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 that deliver stormwater into the ocean.

Current Results

The following beaches are posted: Clam Beach County Park, Luffenholtz Beach and Trinidad State Park.

Water quality test results by location and date.
Locations Resample Sample  Date 
E.Coli Exceeds
Enterococcus Exceeds
North Mad River Mouth No 9/20/2021 63 No 20 No 10 No
Clam Beach County Park No 9/20/2021 1,439 No 75 No 173 Yes
Moonstone Beach No 9/20/2021 441 No 63 No 73 No
Luffenholtz Creek No 9/20/2021 8,664 No 960 Yes 1211 Yes
Trinidad State Park / Mill Creek No 9/20/2021 2,143 No 857 Yes 393 Yes

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

NOWCAST Predictions

NOWCAST Predictive Modeling now includes Luffenholtz Beach. Visit beachreportcard.org and enter "Luffenholtz" into the "search for your favorite beach" form field.

For more information, visit beachreportcard.org.