01The verdict: is Sedro Woolley water safe?
Sedro Woolley's drinking water has significant quality concerns based on EPA testing data. With a grade of A (94/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 1,780 residents using groundwater (wells).
3 unresolved violations on record
EPA records show open compliance items for this system. Most are administrative, but unresolved items are worth watching.
See what was cited ↓Lead is well under the limit
90th-percentile lead is 2.6 ppb — beneath the 15 ppb federal action level and under the 5 ppb watch threshold.
See the trend ↓A flood-prone service area
10 federal disaster declarations on record. After severe weather, watch for boil-water advisories.
See the risk factors ↓Sedro Woolley's drinking water received a grade of A (94 out of 100), indicating excellent water quality. The city's 1 water system serves approximately 1,780 residents using groundwater.
Lead levels were measured at 2.6 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 15 violations on record, including 1 health-based violation. 3 remain unresolved.
Sedro Woolley ranks #7 out of 294 cities in Washington for water quality, placing it one of the best in the state. Sedro Woolley 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, Sedro Woolley may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
02What's in Sedro Woolley's water
Every contaminant flagged in Sedro Woolley, 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.
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. | 2.6 | 15 | ppb | Inorganic | Safe |
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
03Sedro Woolley'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 15 violations on record, including 1 health-based violation. 3 remain unresolved.
All ten of the last ten years were clean — no EPA violations recorded for Sedro Woolley.
▼ Down 1.4 ppb since 1993. Latest reading: 2.6 ppb (2024) — 17% of the action level. Sampled at higher-risk homes (90th percentile).
04Where Sedro Woolley's water comes from
Sedro Woolley'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.
1 system
1 water system, operated under private ownership.
1,780 people
Residents served across Sedro Woolley'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 1,780 people through 1 water system.
| System name | PWSID | Population | Source |
|---|---|---|---|
| GLENHAVEN LAKES CLUB | WA5328050 | 1,780 | Groundwater |
Water bodies near Sedro Woolley
These water bodies shape the regional watershed and can indirectly affect groundwater quality.
05Pressure on Sedro Woolley's watershed
Outside forces that shape what reaches the treatment plant. None of these is a verdict on the tap by itself — but each adds pressure worth knowing about.
Flood & storm history
10 federal disaster declarations on record for Skagit County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.
Drought
Whatcom County is in D1 (moderate drought) per the U.S. Drought Monitor (week of Jul 2026). Drought can raise disinfection-byproduct levels and taste/odor issues as utilities draw from lower reservoirs.
06How Sedro Woolley compares
Scores for nearby Washington cities on one line, with the average marked.
dashed line = Washington average (53/100)
Sedro Woolley scores 94/100 — above the Washington average of 53/100. It outscores 10 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.→
07What to do at home
Steps matched to what testing actually found in Sedro Woolley's water — not generic advice.
A basic carbon filter still helps
Sedro Woolley's water meets federal standards, but a simple carbon filter improves taste and adds a margin of safety against short-term issues.
Compare tested filters →Read your utility's annual report
Every utility must publish a yearly Consumer Confidence Report with its own testing results. It pairs well with the independent data on this page.
How to read a CCR →Watch for Sedro Woolley alerts
This area has a history of flood declarations — after severe weather, watch for boil-water advisories from the utility, and check the live alerts on this page.
All water alerts →Frequently asked questions
Is Sedro Woolley, WA tap water safe to drink?
Sedro Woolley's water quality earned a grade of A (94/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #7 out of 294 cities tested in Washington.
What contaminants are in Sedro Woolley's water?
Lead was measured at 2.6 ppb (90th percentile). 15 violations are on record.
How is Sedro Woolley'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 Sedro Woolley?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Sedro Woolley's water come from?
Sedro Woolley's water is sourced from Groundwater. The city has 1 water system serving approximately 1,780 residents.
What health violations has Sedro Woolley's water system had?
Sedro Woolley has 1 health-based violation on record. The most recent violation was recorded in July 2015. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 3 violations remain unresolved.
Is Sedro Woolley's groundwater at risk of contamination?
Sedro Woolley 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 15 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 Sedro Woolley's water compare to other cities?
Sedro Woolley ranks #7 out of 294 cities in Washington (better than 98% of state cities) and #655 out of 15382 cities nationally (96th percentile). The grade of A reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Sedro Woolley's small water system affect quality?
Sedro Woolley's system serves approximately 1,780 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 15 violations on record.