Data & Methodology — Limestone County

Full contaminant data, sample history, and sourcing for Limestone County. For readers who want to go beyond the summary.

Contaminant Data — All Analytes

238 well testing events on record, covering 19 analytes. Data spans 1965 to 2016.

Contaminant Samples Years Detection Rate Distribution LowModHigh vs. Limit vs. TX Avg
Manganese 50 1938–2018 72%
179% of limit ↑ 178% above
Iron 175 1938–2018 89%
92% of limit ↓ 40% below
Chloride 66 1981–1982 100%
20% of limit ↓ 44% below
Lead 30 1981–2018 27%
20% of limit ~ typical
Sulfate 66 1981–1982 94%
8% of limit ↓ 72% below
Arsenic 30 1981–2018 40%
10% of limit ↓ 74% below
Fluoride 228 1938–2018 94%
5% of limit ↓ 79% below
HFPO-DA (GenX) municipal 8 2024–2025 0%
— —
Nitrate 57 1981–2007 61%
2% of limit ↓ 93% below
Nitrite 28 1981–1982 64%
0% of limit ↓ 100% 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%
— —
Uranium 6 2010–2018 0%
— —
Sodium 66 1981–1982 100%
— ↓ 35% below
pH 66 1981–1982 100%
— ~ typical
PFBS municipal 8 2024–2025 12%
— ~ typical
Hardness 66 1981–1982 100%
— ↓ 62% 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 Limestone County

Of the 30 arsenic tests on record for Limestone County (1981–2018), 60% found none.

Of the 66 chloride tests on record for Limestone County (1981–1982), 0% found none, and half were below 50 mg/L.

Of the 228 fluoride tests on record for Limestone County (1938–2018), 6% found none, and half were below 200 µg/L.

Of the 175 iron tests on record for Limestone County (1938–2018), 11% found none, and half were below 150 µg/L.

Of the 30 lead tests on record for Limestone County (1981–2018), 73% found none.

Of the 50 manganese tests on record for Limestone County (1938–2018), 28% found none, and half were below 40 µg/L.

Of the 57 nitrate tests on record for Limestone County (1981–2007), 39% found none, and half were below 80 µg/L.

Of the 66 sulfate tests on record for Limestone County (1981–1982), 6% found none, and half were below 18.5 mg/L.

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Data Coverage & Gaps

Well-sampled analytes (15+ samples)

  • Manganese 50 samples
  • Iron 175 samples
  • Chloride 66 samples
  • Lead 30 samples
  • Sulfate 66 samples
  • Arsenic 30 samples
  • Fluoride 228 samples
  • Nitrate 57 samples
  • Nitrite 28 samples
  • Sodium 66 samples
  • pH 66 samples
  • Hardness 66 samples

Limited data (<15 samples) — interpret with caution

  • Uranium 6 samples

No private-well PFAS data for Limestone County

We have no private well sampling data for PFAS compounds (PFOA, PFOS, PFNA, and related chemicals) in Limestone County. PFAS has been detected in local public water systems (UCMR 5 data) — indicated by the "municipal" badge in the table above — but this does not directly indicate private well contamination. 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 Limestone County

23 Active public water systems
25,595 Residents on public water
15% Households on private wells

Public water systems in Limestone 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 Limestone 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.

Contaminant Associated Condition Limestone County Prevalence TX Average Source Year
Lead Heart disease rate 9.1% 7.4% 2020

Source: CDC PLACES county-level estimates. Raw data: Download Limestone County CDC PLACES data →

Data Sources

This report aggregates data from the following public databases:

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.

Last updated: 2026-08-04

Full methodology →