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: Luffenholtz Beach and Moonstone Beach.
Water quality test results by location and date.
Locations Resample Sample  Data 
E.Coli Exceeds
Enterococcus Exceeds
Clam Beach County Park Yes 9/21/2017 269 No 20 No 30 No
Luffenholtz Creek Yes 9/21/2017 4,352 No 341 No 218 Yes
Moonstone Beach Yes 9/21/2017 1,414 No 393 No 867 Yes
Trinidad State Park / Mill Cree Yes 9/21/2017 3,255 No 74 No 96 No
Clam Beach County Park No 9/19/2017 368 No 144 No 158
Luffenholtz Creek No 9/19/2017 12,997
Yes 5,794 Yes 7,270 Yes
Moonstone Beach No 9/19/2017 5,794
No 4,106
Yes 7,270 Yes
North Mad River Mouth No 9/19/2017 416 No 20 No
41 No
Trinidad State Park / Mill Creek No 9/19/2017 4,106 No 833 Yes 1,112 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