Washington Water Well Depth & Drilling Cost Guide
Authoritative hydrogeological intelligence for Washington. Regulated by the Washington State Department of Ecology. The statewide median drilling depth is 210 feet (ranging 50–650 ft) with an average drilling cost of $54 per foot ($38 to $90/ft).
Quick Hydrogeological Fact Sheet: Washington
To reach potable water in Washington, residential wells require drilling an average of 210 feet deep. Total turnkey installation costs average $13,800 USD for a completed 6-inch casing well, 1.5 HP submersible pump, pressure tank, and state permits. The standing static water table sits at approximately 35 feet below surface level, producing a reliable average flow rate of 20 GPM across the primary Puget Sound Glacial Aquifer.
Washington County-Level Well Logs & Average Depths
Official USGS hydrogeological monitoring stations, static levels, and driller completion records.
| County Name | Median Depth (ft) | Avg Cost / Foot | Typical Yield | Primary Aquifer | Local Action |
|---|---|---|---|---|---|
| King County (Seattle) | 220 ft | $56 /ft | 18 GPM | Puget Sound Glacial Drift |
|
| Spokane County | 180 ft | $48 /ft | 35 GPM | Spokane Valley-Rathdrum Prairie |
💰 Estimated Turnkey Cost Itemization in Washington
Component-by-component breakdown for a standard residential water well (210 ft average).
| System Component | Specification in Washington | Unit Cost | Estimated Subtotal |
|---|---|---|---|
| Borehole Drilling & Sanitary Casing | 210 ft depth with standard 6" PVC/Steel Casing & Drive Shoe | $54 /ft | $11,340 USD |
| Submersible Pump & Drop Pipe | 1.0 HP – 1.5 HP Stainless Submersible Pump with 12-gauge electrical drop cable | Turnkey Pump Unit | $2,250 USD |
| Pressure Tank & Control Switch | 40-gallon Captive Air Pressure Tank, 40/60 PSI Pressure Switch & Gauge | Standard Assembly | $1,200 USD |
| State Permits, Sanitary Grouting & Lab Water Testing | Mandatory Washington State Department of Ecology permit, bentonite surface seal, and EPA drinking panel | State Fee + Lab | $700 USD |
| TOTAL ESTIMATED TURNKEY INVESTMENT | Includes excavation, drilling, plumbing hookup, and water inspection | $13,800 USD | |
Washington Aquifers & Subsurface Geology
Glacial till, outwash gravel in Puget Sound; thick basalt layers in Eastern WA
Water Quality & Recommended Filtration
⚖️ Washington Well Drilling Regulations & Legal Setbacks
Calculate Drilling Cost in Washington
Pre-loaded with Washington median depth (210 ft) and average cost ($54/ft).
Frequently Asked Questions: Drilling Wells in Washington
1. How deep do you usually have to drill for water in Washington?
Across Washington, the median residential water well is drilled to 210 feet. However, shallow alluvial wells can hit water as high as 50 feet, while deep bedrock or limestone aquifer wells may require drilling down to 650 feet to reach sufficient pressure and yield.
2. How much does a complete water well cost in Washington?
On average, homeowners in Washington invest $13,800 USD for a complete turnkey system. Drilling alone costs $54 per foot (ranging $38–$90/ft), while submersible pumps, pressure tanks, state permit fees ($250), and electrical hookups comprise the remaining balance.
3. What is the required setback from septic tanks in Washington?
State health mandates overseen by the Washington State Department of Ecology require a minimum separation distance of 100 feet from any septic tank, leach field, or potential contamination source, plus at least 30 feet from adjacent property boundaries.
4. What is the groundwater quality like in Washington?
Wells in Washington typically yield water with a hardness reading around 80 PPM and an average pH of 7.2. Key minerals present in natural groundwater include Iron, Manganese, Low Hardness on Coast. The recommended standard filtration configuration is: Iron & Manganese Air Oxidation Filter.
🗺️ Neighboring & Regional Groundwater Guides
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