Nitrate Water Testing Labs in Washington (45 state-certified labs)
Labs on Washington's official certification list that test drinking water for nitrate, with the ones that take homeowner samples first.
45 named for nitrate itself on the list.
Per the state list or a state web page. Call to confirm.
Located outside Washington but on its list.
USGS estimate for Washington.
How many labs test for nitrate in Washington
45 labs on Washington's official drinking-water lab list are certified to test for nitrate. All 45 are named for nitrate on the list. 44 of them are marked as taking samples from the public. They are listed first. 16 are located outside Washington.
The list is published by the Washington State Department of Ecology - Lab Accreditation Program (with WA DOH). List version on file: Information current as of 11/13/2026. Fetched 2026-11-15 (UTC).
Washington labs certified for nitrate
Marked as taking public samples (44)
| Lab | Location | Nitrate certification | Public samples | Cert. expiry |
|---|---|---|---|---|
| 49er Water Laboratory | Jackson, CA | Named on the official list | Public samples: yes (per state) | 05/26/2027 |
| Accurate Testing Labs L.L.C. | Coeur d'Alene, ID | Named on the official list | Public samples: yes (per state) | 04/25/2027 |
| ACZ Laboratories, Inc. | Steamboat Springs, CO | Named on the official list | Public samples: yes (per state) | 08/24/2027 |
| Ag Health Laboratories, Inc. | Sunnyside, WA | Named on the official list | Public samples: yes (per state) | 09/29/2027 |
| ALS Environmental - Kelso | Kelso, WA | Named on the official list | Public samples: yes (per state) | 07/08/2027 |
| AmTest Laboratories | Renton, WA | Named on the official list | Public samples: yes (per state) | 07/25/2027 |
| Analytical Resources, LLC | Tukwila, WA | Named on the official list | Public samples: yes (per state) | 06/30/2027 |
| Anatek Labs, Inc - Moscow | Moscow, ID | Named on the official list | Public samples: yes (per state) | 03/20/2027 |
| Anatek Labs, Inc - Spokane | Spokane, WA | Named on the official list | Public samples: yes (per state) | 11/15/2027 |
| Anatek Labs, Inc. - Yakima | Yakima, WA | Named on the official list | Public samples: yes (per state) | 05/19/2027 |
| Aqua Test, Incorporated | Maple Valley, WA | Named on the official list | Public samples: yes (per state) | 11/05/2027 |
| Benton-Franklin Health District Lab | Kennewick, WA | Named on the official list | Public samples: yes (per state) | 08/23/2027 |
| BSK Associates | Fresno, CA | Named on the official list | Public samples: yes (per state) | 03/10/2027 |
| BSK Associates - Vancouver | Vancouver, WA | Named on the official list | Public samples: yes (per state) | 09/12/2027 |
| City of The Dalles Water Quality Lab | The Dalles, OR | Named on the official list | Public samples: yes (per state) | 11/02/2027 |
| Clallam County Environmental Laboratory | Port Angeles, WA | Named on the official list | Public samples: yes (per state) | 04/30/2027 |
| Columbia Laboratories, Inc. | Portland, OR | Named on the official list | Public samples: yes (per state) | 09/02/2027 |
| Continental Water Laboratory | Sacramento, CA | Named on the official list | Public samples: yes (per state) | 05/22/2027 |
| Energy Northwest Environmental Services Lab | Richland, WA | Named on the official list | Public samples: yes (per state) | 04/11/2027 |
| Eurofins DW and WW West, Washington Laboratory | Burlington, WA | Named on the official list | Public samples: yes (per state) | 01/18/2027 |
| Eurofins Lancaster Laboratories Environmental Testing, LLC | Lancaster, PA | Named on the official list | Public samples: yes (per state) | 04/11/2027 |
| Eurofins Pomona | Pomona, CA | Named on the official list | Public samples: yes (per state) | 03/13/2027 |
| Eurofins South Bend | South Bend, IN | Named on the official list | Public samples: yes (per state) | 01/01/2027 |
| Eurofins Spokane | Spokane Valley, WA | Named on the official list | Public samples: yes (per state) | 01/06/2027 |
| Everett Environmental Laboratory | Everett, WA | Named on the official list | Public samples: yes (per state) | 04/21/2027 |
| Exact Scientific Services, Inc. | Ferndale, WA | Named on the official list | Public samples: yes (per state) | 08/20/2027 |
| Grays Harbor County Water Testing Lab | Montesano, WA | Named on the official list | Public samples: yes (per state) | 02/01/2027 |
| IEH Analytical Laboratories | Seattle, WA | Named on the official list | Public samples: yes (per state) | 06/17/2027 |
| LabTest | Yakima, WA | Named on the official list | Public samples: yes (per state) | 07/13/2027 |
| Lewis County Environmental Health Laboratory | Chehalis, WA | Named on the official list | Public samples: yes (per state) | 01/01/2027 |
| Matrix Sciences International Inc. dba KTL | Pasco, WA | Named on the official list | Public samples: yes (per state) | 09/02/2027 |
| Okanogan County Public Health Laboratory | Okanogan, WA | Named on the official list | Public samples: yes (per state) | 06/30/2027 |
| Olympic Analytical LLC dba Vanguard Laboratory | Olympia, WA | Named on the official list | Public samples: yes (per state) | 03/28/2027 |
| Pace Analytical National Center for Testing & Innovation TN | Mt. Juliet, TN | Named on the official list | Public samples: yes (per state) | 08/19/2027 |
| Pace Analytical Services, LLC - Minneapolis MN | Minneapolis, MN | Named on the official list | Public samples: yes (per state) | 02/18/2027 |
| RJ Lee Group, Inc. - PA | Monroeville, PA | Named on the official list | Public samples: yes (per state) | 12/30/2026 |
| RJ Lee Group, Inc. Columbia Basin Analytical Laboratories | Pasco, WA | Named on the official list | Public samples: yes (per state) | 07/13/2027 |
| Rose City Laboratories, LLC | Portland, OR | Named on the official list | Public samples: yes (per state) | 06/14/2027 |
| Soiltest Farm Consultants, Inc. Laboratory | Moses Lake, WA | Named on the official list | Public samples: yes (per state) | 09/07/2027 |
| Spectra Laboratories - Kitsap, LLC | Poulsbo, WA | Named on the official list | Public samples: yes (per state) | 09/27/2027 |
| Thurston County Health Department Laboratory | Olympia, WA | Named on the official list | Public samples: yes (per state) | 05/11/2027 |
| Tshimakain Creek Laboratories | Spokane Valley, WA | Named on the official list | Public samples: yes (per state) | 11/21/2027 |
| Walla Walla Regional Water Testing Services | College Place, WA | Named on the official list | Public samples: yes (per state) | 08/31/2027 |
| Water Management Laboratories, Inc. | Tacoma, WA | Named on the official list | Public samples: yes (per state) | 01/31/2027 |
Other labs on the list (1)
| Lab | Location | Nitrate certification | Public samples | Cert. expiry |
|---|---|---|---|---|
| DCI Laboratory | Nashville, TN | Named on the official list | Not marked as taking public samples | 10/22/2027 |
How the Washington list marks public samples (whole list). Yes/no from Ecology's 'Search labs that accept public samples' list, where the label is 'Accepts Commercial/Public Samples'. That is broader than 'homeowner' and includes some utility labs, so call before you send a sample.
Before you send a sample, call the lab to confirm it is currently certified for the exact test and method, that it accepts samples from homeowners, and how to collect and ship them. Status can change between list updates.
Why test for nitrate in Washington
Nitrate has no taste or smell, and a lab report can state the same water in two units that differ by a factor of 4.43. Read our nitrate explainer.
EPA advises private-well owners to test every year for total coliform bacteria, nitrates, total dissolved solids and pH. [1]
Washington guidance that mentions nitrate:
- Coliform bacteria and nitrate every year. If nitrate is 5 mg/L or higher, the state says you may want to re-test in six months. It also suggests testing arsenic at least twice while you own the home, once in summer and once in winter. [2]
- Free nitrate and coliform testing for private wells in the Lower Yakima Valley and Western Benton County. [2]
About 1,023,853 people in Washington used private wells in 2015, by the USGS estimate of people on domestic self-supplied water. [3] Federal limits are written for public water systems, not private wells, so testing is up to the owner.
For tests that depend on your home (farms nearby, old plumbing, a new baby), use the which-tests checklist. When results arrive, check your numbers against EPA's limits. State guidance, county data and every lab: Washington.
Other tests in Washington
- U.S. EPA, Protect your home's water
- Washington State Department of Health, Testing your water
- USGS, Estimated use of water in the United States, county-level data for 2015 (Dieter et al., ver. 2.0, 2018)
- WA Ecology - Environmental Laboratories Accredited for Drinking Water Analyses (with scopes) (official list)
WA Ecology - Environmental Laboratories Accredited for Drinking Water Analyses (with scopes).
Official source