Full contaminant data, sample history, and sourcing for Nueces County. For readers who want to go beyond the summary.
Contaminant Data — All Analytes
203 well testing events on record, covering
17 analytes.
Data spans 1934 to 2025.
Contaminant
Samples
Years
Detection Rate
Distribution LowModHigh
vs. Limit
vs. TX Avg
Chloride
41
1934–1966
100%
292% of limit
↑ 716% above
Sulfate
41
1934–1966
100%
146% of limit
↑ 410% above
Arsenic
56
1990–2015
82%
130% of limit
↑ 241% above
Uranium
17
1990–2015
65%
44% of limit
↑ 184% above
Iron
81
1934–2015
75%
39% of limit
↓ 74% below
Manganese
59
1960–2015
75%
34% of limit
↓ 47% below
Fluoride
149
1945–2015
98%
28% of limit
~ typical
HFPO-DA (GenX)
municipal
27
2023–2024
0%
—
—
Lead
56
1990–2015
2%
26% of limit
↑ 52% above
Nitrate
57
1934–1997
91%
5% of limit
↓ 79% below
PFHxS
municipal
27
2023–2024
0%
—
—
PFNA
municipal
27
2023–2024
0%
—
—
PFOA
municipal
27
2023–2024
0%
—
—
PFOS
municipal
27
2023–2024
0%
—
—
PFBS
municipal
27
2023–2024
0%
—
—
pH
39
1955–1966
100%
—
~ typical
Hardness
41
1934–1966
100%
—
↓ 53% 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 Nueces County
Of the 56 arsenic tests on record for Nueces County (1990–2015),
18% found none, and half were below 11.2 µg/L.
Of the 41 chloride tests on record for Nueces County (1934–1966),
0% found none, and half were below 730 mg/L.
Of the 149 fluoride tests on record for Nueces County (1945–2015),
2% found none, and half were below 1.1 mg/L.
Of the 81 iron tests on record for Nueces County (1934–2015),
25% found none, and half were below 56.6 µg/L.
Of the 56 lead tests on record for Nueces County (1990–2015),
98% found none.
Of the 59 manganese tests on record for Nueces County (1960–2015),
25% found none, and half were below 10 µg/L.
Of the 57 nitrate tests on record for Nueces County (1934–1997),
9% found none, and half were below 410 µg/L.
Of the 41 sulfate tests on record for Nueces County (1934–1966),
0% found none, and half were below 364 mg/L.
Data Coverage & Gaps
Well-sampled analytes (15+ samples)
Chloride 41 samples
Sulfate 41 samples
Arsenic 56 samples
Uranium 17 samples
Iron 81 samples
Manganese 59 samples
Fluoride 149 samples
Lead 56 samples
Nitrate 57 samples
pH 39 samples
Hardness 41 samples
No private-well PFAS data for Nueces County
We have no private well sampling data for PFAS compounds (PFOA, PFOS, PFNA, and related chemicals) in Nueces 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 Nueces County
20Active public water systems
371,249Residents on public water
3%Households on private wells
Public water systems in Nueces 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 Nueces 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 Nueces 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 Nueces County. Census data explorer →
USGS Aquifer Atlas — principal aquifer type underlying Nueces 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 Nueces County, used in contamination risk scoring. TRI Explorer →
EPA Superfund NPL — National Priorities List sites in or near Nueces 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.