Quick answer: Use your state drinking-water laboratory certification program or ask your local health or environmental department for its current list. Before ordering a test, confirm the lab is certified for the specific contaminant, ask for the approved sample kit and collection instructions, and check the delivery deadline.
1. Start with your state or local program
The U.S. EPA maintains a directory of state certification program contacts. Select your state and use the program’s current directions to locate laboratories that analyze drinking water. Your local or county health department may also provide a list and explain which tests are relevant to local conditions.
For private wells, you generally arrange and pay for testing directly; the EPA does not test household samples on request. Confirm any local program, eligibility, or assistance directly with the agency.
For one state-specific example, see our Michigan well-water testing guide, which distinguishes state-listed local options from services and prices verified on county laboratory pages.
2. Match certification to the test
A lab’s listing does not necessarily mean it is certified for every contaminant or test method. Tell the lab what you want measured—such as total coliform bacteria, nitrate, arsenic, or lead—and ask whether its current state certification covers that specific analysis for drinking water. Ask the state program if the listing or scope is unclear.
- Confirm the lab’s name and current status in the state program’s directory.
- Ask whether it is certified for each specific analyte, not just “water testing” in general.
- Ask which sample containers, preservatives, and holding times apply.
- Check where and when the sample must be delivered, especially for bacterial testing.
- Ask for the expected cost, reporting time, and report format before you order.
3. Follow the lab’s sampling instructions exactly
Use the lab’s own kit and directions. Different tests can require different containers and handling. Do not substitute a household bottle or combine samples unless the lab instructs you to do so. If a sample is collected incorrectly, delayed, or stored outside the lab’s requirements, contact the lab before relying on the result; it can tell you whether a new sample is needed.
4. Ask which tests fit your well
CDC recommends annual private-well testing for total coliform bacteria, nitrates, total dissolved solids, and pH. Additional tests depend on location and circumstances. Ask your health department about local geology, nearby land uses, flooding, or other known concerns before buying a broad panel. A lab can explain what it measures, while local health officials can help identify which contaminants to consider.
5. Know where to take questions about results
Ask the lab to explain its units, detection limits, and any result flags. For health implications or next steps, contact your local health department or environmental agency. If a result indicates a possible problem, follow local guidance about drinking water and treatment; do not choose a filter solely from a generic product claim.
Primary sources
- CDC: Guidelines for Testing Well Water — annual baseline tests, when to test, and who can help identify certified laboratories.
- U.S. EPA: State certification programs and certified drinking-water laboratories — state program contacts and laboratory lookup guidance.
- U.S. EPA: Protect Your Home’s Water — private-well testing and local risk considerations.
This guide helps you locate testing resources; it does not certify laboratories, recommend a particular lab, interpret an individual report, or replace advice from your state or local health department.