Is Oakville, WA Tap Water Safe to Drink?
Graded F — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
44/100
waterverge.com Oakville, WA — Water Quality Report
Oakville's drinking water received a grade of F (44 out of 100), indicating failing water quality. The city's 3 water systems serve approximately 2,013 residents using groundwater.
Lead levels were measured at 3.9 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 394 violations on record, including 4 health-based violations. 43 remain unresolved.
What to know about Oakville's water
Oakville ranks #257 out of 294 cities in Washington for water quality, placing it among the lowest-rated in the state.
Oakville relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff.
As a small community water system, Oakville may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
The system has seen 55 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Oakville, WA water safe to drink?
Oakville's drinking water has significant quality concerns based on EPA testing data. With a grade of F (44/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 3 water systems serve approximately 2,013 residents using groundwater (wells).
Recent water quality updates for Oakville
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Oakville's water quality assessment. Grade: F (44/100).
Federal disaster declaration (FEMA DR-3629). Flood event — may have impacted local water infrastructure.
Contaminants: Revised Total Coliform Rule, Chlorine, Di(2-ethylhexyl) adipate.
Contaminants: Atrazine, Toxaphene, LASSO.
Contaminants: Revised Total Coliform Rule, Chlorine.
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 Oakville'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
Oakville's water system has 394 total violations on record, including 4 health-based violations. 43 remain unresolved. 55 violations were issued in the last 5 years.
Flood & environmental risk
Grays Harbor 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. Local water sources include Chehalis River.
Where does Oakville's water come from?
Oakville's drinking water comes from groundwater (wells), supplied by 3 water systems serving approximately 2,013 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Chehalis River (river).
What Oakville residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Oakville'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.
Run cold water for 30 seconds before drinking, especially in the morning. Lead and copper leach from household plumbing when water sits in pipes.
Oakville'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
Flood & disaster history
Grays Harbor 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 Oakville'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. | 3.9 | 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. | 1.89 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level trend (90th percentile)
See how Oakville compares by contaminant
Explore where Oakville ranks among all Washington cities for specific contaminants.
Water source & infrastructure
Where Oakville's water comes from
Oakville's drinking water is drawn from underground aquifers through wells.
Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals.
Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds.
The system is operated by local government ownership and serves approximately 2,013 people through 3 water systems.
Water bodies near Oakville
Oakville is located near 1 notable water body. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Oakville
| System Name | PWSID | Population | Source |
|---|---|---|---|
| OAKVILLE CITY OF | WA5362750 | 1,325 | GW |
| CHEHALIS TRIBAL HOUSING | 105300027 | 620 | GW |
| VOSPER PLACE SUBDIVISION | 105338111 | 68 | GWP |
How Oakville compares
Full Washington rankings →Oakville's score of 44/100 is below the average of 53/100 among major Washington cities. It outscores 4 of 10 nearby cities. 6 of 10 nearby cities score higher.
Nearby cities
View Washington rankings →ZIP codes served by Oakville
The water systems serving Oakville cover 1 ZIP code. Select any ZIP to see which water systems serve that area.
About Oakville, WA
Learn more about your water
Guides and resources related to Oakville's water quality findings.
Explore water quality across Grays Harbor
Frequently asked questions
Is Oakville, WA tap water safe to drink?
Oakville's water quality earned a grade of F (44/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #257 out of 294 cities tested in Washington.
What contaminants are in Oakville's water?
Lead was measured at 3.9 ppb (90th percentile). 394 violations are on record.
How is Oakville'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 Oakville?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Oakville's water come from?
Oakville's water is sourced from Groundwater. The city has 3 water systems serving approximately 2,013 residents.
What health violations has Oakville's water system had?
Oakville has 4 health-based violations on record. The most recent violation was recorded in October 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 43 violations remain unresolved.
Is Oakville's groundwater at risk of contamination?
Oakville uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 394 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.
How does Oakville's water compare to other cities?
Oakville ranks #257 out of 294 cities in Washington (better than 13% of state cities) and #14478 out of 15744 cities nationally (8th percentile). The grade of F reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.