Laboratory Accreditation Section Identifier

Laboratory Accreditation

The Department of Ecology is the accrediting institution in Washington State for environmental laboratories, including those that test drinking water.  Accreditation of environmental laboratories ensures a lab is capable of providing accurate and defensible analytical data. Many grant-based or legislatively mandated scientific studies require the use of an accredited laboratory.

Find a lab

Lab Search database - Find an accredited lab. Search by area, analytes, and more.

How to Choose an Analytical Laboratory offers considerations to keep in mind when deciding which lab to hire for your analyses.

The printable lists of accredited labs in PDF format, below, are updated regularly. However, the most up-to-date information is in the Lab Search database, above.

All Accredited Labs by Name | Drinking Water by County | Drinking Water Labs with All Analyses

Become an accredited lab

Applying for Lab Accreditation offers instructions for those laboratories new to the process.

Fee Schedule is at WAC 173-50-190.

News and resources for labs

Manuals and Procedures has links and latest news on procedures, methods, and other accreditation topics.

Renew accreditation

The Lab Accreditation Unit staff sends email notices to labs up to six weeks before the month before accreditation expires. This notice will contain a renewal application and a report of the lab's currently requested parameters. Please keep us updated with your current email address, and contact Ella Rae if you do not receive a notice. To ensure you receive the notices, please add the following address to your contact list:

For more information

Drinking Water in Your Home is a page at the Office of Drinking Water at the Washington State Department of Health that offers tips for drinking-water consumers, with an emphasis on resources for private well owners.

Drinking Water Contaminants at DOH links to information on lead, arsenic, fecal coliform bacteria, nitrate, and more.

Private Drinking Water Wells is a page at the Federal Environmental Protection Agency.

Accreditation of Environmental Laboratories is at Chapter 173-50 of the Washington Administrative Code

Contact the Lab Accreditation Unit to learn more.

Pollution Prevention for Analytical and Industrial Labs contains resources for using greener practices and reducing waste in analytical laboratories.

Environmental Management Guide for Small Laboratories is a publication from the federal Environmental Protection Agency.

Lab Search
Database of Accredited Laboratories

Procedure Manual
for the Environmental Laboratory Accreditation Program

List of Drinking Water Labs by county in PDF format.

Model of a Quality Assurance Manual for a Small Wastewater Treatment Plant Laboratory (Pub.#16-03-025)

Technical Guidance for Laboratories Accredited for EPA Method 200.7 (Pub.#16-03-028)

SW-846 Update Email List from EPA.
Sign up to learn about reviews of and changes to RCRA test methods.

Methods Update Rule
revisions for Nonpotable Water matrix
and Solid and Chemical Materials matrix

Dissolved Oxygen Proficiency Tests are required for those labs with dissolved oxygen testing in their scopes.