Yukon-Koyukuk County, Alaska
31 ZIP codes · Avg score 79/100 · Grade B · Updated 2026-06-04
Within Yukon-Koyukuk County, all 31 tracked ZIP codes show above-average drinking water safety — violations are infrequent and typically minor.
How Yukon-Koyukuk County Compares
How Yukon-Koyukuk County Compares
Yukon-Koyukuk County scores 4 points above the Alaska state average (75/100) and 11 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-04
ZIP Code Risk Map
Water Quality Map: Yukon-Koyukuk County, Alaska
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 16.5 (asthma 12.6%, diabetes 16.4%)
Estimated additional annual cost per homeowner: $559, driven primarily by energy_code_gap
Infrastructure: 0.499% avg pipe failure probability, 65% of ZIPs at high risk
52.3% of homes built before 1978 (lead paint era)
Violation History (2021–2025)
↑ Worsening trendEPA violation counts by year across Yukon-Koyukuk County water systems. Health-based shown in red, total in blue.
Peak year: 2024 with 23 violations. Past 5 years: 91 total (91 health-based). Health-based violations are rising versus the prior 2-year window — worth closer monitoring.
Source: EPA SDWIS historical violations. Data may lag 6–12 months for the most recent year.
County Health Indicators vs National Average
Black markers indicate national averages. Source: CDC PLACES, Census ACS.
Infrastructure Overview
Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.
Compound Risk Breakdown
Estimated additional annual cost per homeowner: $559
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
4,135 housing units in Yukon-Koyukuk County
Source: U.S. Census Bureau ACS B25034 (Year Structure Built).
Water Safety Affordability
How much it costs to fix water issues relative to home values in Yukon-Koyukuk County
Remediation costs are relatively manageable for most homeowners in Yukon-Koyukuk County, representing a small fraction of property value.
Remediation includes water filtration, lead abatement, radon mitigation, and flood protection where applicable. Source: Census ACS, EPA SDWIS.
Health Outcomes vs National Average
CDC PLACES data for Yukon-Koyukuk County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water Systems with Most Violations
Top 5 systems in Yukon-Koyukuk County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | TAKOTNA WATER SYSTEM | 70 | 144 |
| 2 | Chalkyitsik Village Water | 76 | 140 |
| 3 | Hughes Public Water Supply | 107 | 126 |
| 4 | TOO'GHA INC - IN TANANA | 271 | 101 |
| 5 | Arctic Village Water System | 175 | 96 |
26 total water systems serve Yukon-Koyukuk County.
All ZIP Codes in Yukon-Koyukuk County
31 ZIP codes tracked in Yukon-Koyukuk County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 99590 | Grayling | 99 | A | 0 | $110K |
| 2 | 99602 | Holy Cross | 98 | A | 6 (1 health) | $56K |
| 3 | 99765 | Nulato | 98 | A | 7 (1 health) | $65K |
| 4 | 99774 | Stevens Village | 98 | A | 52 (1 health) | — |
| 5 | 99781 | Venetie | 97 | A | 71 (2 health) | — |
| 6 | 99558 | Anvik | 94 | A | 71 (1 health) | — |
| 7 | 99720 | Allakaket | 94 | A | 62 (1 health) | $78K |
| 8 | 99767 | Rampart | 94 | A | 52 (1 health) | — |
| 9 | 99745 | Hughes | 92 | A | 126 (3 health) | — |
| 10 | 99748 | Kaltag | 92 | A | 27 (6 health) | $93K |
| 11 | 99758 | Minto | 92 | A | 56 (3 health) | $33K |
| 12 | 99665 | Shageluk | 87 | A | 79 (4 health) | — |
| 13 | 99756 | Manley Hot Springs | 86 | A | 1 | $122K |
| 14 | 99760 | Nenana | 86 | A | 2 | $143K |
| 15 | 99724 | Beaver | 84 | B | 27 | $36K |
| 16 | 99675 | Takotna | 81 | B | 144 | $131K |
| 17 | 99722 | Arctic Village | 81 | B | 96 | $38K |
| 18 | 99733 | Circle | 81 | B | 37 | — |
| 19 | 99740 | Fort Yukon | 81 | B | 17 | $111K |
| 20 | 99746 | Huslia | 81 | B | 32 | — |
| 21 | 99754 | Koyukuk | 79 | B | 64 | $110K |
| 22 | 99768 | Ruby | 74 | B | 45 | $73K |
| 23 | 99777 | Tanana | 72 | B | 101 (10 health) | $64K |
| 24 | 99741 | Galena | 67 | C | 45 (10 health) | $96K |
| 25 | 99788 | Chalkyitsik | 64 | C | 140 (22 health) | $33K |
| 26 | 99557 | Aniak | 52 | D | 0 | $232K |
| 27 | 99627 | Mc Grath | 50 | D | 0 | $102K |
| 28 | 99691 | Nikolai | 50 | D | 0 | $105K |
| 29 | 99726 | Bettles Field | 50 | D | 0 | — |
| 30 | 99730 | Central | 50 | D | 0 | $81K |
| 31 | 99757 | Lake Minchumina | 50 | D | 0 | — |
Recommended Buyer Guides for Yukon-Koyukuk County
Designed to find the guide that fits the county, not the other way around — the system reads EPA detections, FEMA hazard layers, and CDC lead-exposure markers, then outputs the categories that resolve those specific risks for households here, with NSF-certified products surfaced when the matching contaminant appears in the local monitoring data.
- Best Lead Paint Test Kits — 52.3% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
Deep Dive Reports
Detailed analysis for Yukon-Koyukuk County, Alaska
Overview
Yukon-Koyukuk County in Alaska covers 31 ZIP codes with an average Home Safety Score of B (79/100).
24 of 31 ZIP codes have recorded EPA violations. 66 health-based violations have been documented.
← Back to Alaska water quality report
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Home values: U.S. Census Bureau ACS (median estimates by ZCTA)
Updated daily.