Well Drilling Costs in Washington
A complete private well system in Washington typically costs $10,000–$25,000, depending on depth, geology, and equipment choices.
Cost Tip
Get quotes from 2-3 licensed drillers before deciding. Costs vary significantly by region and geology. Puget Lowland wells (30–150 ft) are typically less expensive than Columbia Basin wells (200–600+ ft).
Timeline: From Decision to Drinking Water
Expect 4–8 weeks from your first call to potable water. The 72-hour Notice of Intent requirement and water testing are key steps.
Permits & Process
Notice of Intent Requirement
Washington requires a Notice of Intent (NOI) filed with the Department of Ecology at least 72 hours before drilling begins. This is not a water-right permit, just a notification.
Notice of Intent (NOI)
Required for all well construction.
- File at least 72 hours before drilling
- Fee: $200 (wells <12") or $300 (wells ≥12")
- Submit online via Ecology's Well Construction & Licensing System
- Driller typically handles paperwork
Permit-Exempt Wells
Domestic wells using <5,000 gal/day are exempt from water-right permits (RCW 90.44.050).
- Single-family household use
- No state water-right permit needed
- NOI still required for construction
- Check local county requirements
Local County Requirements
Many counties (King, Pierce, Snohomish) have additional well permit requirements. Contact your local health department before drilling to verify all local rules.
Who Does What?
Driller Handles:
- Notice of Intent filing and fee
- Drilling and casing installation
- Initial disinfection (chlorination)
- Pump installation
- Filing Well Report (within 30 days)
Homeowner Handles:
- Payment
- Lab testing coordination and fees
- Local county permits (if required)
- Plumbing connections to house
- Record keeping
Water Quality
Important
Washington does not mandate water testing for private wells. However, the Department of Health strongly recommends annual testing. Many dangerous contaminants (arsenic, nitrates, bacteria) are invisible and odorless.
Recommended Testing
- Annually: Total coliform bacteria and nitrates
- At least twice during ownership: Arsenic (summer and winter samples)
- Every 3-5 years: Full chemical analysis including metals
- After any event: Flooding, well repairs, taste/odor changes
Common Washington Water Quality Issues
Arsenic
Found throughout Washington, especially in South Whidbey Island, Spokane County, and western Cascade areas. Safe limit is 10 ppb. Test at least twice during ownership.
Nitrates
Elevated in agricultural areas (Lower Yakima Valley, western Benton/Franklin County). Safe limit is 10 mg/L. DOH offers free testing in some zones.
Iron & Hardness
Very common in Columbia Basin and northeastern Washington. Causes rust-colored water and deposits. Water softeners are common solutions.
Arsenic Alert Zones
If your property is in South Whidbey Island, Spokane County, or near the Cascade foothills, test for arsenic before using well water for drinking. Long-term exposure is carcinogenic.
Treatment Options
Common contaminants and typical fixes:
- Arsenic: Reverse osmosis (RO) or NSF-certified arsenic removal filters
- Nitrates: Reverse osmosis or anion-exchange filtration
- Bacteria: Shock chlorination (bleach) followed by flushing; UV treatment for maintenance
- Iron/Manganese: Oxidizing filters or water softeners
- Hardness: Standard water softener (ion-exchange)
Maintenance & Troubleshooting
Annual Maintenance Checklist
- Test water for coliform bacteria and nitrates
- Test for arsenic every 3–5 years (or twice during ownership)
- Inspect wellhead cap and casing seal
- Check pressure tank (drain sediment annually)
- Replace sediment/carbon pre-filters (every 3–6 months)
- Consider shock chlorination (especially after flooding)
Warning Signs of Well Problems
- Cloudy, discolored, or rust-colored water
- New or sudden odor (rotten egg, metallic)
- Sudden drop in pressure or flow
- Pump running continuously or cycling rapidly
- Positive bacteria test (coliform/E. coli)
- Visible leaks around wellhead
DIY vs. Professional
You can handle annual chlorination, filter changes, and pressure tank maintenance. Major repairs (pump replacement, casing repairs, deepening) require a licensed driller per RCW 18.104.
Find a Licensed Driller
Washington law requires a licensed water well contractor for all well drilling work.
Search Licensed Drillers in Washington
Find Drillers Near You →How to Verify a Driller
- Ask for their WA Ecology license number
- Verify at Ecology's Well Construction & Licensing System
- Check for appropriate license type (Water Well Operator)
- Get 2-3 written quotes
- Ask for references from recent jobs
Resources & Contacts
Key Regulatory References
- WAC 173-160 – Well construction standards
- RCW 90.44.050 – Permit-exempt domestic wells
- RCW 18.104 – Water Well Construction Act (licensed drillers required)
Frequently Asked Questions
A complete well system in Washington typically costs $10,000–$25,000, depending on depth and geology. Drilling and casing (to ~175 ft) costs $8,000–$20,000, with additional costs for pump ($1,000–$3,000), pressure tank, permits ($200–$300), and testing ($50–$150).
You must submit a Notice of Intent (NOI) to the Department of Ecology at least 72 hours before drilling, with a fee of $200 (wells <12") or $300 (wells ≥12"). This is not a water-right permit, just a notification. Domestic wells using <5,000 gal/day are permit-exempt under RCW 90.44.050.
The complete process from planning to usable water typically takes 4–8 weeks. Drilling itself takes 2–5 days, but the Notice of Intent filing (minimum 72 hours), water testing (1–2 weeks for lab results), and final connections extend the timeline.
Yes, arsenic is found in well water throughout Washington, particularly in South Whidbey Island, parts of Spokane County, and some western Cascade areas. DOH recommends testing for arsenic at least twice during ownership (summer and winter). The safe limit is 10 ppb (parts per billion).
Washington law requires licensed drillers for all well work. Use the Department of Ecology's Well Construction & Licensing System online search tool to find licensed drillers by name or region. Verify the driller's license number before hiring.
Are You a Licensed Driller?
Check out our compliance reference for Washington drilling regulations, forms, and requirements.
Washington Driller Compliance Guide →