Certified well water testing labs by state

Short answer: pick your state to open its official list of certified drinking water labs, or its private well testing page that links to them. CDC and EPA advise testing a private well every year at a state-certified lab.

Links checked October 5, 2026 · By the County Road Home team

What to do next

  1. Open your state's page and pick a lab near you. Some labs mail out sample bottles.
  2. Ask for at least total coliform bacteria, nitrate, total dissolved solids and pH, the yearly tests CDC recommends. Which extra tests to add.
  3. Follow the lab's sampling and shipping instructions. Bacteria samples must reach the lab within a set time.
  4. When the report comes back, check each number against EPA limits.

All states

StateOfficial page
AlabamaADEM drinking water lab certification page with certified lab lists · PDF lists: bacteriological, in-state and out-of-state chemical, PFAS
AlaskaAlaska DEC drinking water lab certification page with certified lab lists · Separate chemistry and microbiology lists
ArizonaADHS list of licensed commercial drinking water labs · Updated daily by ADHS; verified via Wayback snapshot (July 2026), site blocks automated checks
ArkansasADH Water Microbiology Lab: private well bacteria testing plus listed commercial labs · State lab tests private wells for coliform/E. coli via local health units
CaliforniaState Water Board ELAP page with map search of accredited labs
ColoradoCDPHE water testing services: private well testing and accredited lab lookup · State lab chemistry testing temporarily suspended; page points to accredited commercial labs
ConnecticutCT DPH lab certification page with labs certified to test drinking water · PDF lists (in-state and out-of-state)
DelawareDelaware DPH list of certified drinking water laboratories · Verified via Wayback snapshot (June 2026); site blocks automated checks
District of ColumbiaEPA directory of certification programs (DC labs certified by EPA Region 3) · EPA fallback: DC has no state lab certification program
FloridaFlorida DOH private well testing page linking to the certified lab search · Lab database is hosted by Florida DEP
GeorgiaGeorgia EPD drinking water page with lists of labs certified by Georgia · PDF lists (chemical, microbiological, PFAS, lead and copper)
HawaiiHawaii DOH Safe Drinking Water Branch with certified labs list · PDF list; also links a private water well guide
IdahoIdaho DHW drinking water testing page with certified lab certificates · Covers private well testing guidance
IllinoisIllinois EPA list of accredited laboratories · PDF lists (chemical and microbiological)
IndianaIndiana DOH drinking water lab certification page with certified lab listings
IowaIowa DNR lab certification page with certified lab search · Mentions free annual private well testing via county Grants to Counties program
KansasKDHE environmental lab accreditation database
KentuckyKentucky DOW water well owner page linking to certified drinking water lab list · PDF list
LouisianaLDH laboratory certification page with certified drinking water lab lists · Verified via Wayback snapshot (July 2026); site blocks automated checks
MaineMaine CDC lab accreditation page with accredited commercial lab list · Includes private well testing advice
MarylandMDE water supply lab certification page with certified drinking water lab list · PDF list; verified via Wayback snapshot (June 2026), site blocks automated checks
MassachusettsMassDEP how-to: find a certified lab for testing your water · Links to searchable database; verified via Wayback snapshot (Sept 2026), site blocks automated checks
MichiganEGLE lab certification program with certified lab lists · PDF lists by analyte group
MinnesotaMDH environmental lab accreditation program with accredited lab search
MississippiMSDH list of certified drinking water laboratories
MissouriMissouri DNR certified chemical and microbiological laboratories · Verified via Wayback snapshot (Oct 2026); site blocks automated checks
MontanaDPHHS water lab certification program with certified lab lists
NebraskaNebraska DHHS lab certification page with certified labs list · PDF list; verified via Wayback snapshot (June 2026), site unreachable from our checker
NevadaNDEP lab certification page with searchable certified lab database
New HampshireNHDES private wells page with water testing guidance and accredited labs · Links a PDF of accredited labs serving private well users
New JerseyNJDEP Office of Quality Assurance laboratory certification programs · Certified lab lists are in NJDEP DataMiner; verified via Wayback snapshot (July 2026)
New MexicoNMED private wells page with testing advice and certified lab list link
New YorkNYSDOH Wadsworth ELAP page with certified lab search
North CarolinaNCDHHS private well water testing FAQs linking to certified commercial labs · Verified via Wayback snapshot (Jan 2026); site unreachable from our checker
North DakotaND HHS water testing: private well bacteria testing kits · No online certified lab list; contact the lab for kits
OhioOhio EPA list of labs certified for drinking water analysis · PDF list (October 2026 edition)
OklahomaOklahoma DEQ accredited lab search by location · Shows whether labs accept private samples
OregonOHA drinking water testing page: accredited labs that accept well water samples
PennsylvaniaPA DEP laboratory accreditation page with accredited lab search
Rhode IslandRIDOH list of certified drinking water testing labs · Verified via Wayback snapshot (May 2026); site blocks automated checks
South CarolinaSCDES map of certified commercial environmental labs · Verified via Wayback snapshot (Feb 2026); site blocks automated checks
South DakotaSD DANR drinking water lab certification page with certified labs
TennesseeTDEC lab certification program with certified lab lists · PDF lists (commercial and microbiological)
TexasTCEQ environmental lab accreditation page with accredited lab search
UtahUtah DDW consumer guide linking to Utah-certified labs · Lab list is a Google Sheet; verified via Wayback snapshot (Aug 2026), site blocks automated checks
VermontVermont Health drinking water testing page with certified labs list · PDF list; includes private well testing advice
VirginiaDCLS find-a-lab directory incl. certified drinking water labs
WashingtonEcology accredited lab search (filter: drinking water, accepts public samples)
West VirginiaWV Office of Laboratory Services list of certified drinking water labs · PDF list
WisconsinWisconsin DNR certified lab lists (chemistry and bacteria)
WyomingEPA Region 8 list of certified drinking water labs for Wyoming · Wyoming has no state program; EPA Region 8 certifies labs

Starting point: EPA's list of state drinking water lab certification programs. Where EPA's link was out of date or not useful to a homeowner, we used the state's current page instead. Some state sites block automated checks, and links move: if one is broken, email us and we'll fix it.