Harmful algal blooms (HABs) pose a threat to Utah’s water-based recreation, culinary water supplies, aquatic ecosystems, and agricultural and residential (secondary) irrigation uses. Multiple agencies manage and protect these uses and users. DEQ has worked with its partners to craft guidance to help response agencies develop health advisory guidance and cyanobacteria response plans.
Recreational Health Advisory Guidance
The Utah Department of Health (DOH) and DEQ’s Division of Water Quality (DWQ) have prepared Recreational Health Advisory Guidance for HABs for local health departments (LHDs). This guidance identifies four independent indicators to protect recreational users from the adverse health effects of HABs:
- Cyanobacteria cell concentration
- Microcystin levels
- Cylindrospermopsin levels
- Anatoxin-a levels
If any one of these indicators is exceeded, a recreational health advisory is recommended.
In Utah, the authority to post health advisories and close water bodies lies with the local health departments.DOH and DWQ support these local partners during bloom events.
Drinking Water Response Plan
The Division of Drinking Water has prepared a Drinking Water Response Plan that provides public water systems with guidelines, important information, and references needed to develop a Cyanotoxin Management Plan. The plan includes a protocol for monitoring, sampling, and analysis of source, raw, and finished water as necessary. The plan also references Drinking Water Health Advisories from both the Environmental Protection Agency (EPA) and the World Health Organization (WHO) for three cyanobacterial toxins (microcystins, cylindrospermopsin, and anatoxin-a) and offers recommendations for public notification based on levels of cyanotoxins detected in the finished water.
DEQ has compiled a list of additional HABs resources for response agencies, including health advisory signage, general information on HABs, EPA guidance documents, and photos.