Water Quality Contaminants

Water testing

Your water is tested for more than 200 contaminants.  These include all contaminants regulated by the EPA, plus a number of unregulated contaminants.  Sampling is conducted at various locations in the water supply and distribution system.  Test results are submitted to the Oregon Health Authority, Drinking Water Program, the local agency responsible for enforcing EPA’s Safe Drinking Water Act. 

Below are the contaminants detected in samples in 2022. If a health related contaminant is not listed in this report it was not detected.

 

 

 

INORGANIC Contaminants
Contaminant Unit of
Measure

Amount Detected
low-high

 MCL MCLG Source
Barium ppm 0.0056-0.0057 2 2 Erosion of natural deposits in groundwater aquifers
Nitrate-N ppm 0.63-0.70 10 10 Runoff from fertilizer use; leaching from septic tanks & sewage; erosion of natural deposits
Chromium ppm ND-0.0032 0.1 0.1 Found naturally in rocks, plants, soil and volcanic dust, and animals; can also be produced by industrial processes; there are demonstrated instances of chromium being released to the environment by leakage, poor storage or inadequate water disposal

 

 MICROBIOLOGICAL CONTAMINANTS
Contaminant Frequency/
Measure		 Amount Detected MCL MCLG Source
Total Coliform Bacteria ♦ ** % in monthly samples 3 out of 240 1 positive sample per month 0 Naturally present in the environment
Fecal Coliform/E.Coli (positive samples) Monthly ND 0.000 0.000 Human and animal waste
Turbidity + NTU 0.01-0.08 < 0.3 NA Soil runoff and sediments

♦ Coliforms are bacteria that are naturally present in the environment and are used as an indicator that other, potentially harmful, water borne pathogens may be present or that a potential pathway exists through which contamination may enter the drinking water distribution system

**During monthly sampling, we found coliform bacteria indicating the need to look for potential problems in the water treatment process or distribution system.  When this occurs, we are required to conduct an investigation to identify problems and to correct any problems that were found during these investigations.  During this last year we were required to conduct a Level 1 coliform investigation. One Level 1 investigation was completed requiring zero (0) corrective actions. 

+ The typical cause of turbidity is sediment suspended in the water that can interfere with disinfection and provide a medium for microbial growth. Turbidity may indicate the presence of disease-causing organisms. These organisms include bacteria, viruses and parasites that can cause symptoms such as nausea, cramps, diarrhea and associated headaches. Turbidity has no serious health effects.

 

BYPRODUCT PRECURSORS AND DISINFECTANT RESIDUALS
Contaminant Unit of
Measure		 Amount
Detected
low - high		 MRDL MRDLG Source
Bromate ppb

1.1-2.8
Avg. 2.0

 10 0 Byproduct of water disinfection
Chlorine ppm 0.1-1.5 4 4 Water additive to control microbes
Haloacetic Acids ppb

4.6-8.7
Avg. 6.7

 60 N/A Byproduct of water disinfection
Total Organic Carbons ppm 0.57-2.4
Avg. 1.186		 TT N/A Naturally present in the environment
Total Trihalomethanes ppb 9.4-19.4
Avg. 13.8		 80 N/A Byproduct of water disinfection

 

Definitions

Action Level (AL): The concentration of a contaminant that, if exceeded, triggers a treatment or other requirements that a water system must follow.

Maximum Contaminant Level (MCL):  The highest level of a contaminant that is allowed in drinking water. MCLs are set as close to the MCLGs as feasible using the best available treatment technology.

Maximum Contaminant Level Goal (MCLG): The level of contaminant in drinking water below which there is no known or expected risk to health.  MCLGs allow for a margin of safety.

Maximum Residual Disinfectant Level (MRDL):  The highest level of disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants.

Maximum Residual Disinfectant Level Goal (MRDLG):  The level of a drinking water disinfectant below which there is no known or expected risk to health.  MRDLGs do not reflect the benefits of the use of disinfectants to control microbial contaminants.

Nephelometric Turbidity Units (NTU):  a measure of turbidity.

No Detection (ND): In all of the testing samples there was no contaminate detected.

Parts per billion (ppb):  1 ppb means that one part of a particular contaminant is present for every 1 billion (1,000,000,000) parts of water. 1 ppb is equivalent to 1 inch in 16,000 miles, 1 second in 32 years and 1 cent in $10 million dollars.

Parts per million (ppm):  1 ppm means that one part of a particular contaminant is present for every 1 million (1,000,000) parts of water.  1 ppm is equivalent to 1 inch in 16 miles, 1 minute in 2 years and 1 cent in $10,000 dollars.

Treatment Technique (TT): A required process intended to reduce the level of a contaminate in water.

Proceed to Water Quality Lead and Copper>>>

 

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