Is Lopez Island, 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 ↓
44.9/100
waterverge.com Lopez Island, WA — Water Quality Report
Lopez Island's drinking water received a grade of F (44.9 out of 100), indicating failing water quality. The city's 11 water systems serve approximately 1,758 residents using groundwater.
Lead levels were measured at 3.3 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 229 violations on record, including 28 health-based violations. 15 remain unresolved.
What to know about Lopez Island's water
Lopez Island ranks #252 out of 294 cities in Washington for water quality, placing it among the lowest-rated in the state.
Lopez Island 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, Lopez Island may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
The system has seen 36 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Lopez Island, WA water safe to drink?
Lopez Island's drinking water has significant quality concerns based on EPA testing data. With a grade of F (44.9/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 11 water systems serve approximately 1,758 residents using groundwater (wells).
Recent water quality updates for Lopez Island
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Lopez Island's water quality assessment. Grade: F (44.9/100).
Contaminants: Consumer Confidence Rule.
Contaminants: p-Dichlorobenzene, trans-1,2-Dichloroethylene, o-Dichlorobenzene.
Contaminants: Consumer Confidence Rule.
Key contaminant findings
Based on the most recent EPA sampling data for Lopez Island'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
Lopez Island's water system has 229 total violations on record, including 28 health-based violations. 15 remain unresolved. 36 violations were issued in the last 5 years.
Where does Lopez Island's water come from?
Lopez Island's drinking water comes from groundwater (wells), supplied by 11 water systems serving approximately 1,758 people. Groundwater is generally less susceptible to surface contamination but can contain naturally occurring contaminants like arsenic, radon, and nitrate.
What Lopez Island residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Lopez Island'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.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Recommended water filters
Based on contaminants detected in Lopez Island'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. | 3.3 | 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. | 1.76 | 1.3 | mg/L | Inorganic | Over Limit |
Lead level trend (90th percentile)
Copper level trend (90th percentile)
See how Lopez Island compares by contaminant
Explore where Lopez Island ranks among all Washington cities for specific contaminants.
Water source & infrastructure
Where Lopez Island's water comes from
Lopez Island'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 private ownership and serves approximately 1,758 people through 11 water systems.
Water systems serving Lopez Island
| System Name | PWSID | Population | Source |
|---|---|---|---|
| FISHERMAN BAY WATER ASSOCIATION | WA5325547 | 1,195 | GW |
| MacKaye Harbor Water District | WA5312911 | 133 | GW |
| NORTH LOPEZ SERVICE | WA5360665 | 114 | GW |
| HARBOR ON FISHERMAN BAY | WA5331024 | 84 | GW |
| ALECK BAY PARK WATER SYSTEM | WA5301338 | 40 | GW |
| HUMPHREY HEAD OWNERS ASSOC | WA5334860 | 37 | GW |
| Common Field Water System | WA53AB738 | 36 | GW |
| SHOAL BAY & SWIFT BAY WATER ASSN. | WA5378398 | 35 | GW |
| Milagra Water System | WA53AA517 | 31 | GW |
| SUNRISE BEACH ASSOCIATION | WA5385641 | 27 | GW |
| Salish Sea Water System | WA53AC941 | 26 | SW |
How Lopez Island compares
Full Washington rankings →Lopez Island's score of 44.9/100 is below the average of 53/100 among major Washington cities. It outscores 5 of 10 nearby cities.
Nearby cities
View Washington rankings →Learn more about your water
Guides and resources related to Lopez Island's water quality findings.
Explore water quality across San Juan
Frequently asked questions
Is Lopez Island, WA tap water safe to drink?
Lopez Island's water quality earned a grade of F (44.9/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #252 out of 294 cities tested in Washington.
What contaminants are in Lopez Island's water?
Lead was measured at 3.3 ppb (90th percentile). 229 violations are on record.
How is Lopez Island'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 Lopez Island?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Lopez Island's water come from?
Lopez Island's water is sourced from Groundwater. The city has 11 water systems serving approximately 1,758 residents.
What health violations has Lopez Island's water system had?
Lopez Island has 28 health-based violations on record. The most recent violation was recorded in July 2024. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 15 violations remain unresolved.
Is Lopez Island's groundwater at risk of contamination?
Lopez Island 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 229 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 Lopez Island's water compare to other cities?
Lopez Island ranks #252 out of 294 cities in Washington (better than 14% of state cities) and #14329 out of 15744 cities nationally (9th percentile). The grade of F reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.