Full contaminant data, sample history, and sourcing for Rensselaer County. For readers who want to go beyond the summary.
Contaminant Data — All Analytes
49 well testing events on record, covering
23 analytes.
Data spans 1954 to 2022.
Contaminant
Samples
Years
Detection Rate
Distribution LowModHigh
vs. Limit
vs. NY Avg
Radon
17
1995–2022
100%
173% of limit
↑ 56% above
Manganese
23
1971–2022
74%
120% of limit
↓ 61% below
Iron
23
1971–2022
78%
15% of limit
↓ 92% below
Arsenic
21
1971–2022
57%
8% of limit
↓ 57% below
Chloride
23
1971–2022
100%
10% of limit
↓ 66% below
Fluoride
23
1971–2022
87%
3% of limit
↓ 53% below
HFPO-DA (GenX)
municipal
26
2023–2025
0%
—
—
Lead
21
1971–2022
62%
1% of limit
↓ 65% below
Nitrate
23
1971–2022
70%
4% of limit
↓ 63% below
Nitrite
19
1973–2022
16%
0% of limit
↓ 63% below
PFHxS
municipal
26
2023–2025
0%
—
—
PFNA
municipal
26
2023–2025
0%
—
—
PFOA
municipal
26
2023–2025
0%
—
—
PFOS
municipal
26
2023–2025
0%
—
—
Sulfate
23
1971–2022
100%
6% of limit
↓ 55% below
Uranium
15
2006–2022
93%
1% of limit
↓ 36% below
E. coli
5
2006–2022
6%
—
~ typical
Fecal Coliform
5
2007–2022
0%
—
—
Hardness
23
1971–2022
100%
—
↓ 24% below
PFBS
municipal
26
2023–2025
0%
—
—
pH
24
1971–2022
100%
—
~ typical
Sodium
23
1971–2022
100%
—
↓ 57% below
Total Coliform
5
2006–2022
6%
—
~ 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 NY.
Compare your result with Rensselaer County
Of the 21 arsenic tests on record for Rensselaer County (1971–2022),
43% found none, and half were below 0.1 µg/L.
Of the 23 chloride tests on record for Rensselaer County (1971–2022),
0% found none, and half were below 25 mg/L.
Of the 23 fluoride tests on record for Rensselaer County (1971–2022),
13% found none, and half were below 100 µg/L.
Of the 23 iron tests on record for Rensselaer County (1971–2022),
22% found none, and half were below 25.2 µg/L.
Of the 21 lead tests on record for Rensselaer County (1971–2022),
38% found none, and half were below 0.1 µg/L.
Of the 23 manganese tests on record for Rensselaer County (1971–2022),
26% found none, and half were below 42.2 µg/L.
Of the 23 nitrate tests on record for Rensselaer County (1971–2022),
30% found none, and half were below 227 µg/L.
Of the 23 sulfate tests on record for Rensselaer County (1971–2022),
0% found none, and half were below 15.4 mg/L.
Data Coverage & Gaps
Well-sampled analytes (15+ samples)
Radon 17 samples
Manganese 23 samples
Iron 23 samples
Arsenic 21 samples
Chloride 23 samples
Fluoride 23 samples
Lead 21 samples
Nitrate 23 samples
Nitrite 19 samples
Sulfate 23 samples
Uranium 15 samples
Hardness 23 samples
pH 24 samples
Sodium 23 samples
Limited data (<15 samples) — interpret with caution
E. coli 5 samples
Fecal Coliform 5 samples
Total Coliform 5 samples
No private-well PFAS data for Rensselaer County
We have no private well sampling data for PFAS compounds (PFOA, PFOS, PFNA, and related chemicals) in Rensselaer 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 →
CDC Health Outcome Correlations
Where contaminants detected in Rensselaer 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 Rensselaer 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 Rensselaer County. Census data explorer →
USGS Aquifer Atlas — principal aquifer type underlying Rensselaer 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 Rensselaer County, used in contamination risk scoring. TRI Explorer →
EPA Superfund NPL — National Priorities List sites in or near Rensselaer 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 NY with at least one sample for that analyte.