Oregon · drinking water · SDWIS through latest publish

Cornelius, City Of Water Quality — Cornelius, Oregon

PWSID OR4100218 · Purchased / wholesaleMunicipal

14,490 people served. No health-based SDWIS violations recorded in the past 5 years. 2 remain unresolved. Last cited 2 years ago.

ALL SDWIS VIOLATIONS · 20202026 (annual count)
Bar chart of annual values from 2020 to 2026, in violations. Most recent year (2026): 0 violations.11 violations'20'21'22'23'24'25'260 violations
Anomaly engine

Active signals

UNRESOLVED VIOLATION · SDWIS VIOLATION

Contaminant 3028

Unresolved Drinking water rule (140) violation cited in 2024 (contaminant 3028).

EPA SDWIS record

UNRESOLVED VIOLATION · SDWIS VIOLATION

Contaminant 3028

Unresolved Drinking water rule (140) violation cited in 2024 (contaminant 3028).

EPA SDWIS record

Most-cited contaminants

What This Utility Gets Cited For

  • Total Trihalomethanes (TTHM)4 citations
  • Haloacetic Acids (HAA5)4 citations
  • Contaminant 30283 citations
  • Contaminant 70003 citations
  • Contaminant 29643 citations
  • Uranium2 citations
Violation history

What's On The SDWIS Record

Health-based violations exceed an MCL or treatment-technique standard. Monitoring violations are reporting failures with no measured exceedance — they tell you the system isn't fully transparent, not that the water is unsafe today.

MONITORING · CONTAMINANT 3028UNRESOLVED

2024 · Contaminant 3028 · Drinking water rule (140)

Failure to monitor as scheduled

CONTAMINANT CODE 3028

MONITORING · CONTAMINANT 3028

2024 · Contaminant 3028 · Drinking water rule (140)

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 3028

MONITORING · CONTAMINANT 3028UNRESOLVED

2024 · Contaminant 3028 · Drinking water rule (140)

Failure to monitor as scheduled

CONTAMINANT CODE 3028

OTHER · CONTAMINANT 7000

2023 · Contaminant 7000 · Phase I/II/V Synthetic Organic Chemical Rules

OTHER; returned to compliance

CONTAMINANT CODE 7000

OTHER · CONTAMINANT 7000

2023 · Contaminant 7000 · Phase I/II/V Synthetic Organic Chemical Rules

OTHER; returned to compliance

CONTAMINANT CODE 7000

OTHER · CONTAMINANT 7000

2023 · Contaminant 7000 · Phase I/II/V Synthetic Organic Chemical Rules

OTHER; returned to compliance

CONTAMINANT CODE 7000

MONITORING · CONTAMINANT 2964

2022 · Contaminant 2964 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2964

MONITORING · CONTAMINANT 2964

2022 · Contaminant 2964 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2964

MONITORING · CONTAMINANT 2964

2022 · Contaminant 2964 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2964

MONITORING · TOTAL TRIHALOMETHANES (TTHM)

2022 · Total Trihalomethanes (TTHM) · Total Trihalomethanes Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2950

MONITORING · TOTAL TRIHALOMETHANES (TTHM)

2022 · Total Trihalomethanes (TTHM) · Total Trihalomethanes Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2950

MONITORING · TOTAL TRIHALOMETHANES (TTHM)

2022 · Total Trihalomethanes (TTHM) · Total Trihalomethanes Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2950

MONITORING · TOTAL TRIHALOMETHANES (TTHM)

2022 · Total Trihalomethanes (TTHM) · Total Trihalomethanes Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2950

MONITORING · HALOACETIC ACIDS (HAA5)

2022 · Haloacetic Acids (HAA5) · Total Trihalomethanes Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2456

MONITORING · HALOACETIC ACIDS (HAA5)

2022 · Haloacetic Acids (HAA5) · Total Trihalomethanes Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2456

MONITORING · HALOACETIC ACIDS (HAA5)

2022 · Haloacetic Acids (HAA5) · Total Trihalomethanes Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2456

MONITORING · HALOACETIC ACIDS (HAA5)

2022 · Haloacetic Acids (HAA5) · Total Trihalomethanes Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2456

MONITORING · URANIUM

2020 · Uranium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 4006

MONITORING · URANIUM

2020 · Uranium · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 4006

MONITORING · CONTAMINANT 4010

2020 · Contaminant 4010 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 4010

MONITORING · CONTAMINANT 4010

2020 · Contaminant 4010 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 4010

MONITORING · COMBINED RADIUM 226/228

2020 · Combined Radium 226/228 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 4000

MONITORING · COMBINED RADIUM 226/228

2020 · Combined Radium 226/228 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 4000

Equity context · ACS 2018-2022 · USEPA-clone EJ disparity

Who Drinks This Water

Cornelius, Oregon (Census place; block-group disparity scores aggregated by centroid containment): a service population of 13,245. Local disparity score for pm2.5 (fine particulate) sits well above the reference burden (150). Why we surface this →

POPULATION SHARE
9.5%

Low-income

POPULATION SHARE
54.5%

People of color

POPULATION SHARE
6.9%

Under age 5

POPULATION SHARE
11.5%

Over age 64

NATIONAL PERCENTILE · vs all US block groups (population-weighted; ranked against the national EJScreen indicator distribution)

  • PM2.5 (fine particulate)Health riskFine inhalable particles 2.5 micrometers or smaller. They travel deep into the lungs and into the bloodstream — linked to asthma, heart disease, stroke, and premature death.86in the highest 20% nationally
  • OzoneHealth riskGround-level ozone (smog) inflames the airways. Even short exposures trigger asthma attacks and worsen chronic lung and heart disease.3below the national median
  • Nitrogen dioxide (NO₂)Health riskA tailpipe and combustion gas. Concentrates near busy roads and industrial sites; raises risk of airway inflammation, asthma, and lower respiratory infections in children.57near the national median
  • Diesel particulateHealth riskSoot from diesel engines (trucks, trains, ports, construction). EPA classifies it as a likely human carcinogen and a major driver of childhood asthma near freight corridors.45near the national median
  • Toxic releases (RSEI)Health riskEPA's Risk-Screening Environmental Indicators score — weights TRI chemical releases by toxicity, where they go, and how many people are nearby. Higher means greater modeled cancer and chronic-health risk.49near the national median
  • Traffic proximityHealth riskPopulation-weighted distance to high-volume roads. Living close to heavy traffic raises exposure to PM2.5, NO₂, and diesel exhaust — and the cardiovascular and asthma risks that follow.46near the national median
  • Lead-paint risk (pre-1960 housing)Health riskShare of housing built before 1960, when lead-based paint was common. Dust from deteriorating paint is the leading cause of childhood lead poisoning, which permanently impairs cognitive development.60above the national median
  • Superfund site proximityHealth riskPopulation-weighted distance to NPL Superfund sites — the most contaminated waste sites in the country. Nearby groundwater, soil, and air can carry industrial solvents, metals, and other long-lived contaminants.56near the national median
  • RMP-facility proximityHealth riskDistance to facilities holding chemicals at quantities large enough to require an EPA Risk Management Plan (refineries, fertilizer plants, etc.). These pose acute exposure risk during accidental releases.83in the highest 20% nationally
  • Hazardous-waste site proximityHealth riskDistance to RCRA hazardous-waste handlers (treatment, storage, disposal facilities). Indicates potential exposure to industrial chemicals in air, soil, and groundwater.58near the national median
  • Underground storage tanksHealth riskDensity of underground tanks (gasoline, heating oil, industrial fluids). Leaking tanks are a leading source of benzene and other volatile organic compounds in groundwater drinking-water supplies.90in the highest 10% nationally
  • NPDES wastewater proximityHealth riskDistance to permitted industrial wastewater dischargers. Closer proximity raises exposure to pollutants released into surface waters used for fishing, recreation, and downstream drinking-water intakes.39below the national median
  • Drinking-water non-complianceHealth riskEPA score for public water systems with health-based Safe Drinking Water Act violations. Higher means more residents on systems that recently exceeded safe limits for contaminants like lead, arsenic, or nitrate.76above the national median
EJ disparity scores · service-area block groups (100 = national reference; higher = greater disparate burden)
IndicatorDisparity scoreReading
PM2.5 (fine particulate)150well above the reference burden
Ozone4well below the reference
Nitrogen dioxide (NO₂)97near the reference
Diesel particulate78below the reference
Toxic releases (RSEI)83below the reference
Traffic proximity79below the reference
Lead-paint risk (pre-1960 housing)92near the reference
Superfund site proximity0well below the reference
RMP-facility proximity140moderately above the reference
Hazardous-waste site proximity99near the reference
Underground storage tanks153well above the reference burden
NPDES wastewater proximity67below the reference
Drinking-water non-compliance0well below the reference

Source: Census ACS 2018-2022 (5-year) + USEPA-clone EJ blockgroup stats (raw indicators + EJ disparity mirror).

Source. EPA Safe Drinking Water Information System · retrieved 2026-05-07. Reporting period 2020-01-012026-05-07.

What this is not. SDWIS records compliance against federal MCLs — not a direct readout of tap-water concentrations. Active health-based violations are not the same as a current crisis; we link to the EPA record so you can verify return-to-compliance status before forming a conclusion.