Sumas, WA Water Safety: 80/100 (2026)
1 ZIP code · 10 water systems · Updated 2026-06-03
Within Sumas, safety indicators for tap water remain above the WA median — documented violations are infrequent and the city's compliance record sits in the upper tier.
How Sumas Compares
Data: EPA SDWIS Last verified: 2026-06-03
Key Facts for Sumas Residents
- Average lead level: 0.001 mg/L.
- Homes built before 1986: 56% — older plumbing may contain lead solder.
- Estimated remediation: $2,500 per household.
- CDC health risk index: 10.84.
Sumas's Water Providers
3 independent water providers serve Sumas, WA — 10 systems appear in federal records.
Overview
We track water quality and home safety data for 1 ZIP code in Sumas, Washington (population ~3,135), covering 10 community water systems serving approximately 14,116 people region-wide.
No EPA violations recorded across any ZIP codes in Sumas — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Sumas: B (80/100)
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
Sumas water systems draw from: Groundwater.
Lead & Copper
- Average lead level (90th percentile): 0.0010 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)
Areas with No Violations
| ZIP Code | Safety Score | System | Population |
|---|---|---|---|
| 98295 | B | Sumas Water Department | 1,740 |
All ZIP Codes in Sumas
- 98295 [B]
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.
Sumas Community Health Snapshot
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
Sumas Infrastructure Age
With 56% of homes built before 1986, lead solder in plumbing is a potential concern. The EPA banned lead solder in 1986, but many older homes retain original plumbing.
Source: U.S. Census Bureau American Community Survey (ACS).
Housing Age Profile
Lead solder was standard in copper plumbing until federally banned in 1986; lead pipes were common in service lines pre-1970. Sumas's median build year of 1985 reflects a housing stock where these older materials are a pervasive feature — not a rare legacy — of the residential plumbing landscape.
Over half of homes in Sumas were built before 1986, when lead solder was banned. Older plumbing may leach lead into drinking water, especially with corrosive water chemistry.
Source: U.S. Census Bureau ACS B25034.
How Remediation Costs Compare in Sumas
At current valuations, Sumas sits in the low remediation-share tier — the equity impact of fixing documented issues is proportionally minor.
Remediation costs in Sumas are relatively low compared to home values. The $1,800–$4,000 estimated range is a small fraction of median property value. Home values are 13% below the Washington average.
Sumas: Lead Risk & Vulnerable Populations
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.
Even where utility-side monitoring meets Lead and Copper Rule requirements, the 56% pre-rule share in Sumas keeps interior-plumbing variation as a household-level question that aggregate data cannot resolve.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Sumas: Flood History & Water Damage Risk
Within the NFIP's national dataset, Sumas falls in moderate-exposure territory — 341 documented incidents spanning multiple decades, with 100% of local ZIP codes sitting inside FEMA flood boundaries. That combination warrants inclusion in any thorough local water quality review.
Sumas has a moderate flood history with 341 FEMA claims averaging $60,523 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>$2,500</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 Sumas, WA