St. Lawrence County Water Quality: 2 Cities Ranked by the Records

Name: St. Lawrence County Water Quality Data (2026)
Creator: PurityMap
License: https://creativecommons.org/licenses/by/4.0/

St. Lawrence County, New York: 2 city reports built from EPA and utility records. A county has many suppliers; each city shows the system that serves it.

Find my system Open on the map Private wells in St. Lawrence County

Across the county's systems

Highest result for each contaminant

One row per contaminant: the highest result any system in the county reported, against its limit. Open a row for the systems behind it.

Lead (90th percentile)Detected in 2 systems15 µg/L federal action level · US EPAHighest1.5 µg/L

MASSENA VILLAGE1.5 µg/LMonitoring period: 2023–2025
OGDENSBURG CITY1.4 µg/LMonitoring period: 2021–2023

Perfluorohexanoic acid (PFHxA)Detected in 1 system of 2 tested400,000 ng/L Michigan EGLE state MCL (strictest US state) · Michigan EGLEHighest4.1 ng/L

OGDENSBURG CITY4.1 ng/LSample date: 2025-03-04 to 2025-12-04
MASSENA VILLAGENot detected · below 3.0 ng/L lab reporting limitSample date: 2024-03-06 to 2024-09-18

Perfluorobutanoic acid (PFBA)Detected in 1 system of 2 testedNo federal or state limit; shown for transparencyHighest5.1 ng/L

OGDENSBURG CITY5.1 ng/LSample date: 2025-03-04 to 2025-12-04
MASSENA VILLAGENot detected · below 5.0 ng/L lab reporting limitSample date: 2024-03-06 to 2024-09-18

28 substances tested, none detected in any systemShow

Tested in these 2 systems: MASSENA VILLAGE, OGDENSBURG CITY

11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)
1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS)
1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS)
1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS)
4,8-Dioxa-3H-perfluorononanoic acid (ADONA)
9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS)
Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals)
Lithium
N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA)
N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA)
Nonafluoro-3,6-dioxaheptanoic acid (NFDHA)
Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA)
Perfluoro-3-methoxypropanoic acid (PFMPA)
Perfluoro-4-methoxybutanoic acid (PFMBA)
Perfluorobutanesulfonic acid (PFBS)
Perfluorodecanoic acid (PFDA)
Perfluorododecanoic acid (PFDoA)
Perfluoroheptanesulfonic acid (PFHpS)
Perfluoroheptanoic acid (PFHpA)
Perfluorohexanesulfonic acid (PFHxS)
Perfluorononanoic acid (PFNA)
Perfluorooctanesulfonic acid (PFOS)
Perfluorooctanoic acid (PFOA)
Perfluoropentanesulfonic acid (PFPeS)
Perfluoropentanoic acid (PFPeA)
Perfluorotetradecanoic acid (PFTA)
Perfluorotridecanoic acid (PFTrDA)
Perfluoroundecanoic acid (PFUnA)

2 cities

Cities ranked by the records

1
MassenaMASSENA VILLAGE
No PFAS detectedLead below action level
Open city report →
2
OgdensburgOGDENSBURG CITY
PFAS detected, within limitLead below action level
Open city report →

Showing 2 of 2 cities · scores are system-level, not tap tests

Ranked by the Purity Score of each city's main water system, highest first. Scores belong to water systems; there is no county score. The score is computed only from contaminants measured in the published EPA record, so this ranks the record, not which city's water is safest. How the score works.

PFAS in St. Lawrence CountyPFAS detected in 1 of 2 cities; none had a sample above a 2024 EPA limit

4.0 ng/L federal MCL · PFOS, ng/LPFAS in New York

Lead

0of 2 cities above the 15 µg/L action level

Based on each system's 90th-percentile result. Lead from household plumbing isn't in this record.

Lead in New York

Who supplies the county

Largest water systems

MassenaMASSENA VILLAGE · NY4404390
16,729 served
OgdensburgOGDENSBURG CITY · NY4404394
10,064 served

Questions

Frequently asked

How does St. Lawrence County tap water compare across cities?

PurityMap ranks 2 cities in St. Lawrence County by the Purity Score of each city's main water system, computed only from contaminants measured in the published EPA record. Scores belong to water systems, not to cities. The highest published score is Massena's main water system: MASSENA VILLAGE · PWSID NY4404390 · Purity Score 98 (Excellent) · Confidence: moderate · Assessed at the water-system level. The ranking compares the records, not which city's water is safest, and your own tap can differ with household plumbing.

How many St. Lawrence County cities had a PFAS sample above a 2024 EPA limit?

None of the 2 St. Lawrence County city reports had a PFAS sample above a 2024 EPA limit in EPA's UCMR 5 testing. PFAS were detected below the limit in 1.

Is there lead in St. Lawrence County tap water?

Utilities report lead as a 90th-percentile result from home taps. 2 of 2 St. Lawrence County cities reported a value above zero, and none was above the 15 µg/L federal action level. Lead usually comes from a building's own pipes and fixtures, so only a test at your tap tells you what you drink.

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