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Dillingham Census Area Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Dillingham Census Area, Alaska.

Water grade

F

Water score

6.2

State rank

#14

of 22

Health violations

31

EPA SDWIS, 5-year lookback

Watershed impaired

Not reported

EPA ATTAINS coverage varies by state

Monitoring sites

12

408 recent measurements

Live streamflow

79%

NUYAKUK R NR DILLINGHAM AK

Water at a glance

Key Water Indicators for Dillingham Census Area

EPA SDWIS

Safety Grade

F

Score: 6.2 / 100

EPA SDWIS

Active Violations

31

5-year health-based lookback

EPA ATTAINS

Watershed Health

Not reported

Coverage varies by state

USGS NWIS

Streamflow Snapshot

79% of mean

NUYAKUK R NR DILLINGHAM AK

EPA WQP

Monitoring Sites

12

408 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.

6.2/100

Health violations

31

Health-based violations

Violations per 100K served

601.4

Population-normalized SDWIS rate

Editorial analysis

Understanding Dillingham Census Area’s Water

Drinking Water Quality Overview

EPA SDWIS

Dillingham Census Area's water systems carry a failing grade, scoring 6.2 out of 100. Over the past five years, EPA SDWIS records 31 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 2026-05-14T10:45:00.000-08:00) puts NUYAKUK R at 5.1k cfs — running somewhat below its historical average at 79% 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. Dillingham Census Area has moderate coverage with 12 active monitoring sites with 408 recent measurements on record. Predominant monitoring categories include physical and microbiological. 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 Dillingham Census Area

Water Verdict

Dillingham Census Area, Alaska receives a poor water quality assessment with a grade of F and a score of 6.2 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. The county's primary USGS gauge drains roughly 1,510 square miles of upstream watershed, giving local source waters a regional footprint. At the most recent USGS reading, local streamflow was below its historical mean at 79.0% — worth watching in drier seasons.

Violation Context

EPA SDWIS records for Dillingham Census Area, Alaska show 31 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 601.4 violations per 100,000 people served, this rate is high and signals significant water quality management issues. Independent monitoring is comparatively sparse here — 408 water-quality results logged in the EPA Water Quality Portal over the past five years — so the utility's own reporting carries extra weight.

Consumer Guidance

Dillingham Census Area has a Grade F compliance record with 31 health-based violations — among the highest levels in the country. Dillingham Census Area's drinking-water compliance score is 6.2 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 Alaska Department of Environmental Quality or Health can expedite utility compliance action. With 12 active water-quality monitoring sites in Dillingham Census Area, data coverage is strong. A pipeline streamflow snapshot from the NUYAKUK R gauge is also available on this page.

Regional Context

Dillingham Census Area has poorer water quality than the average county in Alaska. Its water score is 13.6 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 Dillingham Census Area's water environment

Official EPA Resources for Dillingham Census Area

EPA How's My Waterway

Interactive watershed health data for Dillingham Census Area

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Dillingham Census Area

Consumer Confidence Reports (AK)

Annual water quality reports from utilities in Alaska

Past 5 years

Water Quality Monitoring

Monitoring Sites

12

Active in the past 5 years

Measurements Recorded

408

408 total readings

Most Measured

  • Physical
  • Microbiological
  • Inorganics, Major, 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

5,060cfs

May 14, 6:45 PM UTC

vs Long-Term Average

79%

Below typical

Primary Streamgage

NUYAKUK R NR DILLINGHAM AK

USGS site
15302000
Drainage area
1,510 sq mi
Long-term mean
6,404 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 Dillingham Census Area: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 Dillingham Census Area, Alaska?
Dillingham Census Area, Alaska has a drinking-water quality grade of F with a score of 6.2/100, based on EPA SDWIS compliance data. The county has 31 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 Dillingham Census Area?
Dillingham Census Area has 31 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 Dillingham Census Area?
EPA's Water Quality Portal records 408 measurements from 12 monitoring sites in Dillingham Census Area over the past five years. The most frequently measured characteristic groups are Physical, Microbiological, Inorganics, Major, 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 Dillingham Census Area right now?
Dillingham Census Area's primary USGS streamgage on the NUYAKUK R has a pipeline snapshot of 5,060 cubic feet per second — 79% of the long-term mean of 6,403.73 cfs. Flow is within typical range for this gauge. For the latest gauge feed, visit waterdata.usgs.gov.
How does Dillingham Census Area water compare to the Alaska average?
Dillingham Census Area's SDWIS water quality score of 6.2/100 is lower than the Alaska state average of 19.8. The average water quality grade across Alaska is F, based on data from 22 counties with available SDWIS data.
Is tap water safe to drink in Dillingham Census Area?
Based on EPA SDWIS data, Dillingham Census Area has a water quality grade of F (6.2/100). 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 Dillingham Census Area have so many water violations?
Dillingham Census Area has 31 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 Dillingham Census Area rank for water quality in Alaska?
Dillingham Census Area ranks #14 out of 22 counties in Alaska by SDWIS water quality score (1 = best). With a score of 6.2/100, 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

Kodiak Island Borough

Alaska

F

6.8

Water score

Ketchikan Gateway Borough

Alaska

F

5.1

Water score

Denali Borough

Alaska

F

8.3

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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