Is Oroville, WA Tap Water Safe to Drink?
Graded A- — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
86.1/100
waterverge.com Oroville, WA — Water Quality Report
Oroville's drinking water received a grade of A- (86.1 out of 100), indicating good water quality. The city's 1 water system serves approximately 3,256 residents using groundwater.
Lead levels were measured at 3.2 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 79 violations on record, including 7 health-based violations. 1 remains unresolved.
What to know about Oroville's water
Oroville ranks #88 out of 294 cities in Washington for water quality, placing it mid-range in the state.
Oroville 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, Oroville may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Oroville, WA water safe to drink?
Oroville's tap water meets most EPA standards but has areas that warrant attention. With a grade of A- (86.1/100), some contaminant levels or compliance issues suggest that residents may benefit from additional filtration. The city's 1 water system serves approximately 3,256 residents using groundwater (wells).
Recent water quality updates for Oroville
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Oroville's water quality assessment. Grade: A- (86.1/100).
Federal disaster declaration (FEMA DR-4650). Flood event — may have impacted local water infrastructure.
Contaminants: Endrin, Methoxychlor, Simazine.
Contaminants: Endrin, Toxaphene, Simazine.
Contaminants: 1,2,4-Trichlorobenzene, p-Dichlorobenzene, Vinyl chloride.
Federal disaster declaration (FEMA DR-3227). Coastal Storm event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Oroville'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
Oroville's water system has 79 total violations on record, including 7 health-based violations. 1 remain unresolved.
Flood & environmental risk
Okanogan County has experienced 4 federally declared disasters since 1972. 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 Ninemile Creek, Osoyoos Lake, Okanogan River.
Where does Oroville's water come from?
Oroville's drinking water comes from groundwater (wells), supplied by 1 water system serving approximately 3,256 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate. Nearby water bodies include Ninemile Creek (river), Osoyoos Lake (lake), Okanogan River (river).
What Oroville residents can do
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.
Oroville'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 Oroville
Industrial polluters nearby
Reported releases to surface water by facilities near Oroville, ranked by pounds discharged annually.
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
US CBP OROVILLE PORT OF ENTRY WA0021 OROVILLE, WA98844 | — | — | 3.9 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Drought conditions
D1 — moderate droughtOkanogan County is currently in D1 (moderate drought) per the U.S. Drought Monitor (week of May 5, 2026). Drought can elevate disinfection-byproduct (TTHM/HAA5) levels and taste/odor issues as utilities draw from lower reservoirs.
Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.
Flood & disaster history
Okanogan County has experienced 4 federally declared disasters since 1972. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
Recommended water filters
Based on contaminants detected in Oroville'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. | 3.2 | 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. | 2.18 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level (90th percentile)
Latest reading: 2.180 mg/L (2003)
EPA action level: 1.3 mg/L
See how Oroville compares by contaminant
Explore where Oroville ranks among all Washington cities for specific contaminants.
Water source & infrastructure
Where Oroville's water comes from
Oroville'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 3,256 people through 1 water system.
Water bodies near Oroville
Oroville is located near 3 notable water bodies. These water bodies contribute to the regional watershed and may indirectly affect groundwater quality.
Water systems serving Oroville
| System Name | PWSID | Population | Source |
|---|---|---|---|
| OROVILLE CITY OF | WA5364400 | 3,256 | GW |
How Oroville compares
Full Washington rankings →Oroville's score of 86.1/100 is above the average of 53/100 among major Washington cities. It outscores 9 of 10 nearby cities.
Nearby cities
View Washington rankings →About Oroville, WA
Wikipedia →Oroville is a city located in the northern bulk of the Okanogan Highlands in north-central Washington, United States. Oroville is a member municipality of Okanogan County, Washington situated between Omak and Penticton. The population was 1,795 at the 2020 census.
Learn more about your water
Guides and resources related to Oroville's water quality findings.
Explore water quality across Okanogan
Frequently asked questions
Is Oroville, WA tap water safe to drink?
Oroville's water quality earned a grade of A- (86.1/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #88 out of 294 cities tested in Washington.
What contaminants are in Oroville's water?
Lead was measured at 3.2 ppb (90th percentile). 79 violations are on record.
How is Oroville'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 Oroville?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Oroville's water come from?
Oroville's water is sourced from Groundwater. The city has 1 water system serving approximately 3,256 residents.
What health violations has Oroville's water system had?
Oroville has 7 health-based violations on record. The most recent violation was recorded in January 2014. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 1 violation remains unresolved.
Is Oroville's groundwater at risk of contamination?
Oroville 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 79 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 Oroville's water compare to other cities?
Oroville ranks #88 out of 294 cities in Washington (better than 70% of state cities) and #4926 out of 15744 cities nationally (69th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Oroville's small water system affect quality?
Oroville's system serves approximately 3,256 residents. Small community water systems (under 3,300 people) may have fewer financial resources for infrastructure upgrades and advanced treatment technologies. However, they are held to the same EPA drinking water standards as larger systems. This system has 79 violations on record.