Well water testing labs in Williamson County, TX
Independent directory. Listings come from the TCEQ Public Water System Lab Map Table (updated 03/26/2026). These labs are accredited for public drinking-water samples; call first to confirm they accept private-well samples, which tests they run, sample bottles, drop-off hours and price.
1 accredited lab listed in Williamson County. Bacteria tests usually need a sterile bottle from the lab and delivery within about 30 hours, so check the lab's sample rules before you collect.
Quick answer
| Lab | City | Bacteria | Published price | Phone |
|---|---|---|---|---|
| City of Round Rock Environmental Sciences Laboratory | Round Rock | Yes | Call | (512) 218-5559 |
City of Round Rock Environmental Sciences Laboratory
5200 North IH 35, Round Rock, TX 78681 · map (OpenStreetMap)
Phone: (512) 218-5559
Bacteria (total coliform / E. coli)
Not in this county? See all counties or read how to test your well.