2023 Water Quality Report – Skamania County PUD

Disinfectants & Disinfectant By-Products

There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants

	EPA Regulations		Carson Water System (CA)			Underwood Water System (UW)
Substance (Unit of Measure)	Ideal Goal (MCL)	Highest Level Allowed (MCL)	Amount Detected	Range	Year Sampled	Amount Detected	Range	Year Sampled	Violation	Typical Source
Haloacetic Acids (HAA5) (ppb)	NA	60	ND (one sample)	NA	2023	ND (one sample)	NA	2023	No	By-product of drinking water chlorination
Chlorine (ppm)	MRDLG = 4	MRDL = 4	0.60 (average)	0.39 to 1.0	2023	0.69 (average)	0.58 to 0.81	2023	No	Water additive used to control microbes
TTHMs [Total Trihalomethanes] (ppb)	NA	80	2.3 (one sample)	NA	2023	ND	NA	2023	No	By-product of drinking water disinfection

Inorganic Contaminants

	EPA Regulations		Carson Water System (CA)			Underwood Water System (UW)
Substance (Unit of Measure)	Ideal Goal (MCL)	Highest Level Allowed (MCL)	Amount Detected	Range	Year Sampled	Amount Detected	Range	Year Sampled	Violation	Typical Source
Arsenic (ppb)	0	10	ND	NA	2022	ND	NA	2020	No	Erosion of natural deposits; Runoff from orchards
Sodium (ppm)	NA	NA	6.9 (one sample)	NA	2022	5.6 (one sample)	NA	2019	No	Naturally - occurring
Nitrate (ppm)	10	10	Nd	NA	2023	0.57 (one average)	NA	2023	No	Runoff from fertilizer use; Leaching from septic tanks, sewage; Erosion of natural deposits
Fluoride (ppm)	4	4	Nd	NA	2022	0.09 (one sample)	NA	2011	No	Erosion of natural deposits; Discharge from fertilizer

Microbiological Contaminants

Turbidity is only sampled for surface water sources. 100% of the samples were below the MCL value of 0.3. A value less than 95% constitutes a Treatment Technique (TT) violation. Any measurement in excess of 1 is a violation unless otherwise approved by the state.)

	EPA Regulations		Carson Water System (CA)			Underwood Water System (UW)
Substance (Unit of Measure)	Ideal Goal (MCL)	Highest Level Allowed (MCL)	Amount Detected	Range	Year Sampled	Amount Detected	Range	Year Sampled	Violation	Typical Source
Turbidity (NTU)	NA	0.3	0.03	0.03 to 0.0	2023	NA	NA	NA	No	Soil runoff
Total Coliform (positive samples/month)	0	0	0	NA	2023	0	NA	2023	No	Naturally - occurring
Fecal coliform/E. coli - in the distribution system (positive samples)	0	0	0	NA	2023	0	NA	2023	No	Human and animal fecal waste

(*A violation occurs when a routine sample and a repeat sample, in any given month, are total coliform positive, and one is also fecal coliform or E. coli positive.)

Radioactive Contaminants

	EPA Regulations		Carson Water System (CA)			Underwood Water System (UW)
Substance (Unit of Measure)	Ideal Goal (MCL)	Highest Level Allowed (MCL)	Amount Detected	Range	Year Sampled	Amount Detected	Range	Year Sampled	Violation	Typical Source
Gross Alpha (pCi/L)	0	15	2.67	NA	2022	1.86	NA	2022	No	Erosion of natural deposits
Radium 228 (pCi/L)	0	5	0.783	NA	2022	0.773	NA	2022	No	Erosion of natural deposits

Why is Sodium Included On The List?

Sodium has been included on the list by EPA to provide an opportunity for more study. While high levels of salt intake may be associated with hypertension in some individuals, sodium levels in drinking water are usually low and unlikely to be a significant contribution to adverse health effects, according to the EPA. The EPA has established a recommended level of 20 parts per million for sodium as a level of concern for those consumers that may be restricted for daily sodium intake in their diets. The EPA is considering updating the guidance level for sodium and says the current one is probably low. FDA imposes quality standards for bottled water that are equivalent to EPA’s drinking water standards so switching to bottled water won’t solve the sodium question if that is a concern for you. Instead, EPA recommends talking with your doctor or a dietitian about reducing sodium in food intake.

Does My Drinking Water Contain Fluoride?

The Skamania PUD does not add fluoride to the Carson or Underwood drinking water. Some fluoride compounds, such as sodium fluoride and fluorosilicates, dissolve easily into ground water as it moves through gaps and pore spaces between rocks. Most water supplies contain some naturally occurring fluoride. Fluoride can also enter drinking water in discharge from fertilizer or aluminum factories.

Does My Drinking Water Contain Chlorine?

Yes. Skamania PUD’s water contains a trace amount of chlorine residual added as a precaution against potential contaminants that might somehow enter the system. To reduce chlorine taste or smell, use a filter or fill a pitcher with water and let it sit for a while. The chlorine will react with the air and evaporate from the water.

Lead & Copper Monitoring Results

Sampling Schedule			Carson (2023)			Underwood (2023)
Substance (Unit of Measure)	Ideal Goal (MCLG)	Action Level	90th %	Sites Above AL / Total Sites	Violation	90th %	Sites Above AL / Total Sites	Violation	Typical Source
Lead - at consumer taps (ppm)	0	0.015	0.0015	0/10	No	0.0085	0/10	No	Household plumbing
Copper - at consumer taps (ppm)	1.3	1.3	0.027	0/10	No	0.049	0/10	No	Household plumbing
EPA and state regulations require Skamania PUD and the systems it supplies to monitor for the presence of lead and copper at household taps in their service area every 3 years. The table above reports the results for the 2023 testing. The next round of required sampling will be conducted in 2026.
The results for water tested before it enters household plumbing were even lower. This indicates that there is virtually no lead or copper in the water you are provided, but your household plumbing may contribute to the presence of lead and copper at your tap.

Sampling Schedule

Parameter	Frequency
Chlorine residual	Continuous monitoring
Turbidity	Continuous monitoring
pH	Continuous monitoring
Total coliform bacteria	Monthly
Disinfection by-products	Quarterly (Carson), Annually (Underwood)
Nitrate	Annually
Copper	Every 3 years
Lead	Every 3 years
Pesticides	Every 3 years
Volatile organic compounds	Every 3 years (Carson) Every 6 years (Underwood)
Radionuclides	Every 6 years
Asbestos	Every 9 years
Herbicides	Every 9 years
Inorganic chemicals	Every 9 years

Definitions

Abbreviation	Definition
ppm	Parts per million, or milligrams per liter (mg/L)
ppb	Parts per billion, or micrograms per liter (μg/L)
pCi/L	Picocuries per liter (a measure of radioactivity)
ND	not detected
NTU	NephelometricTurbidity Units. Turbidity is a measure of the cloudiness of the water. We monitor it because it is a good indicator of the effectiveness of our filtration system.
MCLG	Maximum Contaminant Level Goal: The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety.
MCL	Maximum Contaminant Level: 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.
TT	Treatment Technique: A required process intended to reduce the level of a contaminant in drinking water.
MRDLG	Maximum Residual Disinfection Level Goal: The level of a drinking water disinfectant below which there is no known or expected risk to health.
MRDL	Maximum Residual Disinfectant Level: The highest level of a disinfectant allowed in drinking water.
MPL	State Assigned Maximum Permissible Level

Contaminants Table

Types of Contaminants	Description
Microbial Contaminants (Such as viruses, parasites and bacteria)	May come from sewage treatment plants, septic systems, agricultural livestock operations, and wildlife.
Inorganic Contaminants (Such as salts and metals)	Can occur naturally or may result from urban stormwater runoff, industrial or domestic wastewater discharges, oil and gas production, mining, and farming.
Pesticides and Herbicides	May come from a variety of sources such as agriculture, urban stormwater runoff, and residential uses.
Organic Chemical Contaminants (Including synthetic and volatile organic chemicals)	By-products of industrial processes and petroleum production, and can also come from gas stations, urban stormwater runoff, and septic systems.
Radioactive Contaminants	Can be naturally occurring or the result of oil and gas production and mining activities.

Source & Susceptibility Rating Table

Source	Susceptibility Rating
Bear Creek (Carson)	High
Industrial Well (Carson)	Moderate
Calligan Springs (Underwood)	High
Galligan Well (Underwood)	Low
Shaddox Springs (Underwood)	High

Where does my water come from?

Carson

water sytem Carson Water System has two sources of water; surface water from Bear Creek and groundwater from the Industrial Site Well located north of Carson on Old State Road.

Your Bear Creek surface water is treated in a “treatment train” (a series of processes applied in a sequence) that includes coagulation, flocculation, sedimentation, filtration, and disinfection. Coagulation removes dirt and other particles suspended in the source water by adding chemicals (coagulants) to form tiny sticky particles called “floc,” which attract the dirt particles. Flocculation (the formation of larger flocs from smaller flocs) is achieved using gentle, constant mixing. The heavy particles settle naturally out of the water in a sedimentation basin. The clear water then moves to the filtration process where the water passes through anthracite, sand, and garnet that remove even smaller particles. A small amount of chlorine is used to kill bacteria and other microorganisms (viruses, cysts, etc.) that may be in the water before water is stored and distributed to homes and businesses in the community.

Your Industrial Site ground water is treated by disinfection. Disinfection involves the addition of chlorine to kill dangerous bacteria and microorganisms that may be in the water. Disinfection is one of the major public health advances of the 20th century.

Underwood

The Underwood Water System uses groundwater from Galligan Springs, Shaddox Springs, and Galligan Well located north of SR 14 at an elevation of 350 feet. The water is then pumped 925 feet to serve the community of Underwood. Like the Industrial Site, water treatment is provided by chlorination.