Water Infrastructure in Seattle, WA: 27/100 Stress Indicator
Modeled stress 27% · moderate · 15 water systems · Updated
Seattle's heuristic infrastructure stress indicator is in the moderate model band.
Data: EPA ECHO, Census ACS, NTSB Last verified:
What is the infrastructure stress indicator?
The infrastructure stress indicator is a heuristic 0-100 composite of housing age, state funding need, violation history, and lead evidence. It is not a probability, measured pipe condition, or forecast of breaks, pressure loss, or contamination. Seattle's average indicator is 27/100.
What are CO/gas incidents?
Carbon monoxide (CO) and gas incidents tracked by the NTSB include pipeline failures, gas leaks, and CO exposure events. CO is odorless and can be fatal - the CDC reports about 420 deaths annually from unintentional CO poisoning. Every home should have working CO detectors on each floor, tested monthly. Seattle has 15 recorded incidents in the NTSB database.
Infrastructure Risk Distribution
How Seattle's 62 ZIP codes are distributed by infrastructure risk level:
Infrastructure Risk Overview
Seattle, Washington has a moderate modeled infrastructure stress level with an average heuristic indicator of 27/100. The result summarizes model inputs and does not predict service outcomes.
The infrastructure stress indicator combines source inputs for housing age, funding need, violation history, and lead evidence. It does not measure the likelihood of pipe failure, water-main breaks, or system degradation.
Key Infrastructure Metrics
| Metric | Value |
|---|---|
| Stress indicator | 27/100 |
| Modeled stress level | moderate |
| Water systems | 15 |
| Median build year | 1973 |
| Pre-1986 housing | 63% |
| CO/gas incidents | 15 |
| ZIP codes | 62 |
| Population | 994,393 |
Infrastructure Risk Distribution
How Seattle's 62 ZIP codes are distributed by infrastructure risk level:
| Risk Level | ZIP Codes | Percentage |
|---|---|---|
| Low | 30 | 48% |
| Moderate | 30 | 48% |
| High | 2 | 3% |
| Very High | 0 | 0% |
3% of Seattle's ZIP codes have high or very-high infrastructure risk. Residents in these areas should be especially vigilant about water quality and pipe condition.
Water System Age and Pipe Materials
The median home in Seattle was built in 1973 (approximately 53 years old). Housing age is one of the strongest proxies for water infrastructure age, as service lines and interior plumbing were typically installed during construction.
Pipe material risks by era:
| Era | Common Pipe Material | Expected Lifespan | Key Risk |
|---|---|---|---|
| Pre-1940 | Lead, cast iron | 50-75 years | Lead contamination, corrosion |
| 1940-1960 | Galvanized steel, cast iron | 40-60 years | Rust, lead solder, reduced flow |
| 1960-1980 | Copper, galvanized steel | 50-70 years | Lead solder (pre-1986), pinhole leaks |
| 1980-2000 | Copper, PVC, CPVC | 25-50 years | Chlorine degradation of plastics |
| 2000+ | PEX, copper, CPVC | 25-50+ years | Generally low risk |
With 63% of Seattle's homes built before 1986, a significant portion of residential plumbing may contain lead solder or aging pipe materials.
Carbon Monoxide & Gas Safety
15 CO/gas incidents have been recorded in the county covering Seattle. The average CO risk score is 10 out of 100.
Carbon monoxide is odorless and colorless - it is the leading cause of poisoning deaths in the U.S. Risk factors include:
- Gas furnaces, water heaters, and stoves
- Attached garages
- Blocked chimneys or vents
- Portable generators used indoors
Prevention:
- Install CO detectors on every level, especially near bedrooms
- Have gas appliances inspected annually
- Never run generators, grills, or cars in enclosed spaces
- Replace CO detectors every 5-7 years
What Homeowners Can Do
Pipe Inspection
- Hire a licensed plumber to inspect your service line and interior plumbing
- Check for discolored water (brown/orange = rust; white/cloudy = air or sediment)
- Test water pressure - low pressure may indicate buildup in aging pipes
- Look for visible corrosion on exposed pipes in basement or utility areas
Water Heater Maintenance
- Flush your water heater annually to remove sediment
- Check the anode rod every 2-3 years (prevents tank corrosion)
- Set temperature to 120F to prevent scalding and reduce energy use
- Replace water heaters older than 10-15 years proactively
CO Detector Placement
- One detector per floor, minimum
- Within 10 feet of each bedroom door
- Near attached garage and utility room
- 5 feet above the floor (CO rises with warm air) or on the ceiling
- Not near windows, doors, or HVAC vents (air movement causes false readings)
Seattle vs. Nearby Washington Cities
How Seattle's infrastructure compares to nearby cities:
| City | Water Systems | Violations | Population |
|---|---|---|---|
| Seattle | 15 | 4 | 994,393 |
| Spokane | 22 | 49 | 389,529 |
| Tacoma | 15 | 13 | 364,667 |
| Vancouver | 6 | 9 | 356,538 |
ZIP Codes in Seattle
Seattle covers 62 ZIP codes served by 15 water systems. Infrastructure condition varies by ZIP code based on housing age, pipe material, and water system maintenance. Check your specific ZIP code for localized data.
Data Sources
- Water systems: EPA ECHO - Enforcement and Compliance History Online
- Infrastructure risk: Derived model (housing age, violation history, system assessments)
- Housing age: U.S. Census Bureau American Community Survey (ACS)
- CO/gas incidents: NTSB, PHMSA pipeline incident reports
Source reporting periods vary. See each cited source for its publication schedule.
Water Quality Map: Seattle, WA
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Infrastructure Risk by ZIP Code in Seattle
Infrastructure risk varies across Seattle's 62 ZIP codes based on system age, pipe materials, and violation history.
| ZIP Code | Grade | Score | Violations | |
|---|---|---|---|---|
| 98148 | A | 99/100 | 1 | View report → |
| 98188 | A | 99/100 | 3 | View report → |
| 98198 | A | 99/100 | 3 | View report → |
| 98101 | A | 100/100 | 0 | View report → |
| 98102 | A | 100/100 | 0 | View report → |
| 98103 | A | 100/100 | 0 | View report → |
| 98104 | A | 100/100 | 0 | View report → |
| 98105 | A | 100/100 | 0 | View report → |
| 98106 | A | 100/100 | 0 | View report → |
| 98107 | A | 100/100 | 0 | View report → |
| 98108 | A | 100/100 | 0 | View report → |
| 98109 | A | 100/100 | 0 | View report → |
| 98112 | A | 100/100 | 0 | View report → |
| 98115 | A | 100/100 | 0 | View report → |
| 98116 | A | 100/100 | 0 | View report → |
| 98117 | A | 100/100 | 0 | View report → |
| 98118 | A | 100/100 | 0 | View report → |
| 98119 | A | 100/100 | 0 | View report → |
| 98121 | A | 100/100 | 0 | View report → |
| 98122 | A | 100/100 | 0 | View report → |
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