Water Quality Test Results

Ocean Monitoring

Humboldt County is funded by the U.S. Environmental Protection Agency Beach Environmental Assessment and Coastal Health Act (BEACH Act) to monitor for the presence of bacteria in ocean water areas. Water samples are taken near creek mouths (PDF) that deliver stormwater into the ocean.

Current Results

No beaches are currently posted.
Water quality test results by location and date.
Locations Resample Sample  Data 
E.Coli Exceeds
Enterococcus Exceeds
Clam Beach County Park No 6/20/2017 3,448 No 63 No 41 No
Luffenholtz Creek No 6/20/2017 1,259 No 20 No 63 No
Moonstone Beach No 6/20/2017 2,046 No 10
No 10 No
North Mad River Mouth No 6/20/2017 776 No 20 No
<10 No
Trinidad State Park / Mill Creek No 6/20/2017 1,935 No 20 No <10 No
Previous results are available for download (XLS).


All units are in are in MPN/100 ml. MPN = "most probable number".
State water quality standards for bacteria in recreational waters are not to exceed:
Total coliform = 10,000 MPN/100ml
E. coli (a fecal coliform) = 400 MPN/100 ml
Enterococcus (E. faecalis) = 104 MPN/100 ml
*Fecal coliform to total coliform ratio exceeds 0.1, and the total coliform count exceeds 1,000 MPN