Diamond Valley Lake in Riverside County is one of the most recent victims of harmful algal blooms, demonstrating that current conditions are ideal for rapid cyanobacterial growth.
The algal bloom – one of the largest ever seen at the lake since 2003 – caused Metropolitan Water District (MWD) to close the lake to all recreational activities on June 21st due to concerns over high cyanobacteria counts.
Cyanobacteria, also known as blue-green algae, are naturally occurring components of freshwater and estuarine ecosystems. While algae and cyanobacteria provide aquatic communities with many benefits, as the old saying goes, “everything in moderation.” Under certain conditions, these organisms can grow rapidly causing “blooms.” Blooms become problematic because algae and cyanobacteria also produce harmful compounds, such as cyanotoxins and aroma compounds, which pose health risks to humans and animals. When blooms threaten human and environmental health, they are referred to as harmful algal blooms (HABs).
In the case of Diamond Valley Lake, the cyanotoxin concerns are limited to recreational uses of the water, as MWD is not currently using the lake as a drinking water source. However, the event indicates that the high temperatures and extended daylight hours we’re experiencing are creating conditions ideal for harmful algal blooms in bodies of water.
The US EPA included nine cyanotoxins in the fourth round of its Unregulated Contaminant Monitoring Rule (UCMR 4), in addition to a total microcystin test. The cyanotoxin chemical contaminants listed are: microcystin-LA, microcystin-LF, microcystin-LR, microcystin-LY, microcystin-RR, microcystin-YR, nodularin, anatoxin-a, and cylindrospermopsin. Babcock Laboratories is fully accredited to perform all UCMR 4 analyses, including these cyanotoxin chemical contaminants which require EPA Methods 546 (ELISA), 544, and 545.