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WaterVerge

Water quality report · updated Jul 2026

Is Custer, WA Tap Water Safe to Drink?

Graded C+ — but Copper was detected above EPA limits. Here's what's in the water and how to remove it. What to do ↓

1 contaminant over a legal limit
1.5 ppb lead, 90th percentile · low
27 unresolved violations
1K people served by 4 water systems

PWSID WA5363350 · moderate data confidence · private utility

Reviewed by WaterVerge Editorial Team · Last updated July 2026
C 66 / 100

#178 of 294Washington cities
How we grade →

01The verdict: is Custer water safe?

Custer's drinking water has significant quality concerns based on EPA testing data. With a grade of C+ (66/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 4 water systems serve approximately 1,271 residents using groundwater (wells).

The concern

Copper is over its legal limit

Measured at 2.37 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 ↓
The good news

Lead is well under the limit

90th-percentile lead is 1.5 ppb — beneath the 15 ppb federal action level and under the 5 ppb watch threshold.

See the trend ↓
Keep watching

11 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 ↓

Custer's drinking water received a grade of C+ (66 out of 100), indicating fair water quality. The city's 4 water systems serve approximately 1,271 residents using groundwater.

Lead levels were measured at 1.5 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 170 violations on record, including 12 health-based violations. 27 remain unresolved.

Custer ranks #178 out of 294 cities in Washington for water quality, placing it below average in the state. Custer 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, Custer may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities. The system has seen 11 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.

How the 66/100 breaks down Methodology →
ViolationsHistorical violation record including health-based and monitoring violations.
20 / 45F
Lead & CopperLead at 1.5 ppb (90th percentile).
16 / 20B
ContaminantsPFAS + legacy contaminant analysis.
17 / 20B
ComplianceMonitoring and reporting compliance with EPA regulations.
8 / 10B
Source RiskWater source: Groundwater.
5 / 5A

02What's in Custer's water

Every contaminant flagged in Custer, 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.

2 detections · sorted by % of legal limit
Over the limit Elevated — watch Within limits
0 50% LEGAL LIMIT 150%

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.
Exceeds Limit What to do →
2 contaminants tested under EPA SDWIS, LCR and UCMR programs · 2 detected · not yet tested for PFAS under UCMR 5

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 1.5 15 ppb Inorganic Safe
Copper (90th percentile) 2.37 1.3 mg/L Inorganic Over Limit
Data source: EPA SDWIS, UCMR 5, local utility CCR.

03Custer'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 170 violations on record, including 12 health-based violations. 27 remain unresolved.

2 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.

19 monitoring & paperwork 8 still unresolved
UpdateWater quality data updatedLatest EPA compliance and testing data incorporated into Custer's water quality assessment. Grade: C+ (66/100).
DisasterSEVERE STORMS, STRAIGHT-LINE WINDS, FLOODING, LANDSLIDES, AND MUDSLIDESFederal disaster declaration (FEMA DR-3629). Flood event — may have impacted local water infrastructure.
Violation2 drinking water violations recordedContaminants: Consumer Confidence Rule.Open
Violation1 drinking water violation recordedContaminants: Nitrate.Resolved
Violation1 drinking water violation recordedContaminants: Consumer Confidence Rule.Open
DisasterSEVERE WINTER STORM, LANDSLIDES, MUDSLIDES, AND FLOODINGFederal disaster declaration (FEMA DR-1817). Flood event — may have impacted local water infrastructure.
Lead, 90th percentileppb · lower is better
05101520EPA action level · 15 ppb1993 — 6 ppb1994 — 3 ppb1995 — 5 ppb1997 — 3.5 ppb1998 — 4.5 ppb2002 — 2 ppb2003 — 2.5 ppb2006 — 1 ppb2008 — 1 ppb2009 — 1 ppb2011 — 1 ppb2012 — 1 ppb2014 — 5.9 ppb2015 — 3.3 ppb2017 — 1 ppb2018 — 3 ppb2019 — 1 ppb2020 — 1.2 ppb2021 — 1.6 ppb2022 — 1 ppb2023 — 3.6 ppb2024 — 1.5 ppb61.5199320022011201820232024

Down 4.5 ppb since 1993. Latest reading: 1.5 ppb (2024) — 10% of the action level. Sampled at higher-risk homes (90th percentile).

Copper, 90th percentilemg/L · lower is better
0123EPA action level · 1.3 mg/L1997 — 1.8 mg/L2008 — 1.8 mg/L2017 — 2.4 mg/L1.82.4199720082017

Up 0.60 mg/L since 1997. The latest reading (2.4 mg/L, 2017) is over the action level. Sampled at higher-risk homes (90th percentile).

04Where Custer's water comes from

Custer's drinking water is drawn from underground aquifers through wells.

Source

Groundwater

Underground aquifers reached by wells — naturally filtered, but can carry minerals like arsenic and nitrate.

Treatment

Local treatment

Groundwater generally needs less treatment — typically disinfection and, where needed, mineral removal.

Distribution

4 systems

4 water systems (1 wholesaler), operated under private ownership.

Delivery

1,271 people

Residents served across Custer'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 1,271 people through 4 water systems.

System namePWSIDPopulationSource
OLD SETTLERS WATER ASSOCIATION WA5363350 540 Groundwater
Custer Water Association WA5317050 365 Groundwater
PERCIE ROAD WATER ASSOCIATION WA5367020 250 Groundwater
CEDAR LYNN WATER ASSOC WA5312112 116 Groundwater

Water bodies near Custer

North Fork Clover Creek · river Clover Creek · river Flett Creek · river Leach Creek · river Leach · river

These water bodies shape the regional watershed and can indirectly affect groundwater quality.

05Pressure on Custer'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.

Industrial discharge

Moderate — reported releases upstream

5 facilities within 10 miles reported 160k lb released to surface water in the latest EPA Toxics Release Inventory. Proximity doesn't equal tap contamination — treatment and hydrology decide — but it's pressure on the watershed.

PHILLIPS 66 FERNDALE REFINERY — nitrate compounds (water dissociable; reportable only when in aqueous solution) 122k lb · 6.0 mi
BP CHERRY POINT REFINERY — nitrate compounds (water dissociable; reportable only when in aqueous solution) 38k lb · 4.4 mi
LISTER CHAIN & FORGE INC 0 lb · 3.5 mi
+ 2 more facilities

Flood & storm history

Recurring — declared disasters

10 federal disaster declarations on record for Pierce County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.

SEVERE STORMS, STRAIGHT-LINE WINDS, FLOODING, LANDSLIDES, AND MUDSLIDES Dec 2025 · DR-3629
SEVERE WINTER STORM, LANDSLIDES, MUDSLIDES, AND FLOODING Jan 2009 · DR-1817
HURRICANE KATRINA EVACUATION Sep 2005 · DR-3227

Drought

D1 — moderate 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.

Months in D2+ over the last 30 years15.7%

06How Custer compares

Scores for nearby Washington cities on one line, with the average marked.

Custer (this city)
66 · C+
Kent
44.4 · F
Seattle
42.3 · F
Spokane
39.2 · F
Vancouver
32.9 · F
Tacoma
32.2 · F

dashed line = Washington average (53/100)

Custer scores 66/100above the Washington average of 53/100. It outscores 7 of 10 nearby cities. Full Washington rankings →

Whatcom water quality rankings
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 Custer's water — not generic advice.

Because of copper

Filter drinking & cooking water

NSF-certified water filter. Copper exceeds the EPA action level of 1.3 mg/L

Compare tested filters →
Know your report

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 →
Stay informed

Watch for Custer 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 Custer, WA tap water safe to drink?

Custer's water quality earned a grade of C+ (66/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #178 out of 294 cities tested in Washington.

What contaminants are in Custer's water?

Lead was measured at 1.5 ppb (90th percentile). 170 violations are on record.

How is Custer'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 Custer?

Based on current data, basic filtration should suffice for additional peace of mind.

Where does Custer's water come from?

Custer's water is sourced from Groundwater. The city has 4 water systems serving approximately 1,271 residents.

What health violations has Custer's water system had?

Custer has 12 health-based violations on record. The most recent violation was recorded in July 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 27 violations remain unresolved.

Is Custer's groundwater at risk of contamination?

Custer 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 170 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 Custer's water compare to other cities?

Custer ranks #178 out of 294 cities in Washington (better than 39% of state cities) and #11270 out of 15382 cities nationally (27th percentile). The grade of C+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.

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About Custer, WA: Median household income $92,768 · median age 34.5 · 84.7% homeowners · 41.1% college educated. Service area: 2 ZIP codes across Whatcom.
Show ZIP codes 9824098248
Sources: EPA SDWIS & ECHO · UCMR 3–5 · Lead & Copper Rule samples · EPA TRI · U.S. Drought Monitor · FEMA declarations. Data last updated Jul 2026. Analysis by the WaterVerge Editorial Team · methodology.