Texas county well guide

Well Water in Williamson County, TX: Testing, Contractors and Rules

About 3,214 households in Williamson County, 2% of the county, rely on a private well. Nobody tests that water unless the owner does.

Labs within 40 milesLicensed contractors
2%of households on a private well
Share on wells, county vs state
Williamson County2%
Texas average5%
32licensed contractors serve the county
17 mito the nearest certified lab, Integrity Testing, Inc.
Nostatewide test required when a home is sold

Wells are the exception in Williamson County: about 3,214 households, under 2% of the county, are on a private well. Being in the minority means less local help, so this page gathers what applies.

Local rules for wells in Williamson County

The rules that apply in Williamson County are set at the state level in Texas. The state does not require a test on a new well, and nothing is required at sale. Some counties and townships add permits or setbacks of their own, so check locally before drilling. The state's own recommendations are below.

At a glance

Water test for a new wellNot required statewide

No statewide test. The driller must hold a TDLR license, build the well to the 16 TAC Chapter 76 standards (setbacks from septic systems and property lines, cement seal, disinfection) and file a State of Texas Well Report within 60 days. Nobody samples the water unless you do. If your county has a groundwater conservation district, it may require the well to be registered or permitted before drilling; domestic wells on larger tracts are usually exempt from permitting but not from registration.

Water test when a home is soldNot required statewide

No statewide requirement. The seller's disclosure notice only says whether the water comes from a well. FHA, VA and USDA loans normally require a bacteria, nitrate and lead sample from an accredited lab before closing, and a few groundwater districts ask for a well inspection when a tract changes hands.

What the state recommends

Texas A&M AgriLife Extension and TCEQ recommend a coliform bacteria test every year and a nitrate test every year, plus a first-time panel of arsenic, fluoride, total dissolved solids, hardness, iron, manganese, sulfate and pH. Add uranium and gross alpha in the Hill Country and the Panhandle, and PFAS near airfields and military bases. Test again after flooding, repairs or any change in taste, color or smell.

Free or low-cost testingAvailable

The Texas Well Owner Network (Texas A&M AgriLife Extension) runs low-cost screening days around the state, usually $10 to $15 a sample for bacteria, nitrate, arsenic and salinity, with results explained at a follow-up meeting. County and city health department labs listed below sell bacteria tests at cost. The DSHS laboratory in Austin also sells mail-in kits.

Getting your water tested near Williamson County

The nearest certified lab is Integrity Testing, Inc. in Austin, about 17 miles from the county center. There are 2 more within 40 miles, listed below with what each tests for.

3 certified labs within 40 miles

Licensed well contractors serving Williamson County

Licensed help in Williamson County includes Alpine water well service and Apex Drilling, Inc and 30 others. Every listing was matched to the Texas license list; the "verify" link on each profile opens the state lookup.

Well depth and water chemistry

Well depth and water chemistry in Williamson County follow the rock underneath it. Typical wells here run 100 to 400 ft in the Ogallala on the High Plains; 200 to 800 ft in the Trinity and Edwards limestones of the Hill Country and North Texas; 100 to 600 ft in the Gulf Coast and Carrizo-Wilcox sands of East and South Texas; shallower along river alluvium. Contaminants worth testing for in this part of Texas include nitrate (high plains, rolling plains, central texas farm country), arsenic (southern high plains.

Typical well depth

Varies by location. Check the state well record search for logs of nearby wells.

Contaminants to test for
  • Nitrate (High Plains
  • Rolling Plains
  • Central Texas farm country)
  • Arsenic (southern High Plains
  • Gulf Coast
  • Trans-Pecos)
  • Fluoride (West Texas and the Panhandle)
  • Radium and uranium (Hickory aquifer around the Llano Uplift
  • Parts of the Ogallala)
  • High total dissolved solids and salinity (West and South Texas)
  • Coliform bacteria
  • Hardness (Edwards and Trinity limestones)
  • Iron and manganese and hydrogen sulfide (East Texas)
  • PFAS near military airfields

Neighboring counties: Travis County, Burnet County, Bastrop County, Bell County.

What well work costs in Williamson County

Basic bacteria and nitrate test$25 to $75lab fee, homeowner sample
Full panel lab test$150 to $400metals, VOCs, radiologicals
Well inspection$250 to $550flow, pressure, visual, water test
Submersible pump replacement$1,200 to $4,500parts and labor
Pressure tank replacement$400 to $1,200installed
Whole-house treatment system$800 to $6,000softener, iron filter, UV, RO
New well drilled$5,500 to $25,000about $25 to $65 per foot
Shock chlorination$80 to $300or about $20 as a DIY job

National ranges from published 2025 to 2026 contractor pricing. Local quotes vary with depth, access and materials.

Questions Williamson County well owners ask

How many homes in Williamson County are on a well?

About 3,214, or 2% of households, based on Census housing data and state well surveys. The share is highest outside the towns with public water.

Where is the closest certified lab to Williamson County?

Integrity Testing, Inc. in Austin, about 17 miles away. Call first to ask whether they accept homeowner samples.

Do I need a permit to drill a well in Williamson County?

No statewide test. The driller must hold a TDLR license, build the well to the 16 TAC Chapter 76 standards (setbacks from septic systems and property lines, cement seal, disinfection) and file a State of Texas Well Report within 60 days. Nobody samples the water unless you do. If your county has a groundwater conservation district, it may require the well to be registered or permitted before drilling; domestic wells on larger tracts are usually exempt from permitting but not from registration.

What does a well test cost near Williamson County?

A bacteria and nitrate test runs $25 to $75 at most certified labs; a full panel with metals is $150 to $400. Mail-in kits cost about the same as walking in.