Warning issued over 'harmful' algae blooms in Discovery Bay
State water officials have issued a "danger" advisory at multiple locations in Discovery Bay after finding evidence of harmful algae blooms.
The State Water Resources Control Board and Central Valley Regional Water Quality Control Board issued a statement Tuesday, saying HABs can pose a threat to people and pets, and the advisory urges people to avoid swimming, boating and other activities and to keep pets out of the water until further notice.
Those visiting Discovery Bay should be aware of the elevated risk and are encouraged to stay out of the water until further notice, including watercraft.
People should not let pets and other animals drink or go into the water or go near the scum. Stay away from scum and cloudy or discolored water. Do not eat fish or shellfish from this water and don't use the water for drinking or cooking. Boiling or filtering will not make the water safe.
After residents filed multiple reports of a HAB and suspected related illnesses in Discovery Bay, the boards collected water samples at seven sites on June 28 to confirm the presence of cyanobacteria and associated cyanotoxins, focusing on sites where reports were shared across town.
While waterways on the west side of Discovery Bay have the highest advisory level posted, the east side also is posted with lower-level advisories recommending no swimming and keeping dogs out of the water.
Cyanobacteria, a group of organisms that form HABs, can produce potent toxins. Health risks are associated with HABs, as they produce dermatoxins that can cause itching skin and rashes, as well as gastrointestinal distress, headaches, agitation and weakness, or abnormal breathing if HAB material is swallowed while swimming.
The boards said dogs and children are most susceptible to exposure because of their smaller body size, increased potential to swallow water while swimming and tendency to stay in the water longer. If anyone suspects exposure, they should wash their children and dog immediately.
The bloom in Discovery Bay appears suspended near the water's surface. Bloom conditions can change rapidly as the winds and waves move or concentrate the bloom into different regions of the bay. In some areas, the bloom may concentrate and form a film or scum on the water surface. The color of the water may also appear discolored as bright or dark green and brown.
Discovery Bay, in coordination with the Contra Costa County Environmental Health Division, has posted advisory signs and messaging to notify residents and recreational users of the bloom.
Find more information at https://mywaterquality.ca.gov/habs/where/freshwater_events.html.
