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Federal water data

County water report

Benton County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Benton County, Oregon.

Water grade

F

Water score

21.6

State rank

#29

of 36

Health violations

79

EPA SDWIS, 5-year lookback

Watershed impaired

Not reported

EPA ATTAINS coverage varies by state

Monitoring sites

45

5,961 recent measurements

Live streamflow

52%

WILLAMETTE RIVER AT CORVALLIS, OR

Water at a glance

Key Water Indicators for Benton County

EPA SDWIS

Safety Grade

F

Score: 21.6 / 100

EPA SDWIS

Active Violations

79

5-year health-based lookback

EPA ATTAINS

Watershed Health

Not reported

Coverage varies by state

USGS NWIS

Streamflow Snapshot

52% of mean

WILLAMETTE RIVER AT CORVALLIS, OR

EPA WQP

Monitoring Sites

45

5,961 recent readings

Source: EPA SDWIS · Safe Drinking Water Information System

Drinking Water Compliance

Compliance grade

F

Based on EPA SDWIS compliance history.

Water score

Higher scores indicate cleaner recent compliance records.

21.6/100

Health violations

79

Health-based violations

Violations per 100K served

113.9

Population-normalized SDWIS rate

Editorial analysis

Understanding Benton County’s Water

Drinking Water Quality Overview

EPA SDWIS

Benton County's water systems carry a failing grade, scoring 21.6 out of 100. Over the past five years, EPA SDWIS records 79 health-based violations — a pattern that public water utilities are required to disclose and correct.

River & Streamflow Status

USGS NWIS

USGS NWIS gauge data (as of 2026-05-14T11:15:00.000-07:00) puts WILLAMETTE RIVER at 6.5k cfs — well below its long-term average at 52% of mean — low-flow conditions worth noting for water-dependent ecosystems. Streamflow is a leading indicator of drought stress, sediment load, and dilution capacity: low flows concentrate pollutants and warm water temperatures, stressing aquatic life and, in surface-water-dependent systems, the source water quality for treatment plants.

Monitoring Network

EPA WQP

EPA's Water Quality Portal (WQP) aggregates monitoring data from federal, state, and tribal agencies. Benton County has moderate coverage with 45 active monitoring sites with 5,961 recent measurements on record. Predominant monitoring categories include physical and nutrient. More monitoring sites generally indicate greater scientific attention to local water conditions — and provide the baseline data that regulators use to set future impairment listings.

Editorial advisory

What the data suggests for Benton County

Water Verdict

Benton County receives a poor water quality assessment with a grade of F and a score of 21.6 out of 100. The water supply has documented quality issues. Residents are strongly encouraged to use filtered or bottled water for drinking and to stay informed about utility improvement plans.

Violation Context

Benton County has recorded 79 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 113.9 violations per 100,000 people served, this rate is high and signals significant water quality management issues.

Consumer Guidance

Benton County has a Grade F compliance record with 79 health-based violations — among the highest levels in the country. Benton County's drinking-water compliance score is 21.6 out of 100. Residents are strongly advised to use a certified NSF 58 reverse-osmosis filter or bottled water for all drinking and cooking until violations are corrected. Contacting the Oregon Department of Environmental Quality or Health can expedite utility compliance action. With 45 active water-quality monitoring sites in Benton County, data coverage is strong. A pipeline streamflow snapshot from the WILLAMETTE RIVER gauge is also available on this page.

Regional Context

Benton County has poorer water quality than the average county in Oregon. Its water score is 23 points lower than the state average, suggesting more challenges with contamination control or infrastructure than neighboring counties.

Advisory text summarizes county-level public records and is not a replacement for your utility's current Consumer Confidence Report or direct local notices.

Contaminants & Resources

Key issues flagged in Benton County's water environment

Official EPA Resources for Benton County

EPA How's My Waterway

Interactive watershed health data for Benton County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Benton County

Consumer Confidence Reports (OR)

Annual water quality reports from utilities in Oregon

Past 5 years

Water Quality Monitoring

Monitoring Sites

45

Active in the past 5 years

Measurements Recorded

6.0K

5,961 total readings

Most Measured

  • Physical
  • Nutrient
  • Organics, Other

Categories measured most frequently

Data from the EPA Water Quality Portal (WQP), aggregating monitoring records from federal, state, and tribal sources. Each measurement represents a single sample analyzed for a specific characteristic (e.g., E. coli, pH, dissolved oxygen, nitrogen).

Live USGS Streamgage

River & Stream Conditions

Current Discharge

6,460cfs

May 14, 6:15 PM UTC

vs Long-Term Average

52%

Well below typical

Primary Streamgage

WILLAMETTE RIVER AT CORVALLIS, OR

USGS site
14171600
Drainage area
4,420 sq mi
Long-term mean
12.3K cfs

One representative streamgage (the one with the largest drainage area in the county). Many counties have multiple gauges; this view summarizes the primary one. The long-term mean is the full-record annual average; the percent-of-typical value compares the latest reading against that average.

Free tool

Estimate Your Water Costs

Water Cost Estimate

3

3 people  ·  ~225 gal/day

Annual Total

$558

Monthly

$47

Water Bill

$558/yr

Filter Cost

$0/yr

Safety Grade for Benton County:F — Failing

High violation count or severe watershed conditions.

Estimates use the national average residential water rate ($0.0068/gal, EPA/AWWA 2023) and EPA WaterSense per-person consumption baseline (75 gal/person/day). Actual bills vary by utility, usage tier, and local infrastructure fees. For informational purposes only.

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Frequently Asked Questions

What is the water quality in Benton County, Oregon?
Benton County, Oregon has a drinking-water quality grade of F with a score of 21.6/100, based on EPA SDWIS compliance data. The county has 79 health-based drinking water violations over the past 5 years. Watershed health, monitoring records, and streamflow snapshots are reported separately on this page.
Are there any water violations in Benton County?
Benton County has 79 health-based drinking water violations recorded by the EPA over the past 5 years. Health-based violations indicate instances where contaminant levels exceeded EPA Maximum Contaminant Levels (MCLs). Violations may have been resolved — check with your local water utility for current status.
How much water-quality monitoring happens in Benton County?
EPA's Water Quality Portal records 5,961 measurements from 45 monitoring sites in Benton County over the past five years. The most frequently measured characteristic groups are Physical, Nutrient, Organics, Other. Each measurement is a single sample analyzed for one characteristic (E. coli, pH, dissolved oxygen, etc.). High monitoring density means more scientific evidence behind any reported signal — it does not by itself indicate water quality.
What's happening with rivers in Benton County right now?
Benton County's primary USGS streamgage on the WILLAMETTE RIVER has a pipeline snapshot of 6,460 cubic feet per second — 52% of the long-term mean of 12,345.38 cfs. This is well below typical — often a signal of drought stress on source water. For the latest gauge feed, visit waterdata.usgs.gov.
How does Benton County water compare to the Oregon average?
Benton County's SDWIS water quality score of 21.6/100 is lower than the Oregon state average of 44.6. The average water quality grade across Oregon is D, based on data from 36 counties with available SDWIS data.
Is tap water safe to drink in Benton County?
Based on EPA SDWIS data, Benton County has a water quality grade of F (21.6/100). This indicates below-average compliance with significant violations. Residents may want to consider home water filtration or independent testing. The grade speaks to the public water system, not the watershed — for watershed-level concerns, see the Watershed Health zone. For the most up-to-date information, contact your local water utility or review your Consumer Confidence Report (CCR).
Why does Benton County have so many water violations?
Benton County has 79 health-based drinking water violations on record from the EPA SDWIS database. A higher violation count can result from aging infrastructure, underfunded water utilities, agricultural runoff contamination, or industrial pollution. Counties with more water systems may also see more violations simply due to scale. Residents concerned about water quality should consider independent water testing and home filtration systems.
How does Benton County rank for water quality in Oregon?
Benton County ranks #29 out of 36 counties in Oregon by SDWIS water quality score (1 = best). With a score of 21.6/100, it falls in the bottom third of counties statewide. The ranking reflects EPA SDWIS compliance only — not watershed impairment, monitoring density, or streamflow, which are tracked separately on this page.

Counties with Similar Water Quality

Jackson County

Oregon

F

19.6

Water score

Josephine County

Oregon

F

16.9

Water score

Tillamook County

Oregon

F

27.3

Water score

Data Sources

Drinking-water compliance data from the EPA Safe Drinking Water Information System (SDWIS) via the ECHO enforcement database. Scores reflect compliance history and health-based violation counts.

Water-quality monitoring counts from the EPA Water Quality Portal (WQP), federated USGS, EPA, and state agency sampling records over a rolling 5-year window.

Live streamflow from the USGS National Water Information System (NWIS), continuous discharge measurements from the largest-drainage gauge in each county, compared against the full-record long-term annual mean.

Disclaimer: This data is informational only. It is not health, legal, or professional advice. For concerns about your specific water supply, contact your local water utility.

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor

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