Well water in Bastrop County, Texas
In Bastrop County, none of 101 tested well samples exceeded the EPA limit for fluoride, based on public data from Texas Water Development Board Groundwater Database and USGS Water Quality Portal.
143 individual samples from 102 wells, 1941 to 2026. 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 Bastrop 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 | |
|---|---|---|---|---|---|---|---|
| Radium (226 + 228) 2008 to 2015 | 16 | 81% | 6% | 0.57 | 15.3 | 5 pCi/L EPA limit | |
| Fluoride 1952 to 2026 | 101 | 96% | 0% | 0.2 | 1.6 | 4 mg/L EPA limit | |
| Arsenic 1980 to 2026 | 23 | 4% | 0% | 0 | 0 | 10 ug/L EPA limit | |
| Nitrate 1972 to 2026 | 23 | 30% | 0% | 0 | 3.65 | 10 mg/L EPA limit | |
| Copper 1988 to 2026 | 22 | 23% | 0% | 0 | 0.013 | 1.3 mg/L EPA limit | |
| Lead 1989 to 2026 | 17 | 0% | 0% | 0 | 0 | 15 ug/L EPA limit | |
| Uranium 2008 to 2026 | 14 | 36% | 0% | 0 | 2.21 | 30 ug/L EPA limit | |
| Gross alpha 1988 to 2014 | 10 | 10% | 0% | 0 | 3.5 | 15 pCi/L EPA limit | |
| Chloride 1941 to 2026 | 143 | 100% | no limit | 68 | 1,560 | 250 mg/L nuisance level | |
| Sodium 1948 to 2026 | 126 | 100% | no limit | 73 | 465 | 20 mg/L health guideline | |
| Iron 1952 to 2026 | 122 | 93% | no limit | 430 | 52,000 | 300 ug/L nuisance level | |
| Manganese 1962 to 2026 | 25 | 80% | no limit | 24.3 | 1,290 | 300 ug/L health guideline |
Sampled fewer than 10 times, too few to summarize: E. coli (5), Radon (5).
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What this means
The contaminants most often above their limit here are radium (226 + 228) (6% of 16 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, Iron, and Manganese are widespread in local groundwater. They are mainly a staining and taste problem, but high manganese also carries a health advisory for infants.
What to test for in Bastrop County
- Volatile organic compounds (VOCs)73 leaking underground storage tank sites on record locally.
- Radium (226 + 228)6% of 16 local samples were above the limit.
- Coliform bacteriaRecommended for every private well, every year.
- RadonMedian local reading is 280 pCi/L.
- ChlorideDetected in 100% of local samples.
- NitrateRecommended for every private well, especially near farms or septic systems.
- FluorideDetected in 96% of local samples.
- IronDetected in 93% of local samples.
Contamination sources on record in Bastrop County
TCEQ records 73 leaking underground storage tank sites in Bastrop County, among 85 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.
- 73
- leaking underground storage tank sitesGasoline and heating oil that leaked from tanks move through groundwater as benzene, MTBE and other volatile organic compounds.
- 12
- lined landfills and transfer facilities
Treatment that fits the local profile
- Radium (226 + 228)
- Water softener (cation exchange); Point-of-use reverse osmosis
- Fluoride
- Point-of-use reverse osmosis; Activated alumina; Distillation
- Chloride
- Point-of-use reverse osmosis; Distillation
- Iron
- Oxidizing filter whole-house; Water softener (low levels); Aeration plus filtration
- Manganese
- Oxidizing filter (greensand, birm) whole-house; Water softener (low levels); Point-of-use reverse osmosis
Get your Bastrop 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 Bastrop County.
Common questions
Is there arsenic in well water in Bastrop County?
Arsenic was detected in 4% of 23 public well samples in Bastrop 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 Bastrop County?
The median radon level across 5 public samples in Bastrop County was 280 pCi/L, with a high of 390 pCi/L. New Hampshire recommends treatment above 2,000 pCi/L.
How often should I test a private well in Bastrop 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: 618 samples in Bastrop 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: 34 samples in Bastrop 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: 85 regulated sites located in Bastrop 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.