Cyanobacteria Bloom-Central Delta 7/28/20
Good Afternoon,
Central Valley Water Board staff has observed moderate cyanobacteria blooms in various Delta locations during routine recreational water quality monitoring activities. Cyanobacteria water samples were collected at five locations on 7/16/20 and sent to Bend Genetics for lab analysis.
Incident Details:
- Moderate cyanobacteria HABs throughout the San Joaquin River, Disappointment Slough and Honker Cut.
- Two cyanobacteria genera (Microcystis and Aphanizomenon) detected at the locations sampled.
- Microcystins exceeding the Warning Guidance for posting of planktonic blooms at Potato Point and exceeding the Caution Guidance at Tinsley Island and Lost Isle. (https://mywaterquality.ca.gov/habs/resources/habs_response.html#posting_guidance)
| Microcystins (ug/L) | Recommended Signage | |||
| Sample # | Site | Water Sample | Scum Sample | |
| 11 | San Joaquin River at Potato Point | 10.56 | Not collected | Warning |
| 12 | San Joaquin River at Tinsley Island | 1.07 | Not collected | Caution |
| 13 | San Joaquin River at Lost Isle | 2.98 | Not collected | Caution |
| 14 | Disappointment Slough | ND | Not collected | No Advisory |
| 15 | Honker Cut | ND | Not collected | No Advisory |
Next Steps:
- Post recommended Warning and Caution signs (https://mywaterquality.ca.gov/habs/resources/habs_response.html#advisory_signs) at public access points at or near sampling locations.
- Request Division of Drinking Water and Dept. Of Water Resources staff coordinate with entities who have downstream drinking water intakes.
- State Water Board will post the recommended advisories to the Water Boards FHABs web map.
- Continue coordination with State Water Board (via cyanohab.reports@waterboards.ca.gov email) and Central Valley Regional Water Board (Matt Krause as HAB coordinator; Matthew.Krause@Waterboards.ca.gov)
- Report any potentially HAB-related illness reports by submitting an online bloom report California Harmful Algal Blooms Portal (or email to cyanohab.reports@waterboards.ca.gov)
Thank You,
Matt Krause
Environmental Scientist
Region 5 Harmful Algal Bloom Coordinator
California Regional Water Quality Control Board
Central Valley Region (5)
Surface Water Ambient Monitoring Program