Last checked: October 28, 2026

Licensed well drillers, water conditioner installers and certified drinking water labs in Maryland

Maryland licenses well drillers, pump installers and water conditioner installers through the State Board of Well Drillers, and certifies drinking water labs through MDE. This page lists the companies on the Board's current roster and the in-state labs on MDE's certified lab list. Filter by county or search by name.

How Maryland licenses well work

• Only licensed drillers build wells. MDE says only a licensed well driller may construct a new well or modify or properly abandon an existing one.¹
• The State Board of Well Drillers publishes monthly rosters of active licensees, one by name and one by company. License types on the roster include master and journeyman well drillers (general, water supply and geotechnical), pump installers, water conditioner installers, apprentices and well rig operators.²³
• The Board's own caveat: it publishes the list as a resource only, doesn't endorse anyone on it, makes no warranty about performance, and advises consumers to verify with the licensee that the license is active before hiring.³
• Labs are certified test by test. MDE's Laboratory Certification Program lists each lab's approved tests using codes explained in MDE's approved analyte list. MDE notes that certification is reviewed continually and the list may change before the next website update.⁴

Check a license yourself

• People: the Board's roster of active licensees by name (PDF) shows each person's license number, license type, company and expiration date.² Ask whoever works on your well or treatment system for their license number and check it there.
• Companies: the roster by company (PDF) lists each company's address, phone, website and licensed employees.³
• Labs: MDE's Maryland's Certified Drinking Water Laboratories (PDF), linked from the Lab Certification Program page, which also links the approved analyte list and a separate list of PFAS-certified labs.⁴

The list

Drillers and pump installers: companies on the Board's roster (dated September 28, 2026) with at least one active master or journeyman well driller (general or water supply) or pump installer, with those license numbers. Companies whose only licensees are geotechnical drillers, apprentices or rig operators are left out. Water treatment: companies on the same roster with a licensed water conditioner installer (WCI numbers). Labs: the in-state labs on MDE's certified list (latest revisions 10/1/2026), with MDE's codes for the tests each is approved for. Many are city or county utility labs that only test their own system's water, so call before you send a sample.

The roster gives a mailing address but no county. We assigned a county only when the address ZIP code's Census area lies at least 80% in one county (U.S. Census Bureau 2020 ZIP code tabulation area to county file);⁵ otherwise the county shows as not listed, so search by town too. Out-of-state companies are grouped by state. Home inspectors: we haven't loaded a Maryland home inspector list.

Missing or wrong? Email [email protected] with the official listing and we'll recheck it against the source.

Sources for this list

• Maryland State Board of Well Drillers (MDE), Companies With Active Licensees as Employees (list dated September 28, 2026; updated monthly) (2026-09-28): 129 entries
• Maryland Department of the Environment, Laboratory Certification Program, Maryland's Certified Drinking Water Laboratories (latest revisions 10/1/2026), in-state labs (2026-10-01): 39 entries

Home inspectors and well inspections

A standard home inspection usually doesn't include a full check of the well. If you're buying or selling a home with a well, ask the home inspector whether they do a well flow (yield) test and water sampling, which state-certified lab runs the samples, and whether they look at the well cap, pressure tank and pump controls. Otherwise, hire a licensed well contractor for the well itself and a certified lab for the water. Are you a home inspector? See our well inspection guide for home inspectors.

NGWA (the National Ground Water Association, a private trade group) recommends a yearly well checkup by a qualified water well professional: a flow test, checks of the water level, pump, pressure tank and switch, a sanitary and code check, a coliform bacteria and nitrate test (plus anything of local concern), and a written report.⁶ To find one, use NGWA's contractor lookup on wellowner.org and its certified professionals directory. These are run by a trade association, not a state agency, so still check the state license.

Where a state publishes its home inspector license list, we load it on that state's page (currently North Carolina, New York and Virginia). Other states we cover: Texas licenses inspectors through the Texas Real Estate Commission, but TREC's public data file doesn't include a location, so use TREC's license holder search. Wisconsin credentials home inspectors through DSPS, which sells its list rather than publishing it, so use DSPS's credential search. Pennsylvania and Michigan don't have a state license list for home inspectors that we could use.

Water treatment dealers

We list water treatment dealers (softener, filter and treatment system installers) only where a state publishes an official license list. A few states license this work. Where a state publishes its license list we load it (so far Texas: TCEQ Water Treatment Specialists), and where we've found a state license without a usable list, it's noted on that state's page, so check with your state too. To find someone with a voluntary credential, use these lookups. They are run by private trade associations, not by any government agency. A listing there is not a state license, and these groups mostly list their own members:

• Water Quality Association (WQA): Find a WQA-certified professional (people who hold WQA's voluntary certifications) and find WQA-certified treatment products (products WQA has tested and certified).
• National Ground Water Association (NGWA): Find a water well contractor on NGWA's wellowner.org (NGWA members; NGWA says it "neither endorses nor guarantees the work of any company listed")⁷ and the directory of NGWA-certified professionals.

Before you buy treatment, get your water tested by a state-certified lab (each state page lists or links them) and run the results through the free Well Test Results Checker, so you only treat for what's actually in your water.

Questions to ask before hiring a well contractor

Get information on several contractors before you choose.⁸ These questions come from the National Ground Water Association's well owner guidance and New York DEC's consumer checklist:⁸⁹

• Are you licensed, registered or certified by the state for this work? Not every state requires it. Check the answer yourself with the state lookup on this page.
• Is the person supervising the job certified? NGWA offers voluntary certification; its highest level is Master Groundwater Contractor (MGWC).⁸
• Do you file a well log or completion report, and will I get a copy? Some states require the driller to give the owner a copy (New York does, for example).⁹ Keep it with your deed.⁸
• What liability and workers' compensation insurance do you carry?⁸
• Can I talk to recent customers? Ask for references and call them.⁹
• Will you give me a written contract?⁸ In New York, for example, home improvement work over $500 needs a written contract by law.⁹
• Do I need a local permit? Check with your local health and building code officials. Some counties set their own rules.⁹

What to check on a quote

Get more than one estimate.⁹ NGWA says an itemized list of charges is better than a lump sum, because you can't compare offers unless you know what each one covers.⁸ For a drilled well, look for:⁸

• Price per foot of drilling and per foot of casing, plus the casing diameter and thickness
• Other materials (drive shoe, grout, well cap) and other steps (grouting, development, test pumping, disinfection)
• The type of well cap or seal, and the disinfection procedure
• What happens, and what it costs, if they must drill deeper or drill a second well, or abandon and seal a dry or bad hole
• Cleanup of the site, an expected start date, and a guarantee of materials and workmanship
• A statement that the work will meet state and local codes
• What is not included

When the well is finished, NGWA suggests checking the depth against the construction report, asking what yield (gallons per minute) the well was tested at, making sure the cap is secure and at least 6 inches above ground, asking whether the well was disinfected, and getting your copy of the well record.⁸

Buying treatment? Test first. A lab report from a state-certified lab tells you what you're actually treating for. Pennsylvania DEP, for example, says to pick a treatment device for the specific contaminant your test found, and points to NSF's product database.¹⁰ Put your numbers into our free Well Test Results Checker to see how they compare with EPA benchmarks.

More for Maryland well owners

• Private wells in Maryland: the test required at sale (Real Property § 10-713), the rental testing rule, radium and arsenic areas, and where to get well records
• Buying a home with a well · Arsenic in well water · Uranium and radon in well water