Texas Department of State Health Services / South Texas Laboratory
- Coliform Bacteria
About 1,665 households in Cameron County, 1% of the county, rely on a private well. Nobody tests that water unless the owner does.
Wells are the exception in Cameron County: about 1,665 households, under 1% of the county, are on a private well. Being in the minority means less local help, so this page gathers what applies.
The rules that apply in Cameron 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.
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.
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.
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.
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.
The nearest certified lab is Texas Department of State Health Services / South Texas Laboratory in Harlingen, in the county. Mail-in kits fill the gap for anything it does not run.
1 certified labs within 40 miles
Licensed help in Cameron County includes EnviroCore, Inc and Envirotech Drilling Services LLC and 12 others. Every listing was matched to the Texas license list; the "verify" link on each profile opens the state lookup.
14 licensed contractors
License 4694 Active
License 59554 Active
License 2492 Active
License 52037 Active
License 4603 Active
License 54348 Active
License 61094 Active
License 1885 Active
License 59532 Active
License 54267 Active
License 54247 Active
License 2814 Active
Well depth and water chemistry in Cameron 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.
Varies by location. Check the state well record search for logs of nearby wells.
Neighboring counties: Willacy County, Hidalgo County, Kenedy County, Starr County.
City utility labs charge $20 for bacteria (Wichita Falls, Midland); Texas A&M AgriLife screenings cover bacteria, nitrate and salinity for $15 (a screening, not a certified test). Installed costs are national 2026 ranges; local quotes vary with depth, access and materials. Sources, checked September 2026: City of Wichita Falls, Texas A&M AgriLife well screening, HomeGuide cost guides, Angi: cost to shock a well.
About 1,665, or 1% of households, based on Census housing data and state well surveys. The share is highest outside the towns with public water.
Texas Department of State Health Services / South Texas Laboratory in Harlingen, inside the county. Call first to ask whether they accept homeowner samples.
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.
Published lab fees in Texas: $20 for a bacteria test and $15 for nitrate. City utility labs charge $20 for bacteria (Wichita Falls, Midland); Texas A&M AgriLife screenings cover bacteria, nitrate and salinity for $15 (a screening, not a certified test). Mail-in kits cost about the same as walking in.