Monitoring Methods for Harmful Algal Blooms in Source Water

Monitoring methods in source water can include no- to low-cost methods that include the “stick” or “jar” visual tests, regular Secchi disk measurements, satellite remote sensing, or watching for trends in data already collected daily such as increasing turbidity and pH or sudden decrease in free chlorine levels. Using these methods will not confirm a harmful algal bloom or cyanotoxins are present in the source water, but they can give a water system an indication that further evaluation would be appropriate. A “citizen scientist” project could help support these efforts, especially if the source water has been having water quality issues.

Phycocyanin sensors can be found as both handheld devices and attached to buoys that transmit data to a computer. These sensors are used to measure the levels of cyanobacteria in the water. They cannot detect if toxin is present in the water but have been used by water body managers and public water systems to trigger control activities in water bodies and to start monitoring for toxins. This in turn can help a treatment operator in reducing the amount of coagulant and chlorine demand, taste and odor issues, and biofouling of filters. To check for evidence of toxin presence, there are test strips and other immediate monitoring devices coming into the market. While it is recommended to do further testing at a lab if toxin presence is found, these items can help water systems determine type of toxin(s) present and an estimate of concentration.  To help in this, the Idaho Department of Environmental Quality has purchased four (4) scanners to lend to public water systems at no charge if they choose to purchase test strips for this effort. While scanners are not required to read the strips, they have been reported to increase the accuracy of the readings. Please contact your regional office to request borrowing a scanner. While the test strips are not included, there is a limited supply in 2022 for emergency purposes. If your system is interested in trying a DEQ-funded monitoring method during the 2022 season, please contact Jami Delmore at 208-373-0174 or jami.delmore@deq.idaho.gov.

Next month's topic

Laboratory methods for cyanobacteria and cyanotoxin testing

Upcoming trainings

Taking a Secchi Disk Reading – 4:15 minute video Advances in Environmental Monitoring – Water Sensors – Tuesday, March 16, 2022 (12-1 pm PST; 1-2 pm MST) – free webinar from EPA Tools & Resources Webinar Series Vermont 2020 Cyanobacteria Volunteer Training – Visual Assessment Protocol – A 29:15 training video that was used for volunteers who helped Vermont officials identify cyanobacteria harmful algal blooms

Resources

EPA Incident Action Checklist – HAB Incidents and Water Utilities Dealing with Algal Blooms: Time to Make a Plan (Washington State Department of Health)

Idaho Department of Environmental Quality https://www.deq.idaho.gov/

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