Wyoming Nutrient Work Group Update: Harmful Cyanobacterial Blooms

Wyoming Department of Environmental Quality  | view as a webpage

Wyoming Department of Environmental Quality

Wyoming Nutrient Work Group Update

Harmful Cyanobacterial Bloom Program Update

With air and water temperatures on the rise and more folks heading to recreate in Wyoming’s lakes and reservoirs, the Wyoming Department of Environmental Quality (DEQ), the Wyoming Department of Health (WDH), the Wyoming Livestock Board (WLB) as well as other local, state and federal agencies have been preparing to respond to harmful cyanobacterial blooms (HCBs) should they occur in Wyoming surface waters.

Last week, DEQ issued a joint press release with WDH and WLB advising members of the public to be on the lookout for and avoid potential HCBs. As with prior seasons, DEQ will investigate potential HCBs reported to DEQ or identified by satellite imagery from the Cyanobacteria Assessment Network (CyAN). HCB complaint investigation samples will be analyzed to identify the type and density of cyanobacteria present as well as the concentration of four major cyanotoxins: total microcystins, cylindrospermopsin, anatoxin-a, and saxitoxin. The WDH will issue advisories for publicly accessible lakes and reservoirs when cyanobacteria or cyanotoxin concentrations exceed thresholds identified in Wyoming’s HCB Action Plan.

The WyoHCBs.org webpage continues to be the main source of information on HCBs in Wyoming and includes links to DEQ’s Report a Spill portal that can be used to report HCBs, an interactive webmap to view current and past advisories, and a link to sign up for an e-mail listserv specific to HCB advisories. In preparation for the 2020 season, the webpage was updated with revised frequently asked questions (FAQs), the 2020 Wyoming HCB Action Plan, materials for resource management agencies, and a HCB sign that can be posted at lakes and reservoirs for informational or advisory purposes. The revised signage replaces previous UNDER INVESTIGATION and ADVISORY signs and can be posted by resource management agencies at any time. This spring, DEQ purchased metal versions of the HCB sign that were recently posted by Boysen State Park staff at various locations around Boysen Reservoir. Be sure to check them out next time you are visiting.

Major revisions to the 2020 Wyoming HCB Action Plan include:

  • Use of the US Environmental Protection Agency’s (EPA) recommended cyanotoxin criteria and swimming advisory values for total microcystins and cylindrospermopsin;
  • Updated sampling protocols (SOPs) for the collection of four common cyanotoxins;
  • New protocol for lifting HCB advisories: when cyanotoxin and cyanobacteria cell densities fall below thresholds identified in the HCB Action Plan or at the end of the primary recreation season on September 30, whichever comes first;
  • Information on the reporting and tracking of HCB-related illnesses using the One Health Harmful Algal Bloom System (OHHABS); and
  • Procedures for posting HCB signs prior to and when advisories are issued.

DEQ and WDH have also started working with the EPA, who administers the Safe Drinking Water Act in Wyoming, to conduct a public drinking water supply susceptibility analysis to determine if any of Wyoming’s public water supplies may be susceptible to HCB-related issues in finished drinking water. DEQ has provided water quality data to EPA to assist in this effort.

HCB related questions can be directed to Michael Thomas at DEQ, Michael.Thomas@wyo.gov; Karl Musgrave at WDH, Karl.Musgrave@wyo.gov; or Jim Logan at WLB, Jim.Logan@wyo.gov.