COUNTY REPORT NY

Jefferson County, New York

41 ZIP codes · Avg score 65/100 · Grade C · Updated 2026-06-03

The systems supplying Jefferson County's 41 ZIP codes vary in performance — most meet minimum standards, but violations in select areas are on record.

How Jefferson County Compares

Jefferson County65/100
New York avg61/100
National avg68/100

How Jefferson County Compares

C
County Grade
65/100
Avg Safety Score
41
ZIP Codes
45
Water Systems

Jefferson County scores 4 points above the New York state average (61/100) and 3 points below the national average (68/100).

Data: EPA SDWIS Last verified: 2026-06-03

C
County Grade
65
Avg Safety Score
41
ZIP Codes
Best ZIP: 13602 (83/100)
Lowest ZIP: 13603 (46/100)
$188K
Median Home Value
$1,329
Avg Remediation (71% of home value)

ZIP Code Risk Map

Water Quality Map: Jefferson County, New York

Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.

A B C D F

Key Risk Factors

Health risk index: 12.6 (asthma 11.2%, diabetes 10.1%)

Estimated additional annual cost per homeowner: $1,024, driven primarily by energy_code_gap

Infrastructure: 0.453% avg pipe failure probability, 69% of ZIPs at high risk

64.6% of homes built before 1978 (lead paint era)

Violation History (2021–2025)

↓ Improving trend

EPA violation counts by year across Jefferson County water systems. Health-based shown in red, total in blue.

2021
9 (9 health)
2022
31 (31 health)
2023
18 (18 health)
2024
24 (24 health)
2025
3 (2 health)

Peak year: 2022 with 31 violations. Past 5 years: 85 total (84 health-based). Health-based violations are declining versus the prior 2-year window.

Source: EPA SDWIS historical violations. Data may lag 6–12 months for the most recent year.

County Health Indicators vs National Average

Asthma 11.2% (national: 8.9%)
Diabetes 10.1% (national: 10.5%)
Obesity 38.1% (national: 32.4%)

Black markers indicate national averages. Source: CDC PLACES, Census ACS.

Infrastructure Overview

1968
Median Build Year
64.6%
Pre-1978 Housing
45%
Pipe Failure Probability
69%
ZIPs at High Infra Risk
Low
Lead Pipe Risk

Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.

Compound Risk Breakdown

Estimated additional annual cost per homeowner: $1,024

Energy Code Gap $439/yr
Flood $298/yr
Water / Lead $207/yr

Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).

Housing Age Distribution

61,589 housing units in Jefferson County

Pre-1940 32%
1940–1959 10%
1960–1979 16%
1980–1999 23%
2000+ 18%

Source: U.S. Census Bureau ACS B25034 (Year Structure Built).

Water Safety Affordability

How much it costs to fix water issues relative to home values in Jefferson County

$188K
Median Home Value
$1,329
Est. Remediation Cost
0.7%
of Home Value
Remediation as % of home value low burden

Remediation costs are relatively manageable for most homeowners in Jefferson County, representing a small fraction of property value.

Remediation includes water filtration, lead abatement, radon mitigation, and flood protection where applicable. Source: Census ACS, EPA SDWIS.

Health Outcomes vs National Average

CDC PLACES data for Jefferson County residents

Asthma 11.2% (US avg: 8.9%)
Diabetes 10.1% (US avg: 11%)
Obesity 38.1% (US avg: 32.4%)

Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.

Water Systems with Most Violations

Top 5 systems in Jefferson County ranked by EPA violation count.

# Water System Population Violations
1 Sackets Harbor Village 2,200 29
2 Brownville Village 1,200 27
3 Leray Town Water District 1, 2, 4 7,140 22
4 Dexter Village 1,100 21
5 Watertown City 27,861 20

45 total water systems serve Jefferson County.

All ZIP Codes in Jefferson County

41 ZIP codes tracked in Jefferson County.

# ZIP Code City Safety Score Grade Violations Home Value
1 13602 Fort Drum 83 B 0
2 13636 Ellisburg 83 B 0 $175K
3 13673 Philadelphia 83 B 0 $171K
4 13682 Rodman 83 B 0 $216K
5 13685 Sackets Harbor 83 B 0 $286K
6 13691 Theresa 83 B 0 $159K
7 13605 Adams 81 B 1 $188K
8 13608 Antwerp 81 B 1 $121K
9 13628 Deferiet 81 B 0 $117K
10 13612 Black River 79 B 0 $195K
11 13637 Evans Mills 78 B 2 (1 health) $190K
12 13606 Adams Center 75 B 0 $185K
13 13650 Henderson 75 B 7 (3 health) $207K
14 13624 Clayton 74 B 1 (1 health) $224K
15 13607 Alexandria Bay 73 B 2 (2 health) $168K
16 13622 Chaumont 66 C 2 $226K
17 13618 Cape Vincent 64 C 0 $197K
18 13611 Belleville 63 C 0 $197K
19 13640 Wellesley Island 63 C 0 $331K
20 13641 Fishers Landing 63 C 0 $327K
21 13643 Great Bend 63 C 0
22 13651 Henderson Harbor 63 C 0 $339K
23 13674 Pierrepont Manor 63 C 0
24 13679 Redwood 63 C 0 $201K
25 13693 Three Mile Bay 63 C 0 $213K
26 13616 Calcium 53 D 0 $148K
27 13623 Chippewa Bay 53 D 0 $115K
28 13632 Depauville 53 D 0
29 13634 Dexter 53 D 9 (9 health) $215K
30 13638 Felts Mills 53 D 0 $166K
31 13656 La Fargeville 53 D 0 $146K
32 13657 Limerick 53 D 0
33 13659 Lorraine 53 D 0 $151K
34 13665 Natural Bridge 53 D 0 $143K
35 13671 Oxbow 53 D 0
36 13675 Plessis 53 D 0
37 13692 Thousand Island Park 53 D 0 $291K
38 13615 Brownville 52 D 8 (8 health) $182K
39 13601 Watertown 50 D 10 (7 health) $170K
40 13619 Carthage 48 D 12 (12 health) $172K
41 13603 Watertown 46 D 10 (7 health)

Recommended Buyer Guides for Jefferson County

Eight risk categories drive the selection — PFAS exceedance, lead above EPA action level, pre-1978 housing share, EPA Radon Zone 1, flood-top-risk, wildfire-top-risk, multi-contaminant load, and a baseline fallback — and each category maps to a specific buyer-guide track that surfaces when the county data hits its threshold for that hazard signal.

Overview

Jefferson County in New York covers 41 ZIP codes with an average Home Safety Score of C (65/100).

12 of 41 ZIP codes have recorded EPA violations. 50 health-based violations have been documented.

← Back to New York water quality report

Data Sources

Updated daily.

Frequently Asked Questions

Is water safe in Jefferson County?
Jefferson County receives a grade of C. Some ZIP codes have recorded violations and residents in affected areas may want to test their water.
How many water systems serve Jefferson County?
Jefferson County is served by 45 public water systems that supply drinking water to residents across 41 ZIP codes.
What is the biggest environmental risk in Jefferson County?
The primary environmental risk factor in Jefferson County is energy_code_gap. This contributes to an estimated additional annual cost of $1,024 per homeowner.
How old are homes in Jefferson County?
The median home build year in Jefferson County is 1968. 64.6% of homes were built before 1978, which means they may contain lead-based paint and older plumbing materials.
How does Jefferson County compare to New York?
Jefferson County has an average water safety score of 65/100, which is above the New York state average of 61/100.

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