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WaterVerge

Water quality report · updated Jul 2026

Is Carlton, OR Tap Water Safe to Drink?

Graded B- — 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
2.4 ppb lead, 90th percentile · low
10 unresolved violations
2K people served by 1 water system

PWSID OR4100171 · high data confidence · local government utility

Reviewed by WaterVerge Editorial Team · Last updated July 2026
B 73.7 / 100

#72 of 213Oregon cities
How we grade →

01The verdict: is Carlton water safe?

Carlton's drinking water has significant quality concerns based on EPA testing data. With a grade of B- (73.7/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 2,270 residents using surface water (rivers, lakes, or reservoirs).

The concern

Copper is over its legal limit

Measured at 2.10 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 2.4 ppb — beneath the 15 ppb federal action level and under the 5 ppb watch threshold.

See the trend ↓
Keep watching

10 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 ↓

Carlton's drinking water received a grade of B- (73.7 out of 100), indicating fair water quality. The city's 1 water system serves approximately 2,270 residents using surface water.

Lead levels were measured at 2.4 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 133 violations on record, including 9 health-based violations. 10 remain unresolved.

Carlton ranks #72 out of 213 cities in Oregon for water quality, placing it mid-range in the state. The city draws from surface water sources, which are more susceptible to seasonal runoff and agricultural contamination, requiring extensive multi-barrier treatment including coagulation, filtration, and disinfection. As a small community water system, Carlton may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities. The system has seen 10 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.

How the 73.7/100 breaks down Methodology →
ViolationsHistorical violation record including health-based and monitoring violations.
28.7 / 45C
Lead & CopperLead at 2.4 ppb (90th percentile).
16 / 20B
ContaminantsPFAS + legacy contaminant analysis.
17 / 20B
ComplianceMonitoring and reporting compliance with EPA regulations.
8 / 10B
Source RiskWater source: Surface water.
4 / 5B

02What's in Carlton's water

Every contaminant flagged in Carlton, 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) 2.4 15 ppb Inorganic Safe
Copper (90th percentile) 2.10 1.3 mg/L Inorganic Over Limit
Data source: EPA SDWIS, UCMR 5, local utility CCR.

03Carlton'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 133 violations on record, including 9 health-based violations. 10 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.

1 health-based in 10 yrs 10 monitoring & paperwork 3 still unresolved
UpdateWater quality data updatedLatest EPA compliance and testing data incorporated into Carlton's water quality assessment. Grade: B- (73.7/100).
Violation1 drinking water violation recordedContaminants: TTHM.Resolved
Violation1 drinking water violation recordedContaminants: Public Notice.Open
Violation1 drinking water violation recorded1 health-based. Contaminants: Interim Enhanced Surface Water Treatment Rule.Resolved
DisasterHURRICANE KATRINA EVACUATIONFederal disaster declaration (FEMA DR-3228). Coastal Storm event — may have impacted local water infrastructure.
DisasterHIGH WINDS, SEVERE STORMS AND FLOODINGFederal disaster declaration (FEMA DR-1099). Flood event — may have impacted local water infrastructure.
Lead, 90th percentileppb · lower is better
05101520EPA action level · 15 ppb1995 — 3 ppb2000 — 4 ppb2001 — 3 ppb2004 — 3 ppb2007 — 2 ppb2010 — 1 ppb2013 — 0 ppb2014 — 0 ppb2016 — 0 ppb2019 — 0 ppb2021 — 0 ppb2022 — 0 ppb2023 — 2.4 ppb32.419952004201320192023

Down 0.60 ppb since 1995. Latest reading: 2.4 ppb (2023) — 16% of the action level. Sampled at higher-risk homes (90th percentile).

Copper, 90th percentilemg/L

2.1mg/L(1995)

One sampling round on record — 162% of the 1.3mg/L EPA action level. Sampled at higher-risk homes (90th percentile).

04Where Carlton's water comes from

Carlton's drinking water comes primarily from surface water sources such as rivers, lakes, or reservoirs.

Source

Surface Water

Rivers, lakes, or reservoirs — more exposed to runoff, agriculture, and seasonal swings than groundwater.

Treatment

Local treatment

Multi-barrier treatment: coagulation, sedimentation, filtration, and disinfection to meet EPA standards.

Distribution

1 system

1 water system, operated under local government ownership.

Delivery

2,270 people

Residents served across Carlton's service area.

Surface water systems require multi-stage treatment including coagulation, sedimentation, filtration, and disinfection to meet EPA Safe Drinking Water Act standards. These sources can be impacted by seasonal changes, stormwater runoff, upstream agriculture, and industrial discharge. The system is operated by local government ownership and serves approximately 2,270 people through 1 water system.

System namePWSIDPopulationSource
CARLTON, CITY OF OR4100171 2,270 Surface Water

Water bodies near Carlton

South Yamhill River · river Wapato Canal · stream Wapato Creek · river

As a surface-water system, these water bodies may directly influence Carlton's drinking water supply.

05Pressure on Carlton'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

Present — monitored

5 facilities within 10 miles reported 38 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.

CASCADE STEEL ROLLING MILLS INC — copper and copper compounds 38 lb · 4.5 mi
M&W FIBERGLASS INC 0 lb · 7.6 mi
KNIFE RIVER DAYTON ASPHALT 0 lb · 6.8 mi
+ 2 more facilities

Flood & storm history

Recurring — declared disasters

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

HURRICANE KATRINA EVACUATION Sep 2005 · DR-3228
HIGH WINDS, SEVERE STORMS AND FLOODING Feb 1996 · DR-1099
SEVERE STORMS, SNOWMELT & FLOODING Jan 1974 · DR-413

Drought

D1 — moderate drought

Yamhill 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 years20.2%

06How Carlton compares

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

Carlton (this city)
73.7 · B-
Salem
43.6 · F
Bend
41 · F
Beaverton
40.7 · F
Portland
39.4 · F
Eugene
28 · F

dashed line = Oregon average (42/100)

Carlton scores 73.7/100above the Oregon average of 42/100. It outscores 9 of 10 nearby cities. Full Oregon rankings →

Yamhill 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 Carlton'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 Carlton 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 Carlton, OR tap water safe to drink?

Carlton's water quality earned a grade of B- (73.7/100). Some concerns have been identified. Consider a water filter for an extra layer of protection. The city ranks #72 out of 213 cities tested in Oregon.

What contaminants are in Carlton's water?

Lead was measured at 2.4 ppb (90th percentile). 133 violations are on record.

How is Carlton'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 Carlton?

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

Where does Carlton's water come from?

Carlton's water is sourced from Surface water. The city has 1 water system serving approximately 2,270 residents.

What health violations has Carlton's water system had?

Carlton has 9 health-based violations on record. The most recent violation was recorded in October 2025. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 10 violations remain unresolved.

How does Carlton's water compare to other cities?

Carlton ranks #72 out of 213 cities in Oregon (better than 66% of state cities) and #9904 out of 15382 cities nationally (36th percentile). The grade of B- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.

Does Carlton's small water system affect quality?

Carlton's system serves approximately 2,270 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 133 violations on record.

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About Carlton, OR: Carlton is a city in Yamhill County, Oregon, United States. The population was 2,135 as of the 2020 Census. Median household income $92,500 · median home value $368,750 · median age 36.9 · 77.6% homeowners · 23.5% college educated. Wikipedia → Service area: 1 ZIP code across Yamhill.
Show ZIP codes 97111
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.