01The verdict: is Lopez Island water safe?
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).
Copper is over its legal limit
Measured at 1.76 mg/L against the EPA Action Level of 1.3 mg/L. The ledger below shows how far over — and which filter removes it.
See the measurement ↓Lead is well under the limit
90th-percentile lead is 3.3 ppb — beneath the 15 ppb federal action level and under the 5 ppb watch threshold.
See the trend ↓36 violations in the last five years
Recent compliance history is the best predictor of future problems — the year-by-year record is below.
See the record ↓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.
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.
02What's in Lopez Island's water
Every contaminant flagged in Lopez Island, on one shared scale: distance to its own legal limit. The red line is the limit — anything past it is out of compliance, and the closer a bar gets, the less headroom the system has.
Over Limit — EPA Action Level: 1.3 mg/L
Exceeds the EPA action level. Copper leaches from household plumbing — flush taps for 30 seconds before drinking, and consider a certified filter.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 |
Cities ranked by 90th-percentile lead PF PFAS in Washington
Cities ranked by compounds detected Cu Copper in Washington
Cities ranked by 90th-percentile copper
03Lopez Island's ten-year track record
Each box is one year. A green check means no EPA violations; a numbered badge counts that year's violations — red if any were health-based, amber if they were monitoring or paperwork issues. The system has 229 violations on record, including 28 health-based violations. 15 remain unresolved.
4 of the last ten years were clean. The numbered years had EPA violations — red when any were health-based, amber when they were paperwork or missed-testing issues.
▼ Down 1.1 ppb since 1997. Latest reading: 1.4 ppb (2025) — 9% of the action level. Sampled at higher-risk homes (90th percentile).
▼ Down 0 mg/L since 1998. The latest reading (1.8 mg/L, 2004) is over the action level. Sampled at higher-risk homes (90th percentile).
04Where Lopez Island's water comes from
Lopez Island's drinking water is drawn from underground aquifers through wells.
Groundwater
Underground aquifers reached by wells — naturally filtered, but can carry minerals like arsenic and nitrate.
Local treatment
Groundwater generally needs less treatment — typically disinfection and, where needed, mineral removal.
11 systems
11 water systems (1 wholesaler), operated under private ownership.
1,758 people
Residents served across Lopez Island's service area.
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.
| System name | PWSID | Population | Source |
|---|---|---|---|
| FISHERMAN BAY WATER ASSOCIATION | WA5325547 | 1,195 | Groundwater |
| MacKaye Harbor Water District | WA5312911 | 133 | Groundwater |
| NORTH LOPEZ SERVICE | WA5360665 | 114 | Groundwater |
| HARBOR ON FISHERMAN BAY | WA5331024 | 84 | Groundwater |
| ALECK BAY PARK WATER SYSTEM | WA5301338 | 40 | Groundwater |
| HUMPHREY HEAD OWNERS ASSOC | WA5334860 | 37 | Groundwater |
| Common Field Water System | WA53AB738 | 36 | Groundwater |
| SHOAL BAY & SWIFT BAY WATER ASSN. | WA5378398 | 35 | Groundwater |
| Milagra Water System | WA53AA517 | 31 | Groundwater |
| SUNRISE BEACH ASSOCIATION | WA5385641 | 27 | Groundwater |
| Salish Sea Water System | WA53AC941 | 26 | Surface Water |
05How Lopez Island compares
Scores for nearby Washington cities on one line, with the average marked.
dashed line = Washington average (53/100)
Lopez Island scores 44.9/100 — below the Washington average of 53/100. It outscores 5 of 10 nearby cities. Full Washington rankings →
42.3 / 100FTacoma, WA
32.2 / 100FVancouver, WA
32.9 / 100FSpokane, WA
39.2 / 100FKent, WA
44.4 / 100ABellevue, WA
91.6 / 100
Compare all cities in the county — grades, violations, and contaminant data side by side.→
06What to do at home
Steps matched to what testing actually found in Lopez Island's water — not generic advice.
Filter drinking & cooking water
NSF-certified water filter. Copper exceeds the EPA action level of 1.3 mg/L
Compare tested filters →Flush taps & check your service line
Lead leaches from pipes as water sits. Run cold water 30 seconds before drinking (especially mornings), and ask the utility whether your address still has a lead service line.
Lead risks explained →Watch for Lopez Island alerts
We refresh EPA data monthly and surface new violations, advisories, and boil-water notices for your county on this page.
All water alerts →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 #14033 out of 15382 cities nationally (9th percentile). The grade of F reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.