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Federal water data

County water report

Valley County Water Report

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

Water grade

F

Water score

6.3

State rank

#40

of 44

Health violations

44

EPA SDWIS, 5-year lookback

Watershed impaired

22.9%

481 water bodies assessed

Monitoring sites

125

22,121 recent measurements

Live streamflow

515%

MF SALMON RIVER AT MF LODGE NR YELLOW PINE ID

Water at a glance

Key Water Indicators for Valley County

EPA SDWIS

Safety Grade

F

Score: 6.3 / 100

EPA SDWIS

Active Violations

44

5-year health-based lookback

EPA ATTAINS

Watershed Health

23% impaired

481 bodies assessed

USGS NWIS

Streamflow Snapshot

515% of mean

MF SALMON RIVER AT MF LODGE NR YELLOW PINE ID

EPA WQP

Monitoring Sites

125

22,121 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.

6.3/100

Health violations

44

Health-based violations

Violations per 100K served

595.7

Population-normalized SDWIS rate

Editorial analysis

Understanding Valley County’s Water

Drinking Water Quality Overview

EPA SDWIS

Valley County's water systems carry a failing grade, scoring 6.3 out of 100. Over the past five years, EPA SDWIS records 44 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 notable 22.9% of assessed waterways carry an impairment designation (110 of 481 water bodies) across Valley 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 2026-05-14T12:45:00.000-06:00) puts MF SALMON RIVER at 7.5k cfs — running significantly above its long-term average at 515% 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. Valley County has extensive coverage with 125 active monitoring sites with 22,121 recent measurements on record. Predominant monitoring categories include physical and biological, counts. 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 Valley County

Water Verdict

Valley County, Idaho receives a poor water quality assessment with a grade of F and a score of 6.3 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 481 water bodies in the county's watershed, with 22.9% 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 514.7%.

Violation Context

EPA SDWIS records for Valley County, Idaho show 44 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 595.7 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: 22,121 water-quality results have been logged across the county in the EPA Water Quality Portal over the past five years.

Consumer Guidance

Valley County has a Grade F compliance record with 44 health-based violations — among the highest levels in the country. Valley County's drinking-water compliance score is 6.3 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 Valley County's watershed. With 125 active water-quality monitoring sites in Valley County, data coverage is strong. A pipeline streamflow snapshot from the MF SALMON RIVER gauge is also available on this page.

Regional Context

Valley County has poorer water quality than the average county in Idaho. Its water score is 26.3 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 Valley 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 Valley County

EPA How's My Waterway

Interactive watershed health data for Valley County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Valley County

Consumer Confidence Reports (ID)

Annual water quality reports from utilities in Idaho

Clean Water Act §303(d)

Watershed Health

Impaired Water Bodies

22.9%

110 of 481 assessed

Some impairment

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

125

Active in the past 5 years

Measurements Recorded

22K

22,121 total readings

Most Measured

  • Physical
  • Biological, Counts
  • Inorganics, Minor, Metals

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

7,500cfs

May 14, 6:45 PM UTC

vs Long-Term Average

515%

Well above typical

Primary Streamgage

MF SALMON RIVER AT MF LODGE NR YELLOW PINE ID

USGS site
13309220
Drainage area
1,042 sq mi
Long-term mean
1,457 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 Valley County:C — Moderate

Some violations or watershed impairment detected.

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 Valley County, Idaho?
Valley County, Idaho has a drinking-water quality grade of F with a score of 6.3/100, based on EPA SDWIS compliance data. The county has 44 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 Valley County?
Valley County has 44 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 Valley County?
EPA ATTAINS assessments under Clean Water Act §303(d) indicate 22.9% of Valley County's 481 assessed water bodies are classified as impaired (110 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 Valley County?
EPA's Water Quality Portal records 22,121 measurements from 125 monitoring sites in Valley County over the past five years. The most frequently measured characteristic groups are Physical, Biological, Counts, Inorganics, Minor, Metals. 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 Valley County right now?
Valley County's primary USGS streamgage on the MF SALMON RIVER has a pipeline snapshot of 7,500 cubic feet per second — 515% of the long-term mean of 1,457.16 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 Valley County water compare to the Idaho average?
Valley County's SDWIS water quality score of 6.3/100 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 Valley County?
Based on EPA SDWIS data, Valley County has a water quality grade of F (6.3/100). 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 Valley County have so many water violations?
Valley County has 44 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 Valley County rank for water quality in Idaho?
Valley County ranks #40 out of 44 counties in Idaho by SDWIS water quality score (1 = best). With a score of 6.3/100, 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

Boise County

Idaho

F

5.7

Water score

Franklin County

Idaho

F

8.0

Water score

Clark County

Idaho

F

8.7

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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