Susan Buckley, RN, Director, Public Health
Ira Singh, MPH, Deputy Director
Donald I. Baird, MD, Health Officer

100 H Street, Suite 100
Eureka, CA 95501
(707) 445-6215
(707) 441-5699 FAX

Division of Environmental Health
Ocean Monitoring Program

Frequently Asked Questions (FAQ)


Luffenholtz Beach, Humboldt County
Humboldt County Division of Environmental Health began ocean water monitoring in February of 2003.  The ocean water monitoring program was established to protect the public’s health, and is currently funded by the U.S. Environmental Protection Agency.  Total coliform, fecal coliform, and enterococcus are used as indicator bacteria for monitoring marine recreational water quality.

Table of Contents

How does Humboldt County monitor ocean water quality?

From April through October, the 6 beaches between McKinleyville and Trinidad are monitored weekly for 3 types of indicator bacteria. Samples are collected within the creek mouth in ankle to knee-deep surf zone water.

Sampling is usually performed on Tuesdays with results available to the public on this website 2 days later. Re-samples of beaches that do not meet state bacteriological standards are taken on Thursdays.

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How can I find out about the weekly sampling results?

The ocean water sample results are available to the public on this website at Current Test Results.

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When is a beach placed on WARNING status?

If a water sample fails to meet one or more of the health standards, a WARNING status for the beach will be issued.  WARNING signs stating "Warning!  Ocean Water Contact May Cause Illness! Bacteria Levels Exceed Health Standards." will be posted at the beach.  Health standards are exceeded when:

  • Total coliform exceeds 10,000 MPN*
  • Fecal coliform exceeds 400 MPN
  • Enterococcus exceeds 104 MPN
  • Fecal coliform:total coliform ratio exceeds 0.1, and the total coliform count exceeds 1,000 MPN

When a beach is listed under WARNING status, swimmers should stay a minimum of 50 yards away from creek mouths.

*Most Probable Number - bacterial count per 100 ml of water

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When is a beach closed?

A beach will be closed at the discretion of the County Health Officer if there is an imminent public health threat such as a known discharge of pollutants.  CLOSED signs stating "KEEP OUT.  Sewage Contaminated Water.  Contact with Water May Cause Illness." will be posted at the beach.

When a beach is listed under CLOSED status, stay at least 1/4 mile (440 yards) away from both sides of the creek mouth.

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What are indicator bacteria?

Microorganisms are a natural component of the environment, and they also inhabit the intestinal tracts of birds and mammals. When these bacteria are released into the environment, there is a chance that they may cause illnesses in people who come in contact with contaminated water.

Indicator bacteria are selected groups of microorganisms that are found to indicate the likelihood of the presence of disease-causing pathogens.  It is difficult to detect every pathogenic organism in the water due to the wide array of the microbes in the natural environment. As a solution, indicator organisms are used because they are easy to detect. It is important to realize that indicator bacteria only suggest the presence of disease-causing organisms, and generally are not pathogenic themselves. The indicator bacteria currently used by the state health standards are total coliform, fecal coliform, and enterococcus.

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What exactly are total coliform, fecal coliform, and enterococcus?

Total coliform consist of a large group of bacteria that may inhabit the intestinal tracts of both humans and animals. They are also found naturally in water, soils, and vegetation.

Fecal coliform are a subgroup of total coliform bacteria. Their presence is highly correlated with fecal contamination from warm-blooded animals including humans. Water quality testing in Humboldt County indicates that Escherichia coli, a species of fecal coliform, comprises essentially all of the fecal coliform in this region.  E. coli also has a higher degree of association with outbreaks of certain diseases than fecal coliform.  Thus, in Humboldt County we are testing only for E. coli rather than fecal coliform.

Enterococcus, sometimes referred to as fecal streptococcus, is also an intestinal bacterium used to indicate fecal contamination from mammals and birds.

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Does the health risk to swimmers increase as indicator bacterial levels increase?

Swimming in water with sewage contamination or elevated bacterial levels may increase the risk of contracting illnesses such as skin rashes, diarrhea, and ear infections.

Past studies show that as the indicator bacteria levels increase, the swimming-associated illness rate increases. Several studies have established a statistically significant relationship between increasing bacterial levels and increased rates of illness.

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How do I protect myself from illness-causing bacteria in the ocean?

When a beach is listed under WARNING status, swimmers should stay a minimum of 50 yards away from creek mouths and storm drains. When a beach is listed under CLOSED status, stay at least 1/4 mile (440 yards) away from both sides of the creek mouths and storm drains. Also please remember to do the following at all times:

  • Do not swim in the ocean within 3 days of a rainfall event.
  • Watch for WARNING signs.
  • Swim in areas up-current of creek mouths and storm drains.
  • Avoid swallowing creek or ocean water.
  • Rinse off thoroughly (including mouth, nose, and ears) as soon as possible after swimming in the ocean.
  • Stay out of discolored water.

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For further information contact:

Harriet Hill, Registered Environmental Health Specialist
(707) 445-6215 or

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