2025 Drinking Water Quality Report

Carson & Underwood Water Systems

•  2025 Water Quality Report (PDF)

Summary

This 2025 Drinking Water Report is your annual update on the quality and safety of your drinking water. It includes the most recent water quality results through the monitoring period ending December 31, 2025, in accordance with state and federal regulations (not all testing is required every year). This report also provides access through references and telephone numbers to source water assessments, health effects information, and other water system topics. This allows you to make personal health-based decisions regarding your drinking water consumption and become more involved in decisions that may affect your health. Most importantly, this report shows that your drinking water source meets all primary and secondary EPA and Department of Health standards.

For more information, please contact us at:

• PO Box 500
  1492 Wind River Highway, Carson, WA 98610
• (509) 427-5126
• Email Skamania County PUD.

Do I Need To Take Special Precautions?

Some people may be more vulnerable to contaminants in drinking water than the general population. Immunocompromised people, such as people with cancer undergoing chemotherapy, people who have undergone organ transplants, people with HIV/AIDS or other immune system disorders, some elderly, and infants, can be particularly at risk from infections. These people should seek advice about drinking water from their healthcare providers. Environmental Protection Agency’s (EPA) /Centers for Disease Control (CDC) guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and other microbial contaminants are available from the Safe Water Drinking Hotline (800) 426-4791 or on EPA’s website.

Spanish (Español)

Este informe contiene información importante acerca de su agua potable. Haga que alguien lo traduzca para usted, o hable con alguien que lo entienda.

Water System Improvements

Skamania PUD is continually working to maintain and improve the Carson and Underwood Water Systems. The following highlights some of the key projects completed or underway over the past year:

Carson Junction PRV Station & Waterline Improvements

A new Pressure Reducing Valve (PRV) station, along with 930 feet of water main and a new hydrant, was installed along Wind River Highway to replace aging infrastructure. The PRV station was relocated outside an existing slide hazard area, improving resiliency and reliability of the water system.

Carson Water Treatment Plant Upgrade

Skamania PUD has completed the design of a new 1 million-gallon-per-day (MGD) drinking water treatment plant to replace the existing facility constructed in 1978. The current plant can no longer reliably meet the water demands of the Carson community. The project is expected to go out to bid in summer 2026, with construction anticipated to take approximately 1 year.

Pressure Zone 3 Tank

A new 250,000-gallon welded steel tank is being constructed in Underwood. This reservoir will improve water pressure in the area while increasing water storage capacity and enhancing fire protection for the community. The tank is expected to be completed by summer 2026. The project is made possible by a $276,862 Public Works Board grant, a $1,568,884 Public Works Board loan, and a $1,030,000 appropriation from the Washington State Legislature, sponsored by Representative Kevin Waters and Senator Paul Harris.

Underwood Generators

Skamania PUD has completed design and permitting for a project to install backup generators at three booster pump stations within the Underwood water system. The $675,000 project is funded through a $506,250 grant from the FEMA Hazard Mitigation Grant Program, $84,375 in grant funding from the Washington Emergency Management Division, and a $84,375 PUD match. Generator installation is scheduled for 2027.

Where Does My Water Come From?

Carson

Carson Water System(PWS ID 11340 H) has 2 sources of water: surface water from Bear Creek (SO1) and groundwater from the Industrial Site Well(SO2) 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 groundwater 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(PWS ID 90200 J) uses groundwater from Galligan Springs(SO1), Shaddox Springs(SO2), and Galligan Well(SO3) 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.

Source Water Assessment

Washington’s Source Water Assessment Program (SWAP) was revised in June 2025 and is availableon the Source Water Protection page. The susceptibility rating is an assessment of the delineated area around the listed water sources through which contaminants, if present, could migrate and reach our source water. By default, the DOH assigns a susceptibility rating of “high” for all springs and surface water sources.

Substances Expected To Be in Drinking Water

Both tap water and bottled water come from rivers, lakes, streams, ponds, reservoirs, springs, and wells. As water travels over the surface of the land or through the ground, it dissolves naturally occurring minerals and, in some cases, radioactive material. The water can also pick up and transport substances resulting from the presence of animals or from human activity. These substances are also called contaminants. Contaminants are any physical, chemical, biological, or radiological substance or matter in water. Contaminants that may be present in source water include:

To protect public health, the Environmental Protection Agency and the Washington State Board of Health prescribe regulations that limit the amount of certain contaminants in tap water provided by public water systems. Food and Drug Administration and Washington state Department of Agriculture regulations establish limits for contaminants in bottled water that must provide the same protection for public health.

Drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence of contaminants does not necessarily mean that water poses a health risk. More information about contaminants and potential health effects can be obtained by contacting the Environmental Protection Agency by calling the Safe Drinking Water Hotline at (800) 426-4791.

Water Quality Data

The Water Quality Table on the next page lists all the drinking water contaminants that we detected during the most recent testing done in accordance with the regulations. Although many more contaminants were tested, only those substances listed below were found in your water. All sources of drinking water contain some naturally occurring contaminants. At low levels, these substances are generally not harmful in our drinking water. Removing all contaminants would be extremely expensive, and in most cases, would not provide increased protection of public health. A few naturally occurring minerals may improve the taste of drinking water and have nutritional value at low levels.

Unless otherwise noted, the data presented in this table is from testing done in the calendar year of the report. The EPA or the State requires us to monitor for certain contaminants less than once per year because the concentrations of these contaminants do not vary significantly from year to year, or the system is not considered vulnerable to this type of contamination. As such, some of our data, though representative, may be more than one year old. In this table you will find terms and abbreviations that might not be familiar to you. To help you better understand these terms, we have provided the definitions.

Sampling Schedule

Tables of Detected Compounds

Water Hardness

The Carson Water System water is considered soft with readings ranging between 25 and 40 ppm on the hardness scale. Underwood water is considered moderately hard with readings ranging between 60 and 80 ppm.

pH Levels

The pH levels typically range from 6.8 to 7.5 in Carson and 7.3 to 8.0 in Underwood.

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.

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.

Lead in Drinking Water

If present, elevated levels of lead can cause serious health problems, especially for pregnant women and young children. Lead in drinking water is primarily from materials and components associated with service lines and home plumbing. The Carson and Underwood Water Systems are responsible for providing high-quality drinking water, but cannot control the variety of materials used in plumbing components. When your water has been sitting for several hours, you can minimize the potential for lead exposure by flushing your tap for 30 seconds to 2 minutes before using water for drinking or cooking. If you are concerned about lead in your water, you may wish to have your water tested. Information on lead in drinking water, testing methods, and steps you can take to minimize exposure is available from the Safe Drinking Water Hotline or the Safe Water Lead page.

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 twenty 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.

Water Use Efficiency

In 2003, the State Legislature passed the Municipal Water Law, which directed the Department of Health (DOH) to adopt a rule that establishes Water Use Efficiency (WUE) requirements for all municipal water suppliers. There were several components in the requirements of the rule. These requirements included auditing for leakage, setting WUE goals, and submitting annual reports to the State DOH.

The Skamania PUD set goals to reduce the average residential water usage by 2% over a 6-year period and reducing the peak day demand by 12 gallons per day (GPD). These goals focus on customer water use and water savings. All users are encouraged to conserve water in their daily lives.

The distribution water mains in Carson and Underwood are aging and leaks are the primary cause of unaccounted use. Although we have made large strides in replacing old waterlines, we still have 10 miles of steel pipe from the 1950s that are scheduled for replacement. We complete ongoing leak detection efforts to help identify underground leaks that are not visible from the surface. The DOH goal for unaccounted water use is 10% or below in Carson and 20% or below in Underwood based on a three-year rolling average. The current three-year rolling average for unaccounted use is 22.2% in Carson and 26.6% in Underwood.

Chemical Monitoring Violation

The Underwood Water System, I.D. 90200J, located in Skamania County, is required to monitor your drinking water for specific contaminants on a regular basis. Results of regular monitoring indicate whether or not your drinking water meets health standards. We did not meet our monitoring requirements for pesticides sampling, which is once every 3 years, for the specified time period of January 1, 2023 to December 31, 2025. We mistakenly sampled for herbicides instead, and therefore cannot be sure of the quality of your drinking water at that time. We collected the required pesticides sample in May 2026 and no pesticides were detected. We will collect samples in the future as required.

Lead & Copper Monitoring Results

A service line inventory has been prepared and found that there are no lead, galvanized requiring replacement, or lead status unknown service lines in either water system.

Corrosion of pipes, plumbing fittings, and fixtures may cause metals, including lead and copper, to enter drinking water. To assess corrosion of lead and copper, Skamania PUD conducts tap sampling for lead and copper at selected sites every 3 years. The table above reports the results for the 2023 testing. The next round of required sampling will be conducted in 2026. Complete lead tap sampling and service line inventory data are available for review by contacting Skamania PUD at the number or email listed above.

Customer Feedback Welcome

There are several ways you can get involved in water quality issues:

• You can communicate with elected officials
• Participate in public hearings
• Attend Skamania PUD Commission meetings

The Skamania PUD Board of Commissioners meets at 9 a.m. on the first and third Tuesday of each month (when Tuesday is a holiday, the meeting is held the following day) at Skamania PUD, 1492 Wind River Highway in Carson. Board sessions are open to the public. Please check the meeting agenda on our website.

For more information, please contact us at:

• PO Box 500
  1492 Wind River Highway, Carson, WA 98610
• (509) 427-5126
• Skamania website
• Email Skamania PUD