monitoring in Ohio.
• Drinking Water Advisories — Current Advisories for Ohio Public Water Systems
• Recreational and Beach Monitoring Data — Ohio conducts a monitoring and notification program of selected public and semi-private beaches to test the water quality and notify the public whenever bacteria levels present a potential health risk to those engaged in water activities. BeachGuard provides data on advisories as well as monitoring activity.
• State of Ohio Response Strategy — Harmful Algal Bloom Response Strategy for Recreational Waters

Public Water System HAB Response Strategy

• Public Water System Station IDs
• Ohio Public Water System Lakes
• Public Water System Harmful Algal Bloom Response Strategy (2020)

Visual Bloom Severity and Toxin Concentrations

Visual bloom severity is often not the best indication of toxin concentrations at intake depths. When the blooms are concentrated at the surface, toxin concentrations at the intake can be lower. For example, when Lake Erie was covered by extensive surface scums (Figure 1) in 2011, toxins were not detected at the Lake Erie public water system intakes. 

When blooms are more dispersed throughout the water column, and not concentrated in surface scums, intake toxin levels can be higher. For example, when the picture in Figure 2 was taken at Maumee Bay State Park in 2011, the cyanobacteria were dispersed throughout the water column, which resulted in a bloom that did not appear severe visually. However, the microcystin concentrations at the public water system intake exceeded 5.0 ug/L. It should be noted that the toxin concentrations at the beach were also high, with microcystin levels exceeding 100 ug/L.  

Figure 1. HAB at Lake Erie with no toxins detected at the intakes (2011).	Figure 2. HAB at Maumee Bay State Park with a toxin concentration of greater than 5.0 ug/L at the intake (2011).

Laboratory Information

• Laboratories Available for Total Microcystin Testing and Cyanobacteria Screening (qPCR)

Responding to a Suspected Bloom

All public water system owners/operators are encouraged to read through the "Public Water System Harmful Algal Bloom (HAB) Response Strategy" for guidance on responding to HABs.

Anyone Can Report an Algal Bloom

If you see surface scum or something that looks like cyanobacteria at Ohio’s rivers, lakes, or public swimming beaches, report it to Ohio EPA by completing the online bloom report form or the paper form and emailing it to HABmailbox@epa.ohio.gov.

Prevention and Treatment

• AWWA White Paper on Algal Toxin Treatment
• Algaecide Application Fact Sheet

How to Recognize HABs

Use the following reference documents and photographs to learn more about recognizing HABs. For additional photographs and information, please visit Ohioalgaeinfo.com.

• Attend the Algae Identification Workshop offered by Stone Laboratory during the summer months. 
• Bloom Characterization Guide
  • Photographs of assorted blooms: includes HABs, non-harmful green algae blooms 
    and duckweed

Analyze Samples for Cyanotoxins

• Ohio EPA Total (Extracellular and Intracellular) Saxitoxin by ELISA Analytical Methodology (Effective Nov 2016)
• Ohio EPA Total (Extracellular and Intracellular) Microcystins - ADDA by ELISA Analytical Methodology (Revised July 2018)
• Ohio EPA DES 705.0, Quantitative Polymerase Chain Reaction (qPCR) for Determination of Cyanobacteria and Cyanotoxin-Producing Genes Analytical Methodology 
• List of Toxin Producing Cyanobacteria
  • This list includes some genera of cyanobacteria known to produce toxins
• Algal Toxin Analysis Options
  • Includes examples of both laboratories and rapid field test kits
• Environmental Technology Verification (ETV) Reports for microcystin test kits
• Fluorometers and Datasondes for Cyanobacteria
  • Information and contacts of the types of meters and sondes available

Lab Techniques for Detecting Microcystins in Water Using Enzyme-Linked Immunsorbent Assay (ELISA)
This video demonstrates how to measure a particular group of toxins following the Ohio EPA Total Microcystin Analytical Methodology using an ADDA-ELISA kit.

 VIDEO  When in doubt, stay out.

Funding Opportunities for Infrastructure Improvements for HABs

Public Water Systems

Community water systems, publicly or privately owned, that operate surface water treatment systems are eligible for the HAB-discounted interest rate under the Water Supply Revolving Loan Account (WSRLA) program. Eligible projects include treatment system components for HAB treatment, interconnections with other public water systems, elevated storage and development of improved source waters. Nominations for design, and/or construction projects that are directly related to addressing issues from harmful algal blooms (HAB) do not have a deadline and can be submitted to Ohio EPA at any time during the program year. 

For more information, please review the instructions for completing the WSRLA HAB nomination form, available on the Division of Environmental and Financial Assistance webpage.

WPCLF Nutrient Reduction Discount

In response to harmful algal blooms (HABs) and their potential effect on water resources and the raw water supply for drinking water systems, Ohio EPA made $100 million available at a 0% interest rate through the Water Pollution Control Loan Fund (WPCLF) in 2015, 2016 and 2017 for equipment to reduce phosphorus and other nutrients. In 2018, Ohio EPA is offering $50 million at a 0% interest rate for these types of projects. The discounted rate will be available for the portion of the project directly attributed to the nutrient reduction. Standard, below-market interest rate loan funds will be offered for the balance of a proposed project. Ohio EPA will accept nutrient reduction discount (NRD) project nominations for planning, design or construction projects throughout the program year. Applicants who nominated projects for NRD funding in 2017, but did not proceed with projects, and subsequently provided updated schedules during the nomination period to Ohio EPA, will be grandfathered into the 2018 program.

For more information, please review the nutrient reduction guidance and addendum, available on the Division of Environmental and Financial Assistance webpage.

• HAB Rules Outreach Slides
• HAB Rules Outreach Webinar Recording
• Overview of Public Water System Harmful Algal Blooms Rules - Questions and Answers

Information for Partner Agencies

• Summary of Ohio's new HAB Rules and Drinking Water Response Strategy for Health Departments
• State of Ohio Harmful Algal Bloom Seminar for Local Partners

To learn more about HABs, check out the list of key references below or visit ohioalgaeinfo.com.

U.S. EPA

• Recommendations for Public Water Systems to Manage Cyanotoxins in Drinking Water
• Drinking Water Standards and Regulatory Support for Microbiological Contaminants
• Harmful Algal Blooms & Cyanobacteria
• Harmful Algal Blooms & Drinking Water Treatment

World Health Organization (WHO)

• World Health Organization home page
• WHO, 1999. Toxic Cyanobacteria in Water: A Guide to their Public Health Consequences, Monitoring and Management
• WHO, 2003. Guidelines for Safe Recreational Water Environments, Vol. 1, Coastal and Fresh Water
• WHO, 2004. Microcystin LR in Guidelines for Drinking-Water Quality, Chemical
  Fact Sheets.

Water Research Australia (WaterRA)

• Water Quality Research Australia Publication Information
• Newcombe G., House J., Ho L., Baker P. and Burch M., 2009. Management Strategies for Cyanobacteria (Blue-Green Algae) and their Toxins: A Guide for Water Utilities. WQRA research report 74.
• WQRA International Guidance Manual for the Management of Toxic Cyanobacteria, 2009, edited by Dr. Gayle Newcombe, Global Water Research Coalition and Water Quality Research Australia.
• Second National Cyanobacteria Workshop - Melbourne, Aug. 2, 2010, Aug. 3, 2010

U.S. Geological Survey

• U.S. Geological Survey Kansas Algal Toxins Research Team
• Graham, J, Loftin, K., Meyer, M., Ziegler, A., 2010. Cyanotoxin Mixtures and Taste-and-Odor Compounds in Cyanobacterial Blooms from the Midwestern United States, Environmental Science and Technology
• Graham, J., Loftin, K., Ziegler, A., and Meyer, M., 2008. Guidelines for design and sampling for cyanobacterial toxin and taste-and-odor studies in lakes and reservoirs, U.S. Geological Survey Scientific Investigations Report 2008-5038

Water Research Foundation

• Water Research Foundation home page
• Algae: Source to Treatment (M57), 2010
• Removal of Algal Toxins From Drinking Water Using Ozone and GAC, 2002
• Reservoir Management Strategies for Control and Degradation of Algal Toxins, 2009
• Early Warning and Management of Surface Water Taste & Odor Events, AwwaRF, 2006
• Identification of Algae in Water Supplies (CD-ROM), AWWA, 2001

HAB Brochures and Posters

• HAB Be Aware Brochure
• HABs in Ohio Waters Brochure
• HABs in Ohio Waters Poster

HAB Fact Sheets

• Algaecide Application Fact Sheet (Ohio EPA)
  
  • Reference for public water systems interested in applying algaecides to their reservoirs
• Algae in Ponds Fact Sheet (Ohio Department of Health)
• Cyanobacteria Fact Sheet (Ohio Department of Health)
• Cyanobacteria and Cyanotoxins: Information for Drinking Water Systems (U.S. EPA)
• Distribution System Monitoring Fact Sheet (Ohio EPA)
• Generalized Cyanotoxin Treatment Optimization Recommendations (Ohio EPA)
• Impacts of Climate Change on the Occurrence of Harmful Algal Blooms (U.S. EPA)