Is Cathlamet, WA Tap Water Safe to Drink?
Graded C — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
62.1/100
waterverge.com Cathlamet, WA — Water Quality Report
Cathlamet's drinking water received a grade of C (62.1 out of 100), indicating fair water quality. The city's 4 water systems serve approximately 3,606 residents using surface water.
Lead levels were measured at 2.0 ppb (90th percentile), well within EPA limits. This system has not yet been tested for PFAS under the EPA UCMR 5 program.
The system has 299 violations on record, including 66 health-based violations. 12 remain unresolved.
What to know about Cathlamet's water
Cathlamet ranks #190 out of 294 cities in Washington for water quality, placing it below average in the state.
The city draws from surface water sources, which are more susceptible to seasonal runoff and agricultural contamination, requiring extensive multi-barrier treatment including coagulation, filtration, and disinfection.
The system has seen 6 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Cathlamet, WA water safe to drink?
Cathlamet's drinking water has significant quality concerns based on EPA testing data. With a grade of C (62.1/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 4 water systems serve approximately 3,606 residents using surface water (rivers, lakes, or reservoirs).
Recent water quality updates for Cathlamet
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Cathlamet's water quality assessment. Grade: C (62.1/100).
Federal disaster declaration (FEMA DR-3629). Flood event — may have impacted local water infrastructure.
Contaminants: Surface Water Treatment Rule.
Contaminants: Consumer Confidence Rule.
Contaminants: Consumer Confidence Rule.
Federal disaster declaration (FEMA DR-4650). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Cathlamet's water supply.
Well within EPA limits.
Exceeds EPA action level. Copper can leach from household plumbing — flush taps for 30 seconds before drinking.
Violation history
Cathlamet's water system has 299 total violations on record, including 66 health-based violations. 12 remain unresolved. 6 violations were issued in the last 5 years.
Flood & environmental risk
Wahkiakum County has experienced 10 federally declared disasters since 1990. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies.
Where does Cathlamet's water come from?
Cathlamet's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 4 water systems serving approximately 3,606 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment.
What Cathlamet residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Cathlamet's water.
Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.
Cathlamet's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Top industrial polluters within 10 miles of Cathlamet
Industrial polluters nearby
Reported releases to surface water by facilities near Cathlamet, ranked by pounds discharged annually.
Total reported releases to surface water: 69,800 lbs
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
GEORGIA-PACIFIC WAUNA LLC CLATSKANIE, OR97016 | Methanol | 69,800 | 3.9 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Flood & disaster history
Wahkiakum County has experienced 10 federally declared disasters since 1990. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Cathlamet's water supply, we recommend the following filter types.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 2.0 | 15 | ppb | Inorganic | Safe |
| Copper (90th percentile) CopperInorganic A metal that enters drinking water mainly through corrosion of copper plumbing. Small amounts are essential for health, but excess levels are harmful. Health EffectsGastrointestinal distress (nausea, vomiting, diarrhea) at short-term high levels; liver and kidney damage from long-term exposure. EPA Limit1.3 mg/L action level Common SourcesCorrosion of copper household plumbing, erosion of natural deposits. | 2.02 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level trend (90th percentile)
See how Cathlamet compares by contaminant
Explore where Cathlamet ranks among all Washington cities for specific contaminants.
Water source & infrastructure
Where Cathlamet's water comes from
Cathlamet's drinking water comes primarily from surface water sources such as rivers, lakes, or reservoirs.
Surface water systems require multi-stage treatment including coagulation, sedimentation, filtration, and disinfection to meet EPA Safe Drinking Water Act standards.
These sources can be impacted by seasonal changes, stormwater runoff, upstream agriculture, and industrial discharge.
The system is operated by local government ownership and serves approximately 3,606 people through 4 water systems.
Water systems serving Cathlamet
| System Name | PWSID | Population | Source |
|---|---|---|---|
| CATHLAMET WATER DEPT | WA5311850 | 1,636 | SW |
| PUGET ISLAND | WA5369760 | 920 | SWP |
| WESTERN WAHKIAKUM | WA5395167 | 791 | GW |
| Skamokawa Water System | WA5305198 | 259 | GW |
How Cathlamet compares
Full Washington rankings →Cathlamet's score of 62.1/100 is above the average of 53/100 among major Washington cities. It outscores 7 of 10 nearby cities.
Nearby cities
View Washington rankings →About Cathlamet, WA
Wikipedia →Cathlamet is a town located along the Ocean Beach Highway in Wahkiakum County, Washington, United States, where it is the county seat. The population was 560 at the 2020 census.
Learn more about your water
Guides and resources related to Cathlamet's water quality findings.
Explore water quality across Wahkiakum
Frequently asked questions
Is Cathlamet, WA tap water safe to drink?
Cathlamet's water quality earned a grade of C (62.1/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #190 out of 294 cities tested in Washington.
What contaminants are in Cathlamet's water?
Lead was measured at 2.0 ppb (90th percentile). 299 violations are on record.
How is Cathlamet's water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in Cathlamet?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Cathlamet's water come from?
Cathlamet's water is sourced from Surface water. The city has 4 water systems serving approximately 3,606 residents.
What health violations has Cathlamet's water system had?
Cathlamet has 66 health-based violations on record. The most recent violation was recorded in September 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 12 violations remain unresolved.
How does Cathlamet's water compare to other cities?
Cathlamet ranks #190 out of 294 cities in Washington (better than 35% of state cities) and #11917 out of 15744 cities nationally (24th percentile). The grade of C reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.