Sammamish, WA: 8 Violations — 88/100 (2026)
2 ZIP codes · 4 water systems · Updated 2026-06-03
In current WA EPA data, Sammamish's tap water sits in the high-safety tier.
How Sammamish Compares
Data: EPA SDWIS Last verified: 2026-06-03
What You Should Know About Sammamish Water
- Your city's water systems recorded 8 violations in the past 5 years.
- Average lead level: 0.0015 mg/L.
- Homes built before 1986: 31% — older plumbing may contain lead solder.
- Estimated remediation: $1,800 per household.
- CDC health risk index: 8.82.
Who Supplies Your Water in Sammamish
4 water systems are tracked federally in Sammamish, WA. The top 3 providers collectively serve most residential addresses, but because they operate independently, infrastructure maintenance standards and compliance histories differ from one service zone to another.
Overview
We track water quality and home safety data for 2 ZIP codes in Sammamish, Washington (population ~56,081), covering 4 community water systems serving approximately 96,763 people region-wide.
2 of 2 ZIP codes (100%) have recorded EPA violations. All violations are monitoring/reporting type.
Home Safety Score
Average Home Safety Score for Sammamish: A (88/100)
The score combines three factors:
| Factor | What It Measures |
|---|---|
| Water Quality | EPA violations and compliance history |
| Lead Levels | 90th percentile lead concentration vs EPA action level |
| Radon Risk | EPA radon zone classification |
Water Sources
Sammamish water systems draw from: Groundwater, Surface water.
Lead & Copper
- Average lead level (90th percentile): 0.0015 mg/L (EPA action level: 0.015 mg/L)
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 3 (Low Risk)
- Zone 1 (High): 0 ZIP codes
- Zone 2 (Moderate): 0 ZIP codes
- Zone 3 (Low): 2 ZIP codes
Top Contaminants
| Contaminant | Category | Violations | ZIPs Affected |
|---|---|---|---|
| Consumer Confidence Report Rule | Reporting | 6 | 2 |
| Lead | Inorganic | 3 | 2 |
| Surface Water Treatment Rule | Treatment Technique | 3 | 2 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 98074 | A | 4 | 0 | Sammamish Plateau Water & Sewer |
| 98075 | A | 4 | 0 | Sammamish Plateau Water & Sewer |
All ZIP Codes in Sammamish
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
Updated daily.
Health Outcomes in Sammamish
Source: CDC PLACES (County-level estimates). Water contamination can correlate with respiratory and chronic health conditions.
Compared to National Average
Vertical line = national average. ■ Above national · ■ Below national
Top Contaminants in Sammamish Water
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
Housing & Infrastructure in Sammamish
Housing age data helps assess potential lead pipe and infrastructure risks. Newer housing stock generally means lower plumbing-related contamination risk.
Source: U.S. Census Bureau American Community Survey (ACS).
Housing Age Profile
Prohibited from residential plumbing since 1986, lead solder divides Sammamish's housing stock along a timeline that the median build year of 1994 straddles. A meaningful share of homes predates the ban — a configuration that places moderate aggregate pressure on plumbing-related lead risk, distributed unevenly across neighborhoods.
Most homes in Sammamish were built after 1986, reducing the risk of lead contamination from plumbing. Older homes should still be tested.
Source: U.S. Census Bureau ACS B25034.
Cost Context: What Remediation Means for Sammamish Homeowners
Within the Sammamish market, estimated remediation claims a small portion of typical property equity — the financial burden is proportionally low.
Remediation costs in Sammamish are relatively low compared to home values. The $1,200–$2,600 estimated range is a small fraction of median property value. Home values are 212% above the Washington average.
Lead Exposure Risk for Children in Sammamish
Why children are most at risk: The CDC states there is no safe level of lead exposure for children. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.
Pulling a tap sample fills the gap that utility data cannot close, particularly here where 31% of housing dates from the pre-rule era and citywide monitoring sits at or above the regulatory mark in Sammamish.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Flood & Climate Risk in Sammamish
Multiple flood events have been recorded for Sammamish through the NFIP — 27 claims in total, with 100% of ZIP codes in FEMA-designated zones — pointing to a flood exposure profile that merits inclusion in a water quality assessment without reaching high-severity planning territory.
Sammamish has a moderate flood history with 27 FEMA claims averaging $11,828 per payout. 100% of ZIP codes fall within FEMA flood zones. Flood events can contaminate drinking water and overwhelm treatment systems.
How flooding affects water quality: Flood events can introduce sewage, agricultural runoff, and industrial chemicals into water supplies. Even after floodwaters recede, contamination can persist in wells and aging infrastructure. Flood damage can add significantly to the estimated <strong>$1,800</strong> remediation cost per household.
Residents in flood-prone areas should consider flood insurance even outside FEMA zones — over 25% of flood claims come from low-to-moderate risk areas. After any flood event, test your water before drinking.
Source: FEMA National Flood Insurance Program (NFIP) claims data, FEMA flood zone designations.
Deep Dive Reports
Detailed analysis for Sammamish, WA