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County water report

Oswego County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Oswego County, New York.

Water grade

D

Water score

45.2

State rank

#22

of 57

Health violations

18

EPA SDWIS, 5-year lookback

Watershed impaired

Not reported

EPA ATTAINS coverage varies by state

Monitoring sites

22

5,845 recent measurements

Live streamflow

146%

OSWEGO RIVER AT LOCK 7, OSWEGO NY

Water at a glance

Key Water Indicators for Oswego County

EPA SDWIS

Safety Grade

D

Score: 45.2 / 100

EPA SDWIS

Active Violations

18

5-year health-based lookback

EPA ATTAINS

Watershed Health

Not reported

Coverage varies by state

USGS NWIS

Streamflow Snapshot

146% of mean

OSWEGO RIVER AT LOCK 7, OSWEGO NY

EPA WQP

Monitoring Sites

22

5,845 recent readings

Source: EPA SDWIS · Safe Drinking Water Information System

Drinking Water Compliance

Compliance grade

D

Based on EPA SDWIS compliance history.

Water score

Higher scores indicate cleaner recent compliance records.

45.2/100

Health violations

18

Health-based violations

Violations per 100K served

23.5

Population-normalized SDWIS rate

Editorial analysis

Understanding Oswego County’s Water

Drinking Water Quality Overview

EPA SDWIS

Oswego County's drinking water received a D grade, scoring 45.2 out of 100. Over the past five years, EPA SDWIS records 18 health-based violations — a pattern that public water utilities are required to disclose and correct.

River & Streamflow Status

USGS NWIS

USGS NWIS gauge data (as of 2026-05-14T13:45:00.000-05:00) puts OSWEGO RIVER at 10.2k cfs — flowing above its historical average at 146% of mean. Streamflow is a leading indicator of drought stress, sediment load, and dilution capacity: low flows concentrate pollutants and warm water temperatures, stressing aquatic life and, in surface-water-dependent systems, the source water quality for treatment plants.

Monitoring Network

EPA WQP

EPA's Water Quality Portal (WQP) aggregates monitoring data from federal, state, and tribal agencies. Oswego County has moderate coverage with 22 active monitoring sites with 5,845 recent measurements on record. Predominant monitoring categories include physical and organics, other. More monitoring sites generally indicate greater scientific attention to local water conditions — and provide the baseline data that regulators use to set future impairment listings.

Editorial advisory

What the data suggests for Oswego County

Water Verdict

Oswego County, New York receives a below-average water quality assessment with a grade of D and a score of 45.2 out of 100. Residents should review their utility's Consumer Confidence Report and may want to consider additional water filtration for drinking. The county's primary USGS gauge drains roughly 5,100 square miles of upstream watershed, giving local source waters a regional footprint. At the most recent USGS reading, local streamflow was running above its historical mean at 146.1%.

Violation Context

EPA SDWIS records for Oswego County, New York show 18 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 23.5 violations per 100,000 people served, this rate is high and signals significant water quality management issues. For independent context, 5,845 water-quality monitoring results have been recorded across the county in the EPA Water Quality Portal over the past five years.

Consumer Guidance

Oswego County's drinking-water compliance is below average with a Grade D, indicating repeated or unresolved violations in the recent record. Oswego County's drinking-water compliance score is 45.2 out of 100. The violation rate for Oswego County is 23.5 per 100,000 people served. Residents are encouraged to use an NSF 53 or NSF 58-certified filter for drinking and cooking water until the underlying violations are resolved. Running tap water for 30 seconds before use and avoiding older lead-pipe connections can also reduce exposure risk. The current Consumer Confidence Report from your utility will specify the contaminants of concern. With 22 active water-quality monitoring sites in Oswego County, data coverage is strong. A pipeline streamflow snapshot from the OSWEGO RIVER gauge is also available on this page.

Regional Context

Oswego County has better water quality than the average county in New York. Its water score is 5.1 points higher than the state average, indicating stronger water system performance relative to neighboring counties.

Advisory text summarizes county-level public records and is not a replacement for your utility's current Consumer Confidence Report or direct local notices.

Contaminants & Resources

Key issues flagged in Oswego County's water environment

Official EPA Resources for Oswego County

EPA How's My Waterway

Interactive watershed health data for Oswego County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Oswego County

Consumer Confidence Reports (NY)

Annual water quality reports from utilities in New York

Past 5 years

Water Quality Monitoring

Monitoring Sites

22

Active in the past 5 years

Measurements Recorded

5.8K

5,845 total readings

Most Measured

  • Physical
  • Organics, Other
  • Nutrient

Categories measured most frequently

Data from the EPA Water Quality Portal (WQP), aggregating monitoring records from federal, state, and tribal sources. Each measurement represents a single sample analyzed for a specific characteristic (e.g., E. coli, pH, dissolved oxygen, nitrogen).

Live USGS Streamgage

River & Stream Conditions

Current Discharge

10.2Kcfs

May 14, 6:45 PM UTC

vs Long-Term Average

146%

Well above typical

Primary Streamgage

OSWEGO RIVER AT LOCK 7, OSWEGO NY

USGS site
04249000
Drainage area
5,100 sq mi
Long-term mean
6,979 cfs

One representative streamgage (the one with the largest drainage area in the county). Many counties have multiple gauges; this view summarizes the primary one. The long-term mean is the full-record annual average; the percent-of-typical value compares the latest reading against that average.

Free tool

Estimate Your Water Costs

Water Cost Estimate

3

3 people  ·  ~225 gal/day

Annual Total

$558

Monthly

$47

Water Bill

$558/yr

Filter Cost

$0/yr

Safety Grade for Oswego County:D — Poor

Elevated violations or significant watershed impairment.

Estimates use the national average residential water rate ($0.0068/gal, EPA/AWWA 2023) and EPA WaterSense per-person consumption baseline (75 gal/person/day). Actual bills vary by utility, usage tier, and local infrastructure fees. For informational purposes only.

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Frequently Asked Questions

What is the water quality in Oswego County, New York?
Oswego County, New York has a drinking-water quality grade of D with a score of 45.2/100, based on EPA SDWIS compliance data. The county has 18 health-based drinking water violations over the past 5 years. Watershed health, monitoring records, and streamflow snapshots are reported separately on this page.
Are there any water violations in Oswego County?
Oswego County has 18 health-based drinking water violations recorded by the EPA over the past 5 years. Health-based violations indicate instances where contaminant levels exceeded EPA Maximum Contaminant Levels (MCLs). Violations may have been resolved — check with your local water utility for current status.
How much water-quality monitoring happens in Oswego County?
EPA's Water Quality Portal records 5,845 measurements from 22 monitoring sites in Oswego County over the past five years. The most frequently measured characteristic groups are Physical, Organics, Other, Nutrient. Each measurement is a single sample analyzed for one characteristic (E. coli, pH, dissolved oxygen, etc.). High monitoring density means more scientific evidence behind any reported signal — it does not by itself indicate water quality.
What's happening with rivers in Oswego County right now?
Oswego County's primary USGS streamgage on the OSWEGO RIVER has a pipeline snapshot of 10,200 cubic feet per second — 146% of the long-term mean of 6,979.49 cfs. This is well above typical — often a signal of recent precipitation or storm runoff. For the latest gauge feed, visit waterdata.usgs.gov.
How does Oswego County water compare to the New York average?
Oswego County's SDWIS water quality score of 45.2/100 is higher than the New York state average of 40.1. The average water quality grade across New York is D, based on data from 57 counties with available SDWIS data.
Is tap water safe to drink in Oswego County?
Based on EPA SDWIS data, Oswego County has a water quality grade of D (45.2/100). This indicates below-average compliance with significant violations. Residents may want to consider home water filtration or independent testing. The grade speaks to the public water system, not the watershed — for watershed-level concerns, see the Watershed Health zone. For the most up-to-date information, contact your local water utility or review your Consumer Confidence Report (CCR).
Why does Oswego County have so many water violations?
Oswego County has 18 health-based drinking water violations on record from the EPA SDWIS database. A higher violation count can result from aging infrastructure, underfunded water utilities, agricultural runoff contamination, or industrial pollution. Counties with more water systems may also see more violations simply due to scale. Residents concerned about water quality should consider independent water testing and home filtration systems.
How does Oswego County rank for water quality in New York?
Oswego County ranks #22 out of 57 counties in New York by SDWIS water quality score (1 = best). With a score of 45.2/100, it falls in the middle third of counties statewide. The ranking reflects EPA SDWIS compliance only — not watershed impairment, monitoring density, or streamflow, which are tracked separately on this page.

Counties with Similar Water Quality

Rensselaer County

New York

D

43.5

Water score

Ulster County

New York

D

47.0

Water score

Allegany County

New York

D

43.1

Water score

Data Sources

Drinking-water compliance data from the EPA Safe Drinking Water Information System (SDWIS) via the ECHO enforcement database. Scores reflect compliance history and health-based violation counts.

Water-quality monitoring counts from the EPA Water Quality Portal (WQP), federated USGS, EPA, and state agency sampling records over a rolling 5-year window.

Live streamflow from the USGS National Water Information System (NWIS), continuous discharge measurements from the largest-drainage gauge in each county, compared against the full-record long-term annual mean.

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.

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor

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