Certified well water labs in Washington (2026)
Washington DOH and Ecology put the same baseline on private-well owners: test every year for coliform bacteria and nitrate — the two contaminants that can hurt someone fast, sometimes with a single drink. Those taps are not under Safe Drinking Water Act monitoring the way public systems are. You pick an Ecology-accredited lab that accepts public samples (or a county health lab on DOH’s nitrate/coliform list), match the panel to Washington’s arsenic and nitrate hedges, and keep the report.
The short version
- Order bottles from an Ecology-accredited lab that takes public samples — or from a county health lab on DOH’s list. Start with Ecology’s Interactive Lab Search (filter Show only labs that accept public samples) or DOH’s March 2026 Nitrate and Coliform Testing Labs by county (331-798). Accreditation ≠ walk-in this week — confirm acceptance, hold times, and fees.
- Hit the bacteria clock the kit names. Benton-Franklin’s materials put BacT samples within about 30 hours cold; Thurston will not take bacteriological samples on holidays or the weekday before a holiday because of the 2-day processing window. Follow your lab’s bottles, ice, and drop-off days.
- Match the panel to Washington rock, agriculture, and the purpose of the test. DOH: annual coliform + nitrate; if nitrate is 5 mg/L or higher, consider retesting in six months. At least twice while you own the well, add arsenic (late summer + early spring). Buying or borrowing? Many counties or lenders want current sampling results — check your county health or planning department.
How Washington’s system actually works
DOH’s Testing Your Water page is blunt: if you own a private well, you are responsible for testing. Ecology regulates well construction and accredits laboratories; DOH’s Office of Drinking Water assigns a separate ODW ID once Ecology’s Laboratory Accreditation Unit (LAU) has accredited a lab. For homeowners, the practical filter is Ecology’s lab search with accept public samples turned on — see DOH’s Drinking Water Laboratory Resources.
DOH publication 331-798 (March 27, 2026) lists certified drinking-water labs by county for nitrate and/or coliform and states that those tests range from $21–$55 depending on the lab. Some counties run their own health-district labs; others point you to commercial Ecology-accredited shops. Ecology’s testing page also links local health departments and districts (linked from Ecology’s testing page).
If you live in a defined boundary of the Lower Yakima Valley or Western Benton County, DOH notes you may qualify for free nitrate and coliform testing — use the Well Water Sampling and Site Assessment form linked from the Testing Your Water page. That path is geography-limited; it is not a statewide free annual program.
Options we verified
Fees and rules live on DOH checklists, Ecology’s lab search, county lab pages, Anatek’s published 2026 private-well price PDFs, and the mail-in product pages. What we could verify with a public URL tonight:
The table scrolls sideways on a phone.
| Option | What they offer | Listed cost | Catch |
|---|---|---|---|
| Thurston County Water Lab | County drinking-water lab: total coliform / E. coli presence-absence, nitrate, and bacteria counts. Drop-off at 412 Lilly Rd NE, Olympia (Atrium drop-off ended Jan 2026). | P/A coliform $32; nitrate $32; count $40 (Oct 1, 2026 page). | Bacteria Mon–Wed 8–5, Thu to 12:30; nitrate Mon after 2 p.m. + Tue 8–5. No bact samples on holidays or the weekday before. (360) 867-2631 · waterlab@co.thurston.wa.us |
| Benton-Franklin Health District Lab | District lab in Kennewick (7102 W Okanogan Place) listed on DOH 331-798 for nitrate and coliform. Containers from the lab; EH front desk drop-off. | Total coli/E. coli P/A $30; nitrate $32; fluoride $45; QTray $40 (fee schedule effective Jan 1, 2025; lab page says fees continue through 2026). | BacT within ~30 hours cold. Mon–Fri 8–5; call around holidays. (509) 460-4206. Western Benton free-testing geography (DOH form) is separate — check eligibility before you pay. |
| Anatek Labs — Spokane County / Tri-County packages | Ecology-accredited commercial lab (Spokane + Yakima on DOH 331-798). Published 2026 private-well price list: Spokane County package (coliform + nitrate); Tri-County package adds lead, arsenic, uranium. | Spokane County package $100; Tri-County package $200 (3-day TAT). À la carte: coliform P/A $42; nitrate/nitrite $58; arsenic $57 (PDF dated 1/07/2026). | Base “Private Well List” package lists analytes but says Call for Pricing on the private-well PDF — we are not inventing that dollar. Spokane (509) 838-3999; Yakima (509) 225-9404. |
| Ecology Interactive Lab Search | Official searchable list of Ecology-accredited labs. Filter by analyte; check “Show only labs that accept public samples.” DOH Laboratory Resources points homeowners here. | Fees not on the search page (except what each lab publishes separately). | Accreditation ≠ private-well bottles this week. Confirm acceptance, analyte scope, hold times, and current fees. LAU: (360) 871-8840. |
| DOH 331-798 — labs by county (Mar 2026) | State PDF of certified drinking-water labs offering nitrate and/or coliform, organized by county — including Seattle-King County Public Health Lab (coliform), Pierce Water Management Labs, Eurofins Edge (Skagit/Whatcom), Clallam County EH Lab, and more. | DOH blurb: nitrate + coliform tests $21–$55 depending on the lab. | PDF phones/addresses are a starting list — call for private-well acceptance and today’s fee. Seattle-King County PH Lab: (206) 744-8950 (coliform on the PDF; we did not verify a public dollar table tonight). |
| Lower Yakima Valley / Western Benton — free nitrate + coliform | DOH: if you live within a specific program boundary, you may qualify for free nitrate and coliform testing via the Well Water Sampling and Site Assessment form on the Testing Your Water page. | No charge if you qualify — use DOH’s form first. | Geography-limited. Not a substitute for annual testing outside the boundary. Still keep your own Ecology-accredited path when you do not qualify. |
We listed published county and Anatek dollars we could cite tonight. Softener-shop “free in-office” TDS/hardness screens are screening-only and are not on this page. Labs on 331-798 without a public homeowner fee sheet stay in the PDF / Ecology search — we are not inventing town fees.
Labs on DOH’s March 2026 nitrate/coliform list (selected)
Names, phones, and counties below are copied from DOH 331-798 (March 27, 2026). For live accreditation status and methods, use Ecology’s lab search. DOH does not endorse specific labs. Call for private-well acceptance, bottles, hold times, current fees, and whether your lender’s analyte list is covered.
The table scrolls sideways on a phone.
| Lab | County | Phone (as printed) | Notes |
|---|---|---|---|
| Benton-Franklin Health District Lab | Benton | 509-460-4206 | Nitrate and coliform; published district fees (see table above) |
| Seattle-King County Department of Public Health Lab | King | (206)-744-8950 | Coliform on 331-798 — call for fees / nitrate path |
| Water Management Laboratories, Inc. | Pierce | (253)-531-3121 | Nitrate and coliform — Tacoma |
| Thurston County Health Department Laboratory | Thurston | (360)-867-2631 | Nitrate and coliform; published county fees |
| Olympic Analytical LLC dba Vanguard Laboratory | Thurston | (360)-967-7010 | Nitrate and coliform on 331-798 |
| Anatek Labs, Inc. — Spokane | Spokane | (509)-838-3999 | Nitrate and coliform; published private-well packages |
| Eurofins Spokane | Spokane | (509)-924-9200 | Nitrate and coliform on 331-798 |
| Anatek Labs, Inc. — Yakima | Yakima | (509)-225-9404 | Nitrate and coliform; same Anatek price list |
| Eurofins Edge Analytical — Burlington | Skagit | (360)-757-1400 | Nitrate and coliform on 331-798 |
| Clallam County Environmental Laboratory | Clallam | (360)-417-2334 | Nitrate and coliform; PDF notes limited lab hours |
331-798 has many more county rows (Grays Harbor, Lewis, Okanogan, Whatcom Exact Scientific, and others). Use the PDF or Ecology search for your county — we are not reprinting every row without a fee or phone we can cite cleanly.
What DOH (and Ecology) actually warrant
Match the panel to the land and to why you are testing:
- Every year: total coliform / E. coli and nitrate. DOH: these two can affect health quickly. If nitrate is 5 mg/L or higher, consider retesting in six months. Public-supply MCL guidance is 10 mg/L as nitrogen. Do not boil high-nitrate water — boiling concentrates it.
- Arsenic (statewide rock): DOH’s Arsenic and Your Private Well page: test once in late summer and once in early spring for seasonal differences. Labs usually about $20–$35 on that page (Testing Your Water still quotes a 2010 $25–$50 range). Recommend drinking/food-prep water ≤ 10 ppb; there is no statewide private-well arsenic standard (a few counties have rules).
- Nitrate near septic or agriculture: take the annual nitrate seriously — especially in agricultural basins and where DOH runs the Lower Yakima / Western Benton free-testing geography.
- After a flood, well work, or a change in taste / color / odor: bacteria first. Ecology’s testing page also flags flooding as a reason to test. See our after-a-flood guide.
- PFAS concern: use an Ecology-accredited lab for the method your situation needs. Details: PFAS Method 533 / 537.1. Anatek’s 2026 private-well PDF lists a PFAS EPA 533 package at $375 (+ blank fee if analyzed) — confirm scope before you order.
When the Certificate of Analysis arrives, more: how to read a well water report.
Hardware-store strips are screening-only. Softener sales “tests” are screening-only. Neither is what a lender means by “tested.”
Hold times, collection, and shipping
Plan around the lab you chose. Benton-Franklin materials: keep BacT samples cold and deliver within about 30 hours. Thurston: no bacteriological samples on legal holidays or the weekday before a holiday (2-day processing). Use the lab’s bottles and forms — wrong container, fill line, or missing date/time can invalidate the sample. County labs often want you to pick bottles at the counter first. More after weather events: what to test after a flood.
Mail-in kits that work from Washington
Independent mail-in labs ship to and from Washington as ordinary domestic US kits. They email a PDF. They are not selling you a softener in the same breath. For a lender or a named-lab letter, confirm the analyzing lab is Ecology-accredited for the analytes named — mail-in self-collect often does not satisfy that path. Listed prices we checked for this ship (same national SKUs as other state pages):
- Tap Score / SimpleLab Essential Well: $209 listed (54 analytes; standard shipping and prepaid return on the product page).
- National Testing Laboratories WaterCheck Basic: $220 listed plus free delivery on watercheck.com. Next-day return shipping is not included. Budget for overnight return on the bacteria bottle.
Those are listed prices, not coupons. Kits change. Read the current product page before you buy. If a county health lab’s annual coliform + nitrate fees cover your yearly question and you can hit the hold window — check that path before you spend $200 on a national kit for the same core question.
Side by side for a Washington well
The table scrolls sideways on a phone.
| County health lab (e.g. Thurston / Benton-Franklin) | Ecology-accredited commercial lab | Mail-in (Tap Score / NTL) | |
|---|---|---|---|
| Best for | Published local coliform + nitrate dollars; short drive; annual DOH baseline when hours fit | Published or quoted private-well packages (Anatek and others); broader metals / lender panels; Ecology search statewide | Broader baseline panel and a PDF when county hours do not fit — informational unless the underwriter accepts it |
| PDF? | Lab / county report — ask format | Lab report — ask format and turnaround | Yes. Email is the product |
| Sales visit? | No | No (if you stay on independent labs) | No |
| Lender / sale? | Often yes if the county or underwriter accepts that lab — confirm first | Often yes if lab, analytes, and accreditation match — confirm first | Often not for named-lab / CoC letters. See home purchase / lender CoC |
Real estate and lenders
DOH and Ecology both say that in most counties, when you buy or sell a home with a private well, the county health or planning department — or the lender — may require water-sampling results to show the water is safe to drink. That is county-specific, not a single statewide sale-test statute like Maryland’s § 10-713. Contact your local county health or planning department for the requirements and the testing needed. Buyers should not skip a current panel for comfort or underwriting even when your county is quiet about it.
Lenders and title companies may name a lab, form, or “mortgage test” panel — use what they named. More: home purchase / lender chain of custody.
Remind me to test my well every year
CDC and EPA say to test a private well at least once a year. We’ll send one email a year, about when your test is due, with your state’s lab options.
Thanks, you’re on the list. We’ll email you once a year when it’s time to test your well. Nothing else.
What to do in Washington
- Start with DOH annual advice — coliform + nitrate every year — then pick a lab from Ecology’s search (public samples) or DOH 331-798.
- Order bottles from Thurston, Benton-Franklin, Anatek, or another Ecology-accredited lab that confirms private-well acceptance. Call Ecology LAU (360) 871-8840 if you need help reading the accredited-lab list.
- Annual panel: coliform + nitrate. If nitrate ≥ 5 mg/L, plan a six-month recheck. Add arsenic at least twice while you own the well (late summer + early spring).
- Buying or selling: ask your county health/planning department and lender what they require — do not assume a statewide sale-test mandate.
- Lower Yakima / Western Benton: check DOH’s free Well Water Sampling form if you may be inside the boundary; do not wait on it for closing week outside that geography.
- If you want a broader PDF this month and local lab hours do not fit, use Tap Score / SimpleLab or National Testing Laboratories (Watercheck) — still confirm lender fit first.
- Questions on well-water health / arsenic: start with DOH’s Testing Your Water and Arsenic pages, then your local health department.
Not this if…
- A lender or title company named a lab and analytes. Use that path. Do not assume every accredited name takes private bottles this week.
- Someone offered a free in-home or in-office “test” that ends in a softener pitch. That is not on this page. See the Home Depot free-kit comparison.
- You only wanted a strip from the hardware aisle. Fine as screening-only. It is not a certified analysis.
- You assumed Washington requires a sale test the way Maryland § 10-713 does. We found county/lender conditions in most counties, not a single statewide sale-test statute.
- You assumed the Lower Yakima / Western Benton free path covers every private well in the state. It is geography-limited — use DOH’s form to check.
- You invented a county fee because a neighbor once paid one. We only listed published Thurston, Benton-Franklin, Anatek, and DOH’s $21–$55 range.
- You treated Anatek’s base Private Well List package as a fixed dollar without calling. Their private-well PDF says Call for Pricing on that SKU; we listed the Spokane County and Tri-County package dollars they did publish.
- You boiled high-nitrate or high-arsenic water as a fix. Boiling does not remove arsenic or nitrate (and concentrates nitrate). Find another drinking source or appropriate treatment — DOH’s arsenic page has options.
Related: Arizona · New Hampshire · California · Colorado · PFAS 533 / 537.1 · how to read a report · after a flood · lender / CoC · cost table · Home Depot free kit vs a certified lab · How it works · back to the directory.