Data & Methodology — Fort Bend County

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

Contaminant Data — All Analytes

891 well testing events on record, covering 20 analytes. Data spans 1936 to 2025.

Contaminant Samples Years Detection Rate Distribution LowModHigh vs. Limit vs. TX Avg
Radon 9 2002–2015 100%
363% of limit ↑ 909% above
Iron 280 1933–2021 82%
47% of limit ↓ 70% below
Manganese 208 1958–2021 75%
51% of limit ↓ 21% below
Chloride 356 1936–2018 99%
24% of limit ↓ 33% below
PFOS municipal 299 2023–2025 2%
105% of limit ~ typical
Nitrate 89 1967–2014 73%
0% of limit ↓ 99% below
Arsenic 164 1988–2021 46%
31% of limit ~ typical
PFOA municipal 299 2023–2025 1%
101% of limit ~ typical
Fluoride 447 1939–2021 100%
8% of limit ↓ 69% below
HFPO-DA (GenX) municipal 299 2023–2025 0%
— —
Lead 149 1988–2021 5%
12% of limit ↓ 29% below
Nitrite 4 2002–2014 0%
— —
PFHxS municipal 299 2023–2025 4%
33% of limit ↓ 25% below
PFNA municipal 299 2023–2025 0%
— —
Sulfate 109 1936–2015 98%
5% of limit ↓ 82% below
Uranium 51 2002–2021 63%
6% of limit ↓ 65% below
Hardness 96 1936–2015 100%
— ~ typical
PFBS municipal 299 2023–2025 9%
— ~ typical
pH 333 1963–2018 100%
— ~ typical
Sodium 95 1936–2015 100%
— ↓ 39% 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 Fort Bend County

Of the 164 arsenic tests on record for Fort Bend County (1988–2021), 54% found none.

Of the 356 chloride tests on record for Fort Bend County (1936–2018), 1% found none, and half were below 59.6 mg/L.

Of the 447 fluoride tests on record for Fort Bend County (1939–2021), 0% found none, and half were below 300 µg/L.

Of the 280 iron tests on record for Fort Bend County (1933–2021), 18% found none, and half were below 100 µg/L.

Of the 149 lead tests on record for Fort Bend County (1988–2021), 95% found none.

Of the 208 manganese tests on record for Fort Bend County (1958–2021), 25% found none, and half were below 20 µg/L.

Of the 89 nitrate tests on record for Fort Bend County (1967–2014), 27% found none.

Of the 109 sulfate tests on record for Fort Bend County (1936–2015), 2% found none, and half were below 12.3 mg/L.

Of the 51 uranium tests on record for Fort Bend County (2002–2021), 37% found none, and half were below 0.737 µg/L.

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Data Coverage & Gaps

Well-sampled analytes (15+ samples)

  • Iron 280 samples
  • Manganese 208 samples
  • Chloride 356 samples
  • Nitrate 89 samples
  • Arsenic 164 samples
  • Fluoride 447 samples
  • Lead 149 samples
  • Sulfate 109 samples
  • Uranium 51 samples
  • Hardness 96 samples
  • pH 333 samples
  • Sodium 95 samples

Limited data (<15 samples) — interpret with caution

  • Radon 9 samples
  • Nitrite 4 samples

No private-well PFAS data for Fort Bend County

We have no private well sampling data for PFAS compounds (PFOA, PFOS, PFNA, and related chemicals) in Fort Bend 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 Fort Bend County

293 Active public water systems
891,650 Residents on public water
10% Households on private wells

Public water systems in Fort Bend 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 Fort Bend 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 Fort Bend County Prevalence TX Average Source Year
Arsenic Cancer prevalence 5.1% 6.1% 2020
Arsenic Kidney disease rate 2.5% 3.3% 2020

Source: CDC PLACES county-level estimates. Raw data: Download Fort Bend 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 →