Fresh Water Quality Sampling: More Information

On this page:

• Overview
• Water Sampling Locations Maps
• Bacteriological Testing
• Test Results
• Sources of Bacterial Contamination
• Swimmer's Itch (Cercarial Dermatitis)

Overview

The Sonoma County Department of Health Services, in cooperation with the North Coast Regional Water Quality Control Board and the Sonoma County Water Agency, monitors bacterial levels in the water at beaches on the Russian River, and also monitors Spring Lake Lagoon in cooperation with the Sonoma County Regional Parks Department. Sampling is conducted once a week each summer between Memorial Day and Labor Day.

Fresh Water Quality Sampling Test Results

For current postings, call the Beach Sampling Hotline at (707) 565-6552

Water Sampling Locations Maps

Twelve beaches are sampled along the Russian River:

• Cloverdale River Park
• Geyserville Hwy 128 Bridge
• Alexander Valley Rd Bridge
• Camp Rose Rd. (Fitch Mountain)
• Healdsburg Veterans Memorial Beach
• Steelhead Beach
• Forestville Access Beach
• Sunset Beach/Hacienda Bridge
• Johnsons Beach
• Monte Rio Beach
• Monte Rio Beach Kiddie Area
• Monte Rio Beach Downstream

Seven locations are sampled within Spring Lake Lagoon and one sample location in Spring Lake proper (for comparison purposes).

Bacteriological Testing

Samples are tested for levels of total coliform, E. coli (Eschericha coli), and enterococcus bacteria as indicators of water quality. Though these are not considered disease-causing agents, their presence above certain numeric levels is suggestive of the presence of other, difficult to detect and quantify pathogenic microorganisms that can cause health effects. The use of these indicators is an effective way of monitoring the overall well-being of recreational waters.

The term total coliform bacteria refers to a number of bacteria including Escherichia, Klebsiella, Citrobacter and Enterobacter. They are associated with feces of warm-blooded animals and are also present in soil.

E. coli is a type of fecal coliform and is an indicator of fresh fecal pollution. Fecal coliform bacteria are a subgroup of the total coliform group. They are indicators of fecal contamination because they are restricted to the intestinal tract of warm-blooded animals. Their use enables separation of bacteria from soil and fecal origin.

Enterococcus is another fecal bacteria and is the most sensitive of the three indicator bacteria.

Test Results

The California Department of Public Health has issued the Draft Guidance for Fresh Water Beaches (pdf). It contains recommended bacterial levels for public notification and posting of beaches, however, they are not enforceable since the Draft Guidance has not been adopted and is subject to change.

Single Sample Values

Beach posting is recommended when indicator organisms exceed any of the following levels:

• Total coliforms: 10,000 per 100 ml
• Enterococcus: 61 per 100 ml
• E. Coli: 235 per 100 ml
• Swimming Not Advised Warning Sign

Thirty-Day Average Values

Additional sanitary surveys and other related evaluations, including more frequent sampling if levels appear to be on an increasing trend, are recommended when indicator organisms exceed any of the following, based on the log mean of at least 5 equally spaced samples in a 30-day period:

• Total coliforms: 1,000 per 100 ml
• Fecal coliforms: 200 per 100 ml
• Either Enterococcus: 33 per 100 ml, or E. coli: 126 per 100 ml

Sources of Bacterial Contamination

Potential sources of contamination include surface water runoff, animal waste, leachate from sewage disposal systems and improperly disposed of human waste from visitors to the river.

Swimmer's Itch (Cercarial Dermatitis)

Although Swimmer's Itch (Cercarial Dermatitis) is not related to bacterial water quality monitoring described above, it is of interest to bathers in fresh water environments, and is worth mentioning here.

During the summer 2000 season, Spring Lake Lagoon experienced an outbreak of Swimmer's Itch. In response to that outbreak, Sonoma County Regional Parks Department solved the problem by removing the flow-through between Spring Lake and Spring Lake Lagoon, and by installing a recirculation system for the lagoon that is equipped with filters and chlorinators (similar to that installed for a public pool). The chlorine residual essentially kills the larval stage of the parasite causing Swimmer's Itch, thus ending the lifecycle. Incidentally, occurrences of Swimmer's Itch have also been reported on occasion at beaches on the Russian River.

Swimmer's Itch is caused by the minute larval stages of certain trematode worms (cercariae) penetrating into the skin of humans resulting in an itchy rash and/or bumps that resemble mosquito bites. The rash is not contagious.

The lifecycle of these worms is such that infected water fowl or other mammals release eggs from the parasite in their feces when the definitive hosts contact water. The eggs hatch and the parasite enters the intermediate hosts, aquatic snails. Free-swimming cercariae emerge from the snails after several weeks and penetrate the definitive hosts. In the case of Swimmers Itch, humans are mistaken for the definitive host water fowl.

Swimmers usually do not feel the worms burrowing into the skin, but once penetrated, the cercariae die causing an allergic reaction and resultant itchy rash. Discomfort is usually short-lived, although it can persist for several weeks. Most cases of Swimmers Itch do not require medical attention. If you have a rash, you may try the following for relief:

• Use corticosteroid cream
• Apply cool compresses to the affected area
• Bathe in Epsom salts or baking soda

To reduce the likelihood of developing Swimmer's Itch:

• Do not swim in areas where Swimmers Itch is a known problem or where signs have been posted warning of unsafe water.
• Do not swim near or wade in marshy areas where snails are commonly found.
• Towel dry or shower immediately after leaving the water.
• Do not attract birds (e.g., by feeding them) to areas where Swimmers Itch is a current problem.

Parasites - Cercarial Dermatitis (also known as Swimmer's Itch)
Source: The Centers for Disease Control and Prevention.