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County water report

Eureka County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Eureka County, Nevada.

Water grade

F

Water score

23.3

State rank

#14

of 16

Health violations

1

EPA SDWIS, 5-year lookback

Watershed impaired

0.0%

1 water bodies assessed

Monitoring sites

6

1,540 recent measurements

Live streamflow

28%

HUMBOLDT RV AT OLD US 40 BRG AT DUNPHY, NV

Water at a glance

Key Water Indicators for Eureka County

EPA SDWIS

Safety Grade

F

Score: 23.3 / 100

EPA SDWIS

Active Violations

1

5-year health-based lookback

EPA ATTAINS

Watershed Health

0% impaired

1 bodies assessed

USGS NWIS

Streamflow Snapshot

28% of mean

HUMBOLDT RV AT OLD US 40 BRG AT DUNPHY, NV

EPA WQP

Monitoring Sites

6

1,540 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.

23.3/100

Health violations

1

Health-based violations

Violations per 100K served

101.3

Population-normalized SDWIS rate

Editorial analysis

Understanding Eureka County’s Water

Drinking Water Quality Overview

EPA SDWIS

Eureka County's water systems carry a failing grade, scoring 23.3 out of 100. Over the past five years, EPA SDWIS records 1 health-based violation — a single incident worth monitoring.

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). None of the assessed waterways are listed as impaired (0 of 1 water bodies) across Eureka County's watersheds. 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 2026-05-14T11:45:00.000-07:00) puts HUMBOLDT RV at 104.0 cfs — well below its long-term average at 28% 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. Eureka County has limited coverage with 6 active monitoring sites with 1,540 recent measurements on record. Predominant monitoring categories include inorganics, minor, metals and physical. 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 Eureka County

Water Verdict

Eureka County receives a poor water quality assessment with a grade of F and a score of 23.3 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.

Violation Context

Eureka County has recorded 1 health-based violation, meaning the water system experienced at least one exceedance of federal contaminant limits or treatment requirements. At 101.3 violations per 100,000 people served, this rate is high and signals significant water quality management issues.

Consumer Guidance

Drinking-water compliance in Eureka County is rated Grade F, reflecting significant health-based violations in the recent reporting period. Eureka County's drinking-water compliance score is 23.3 out of 100. An NSF 53 or NSF 58-certified filter is recommended for drinking and cooking water. Check the Consumer Confidence Report from your utility to identify the specific contaminants and required corrective actions — utilities are legally required to notify customers of violations. There are 6 active water-quality monitoring sites in Eureka County. A pipeline streamflow snapshot from the HUMBOLDT RV gauge is also available on this page.

Regional Context

Eureka County has poorer water quality than the average county in Nevada. Its water score is 25.2 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 Eureka County's water environment

Official EPA Resources for Eureka County

EPA How's My Waterway

Interactive watershed health data for Eureka County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Eureka County

Consumer Confidence Reports (NV)

Annual water quality reports from utilities in Nevada

Clean Water Act §303(d)

Watershed Health

Impaired Water Bodies

0.0%

0 of 1 assessed

Mostly healthy

Top Impairment Causes

No specific impairment causes reported for the assessed water bodies in this county.

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

6

Active in the past 5 years

Measurements Recorded

1.5K

1,540 total readings

Most Measured

  • Inorganics, Minor, Metals
  • Physical
  • Nutrient

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

104cfs

May 14, 6:45 PM UTC

vs Long-Term Average

28%

Well below typical

Primary Streamgage

HUMBOLDT RV AT OLD US 40 BRG AT DUNPHY, NV

USGS site
10323425
Drainage area
7,470 sq mi
Long-term mean
377 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 Eureka 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 Eureka County, Nevada?
Eureka County, Nevada has a drinking-water quality grade of F with a score of 23.3/100, based on EPA SDWIS compliance data. The county has 1 health-based drinking water violation over the past 5 years. Watershed health, monitoring records, and streamflow snapshots are reported separately on this page.
Are there any water violations in Eureka County?
Eureka County has 1 health-based drinking water violation 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 Eureka County?
EPA ATTAINS assessments under Clean Water Act §303(d) indicate 0.0% of Eureka County's 1 assessed water bodies are classified as impaired (0 impaired). 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 Eureka County?
EPA's Water Quality Portal records 1,540 measurements from 6 monitoring sites in Eureka County over the past five years. The most frequently measured characteristic groups are Inorganics, Minor, Metals, Physical, Nutrient. 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 Eureka County right now?
Eureka County's primary USGS streamgage on the HUMBOLDT RV has a pipeline snapshot of 104 cubic feet per second — 28% of the long-term mean of 376.96 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 Eureka County water compare to the Nevada average?
Eureka County's SDWIS water quality score of 23.3/100 is lower than the Nevada state average of 48.5. The average water quality grade across Nevada is D, based on data from 16 counties with available SDWIS data.
Is tap water safe to drink in Eureka County?
Based on EPA SDWIS data, Eureka County has a water quality grade of F (23.3/100). 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).
Does Eureka County have clean drinking water?
Eureka County has 1 health-based drinking water violation according to EPA records. With a water quality score of 23.3/100 and grade F, the county's drinking water has had some compliance issues but continues to be monitored. Note: drinking-water compliance speaks to the public water system, not necessarily to the watershed itself — check the Watershed Health zone for ATTAINS §303(d) data.
How does Eureka County rank for water quality in Nevada?
Eureka County ranks #14 out of 16 counties in Nevada by SDWIS water quality score (1 = best). With a score of 23.3/100, 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

Lander County

Nevada

F

29.6

Water score

Churchill County

Nevada

F

30.6

Water score

Esmeralda County

Nevada

F

14.6

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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