Drilling a new well in Washington: permits, rules and quotes

A new well is usually the biggest single cost in building on rural land in Washington, and nobody can guarantee there is water under your lot. Ecology’s homeowner guide says it plainly: “There is no guarantee that the well driller will find water on your property.” What you can control is the homework before the rig arrives: whether you can legally use the water, what nearby wells found, what the state’s construction rules require, and what your contract says if the hole comes up dry.

Step 1: Can you legally use the water?

The permit exemption. Under RCW 90.44.050, most single homes don’t need a water right permit. The exemption covers stock watering, a lawn or noncommercial garden of up to half an acre, and “single or group domestic uses in an amount not exceeding five thousand gallons a day”. Ecology says you get one exemption of each type per project, however many wells it has. A small subdivision, for example, shares one 5,000 gallon-per-day domestic limit. Exempt use still creates a water right, with a priority date set when water is first put to use, so it can be regulated if it interferes with senior rights.

Hirst and the Streamflow Restoration Act. In the Hirst decision (October 6, 2016), the state Supreme Court ruled that counties had to decide for themselves whether water was legally available before approving a building permit that relied on a well. Ecology says several counties then severely restricted those approvals. The Legislature responded in January 2018 with the Streamflow Restoration Act (chapter 90.94 RCW), which sets interim rules for new permit-exempt domestic wells in some watersheds (WRIAs):

County building permits. Under RCW 19.27.097, you must show an adequate water supply to get a building permit. Acceptable evidence includes a water right permit, a letter from a water purveyor, or other proof; in some areas a well report can serve. A pending water right application doesn’t count. Counties and cities can also require you to connect to a public water system if one can serve you at reasonable cost. Many counties add their own water review. Clark County, for example, says new and replacement wells must be tested for coliform bacteria, arsenic and nitrate, and building permits often require a water availability evaluation by Clark County Public Health.

Ask your county building and health departments what they require before you drill. NGWA’s advice is to “drill first, build later”, so a dry or poor well doesn’t leave you with a house and no water.

Step 2: Look at your neighbors’ well logs

Every well drilled in Washington should have a well report (well log) on file with Ecology. Neighbors’ logs are the best preview of what you might find: depth, the materials logged at each depth, static water level and tested yield. Ecology’s homeowner guide recommends gathering this data from neighbors, local drillers, county health offices and Ecology’s website, while warning that geology can be complex and a nearby well doesn’t guarantee water on your lot.

Use Ecology’s well report search tools. Ecology’s tips:

• Search by map or by text, and if the first search fails, try another way.
• You can search with partial address information.
• Locations are only accurate to the township, section and range, so look at several logs in your section and the ones around it.
• Most reports are historical documents submitted by drillers, and some are inaccurate, incomplete or hard to read.

NGWA suggests most homes need a well that produces 7 gallons per minute. If a well can’t, it says a storage tank holding at least one day’s supply for the household can make up the difference.

Step 3: Understand your geology and the drilling method

Washington’s geology changes the job a great deal:

• Puget Sound lowland. USGS says the aquifers are mainly glacial deposits, as much as 3,000 feet thick near Seattle. The most productive are sand and gravel from the last glaciation, typically in the upper 200 to 300 feet. Deeper sand and gravel is usually less permeable because it has been compacted.
• Columbia Plateau basalt. Water moves mainly through fractures, rubble and interflow zones between lava flows. USGS says yields range from about 1 to several thousand gallons per minute, and “the more water-contributing interflow zones that are penetrated by a well, the greater the well yield”.
• Older bedrock (much of the Cascades, the San Juans and northeast Washington). Water sits in fractures, faults and weathered zones. USGS says wells generally yield only about 1 to 100 gpm, that yields tend to fall with depth, and that igneous and metamorphic rocks have few open spaces below about 300 to 400 feet. Drilling deeper in hard rock doesn’t always help.

NGWA describes the main methods:

NGWA notes that every method leaves fine particles that clog the formation. Removing them is called development, done “to make the well clean and as productive as possible”. Ask how the driller will develop and test your well.

Step 4: Know the construction rules

Washington’s minimum standards are in chapter 173-160 WAC. Ecology says you and your driller share responsibility for meeting them. The rules worth knowing:

• Surface seal: at least 18 feet. The seal must run from land surface to at least 18 feet deep, be at least 4 inches wider than the casing, and be made of bentonite, neat cement grout or neat cement. Leaving a gap for a future pitless adapter is not allowed (WAC 173-160-231).
• Sealing into the formation. Where casing ends in rock, it must be driven and sealed into “sound, unfractured, consolidated formation”, and the casing must still reach at least 18 feet even if rock is shallower (WAC 173-160-241). Where a clay layer at least 6 feet thick sits above the aquifer, the casing must be sealed into it.
• Casing at least 6 inches above grade. Where the site can flood, the top must be at least 2 feet above the 100-year flood level. “Pit completion is prohibited.” Every drilled well needs a secured metal or plastic cap, and an access port for measuring the water level (WAC 173-160-291).
• Setbacks (WAC 173-160-171), for wells that are not public water supplies:

The well must also be sited where it isn’t subject to ponding and isn’t in a floodway. Check with your county too: Ecology says counties may have additional rules.

Step 5: The notice of intent and the well report

• Notice of intent (NOI). Drillers often call it the “start card”. It must reach Ecology at least 72 hours before construction begins. The property owner, the owner’s agent or the well operator can file it. Fees are $200 for a well with casing under 12 inches and $300 for 12 inches or larger (WAC 173-160-151). Ecology takes payment through its EcoEPay system; cards carry a 3% surcharge and e-checks don’t. Ecology stresses that an NOI “is not a permit, certificate, or application for a water right”.
• Well report. The driller must file it within 30 days of completing the well (WAC 173-160-141). It records the well’s dimensions, casing, seal, drilling method, the formations and water-bearing zones, static water level and yield-test results. Ecology’s guide says to get your own copy, along with a bill of materials, and to make sure the driller attaches an Ecology well identification tag.

Delegated counties. Ecology says some county health agencies are authorized to inspect well construction and decommissioning. Its contact list (revised July 2025) names 14: Clark, Grant, Jefferson, Kitsap, Kittitas, Mason, Okanogan, Pierce (Tacoma-Pierce County Health Department), San Juan, Snohomish, Spokane (Spokane Regional Health District), Thurston, Whatcom and Yakima. In those counties the driller must also follow county notification and inspection rules.

Step 6: Get itemized quotes

Ecology tells homeowners to require an itemized estimate, and NGWA says an itemized list “is better than a lump sum”. Ask each driller to price:

• Drilling, per foot, and the rate if the hole goes deeper than planned.
• Casing, per foot: diameter, material and wall thickness.
• Surface seal: depth (at least 18 ft) and material.
• Other materials: drive shoe, screen or perforations, well cap.
• Development: NGWA flags development longer than an hour, as in screened wells, as a separate charge.
• Yield (pump) test: method and length.
• Pump, tank and controls, if the driller sets the pump. Ecology says not to buy a pump before the well is drilled.
• Electrical work from the panel to the well, and trenching to the house.
• Mobilization to the site.
• Disinfection and water-quality testing.
• Dry-hole policy: what you pay if there’s no usable water, and the cost of decommissioning the hole. NGWA suggests pricing abandonment up front, “for instance, if saltwater is encountered”.
• What is not included.

Dry holes. An unusable hole must be decommissioned with its own notice and $50 fee. A follow-up attempt at the same site needs no new notice or fee if it starts immediately, the dry hole is properly decommissioned before the rig leaves, and the other conditions in WAC 173-160-151 are met. NGWA reminds owners: “Don’t expect the contractor to work for free if the well does not fulfill expectations.” Get the terms in writing.

What it costs (indicative only)

There is no authoritative Washington survey of residential drilling prices. The figures below come from two private websites, and they disagree. Use them only for a rough budget:

• Wenatchee Well Pros (July 2, 2026), a north-central Washington pump company that doesn’t drill wells itself, says its figures reflect drilling invoices it saw in 2026:
  • drilling: $45 to $65 per foot in soft ground and $65 to $95 in basalt;
  • 6 inch steel casing: $55 to $90 per foot, installed;
  • seal and grout: $500 to $1,500; development and yield test: $500 to $2,000; mobilization: $500 to $2,500;
  • a complete 200 ft well in decent ground: about $18,000 to $25,000. A 500 ft basalt well with a long trench: $45,000 or more.
  • Its local dry-hole rates are “rarely less than half” the normal rate. One 460 ft dry bore near Quincy cost about $14,000.
• DrillerDB (labelled 2024–2025 estimates; method not stated): drilling and steel casing at about $25 to $50 per foot, and $10,000 to $25,000+ for a complete home well system.

Step 7: Choose a licensed driller

• Ecology license. Ecology licenses well drillers, and its homeowner guide says never to hire an unlicensed one. Check the operator’s license with Ecology’s licensed driller search, which shows status (active or inactive) and type (water or resource protection). The person drilling your well needs a water well license.
• L&I registration. The driller must also be registered and bonded with L&I. Check with L&I’s Verify tool.
• No recommendations. Ecology says it “is unable to recommend a driller”, but your regional well drilling coordinator can tell you about enforcement actions against one.
• Several quotes. NGWA says to get several quotes and “don’t always go with the bargain price”.

Our drilling directory lists only companies with an active Ecology water well license on staff. See also domestic well drilling and water rights and availability for help with Step 1.

Seawater and arsenic: test before you rely on the well

• Seawater intrusion. Ecology says over-pumping wells near the coast can draw seawater into freshwater aquifers, and some coastal wells are already unusable. Island and Jefferson counties have local seawater intrusion policies. If you’re building near the shore, ask your county about local rules and ask the driller how deep they plan to go. Have the new well tested for chloride by an accredited lab.
• Arsenic. DOH says arsenic is “found in well water throughout Washington”, with levels from 10 ppb up to 33,000 ppb in some wells. It also says a new well at a different location or depth “may or may not” avoid it. Test a new well for arsenic, as Clark County requires. See testing your well water.

Questions to ask a driller

1. What do nearby well logs show, and what depth and yield do you expect here?
2. What drilling method will you use, and why for this geology?
3. What casing will you use: diameter, material and wall thickness?
4. How deep and with what material will you seal it?
5. How will you develop and test the well, and for how long?
6. What do you charge per foot if you have to go deeper, and at what depth will you stop and talk to me?
7. What happens, and what do I pay, if the hole is dry or salty?
8. Who files the notice of intent? When will I get the well report?
9. Will you disinfect the well and leave the cap secured with the casing at least 6 inches above grade?

Before the rig leaves, NGWA suggests measuring the depth with a weighted tape and asking for the tested yield, the drawdown and the recovery. Confirm the cap is secured and the well was disinfected.

Red flags

• No Ecology water well license, or no L&I registration.
• A lump-sum bid with no per-foot rates or breakdown.
• No mention of the 18 ft surface seal or the notice of intent.
• Pressure to buy the pump before the well is drilled.
• No written dry-hole terms.
• A proposed site closer than 100 ft to a drainfield, or a well in a pit.
• A request to build a well that “will not meet state standards”. Ecology warns that you’ll bear the cost of fixing it later.
• No well report within about 30 days of completion.