EPA data as of Oct 2026 · page updated 2026-10-29

Home hazard report for 99116 — Coulee Dam, WA

ZIP 99116 is served by Coulee Dam Water Dept: no health-based violations since 2016, latest lead result 1.7 ppb, PFAS not tested. Okanogan County is in EPA radon zone 1.

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Where ZIP 99116 is

Dashed: ZIP area · blue: utility service area · scroll or pinch to zoom
ZIP code areaZIP center Water utility service area PFOA/PFOS ≥ 4 ppt Lead > 15 ppb 5+ violations Superfund site (active) proposed cleaned up Circles: other water systems flagged nearby; size = people served. Tap any symbol for details.

Drinking water: Coulee Dam Water Dept

EPA IDWA5315400
People served1,454
Sourcesurface water (rivers, lakes)
Connections628

Health-based violations

No health-based violations reported since 2016.

Full record for Coulee Dam Water Dept →

Lead

Jan 20211.7 ppb
Jan 20181.1 ppb
Jan 20152.4 ppb
Jan 20123.8 ppb
Jan 20091.8 ppb
Jan 20061 ppb
Jan 20052 ppb
Jul 20042 ppb

90th-percentile lead per sampling round (90% of the homes sampled were at or below this level). Black line: EPA’s 15 ppb action level; under the Lead and Copper Rule Improvements the action level becomes 10 ppb from 2027.

PFAS (“forever chemicals”)

This system was not part of EPA’s 2023–2025 nationwide PFAS testing (UCMR 5).

Radon in Okanogan County

EPA radon zone 1 — highest potential. Predicted average indoor radon above 4 pCi/L — EPA’s action level. Test your home.

Radon is a colorless, odorless radioactive gas from soil and rock, and the leading cause of lung cancer among non-smokers. EPA recommends fixing a home at 4 pCi/L or above and considering it from 2 pCi/L. A short-term test kit costs about $15–30. How radon zones work →

Natural hazard risk

FEMA rates the overall natural-hazard risk of this neighborhood (census tract) as Relatively High, with very high social vulnerability and very low community resilience.

Cold waveRelatively High
Riverine floodingRelatively High
WildfireRelatively High
AvalancheRelatively Moderate
Heat waveRelatively Moderate
LightningRelatively Moderate
Winter weatherRelatively Moderate
EarthquakeRelatively Low
HailRelatively Low
LandslideRelatively Low
Strong windRelatively Low
DroughtVery Low
Ice stormVery Low
TornadoVery Low
Volcanic activityVery Low

FEMA National Risk Index (December 2025): expected annual losses from each hazard combined with social vulnerability and community resilience, rated relative to all U.S. census tracts. Hazards not listed are not applicable here. It describes the area, not a single building; flood insurance maps (FEMA FIRMs) decide flood-insurance requirements.

Live conditions: river gauges and flood levels · tornado warnings · wildfire detections · earthquakes — our sister maps, updated from NOAA, USGS and NASA every few minutes.

Superfund sites nearby

No site on EPA’s Superfund National Priorities List lies within 10 miles of the center of this ZIP code.

EPA Superfund National Priorities List (NPL): the country’s most serious known hazardous-waste sites, each with an EPA cleanup record (linked). Distance is measured from the ZIP center to the site’s reference point; being near a site does not by itself mean exposure — EPA site pages describe what was found and how it is being cleaned up.

Buying a home in Coulee Dam? See the 2026 conforming, FHA and jumbo loan limits for Okanogan County →

What this is — and isn’t. These are records your water utility and state reported to the EPA, and the EPA’s radon map for your county. They describe the system and the area, not the water from your own tap or the air in your home. For that, read your utility’s annual Consumer Confidence Report and test: lead and radon tests are inexpensive.

Questions about 99116

Who supplies drinking water to ZIP 99116?

Coulee Dam Water Dept (EPA ID WA5315400), a surface water (rivers, lakes) system serving about 1,454 people.

Is there lead in Coulee Dam, WA tap water?

The utility’s latest 90th-percentile lead result (Jan 2021) was 1.7 ppb; EPA’s action level is 15 ppb, falling to 10 ppb from 2027. Lead mostly comes from service lines and home plumbing, so the only way to know your tap is to test it.

Does Coulee Dam, WA water have PFAS?

This system was not part of EPA’s 2023–2025 nationwide PFAS testing (UCMR 5 covers systems serving over 3,300 people and a sample of smaller ones).

Has the water system in 99116 had violations?

No health-based violations reported since 2016.

What natural hazards affect ZIP 99116?

FEMA’s National Risk Index rates the overall natural-hazard risk here as Relatively High; the highest-rated hazards are cold wave (relatively high), riverine flooding (relatively high), wildfire (relatively high).

Are there Superfund sites near 99116?

No active Superfund site within 10 miles of the ZIP center.

Is radon a problem in Okanogan County?

Okanogan County is in EPA radon zone 1 (highest potential). Predicted average indoor radon above 4 pCi/L — EPA’s action level. Test your home.