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Algae and Cyanotoxins Resources

Erik Rosenfeldt, Bill Becker, Ben Stanford, Liz Crafton - Hazen and Sawyer

Last Modified Nov 04, 2025

Water utilities are facing increased threats of harmful algal blooms (HABs) and cyanotoxins in their drinking water supplies, particularly in the summer months. Algae-related toxins may cause taste and odor issues, and more importantly, can result in shutdowns of the water system to protect public health.

A holistic approach for reducing risk from HABs and cyanotoxins considers monitoring and managing HABs in source water, and treatment barriers for algal toxins in the plant. The resources at this link can help guide your utility through the monitoring process and help you develop a response should you face an algal event.

These resources include:

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WRF Informational Videos Information on the science behind cyanobacteria and cyanotoxins and a utility perspective on the latest in source water protection, monitoring, detection, and treatment.

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WRF #4692: Algae and Cyanotoxin Guidance for Utilities The Hazen team developed a suite of deliverables and graphics to support this project, culminating in a Guidance Manual.

"A 11x17 Printable Wall Poster": This wall poster walks you through the steps involved in monitoring for - and responding to - algae events of varying severity.

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"Fact Sheet":https://www.hazenandsawyer.com...Sheet-_Summer_2018.pdf This fact sheet covers the EPA guidance recommendations issued in May 2015.

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Hazen-Adams CyanoTOX Model This model, available to AWWA subscribers, calculates how various oxidants at a water treatment plant impact cyanotoxin concentrations.