Full contaminant data, sample history, and sourcing for Val Verde County. For readers who want to go beyond the summary.
Contaminant Data — All Analytes
674 well testing events on record, covering
22 analytes.
Data spans 1953 to 2017.
Contaminant
Samples
Years
Detection Rate
Distribution LowModHigh
vs. Limit
vs. TX Avg
Radon
2
2017
100%
177% of limit
↑ 391% above
Iron
217
1942–2019
38%
13% of limit
↓ 92% below
Sulfate
237
1953–2017
100%
21% of limit
↓ 26% below
Chloride
302
1953–2017
100%
14% of limit
↓ 61% below
Nitrate
65
1990–2017
97%
17% of limit
↓ 25% below
Manganese
176
1967–2019
45%
4% of limit
↓ 93% below
Arsenic
172
1993–2019
16%
20% of limit
↓ 49% below
Fluoride
408
1939–2019
99%
12% of limit
↓ 50% below
HFPO-DA (GenX)
municipal
8
2024–2025
0%
—
—
Lead
172
1993–2019
6%
18% of limit
~ typical
Nitrite
19
1990–2017
11%
15% of limit
↑ 1400% above
PFHxS
municipal
8
2024–2025
0%
—
—
PFNA
municipal
8
2024–2025
0%
—
—
PFOA
municipal
8
2024–2025
0%
—
—
PFOS
municipal
8
2024–2025
0%
—
—
Uranium
35
2009–2019
51%
5% of limit
↓ 68% below
Sodium
237
1953–2017
100%
—
↓ 77% below
pH
302
1953–2017
100%
—
~ typical
PFBS
municipal
8
2024–2025
0%
—
—
Hardness
303
1953–2017
100%
—
↑ 23% above
E. coli
1
2017
0%
—
—
Total Coliform
1
2017
0%
—
—
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 Val Verde County
Of the 172 arsenic tests on record for Val Verde County (1993–2019),
84% found none.
Of the 302 chloride tests on record for Val Verde County (1953–2017),
0% found none, and half were below 34.5 mg/L.
Of the 408 fluoride tests on record for Val Verde County (1939–2019),
1% found none, and half were below 475 µg/L.
Of the 217 iron tests on record for Val Verde County (1942–2019),
62% found none.
Of the 172 lead tests on record for Val Verde County (1993–2019),
94% found none.
Of the 176 manganese tests on record for Val Verde County (1967–2019),
55% found none.
Of the 65 nitrate tests on record for Val Verde County (1990–2017),
3% found none, and half were below 1.61 mg/L.
Of the 237 sulfate tests on record for Val Verde County (1953–2017),
0% found none, and half were below 53 mg/L.
Of the 35 uranium tests on record for Val Verde County (2009–2019),
49% found none, and half were below 0.195 µg/L.
Data Coverage & Gaps
Well-sampled analytes (15+ samples)
Iron 217 samples
Sulfate 237 samples
Chloride 302 samples
Nitrate 65 samples
Manganese 176 samples
Arsenic 172 samples
Fluoride 408 samples
Lead 172 samples
Nitrite 19 samples
Uranium 35 samples
Sodium 237 samples
pH 302 samples
Hardness 303 samples
Limited data (<15 samples) — interpret with caution
Radon 2 samples
E. coli 1 sample
Total Coliform 1 sample
No private-well PFAS data for Val Verde County
We have no private well sampling data for PFAS compounds (PFOA, PFOS, PFNA, and related chemicals) in Val Verde 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 Val Verde County
37Active public water systems
46,250Residents on public water
28%Households on private wells
Public water systems in Val Verde 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 Val Verde 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 Val Verde 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 Val Verde County. Census data explorer →
USGS Aquifer Atlas — principal aquifer type underlying Val Verde 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 Val Verde County, used in contamination risk scoring. TRI Explorer →
EPA Superfund NPL — National Priorities List sites in or near Val Verde 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.