Well water in Travis County, Texas
In Travis County, 11% of 536 tested well samples exceeded the EPA limit for fluoride (4 mg/L), based on public data from Texas Water Development Board Groundwater Database and USGS Water Quality Portal.
603 individual samples from 359 wells, 1931 to 2025. Data refreshed September 9, 2026.
TWDB samples an ambient monitoring network of wells on a rotation, so these describe aquifers, not a survey of homeowners' tests.
What individual samples found
Each row summarizes every public sample for that contaminant inside Travis County. Above limit means above the EPA maximum contaminant level; where EPA has no enforceable limit, the row shows a health guideline or nuisance level instead.
| Contaminant | Samples | Detected | Above limit | Median | Highest | Limit | |
|---|---|---|---|---|---|---|---|
| E. coli 2008 to 2017 | 21 | 19% | 19% | 0 | 140 | 0 MPN/100mL EPA limit | |
| Gross alpha 1977 to 2016 | 11 | 73% | 18% | 4 | 21 | 15 pCi/L EPA limit | |
| Fluoride 1937 to 2025 | 536 | 99% | 11% | 0.969 | 13 | 4 mg/L EPA limit | |
| Lead 1977 to 2025 | 91 | 12% | 1% | 0 | 40 | 15 ug/L EPA limit | |
| Nitrate 1971 to 2025 | 216 | 86% | <1% | 1.1 | 10.7 | 10 mg/L EPA limit | |
| Uranium 1980 to 2025 | 141 | 73% | 0% | 0.757 | 6.9 | 30 ug/L EPA limit | |
| Arsenic 1978 to 2025 | 105 | 31% | 0% | 0 | 3.99 | 10 ug/L EPA limit | |
| Copper 1982 to 2025 | 87 | 68% | 0% | 0.002 | 0.073 | 1.3 mg/L EPA limit | |
| Radium (226 + 228) 1977 to 2017 | 19 | 74% | 0% | 0.33 | 3.2 | 5 pCi/L EPA limit | |
| Chloride 1931 to 2025 | 603 | 100% | no limit | 23 | 3,270 | 250 mg/L nuisance level | |
| Sodium 1937 to 2025 | 576 | 100% | no limit | 18 | 1,980 | 20 mg/L health guideline | |
| Iron 1955 to 2025 | 145 | 49% | no limit | 0 | 46,500 | 300 ug/L nuisance level | |
| Manganese 1966 to 2025 | 99 | 37% | no limit | 0 | 113 | 300 ug/L health guideline |
Sampled fewer than 10 times, too few to summarize: PFOA (1), PFOS (1), Total coliform (2), Radon (1).
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What this means
The contaminants most often above their limit here are e. coli (19% of 21 samples), gross alpha (18% of 11 samples), and fluoride (11% of 536 samples). A well next door can differ sharply from yours because bedrock fractures, well depth and plumbing all matter, so these rates describe the area, not your tap.
Chloride is widespread in local groundwater. It is mainly a staining and taste problem, but high manganese also carries a health advisory for infants.
What to test for in Travis County
- Volatile organic compounds (VOCs)773 leaking underground storage tank sites on record locally.
- E. coli19% of 21 local samples were above the limit.
- Gross alpha18% of 11 local samples were above the limit.
- Fluoride11% of 536 local samples were above the limit.
- Lead1% of 91 local samples were above the limit.
- Nitrate<1% of 216 local samples were above the limit.
- RadonMedian local reading is 122 pCi/L.
- PFOAAbove the limit in 1 of 1 local samples; too few to quote a rate.
Contamination sources on record in Travis County
TCEQ records 773 leaking underground storage tank sites in Travis County, among 846 regulated sites in total. Groundwater does not follow property lines, so a well within a few hundred feet of one of these is worth testing for what that site could release.
- 773
- leaking underground storage tank sitesGasoline and heating oil that leaked from tanks move through groundwater as benzene, MTBE and other volatile organic compounds.
- 73
- lined landfills and transfer facilities
Treatment that fits the local profile
- E. coli
- Shock chlorination and fix the well cap or casing; UV disinfection whole-house; Chlorination system
- Gross alpha
- Point-of-use reverse osmosis; Water softener (cation exchange) for radium; Anion exchange for uranium
- Fluoride
- Point-of-use reverse osmosis; Activated alumina; Distillation
- Lead
- Point-of-use reverse osmosis; Certified lead-removal carbon filter; Neutralizing filter to raise pH and stop leaching
- Nitrate
- Point-of-use reverse osmosis; Anion exchange; Distillation
Get your Travis County water tested at home
A licensed local water treatment company tests your tap water in your home, walks you through the numbers, and quotes treatment only if something needs fixing. Free, about 30 minutes, no obligation. Tell us what you need and we match you with a company that serves Travis County.
Common questions
Is there arsenic in well water in Travis County?
Arsenic was detected in 31% of 105 public well samples in Travis County, and 0% were above the EPA limit of 10 ug/L. Arsenic has no taste or smell; a lab test is the only way to know your level.
How high is radon in well water in Travis County?
The median radon level across 1 public samples in Travis County was 122 pCi/L, with a high of 122 pCi/L. New Hampshire recommends treatment above 2,000 pCi/L.
How often should I test a private well in Travis County?
Test for bacteria and nitrate every year. Test once for arsenic, uranium, radon, fluoride, manganese and PFAS, then again every three to five years or after any change in taste, color, or plumbing.
Sources
- Texas Water Development Board Groundwater Database: 2,456 samples in Travis County. Water quality samples from the Texas Water Development Board Groundwater Database, collected by TWDB, groundwater conservation districts and cooperators. Retrieved September 9, 2026.
- USGS Water Quality Portal: 199 samples in Travis County. Data from the Water Quality Portal, a service of USGS, EPA and USDA; groundwater samples collected by USGS and cooperators. Retrieved September 3, 2026.
- TCEQ regulated sites: 846 regulated sites located in Travis County. Leaking petroleum storage tank sites, state Superfund sites and municipal solid waste landfills from the Texas Commission on Environmental Quality. Retrieved September 9, 2026.
Non-detects count as samples and are treated as zero when computing medians. Exactly at the limit counts as not above it. A sample belongs to the town containing the well's reported coordinates.