Full contaminant data, sample history, and sourcing for Liberty County. For readers who want to go beyond the summary.
Contaminant Data — All Analytes
384 well testing events on record, covering
20 analytes.
Data spans 1937 to 2022.
Contaminant
Samples
Years
Detection Rate
Distribution LowModHigh
vs. Limit
vs. TX Avg
Manganese
183
1950–2021
70%
95% of limit
↑ 48% above
Radon
11
2002–2014
100%
10% of limit
↓ 73% below
Iron
250
1942–2021
74%
37% of limit
↓ 76% below
Chloride
112
1937–2014
100%
18% of limit
↓ 50% below
Nitrate
91
1943–2014
71%
5% of limit
↓ 78% below
Arsenic
177
1990–2021
41%
28% of limit
↓ 27% below
Fluoride
256
1943–2021
98%
6% of limit
↓ 73% below
HFPO-DA (GenX)
municipal
28
2023–2025
0%
—
—
Lead
170
1990–2021
11%
12% of limit
↓ 31% below
Nitrite
19
1994–2014
11%
1% of limit
~ typical
PFHxS
municipal
28
2023–2025
0%
—
—
PFNA
municipal
28
2023–2025
0%
—
—
PFOA
municipal
28
2023–2025
0%
—
—
PFOS
municipal
28
2023–2025
0%
—
—
Sulfate
110
1937–2014
98%
2% of limit
↓ 92% below
Uranium
74
1994–2021
22%
7% of limit
↓ 58% below
Sodium
104
1937–2014
100%
—
↓ 58% below
pH
52
1943–2014
100%
—
~ typical
PFBS
municipal
28
2023–2025
0%
—
—
Hardness
108
1943–2014
100%
—
↓ 49% below
Distribution shows the share of samples in each concentration band relative to the EPA Maximum Contaminant Level (MCL): Low = below half the MCL, Moderate = between half and the MCL, High = above the MCL. Analytes without an MCL (e.g. sodium, pH) show — in the limit columns. State average is based on county median values across TX.
Compare your result with Liberty County
Of the 177 arsenic tests on record for Liberty County (1990–2021),
59% found none.
Of the 112 chloride tests on record for Liberty County (1937–2014),
0% found none, and half were below 45 mg/L.
Of the 256 fluoride tests on record for Liberty County (1943–2021),
2% found none, and half were below 260 µg/L.
Of the 250 iron tests on record for Liberty County (1942–2021),
26% found none, and half were below 71 µg/L.
Of the 170 lead tests on record for Liberty County (1990–2021),
89% found none.
Of the 183 manganese tests on record for Liberty County (1950–2021),
30% found none, and half were below 28.9 µg/L.
Of the 91 nitrate tests on record for Liberty County (1943–2014),
29% found none, and half were below 200 µg/L.
Of the 110 sulfate tests on record for Liberty County (1937–2014),
2% found none, and half were below 5.15 mg/L.
Of the 74 uranium tests on record for Liberty County (1994–2021),
78% found none.
Data Coverage & Gaps
Well-sampled analytes (15+ samples)
Manganese 183 samples
Iron 250 samples
Chloride 112 samples
Nitrate 91 samples
Arsenic 177 samples
Fluoride 256 samples
Lead 170 samples
Nitrite 19 samples
Sulfate 110 samples
Uranium 74 samples
Sodium 104 samples
pH 52 samples
Hardness 108 samples
Limited data (<15 samples) — interpret with caution
Radon 11 samples
No private-well PFAS data for Liberty County
We have no private well sampling data for PFAS compounds (PFOA, PFOS, PFNA, and related chemicals) in Liberty County.
PFAS testing for private wells requires a dedicated lab panel (~$300–$500). If you are near a military base, airport, or industrial site, consider testing proactively. Learn more about PFAS →
Public vs. Private Water in Liberty County
94Active public water systems
105,523Residents on public water
23%Households on private wells
Public water systems in Liberty County are regulated by the EPA and must test and report contaminant levels. Private well owners are responsible for their own testing — there is no routine monitoring of private wells by any government agency.
CDC Health Outcome Correlations
Where contaminants detected in Liberty County have established associations with specific health outcomes, we cross-reference CDC PLACES county-level prevalence data. This is a contextual signal, not a causal claim.
This report aggregates data from the following public databases:
Water Quality Portal (WQP) — groundwater sample results for Liberty County from EPA, USGS, and state agencies. Browse WQP data →
EPA Safe Drinking Water Information System (SDWIS) — public water system inventory used to estimate the share of residents on private wells. Browse SDWIS →
Census ACS 5-Year Estimates — well and cistern household counts (variable DP04_0074E) used to calculate the private-well percentage for Liberty County. Census data explorer →
USGS Aquifer Atlas — principal aquifer type underlying Liberty County, which informs which contaminants are geologically likely. USGS Aquifer Atlas →
EPA UCMR 5 (2023–2025) — PFAS occurrence data from public water systems, used as a proxy indicator for aquifer PFAS exposure. Rows marked "municipal" in the table above come from this source. About UCMR 5 →
EPA Toxics Release Inventory (TRI) — industrial facility chemical releases near Liberty County, used in contamination risk scoring. TRI Explorer →
EPA Superfund NPL — National Priorities List sites in or near Liberty County, used in contamination risk scoring. Superfund site search →
CDC PLACES — county-level health outcome prevalence (kidney disease, cancer, heart disease) correlated with detected contaminants. About CDC PLACES →
Methodology
Raw records are downloaded from the Water Quality Portal and normalized to µg/L (ppb). Records are deduplicated by sample ID and date, and certified outliers are excluded. Analyte names are mapped to EPA canonical forms. Detection rates, distribution bands, and MCL comparisons are computed from the normalized dataset.
Distribution bands use the EPA Maximum Contaminant Level as the threshold: concentrations below 50% of the MCL are classed as Low, between 50% and 100% as Moderate, and above 100% as High. For analytes without an MCL (sodium, hardness, pH), distribution is not computed.
State comparison uses the median of county median values across all counties in TX with at least one sample for that analyte.