Data & Methodology — Volusia County Well Water

Contaminant Data — All Analytes

710 well testing events on record, covering 23 analytes. Data spans 1954 to 2025.

Contaminant	Samples	Years	Detection Rate	vs. Limit	vs. FL Avg
PFOS municipal	72	2023–2025	47%	178% of limit	~ typical
Iron	588	1965–2025	100%	29% of limit	↓ 86% below
Chloride	641	1955–2025	100%	22% of limit	↓ 55% below
PFOA municipal	72	2023–2025	33%	139% of limit	~ typical
Manganese	574	2002–2025	100%	11% of limit	↓ 59% below
Sulfate	599	1965–2025	100%	2% of limit	↓ 92% below
Arsenic	574	2002–2025	99%	5% of limit	↓ 62% below
Lead	574	2002–2025	99%	0% of limit	↓ 89% below
Fluoride	77	1965–2025	97%	3% of limit	↓ 61% below
HFPO-DA (GenX) municipal	72	2023–2025	0%	—	—
Nitrite	12	1987–2022	50%	2% of limit	↑ 81% above
Radon	6	2002–2015	100%	6% of limit	↓ 78% below
Uranium	6	2002–2015	17%	0% of limit	↓ 82% below
PFNA municipal	72	2023–2025	0%	—	—
Nitrate	21	1965–2022	71%	0% of limit	↓ 93% below
PFHxS municipal	72	2023–2025	42%	46% of limit	~ typical
Hardness	26	1965–2015	100%	—	↑ 27% above
Total Coliform	38	2015–2025	95%	—	~ typical
E. coli	19	2015–2025	90%	—	~ typical
Fecal Coliform	19	2017–2021	100%	—	~ typical
PFBS municipal	72	2023–2025	54%	—	~ typical
pH	619	1965–2025	100%	—	~ typical
Sodium	598	1965–2025	100%	—	↓ 51% 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 FL.

Data Coverage & Gaps

Well-sampled analytes (15+ samples)

Iron 588 samples
Chloride 641 samples
Manganese 574 samples
Sulfate 599 samples
Arsenic 574 samples
Lead 574 samples
Fluoride 77 samples
Nitrate 21 samples
Hardness 26 samples
Total Coliform 38 samples
E. coli 19 samples
Fecal Coliform 19 samples
pH 619 samples
Sodium 598 samples

Limited data (<15 samples) — interpret with caution

Nitrite 12 samples
Radon 6 samples
Uranium 6 samples

No private-well PFAS data for Volusia County

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

135 Active public water systems

557,112 Residents on public water

Public water systems in Volusia 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 Volusia 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	Volusia County Prevalence	FL Average	Source Year
Arsenic	Cancer prevalence	8.3%	6.8%	2020
Arsenic	Kidney disease rate	3.8%	3.4%	2020
Lead	Heart disease rate	6.2%	7.7%	2020

Data Sources

This report aggregates data from the following public databases:

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