waterbycounty
Compiled federal source snapshot

New York Water Quality

Drinking water data for all 57 counties.

Avg SDWIS Compliance Index

48.6

Most Common Five-Year SDWIS Compliance Band

C

Counties with Data

57

of 57 total

County water atlas

New York water signals by county

A state-level 2.5D view across drinking-water compliance, watershed impairment, monitoring density, and streamflow snapshot context. Pin any county, switch layers, then use the lens controls to compare index ranges, recorded violation rates, or impaired watersheds without leaving the page.

Counties

57

Avg SDWIS index

48.6

Watersheds

0

ATTAINS counties

Monitoring

57

50 fresh USGS snapshots

State atlas layers combine EPA SDWIS health-based violations, EPA ATTAINS 303(d) impairment assessments, EPA Water Quality Portal monitoring sites, and representative USGS NWIS streamflow gauges. Streamflow values appear only for fresh pipeline snapshots, not as a continuously updated stream. County pages include the observation time and year.

Prepared by ByCounty Editorial TeamPublished by WaterByCounty

Multi-source coverage in New York

Beyond Drinking Water

EPA SDWIS

57/ 57

counties with drinking-water compliance data

1,190 health violations statewide (5yr)

EPA ATTAINS

—

No §303(d) assessments yet for New York

EPA WQP

2,175

monitoring sites across 57 counties

614,668 total readings (5yr window)

USGS NWIS

50

counties with a fresh pipeline snapshot

5 above44 below

State atlas notes

What stands out in New York

County water quality is not one number. The strongest read comes from comparing drinking-water compliance against watershed impairment, monitoring density, and streamflow context. Use these signals as a starting point, then open any county profile for source-level detail.

Compliance spread

Niagara County has the highest value in the published state SDWIS Compliance Index table at 86.2/100, while Putnam County has the lowest at 4.7/100. That is a 81.5 point gap inside one state.

Zero health violations

5

3+ health violations

39

Monitoring hubs

Suffolk County483 sitesNassau County268 sitesEssex County141 sites

Lowest flow reads

Yates County11%Genesee County13%Chautauqua County15%

Highest fresh streamflow pipeline snapshots: Putnam County (483%, observation 2026), Westchester County (418%, observation 2026), Orleans County (174%, observation 2026). These are source-data observations, not household tap-water conclusions.

All New York Counties

CountySDWIS Compliance Index
Niagara County86.2
Orleans County86.2
St. Lawrence County86.2
Tioga County86.2
Yates County86.2
Suffolk County72.3
Monroe County69.8
Chautauqua County69.3
Nassau County69.3
Chemung County68.5
Erie County66.9
Wayne County65.1
Schenectady County63.6
Essex County63.3
Cayuga County60.7
Tompkins County60.3
Genesee County59.6
Chenango County58.9
Broome County58.6
Livingston County56.5
Warren County56.2
Onondaga County54.5
Ontario County54.3
Oneida County53.5
Seneca County52.2
Cortland County51.2
Rockland County50.1
Allegany County49.1
Clinton County48.1
Albany County46.4
Cattaraugus County45.4
Rensselaer County45.2
Ulster County45.0
Fulton County43.2
Franklin County41.7
Oswego County41.7
Lewis County41.2
Madison County40.2
Jefferson County39.3
Hamilton County37.3
Steuben County36.0
Otsego County35.8
Saratoga County34.5
Sullivan County33.6
Dutchess County32.9
Schuyler County31.3
Wyoming County30.7
Westchester County27.1
Orange County26.8
Delaware County25.3
Columbia County25.1
Greene County22.2
Washington County21.7
Montgomery County18.3
Herkimer County17.2
Schoharie County16.8
Putnam County4.7

Frequently Asked Questions

Which New York county has the highest SDWIS Compliance Index?
Niagara County has the highest SDWIS Compliance Index in the published New York cohort at 86.2/100. This WaterByCounty relative comparison is not an EPA score and does not establish current conditions for a utility or address.
What does the Five-Year SDWIS Compliance Band mean?
The band is derived only from each county aggregation's recorded health-violation rate per 100,000 people served for the stated five-year source window. It is separate from the relative SDWIS Compliance Index and is not a current determination for a specific utility or address.
Which USGS streamflow records are shown across New York?
WaterByCounty has 50 fresh USGS pipeline snapshots in the published New York cohort. Each county page shows its observation timestamp and year. A pipeline snapshot is not a continuously updated reading or a tap-water safety measure.
Where can New York residents find current official information?
Review the applicable utility's Consumer Confidence Report, active notices, and the state drinking-water agency. WaterByCounty's county-level historical aggregations do not establish the current status of a specific utility, address, private well, or household plumbing system.
What does Water Quality Portal monitoring volume show in New York?
The published county records contain 614,668 results from 2,175 monitoring locations in the site's five-year aggregation. Monitoring volume does not by itself indicate better or worse water quality.

Data Sources

Drinking-water compliance data from the EPA Safe Drinking Water Information System (SDWIS) via the ECHO enforcement database. The WaterByCounty SDWIS Compliance Index reflects the recorded rate and is not an EPA score.

Disclaimer: This data is informational only. It is not health, legal, or professional advice. For concerns about your specific water supply, contact your local water utility.

← Back to All States

Explore more data for New York

Property TaxCost of LivingCrime RateIncomeHealthSchoolsDisaster RiskWeatherCounty Score