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County water report

Bonner County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Bonner County, Idaho.

Water grade

F

Water score

19.7

State rank

#24

of 44

Health violations

39

EPA SDWIS, 5-year lookback

Watershed impaired

53.4%

326 water bodies assessed

Monitoring sites

122

60,708 recent measurements

Live streamflow

208%

PEND OREILLE RIVER AT NEWPORT WA

Water at a glance

Key Water Indicators for Bonner County

EPA SDWIS

Safety Grade

F

Score: 19.7 / 100

EPA SDWIS

Active Violations

39

5-year health-based lookback

EPA ATTAINS

Watershed Health

53% impaired

326 bodies assessed

USGS NWIS

Streamflow Snapshot

208% of mean

PEND OREILLE RIVER AT NEWPORT WA

EPA WQP

Monitoring Sites

122

60,708 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.

19.7/100

Health violations

39

Health-based violations

Violations per 100K served

135.3

Population-normalized SDWIS rate

Editorial analysis

Understanding Bonner County’s Water

Drinking Water Quality Overview

EPA SDWIS

Bonner County's water systems carry a failing grade, scoring 19.7 out of 100. Over the past five years, EPA SDWIS records 39 health-based violations — a pattern that public water utilities are required to disclose and correct.

Watershed Conditions

EPA ATTAINS

Under the Clean Water Act §303(d), EPA ATTAINS tracks whether waterways meet quality standards for drinking, recreation, and aquatic life (reporting cycle: 2022). A substantial 53.4% of assessed waterways are impaired (174 of 326 water bodies) across Bonner County's watersheds. The leading impairment causes are temperature and sedimentation/siltation. Impairment does not mean tap water is unsafe — it measures ambient waterway conditions upstream of treatment, not finished drinking water.

River & Streamflow Status

USGS NWIS

USGS NWIS gauge data (as of 2026-05-14T11:30:00.000-07:00) puts PEND OREILLE RIVER at 51.9k cfs — running significantly above its long-term average at 208% of mean flow. 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. Bonner County has extensive coverage with 122 active monitoring sites with 60,708 recent measurements on record. Predominant monitoring categories include physical and biological, fish. 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 Bonner County

Water Verdict

Bonner County, Idaho receives a poor water quality assessment with a grade of F and a score of 19.7 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. Separately, EPA ATTAINS assessments cover 326 water bodies in the county's watershed, with 53.4% listed as impaired under the Clean Water Act — a source-water measure that is tracked independently of tap-water compliance. At the most recent USGS reading, local streamflow was running above its historical mean at 207.8%.

Violation Context

EPA SDWIS records for Bonner County, Idaho show 39 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 135.3 violations per 100,000 people served, this rate is high and signals significant water quality management issues. This compliance record sits alongside an unusually deep monitoring archive: 60,708 water-quality results have been logged across the county in the EPA Water Quality Portal over the past five years.

Consumer Guidance

Bonner County has a Grade F compliance record with 39 health-based violations — among the highest levels in the country. Bonner County's drinking-water compliance score is 19.7 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 Idaho Department of Environmental Quality or Health can expedite utility compliance action. Temperature is the leading impairment cause in Bonner County's watershed. With 122 active water-quality monitoring sites in Bonner County, data coverage is strong. A pipeline streamflow snapshot from the PEND OREILLE RIVER gauge is also available on this page.

Regional Context

Bonner County has poorer water quality than the average county in Idaho. Its water score is 12.9 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 Bonner County's water environment

Watershed Impairment Causes (EPA ATTAINS)

  • 1

    Elevated temperature

    Impairment cause per EPA Clean Water Act §303(d) assessment

  • 2

    Sedimentation and siltation

    Impairment cause per EPA Clean Water Act §303(d) assessment

  • 3

    Phosphorus (excess nutrients)

    Impairment cause per EPA Clean Water Act §303(d) assessment

Source: EPA ATTAINS · Reporting cycle 2022

Official EPA Resources for Bonner County

EPA How's My Waterway

Interactive watershed health data for Bonner County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Bonner County

Consumer Confidence Reports (ID)

Annual water quality reports from utilities in Idaho

Clean Water Act §303(d)

Watershed Health

Impaired Water Bodies

53.4%

174 of 326 assessed

Moderate concern

Top Impairment Causes

  • 1

    TEMPERATURE

  • 2

    SEDIMENTATION/SILTATION

  • 3

    PHOSPHORUS, TOTAL

Source: EPA ATTAINS · Reporting cycle 2022

Impairment is determined under the Clean Water Act §303(d): a water body is impaired when it fails to meet state-defined quality standards for designated uses (drinking, recreation, aquatic life). Assessment coverage varies by state; counties without assessed water bodies are not shown.

Past 5 years

Water Quality Monitoring

Monitoring Sites

122

Active in the past 5 years

Measurements Recorded

61K

60,708 total readings

Most Measured

  • Physical
  • Biological, Fish
  • Biological, Counts

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

51.9Kcfs

May 14, 6:30 PM UTC

vs Long-Term Average

208%

Well above typical

Primary Streamgage

PEND OREILLE RIVER AT NEWPORT WA

USGS site
12395500
Drainage area
24,200 sq mi
Long-term mean
25.0K 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.

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Water Cost Estimate

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Annual Total

$558

Monthly

$47

Water Bill

$558/yr

Filter Cost

$0/yr

Safety Grade for Bonner 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 Bonner County, Idaho?
Bonner County, Idaho has a drinking-water quality grade of F with a score of 19.7/100, based on EPA SDWIS compliance data. The county has 39 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 Bonner County?
Bonner County has 39 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 healthy are the watersheds in Bonner County?
EPA ATTAINS assessments under Clean Water Act §303(d) indicate 53.4% of Bonner County's 326 assessed water bodies are classified as impaired (174 impaired). The top reported causes are TEMPERATURE, SEDIMENTATION/SILTATION, PHOSPHORUS, TOTAL. Impairment means the water body fails to meet state quality standards for at least one designated use — drinking water source, recreation, aquatic life, or fish consumption. Note: watershed impairment doesn't always translate to tap-water issues; treatment plants can remove most regulated contaminants.
How much water-quality monitoring happens in Bonner County?
EPA's Water Quality Portal records 60,708 measurements from 122 monitoring sites in Bonner County over the past five years. The most frequently measured characteristic groups are Physical, Biological, Fish, Biological, Counts. 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 Bonner County right now?
Bonner County's primary USGS streamgage on the PEND OREILLE RIVER has a pipeline snapshot of 51,900 cubic feet per second — 208% of the long-term mean of 24,975.98 cfs. This is well above typical — often a signal of recent precipitation or storm runoff. For the latest gauge feed, visit waterdata.usgs.gov.
How does Bonner County water compare to the Idaho average?
Bonner County's SDWIS water quality score of 19.7/100 is lower than the Idaho state average of 32.6. The average water quality grade across Idaho is F, based on data from 44 counties with available SDWIS data.
Is tap water safe to drink in Bonner County?
Based on EPA SDWIS data, Bonner County has a water quality grade of F (19.7/100). 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 Bonner County have so many water violations?
Bonner County has 39 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 Bonner County rank for water quality in Idaho?
Bonner County ranks #24 out of 44 counties in Idaho by SDWIS water quality score (1 = best). With a score of 19.7/100, it falls in the middle 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

Owyhee County

Idaho

F

19.8

Water score

Butte County

Idaho

F

18.7

Water score

Blaine County

Idaho

F

18.1

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.

Watershed health and impaired-waterway data from the EPA ATTAINS Clean Water Act §303(d) assessments, state-reported and EPA-finalized.

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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