Washington Water Well Statistics 2026: 48 Facts & Data You Need to Know
Washington Water Well Overview
Source: Washington Department of Ecology
Key Washington Well Facts
- 1.6 million Washingtonians rely on private wells for drinking water
- 21% of Washington's population uses private well water
- Groundwater provides 25% of Washington's total water supply
- Spokane Valley-Rathdrum Prairie Aquifer: One of most productive in US
- 12,000+ new wells drilled annually
- 625 licensed well drillers in Washington
- Permit-exempt limit: 5,000 gallons/day domestic use
Major Aquifers
| Aquifer | Location | Avg Depth | Condition |
|---|---|---|---|
| Columbia River Basalt | Eastern WA | 385 ft | Declining in areas |
| Spokane Valley-Rathdrum | Spokane area | 145 ft | Excellent |
| Puget Sound Lowland | Seattle/Tacoma | 185 ft | Variable |
| Yakima Basin | Central WA | 285 ft | Declining |
| Quincy/Odessa | Central WA | 425 ft | Declining |
| Olympic Peninsula | Western WA | 125 ft | Good |
Wells by County
| County | Est. Wells | Primary Aquifer | Avg Depth |
|---|---|---|---|
| Spokane | 57,000 | Spokane Valley-Rathdrum | 145 ft |
| King | 47,500 | Puget Lowland | 195 ft |
| Pierce | 38,000 | Puget Lowland | 175 ft |
| Snohomish | 33,250 | Puget Lowland | 165 ft |
| Yakima | 28,500 | Basalt/Alluvial | 285 ft |
| Clark | 26,125 | Basalt/Alluvial | 225 ft |
| Thurston | 23,750 | Puget Lowland | 155 ft |
| Kitsap | 21,375 | Glacial | 135 ft |
| Whatcom | 19,000 | Glacial/Alluvial | 145 ft |
| Benton | 16,625 | Basalt | 385 ft |
Well Drilling Costs (2026)
| Region | Low | Average | High |
|---|---|---|---|
| Seattle Metro | $14,000 | $24,000 | $42,000 |
| Spokane Area | $10,000 | $16,000 | $28,000 |
| Puget Sound | $12,000 | $20,000 | $35,000 |
| Central WA (Yakima) | $16,000 | $26,000 | $45,000 |
| Eastern WA (Columbia Basin) | $18,000 | $28,000 | $48,000 |
| Olympic Peninsula | $10,000 | $16,000 | $28,000 |
Cost per Foot
- Glacial/alluvial: $18-35/foot
- Basalt: $30-55/foot
- Hard rock: $40-65/foot
Water Quality Statistics
| Parameter | % Affected | Areas |
|---|---|---|
| Iron (>0.3 mg/L) | 20% | Western WA, glacial |
| Hardness (>180 mg/L) | 28% | Eastern WA |
| Arsenic | 6% | Select areas |
| Nitrate (>5 mg/L) | 10% | Agricultural areas |
| Manganese | 15% | Western WA |
| Radon | 12% | Granite/basalt |
We service all major pump brands including Franklin Electric, Grundfos, Goulds (Xylem), and Sta-Rite (Pentair). Our trucks carry common parts and components for same-day repairs.
Frequently Asked Questions
How many water wells are in Washington?
Washington has approximately 475,000 registered water wells. Spokane County has the most with about 57,000.
What is the average well depth in Washington?
Average is 200-350 feet. Western WA averages 150-300 feet; eastern WA basalt areas 250-500 feet. Spokane area is notably shallow at 100-200 feet.
How much does it cost to drill a well in Washington?
A complete residential well costs $12,000-$30,000. Seattle metro typically $15,000-$28,000; Spokane $10,000-$20,000.
Do you need a permit for a well in Washington?
Washington allows permit-exempt wells for domestic use up to 5,000 gallons/day. However, restrictions apply in some basins since 2018 legislation.
Need Well Service Information?
Southern California Well Service serves San Diego and Riverside Counties.
California service: (760) 440-8520
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