Full contaminant data, sample history, and sourcing for Flagler County. For readers who want to go beyond the summary.
Contaminant Data — All Analytes
113 well testing events on record, covering
23 analytes.
Data spans 1955 to 2024.
Contaminant
Samples
Years
Detection Rate
Distribution LowModHigh
vs. Limit
vs. FL Avg
Chloride
106
1978–2025
100%
239% of limit
↑ 388% above
Radon
3
2019
100%
110% of limit
↑ 275% above
Iron
105
1978–2025
97%
18% of limit
↓ 91% below
Sulfate
106
1978–2025
100%
40% of limit
↑ 51% above
Manganese
102
1982–2025
100%
25% of limit
~ typical
Lead
99
2017–2025
97%
1% of limit
↓ 71% below
Arsenic
99
2017–2025
97%
5% of limit
↓ 62% below
Nitrate
3
2019
0%
—
—
PFHxS
municipal
11
2023–2025
0%
—
—
PFOS
municipal
11
2023–2025
0%
—
—
Uranium
3
2019
0%
—
—
PFNA
municipal
11
2023–2025
0%
—
—
PFOA
municipal
11
2023–2025
0%
—
—
Fluoride
23
1978–2024
100%
7% of limit
~ typical
HFPO-DA (GenX)
municipal
11
2023–2025
0%
—
—
Nitrite
3
2019
0%
—
—
PFBS
municipal
11
2023–2025
0%
—
—
pH
103
1978–2025
100%
—
~ typical
Sodium
106
1978–2025
100%
—
↑ 272% above
Fecal Coliform
5
2017–2020
100%
—
~ typical
E. coli
11
2019–2024
73%
—
~ typical
Total Coliform
16
2017–2024
81%
—
~ typical
Hardness
10
1978–2019
100%
—
↑ 203% above
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.
Compare your result with Flagler County
Of the 99 arsenic tests on record for Flagler County (2017–2025),
3% found none, and half were below 0.5 µg/L.
Of the 106 chloride tests on record for Flagler County (1978–2025),
0% found none, and half were below 597 mg/L.
Of the 23 fluoride tests on record for Flagler County (1978–2024),
0% found none, and half were below 270 µg/L.
Of the 105 iron tests on record for Flagler County (1978–2025),
3% found none, and half were below 50.1 µg/L.
Of the 99 lead tests on record for Flagler County (2017–2025),
3% found none, and half were below 0.131 µg/L.
Of the 102 manganese tests on record for Flagler County (1982–2025),
0% found none, and half were below 12.5 µg/L.
Of the 106 sulfate tests on record for Flagler County (1978–2025),
0% found none, and half were below 99.5 mg/L.
Data Coverage & Gaps
Well-sampled analytes (15+ samples)
Chloride 106 samples
Iron 105 samples
Sulfate 106 samples
Manganese 102 samples
Lead 99 samples
Arsenic 99 samples
Fluoride 23 samples
pH 103 samples
Sodium 106 samples
Total Coliform 16 samples
Limited data (<15 samples) — interpret with caution
Radon 3 samples
Nitrate 3 samples
Uranium 3 samples
Nitrite 3 samples
Fecal Coliform 5 samples
E. coli 11 samples
Hardness 10 samples
No private-well PFAS data for Flagler County
We have no private well sampling data for PFAS compounds (PFOA, PFOS, PFNA, and related chemicals) in Flagler 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 Flagler County
25Active public water systems
132,797Residents on public water
9%Households on private wells
Public water systems in Flagler 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 Flagler 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 Flagler 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 Flagler County. Census data explorer →
USGS Aquifer Atlas — principal aquifer type underlying Flagler 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 Flagler County, used in contamination risk scoring. TRI Explorer →
EPA Superfund NPL — National Priorities List sites in or near Flagler 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.