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Federal water data

County water report

Grant County Water Report

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

Water grade

D

Water score

42.5

State rank

#33

of 39

Health violations

25

EPA SDWIS, 5-year lookback

Watershed impaired

Not reported

EPA ATTAINS coverage varies by state

Monitoring sites

76

9,766 recent measurements

Live streamflow

131%

COLUMBIA RIVER BELOW PRIEST RAPIDS DAM, WA

Water at a glance

Key Water Indicators for Grant County

EPA SDWIS

Safety Grade

D

Score: 42.5 / 100

EPA SDWIS

Active Violations

25

5-year health-based lookback

EPA ATTAINS

Watershed Health

Not reported

Coverage varies by state

USGS NWIS

Streamflow Snapshot

131% of mean

COLUMBIA RIVER BELOW PRIEST RAPIDS DAM, WA

EPA WQP

Monitoring Sites

76

9,766 recent readings

Source: EPA SDWIS · Safe Drinking Water Information System

Drinking Water Compliance

Compliance grade

D

Based on EPA SDWIS compliance history.

Water score

Higher scores indicate cleaner recent compliance records.

42.5/100

Health violations

25

Health-based violations

Violations per 100K served

27.8

Population-normalized SDWIS rate

Data center water stress

Grant County has 38 facilities in the DCWSI dataset.

ByCounty's DCWSI ranks this county #100 nationally by combining its water score with mapped data center density.

DCWSIThe Data Center Water Stress Index: 60% the county's water-system stress plus 40% how concentrated data centers already are, scored 0-100. Higher means data-center density and water pressure overlap more here.

64.2

0-100 index

Facility count

38

96.7 density percentile

Discharge estimate

Not reported

EPA CWA fields where available

Water vs median

-7.5

Compared with US county median

Named operators

Microsoft

Mapped facilities

  • CyrusOne Quincy

    CyrusOne

    OSM

  • H5 Data Center

    Intuit

    OSM

  • Intergate Quincy Data Center

    Sabey Data Centers

    OSM

  • Microsoft

    Microsoft

    OSM

  • Microsoft

    Microsoft

    OSM

  • Microsoft

    Microsoft

    OSM

32 more mapped facilities included in the county score.

See the Grant County data-center reportReview methodology

Data Center Water Budget Calculator

Estimate daily water use for a hypothetical facility in Grant County.

1 MW1,000 MW
40%100%
799K gallons/dayHigh Impact

Your facility would use 81.2% of this county's industrial water baseline. Verify water rights and long-term drought projections before committing.

81.2% of county industrial baseline0.18 Mgal/day remaining headroom

Based on USGS 2020 water-use data and EPA-standard cooling intensity constants. Not a substitute for site-specific water rights analysis.

Editorial analysis

Understanding Grant County’s Water

Drinking Water Quality Overview

EPA SDWIS

Grant County's drinking water received a D grade, scoring 42.5 out of 100. Over the past five years, EPA SDWIS records 25 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 COLUMBIA RIVER BELOW PRIEST RAPIDS DAM, WA at 154.0k cfs — flowing above its historical average at 131% of mean. 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. Grant County has extensive coverage with 76 active monitoring sites with 9,766 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 Grant County

Water Verdict

Grant County receives a below-average water quality assessment with a grade of D and a score of 42.5 out of 100. Residents should review their utility's Consumer Confidence Report and may want to consider additional water filtration for drinking.

Violation Context

Grant County has recorded 25 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 27.8 violations per 100,000 people served, this rate is high and signals significant water quality management issues.

Consumer Guidance

Grant County's drinking-water compliance is below average with a Grade D, indicating repeated or unresolved violations in the recent record. Grant County's drinking-water compliance score is 42.5 out of 100. The violation rate for Grant County is 27.8 per 100,000 people served. Residents are encouraged to use an NSF 53 or NSF 58-certified filter for drinking and cooking water until the underlying violations are resolved. Running tap water for 30 seconds before use and avoiding older lead-pipe connections can also reduce exposure risk. The current Consumer Confidence Report from your utility will specify the contaminants of concern. With 76 active water-quality monitoring sites in Grant County, data coverage is strong. A pipeline streamflow snapshot from the COLUMBIA RIVER BELOW PRIEST RAPIDS DAM, WA gauge is also available on this page.

Regional Context

Grant County has poorer water quality than the average county in Washington. Its water score is 16.8 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 Grant County's water environment

Official EPA Resources for Grant County

EPA How's My Waterway

Interactive watershed health data for Grant County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Grant County

Consumer Confidence Reports (WA)

Annual water quality reports from utilities in Washington

Past 5 years

Water Quality Monitoring

Monitoring Sites

76

Active in the past 5 years

Measurements Recorded

9.8K

9,766 total readings

Most Measured

  • Physical
  • Nutrient
  • Inorganics, Major, Non-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

154.0Kcfs

May 14, 6:15 PM UTC

vs Long-Term Average

131%

Well above typical

Primary Streamgage

COLUMBIA RIVER BELOW PRIEST RAPIDS DAM, WA

USGS site
12472800
Drainage area
96,000 sq mi
Long-term mean
117.3K 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 Grant 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.

Try the full calculator →

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Frequently Asked Questions

What is the water quality in Grant County, Washington?
Grant County, Washington has a drinking-water quality grade of D with a score of 42.5/100, based on EPA SDWIS compliance data. The county has 25 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 Grant County?
Grant County has 25 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 Grant County?
EPA's Water Quality Portal records 9,766 measurements from 76 monitoring sites in Grant County over the past five years. The most frequently measured characteristic groups are Physical, Nutrient, Inorganics, Major, Non-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 Grant County right now?
Grant County's primary USGS streamgage on the COLUMBIA RIVER BELOW PRIEST RAPIDS DAM, WA has a pipeline snapshot of 154,000 cubic feet per second — 131% of the long-term mean of 117,251.82 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 Grant County water compare to the Washington average?
Grant County's SDWIS water quality score of 42.5/100 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 Grant County?
Based on EPA SDWIS data, Grant County has a water quality grade of D (42.5/100). 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 Grant County have so many water violations?
Grant County has 25 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 Grant County rank for water quality in Washington?
Grant County ranks #33 out of 39 counties in Washington by SDWIS water quality score (1 = best). With a score of 42.5/100, 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

Benton County

Washington

F

41.0

Water score

Stevens County

Washington

F

40.7

Water score

Whatcom County

Washington

D

45.3

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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