Data & Methodology — Highlands County Well Water

Contaminant Data — All Analytes

394 well testing events on record, covering 23 analytes. Data spans 1939 to 2024.

Contaminant	Samples	Years	Detection Rate	vs. Limit	vs. FL Avg
Radon	3	2015–2019	100%	130% of limit	↑ 343% above
PFOS municipal	29	2023–2025	28%	118% of limit	↓ 44% below
Sulfate	356	1975–2025	98%	6% of limit	↓ 79% below
Iron	314	1975–2025	94%	3% of limit	↓ 99% below
PFOA municipal	29	2023–2025	3%	138% of limit	~ typical
Lead	33	1976–2024	73%	2% of limit	↓ 45% below
Nitrate	104	1975–2019	37%	8% of limit	↑ 158% above
Chloride	356	1975–2025	100%	4% of limit	↓ 92% below
Manganese	275	1977–2025	91%	2% of limit	↓ 94% below
PFHxS municipal	29	2023–2025	7%	30% of limit	↓ 41% below
Uranium	8	1979–2019	75%	0% of limit	↓ 83% below
PFNA municipal	29	2023–2025	0%	—	—
Fluoride	281	1975–2025	98%	7% of limit	~ typical
HFPO-DA (GenX) municipal	29	2023–2025	0%	—	—
Nitrite	112	1975–2019	33%	1% of limit	~ typical
Arsenic	33	1976–2024	94%	2% of limit	↓ 89% below
Sodium	347	1975–2025	99%	—	↓ 88% below
pH	322	1975–2025	100%	—	~ typical
PFBS municipal	29	2023–2025	0%	—	—
E. coli	11	2015–2024	77%	—	~ typical
Fecal Coliform	13	2017–2021	100%	—	~ typical
Hardness	110	1975–2019	99%	—	↓ 77% below
Total Coliform	24	2015–2024	88%	—	~ 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 FL.

Data Coverage & Gaps

Well-sampled analytes (15+ samples)

Sulfate 356 samples
Iron 314 samples
Lead 33 samples
Nitrate 104 samples
Chloride 356 samples
Manganese 275 samples
Fluoride 281 samples
Nitrite 112 samples
Arsenic 33 samples
Sodium 347 samples
pH 322 samples
Hardness 110 samples
Total Coliform 24 samples

Limited data (<15 samples) — interpret with caution

Radon 3 samples
Uranium 8 samples
E. coli 11 samples
Fecal Coliform 13 samples

No private-well PFAS data for Highlands County

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

72 Active public water systems

101,392 Residents on public water

Public water systems in Highlands 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 Highlands 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	Highlands County Prevalence	FL Average	Source Year
Nitrate	Cancer prevalence	10.4%	6.8%	2020
Lead	Heart disease rate	12.4%	7.7%	2020

Data Sources

This report aggregates data from the following public databases:

Water Quality Portal (WQP) — groundwater sample results for Highlands 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 Highlands County. Census data explorer →
USGS Aquifer Atlas — principal aquifer type underlying Highlands 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 Highlands County, used in contamination risk scoring. TRI Explorer →
EPA Superfund NPL — National Priorities List sites in or near Highlands 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 FL with at least one sample for that analyte.

Last updated: 2026-08-12

Full methodology →