Full contaminant data, sample history, and sourcing for Terry County. For readers who want to go beyond the summary.
Contaminant Data — All Analytes
284 well testing events on record, covering
20 analytes.
Data spans 2001 to 2014.
Contaminant
Samples
Years
Detection Rate
Distribution LowModHigh
vs. Limit
vs. TX Avg
Sulfate
24
2001–2014
100%
135% of limit
↑ 372% above
Arsenic
132
1980–2021
95%
146% of limit
↑ 283% above
Fluoride
273
1941–2021
100%
110% of limit
↑ 361% above
Nitrate
40
1990–2014
100%
95% of limit
↑ 328% above
Chloride
24
2001–2014
100%
78% of limit
↑ 117% above
Uranium
54
2001–2021
100%
41% of limit
↑ 165% above
Iron
142
1941–2021
47%
17% of limit
↓ 89% below
Manganese
139
1941–2021
34%
5% of limit
↓ 92% below
HFPO-DA (GenX)
municipal
8
2024–2025
0%
—
—
Lead
131
1980–2021
25%
3% of limit
↓ 82% below
Nitrite
24
2001–2014
33%
0% of limit
↓ 85% below
PFHxS
municipal
8
2024–2025
0%
—
—
PFNA
municipal
8
2024–2025
0%
—
—
PFOA
municipal
8
2024–2025
0%
—
—
PFOS
municipal
8
2024–2025
0%
—
—
Radon
3
2001
100%
8% of limit
↓ 78% below
Hardness
24
2001–2014
100%
—
↑ 164% above
PFBS
municipal
8
2024–2025
0%
—
—
pH
24
2001–2014
100%
—
~ typical
Sodium
24
2001–2014
100%
—
~ typical
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 Terry County
Of the 132 arsenic tests on record for Terry County (1980–2021),
5% found none, and half were below 14.4 µg/L.
Of the 24 chloride tests on record for Terry County (2001–2014),
0% found none, and half were below 194 mg/L.
Of the 273 fluoride tests on record for Terry County (1941–2021),
0% found none, and half were below 4.41 mg/L.
Of the 142 iron tests on record for Terry County (1941–2021),
53% found none.
Of the 131 lead tests on record for Terry County (1980–2021),
75% found none.
Of the 139 manganese tests on record for Terry County (1941–2021),
66% found none.
Of the 40 nitrate tests on record for Terry County (1990–2014),
0% found none, and half were below 9.52 mg/L.
Of the 24 sulfate tests on record for Terry County (2001–2014),
0% found none, and half were below 336 mg/L.
Of the 54 uranium tests on record for Terry County (2001–2021),
0% found none, and half were below 12.3 µg/L.
Data Coverage & Gaps
Well-sampled analytes (15+ samples)
Sulfate 24 samples
Arsenic 132 samples
Fluoride 273 samples
Nitrate 40 samples
Chloride 24 samples
Uranium 54 samples
Iron 142 samples
Manganese 139 samples
Lead 131 samples
Nitrite 24 samples
Hardness 24 samples
pH 24 samples
Sodium 24 samples
Limited data (<15 samples) — interpret with caution
Radon 3 samples
No private-well PFAS data for Terry County
We have no private well sampling data for PFAS compounds (PFOA, PFOS, PFNA, and related chemicals) in Terry 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 Terry County
3Active public water systems
9,444Residents on public water
8%Households on private wells
Public water systems in Terry 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 Terry 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 Terry 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 Terry County. Census data explorer →
USGS Aquifer Atlas — principal aquifer type underlying Terry 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 Terry County, used in contamination risk scoring. TRI Explorer →
EPA Superfund NPL — National Priorities List sites in or near Terry 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.