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Walla Walla County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Walla Walla County, Washington.

Water grade

C

Water score

53.3

State rank

#28

of 39

Health violations

8

EPA SDWIS, 5-year lookback

Watershed impaired

Not reported

EPA ATTAINS coverage varies by state

Monitoring sites

123

103,166 recent measurements

Live streamflow

45%

WALLA WALLA RIVER NEAR TOUCHET, WA

Water at a glance

Key Water Indicators for Walla Walla County

EPA SDWIS

Safety Grade

C

Score: 53.3 / 100

EPA SDWIS

Active Violations

8

5-year health-based lookback

EPA ATTAINS

Watershed Health

Not reported

Coverage varies by state

USGS NWIS

Streamflow Snapshot

45% of mean

WALLA WALLA RIVER NEAR TOUCHET, WA

EPA WQP

Monitoring Sites

123

103,166 recent readings

Source: EPA SDWIS · Safe Drinking Water Information System

Drinking Water Compliance

Compliance grade

C

Based on EPA SDWIS compliance history.

Water score

Higher scores indicate cleaner recent compliance records.

53.3/100

Health violations

8

Health-based violations

Violations per 100K served

12.1

Population-normalized SDWIS rate

Editorial analysis

Understanding Walla Walla County’s Water

Drinking Water Quality Overview

EPA SDWIS

Walla Walla County's drinking water earned a C grade, scoring 53.3 out of 100. Over the past five years, EPA SDWIS records 8 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 2026-05-14T11:30:00.000-07:00) puts WALLA WALLA RIVER at 262.0 cfs — well below its long-term average at 45% 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. Walla Walla County has extensive coverage with 123 active monitoring sites with 103,166 recent measurements on record. Predominant monitoring categories include physical and organics, pesticide. 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 Walla Walla County

Water Verdict

Walla Walla County receives a below-average water quality assessment with a grade of C and a score of 53.3 out of 100. Residents should review their utility's Consumer Confidence Report and may want to consider additional water filtration for drinking.

Violation Context

Walla Walla County has recorded 8 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 12.1 violations per 100,000 people served, this rate is high and signals significant water quality management issues.

Consumer Guidance

Tap water in Walla Walla County meets baseline standards but the compliance record shows room for improvement, with a Grade C rating. Walla Walla County's drinking-water compliance score is 53.3 out of 100. The violation rate for Walla Walla County is 12.1 per 100,000 people served. Residents who are immunocompromised, pregnant, or have young children may benefit from using an NSF 53-certified filter. Contacting your local utility for the current Consumer Confidence Report will confirm which specific violations were recorded and whether they have been resolved. With 123 active water-quality monitoring sites in Walla Walla County, data coverage is strong. A pipeline streamflow snapshot from the WALLA WALLA RIVER gauge is also available on this page.

Regional Context

Walla Walla County has poorer water quality than the average county in Washington. Its water score is 6 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 Walla Walla County's water environment

Official EPA Resources for Walla Walla County

EPA How's My Waterway

Interactive watershed health data for Walla Walla County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Walla Walla County

Consumer Confidence Reports (WA)

Annual water quality reports from utilities in Washington

Past 5 years

Water Quality Monitoring

Monitoring Sites

123

Active in the past 5 years

Measurements Recorded

103K

103,166 total readings

Most Measured

  • Physical
  • Organics, Pesticide
  • Not Assigned

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

262cfs

May 14, 6:30 PM UTC

vs Long-Term Average

45%

Well below typical

Primary Streamgage

WALLA WALLA RIVER NEAR TOUCHET, WA

USGS site
14018500
Drainage area
1,657 sq mi
Long-term mean
585 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

3

3 people  ·  ~225 gal/day

Annual Total

$558

Monthly

$47

Water Bill

$558/yr

Filter Cost

$0/yr

Safety Grade for Walla Walla County:D — Poor

Elevated violations or significant watershed impairment.

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 Walla Walla County, Washington?
Walla Walla County, Washington has a drinking-water quality grade of C with a score of 53.3/100, based on EPA SDWIS compliance data. The county has 8 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 Walla Walla County?
Walla Walla County has 8 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 Walla Walla County?
EPA's Water Quality Portal records 103,166 measurements from 123 monitoring sites in Walla Walla County over the past five years. The most frequently measured characteristic groups are Physical, Organics, Pesticide, Not Assigned. 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 Walla Walla County right now?
Walla Walla County's primary USGS streamgage on the WALLA WALLA RIVER has a pipeline snapshot of 262 cubic feet per second — 45% of the long-term mean of 584.7 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 Walla Walla County water compare to the Washington average?
Walla Walla County's SDWIS water quality score of 53.3/100 is lower than the Washington state average of 59.3. The average water quality grade across Washington is D, based on data from 39 counties with available SDWIS data.
Is tap water safe to drink in Walla Walla County?
Based on EPA SDWIS data, Walla Walla County has a water quality grade of C (53.3/100). This indicates moderate compliance. Some violations have been recorded but overall standards are maintained. 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 Walla Walla County have so many water violations?
Walla Walla County has 8 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 Walla Walla County rank for water quality in Washington?
Walla Walla County ranks #28 out of 39 counties in Washington by SDWIS water quality score (1 = best). With a score of 53.3/100, 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

Klickitat County

Washington

C

53.5

Water score

Grays Harbor County

Washington

C

53.6

Water score

Skamania County

Washington

C

54.0

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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