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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.
Funding Opportunities for Cyanotoxin Testing Equipment and Infrastructure Improvements
Guidance for Conducting ELISA Testing for Microcystin
VIDEO When in doubt, stay out.
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. So far in 2013, no scums have been reported on Grand Lake St. Marys, but microcystin concentrations at the intake have been much higher (e.g., up to 102.8 ug/L).
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.
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.
Individuals reporting algal blooms are encouraged to fill out the HAB Report Form and email it, with attached digital photographs if available, to Ohio EPA's HAB Mailbox.
Use the following reference documents and photographs to learn more about recognizing HABs. For additional photographs and information, please visit Ohioalgaeinfo.com.
To learn more about HABs, check out the list of key references below or visit ohioalgaeinfo.com.
Learn more about types of treatment to address HABs:
Division of Drinking and Ground Waters
Phone: (614) 644-2752 ~ Fax: (614) 644-2909
Contact ~ Emergency Contacts
Staff Contacts and Expertise ~ Electronic Mailing Lists
Mailing Address: P.O. Box 1049, Columbus, OH 43216-1049
Street Address: 50 West Town Street, Suite 700, Columbus, OH 43215
Report a Spill, Release or Environmental Crime (800) 282-9378
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