Jefferson, WI

Compiled by PlainEnviro Editorial, Environmental Data Editorial Team · July 13, 2026

Moderate Risk (51/100)

A PlainEnviro-computed score from reported facility/violation counts, not an official EPA rating, health forecast, or population-adjusted rate. See methodology.

Environmental data for Jefferson in Wisconsin · Population: 85,867

Jefferson, WI is tracked across three EPA datasets covering 21 Toxics Release Inventory (TRI) facilities, 8 Safe Drinking Water Act systems, and 0 Superfund National Priorities List sites. Together these generate an environmental burden score of 51/100 (Moderate Risk), calibrated against national distributions for facility density, chemical release volume, Superfund concentration, and water-system health violations.

Industrial disclosures inside the county total 2.8M lbs of reported toxic releases under EPCRA Section 313, while 4 water systems carry an active health-based violation in the SDWIS record. EPA Air Quality System monitors logged a median AQI of 39 and a peak AQI of 93 in 2024, with 89% of observed days rated "Good" (0–50).

All figures below draw directly from federal EPA records, TRI self-reported emissions, SDWIS compliance history, NPL Hazard Ranking System scores, and AQS daily AQI summaries, and are not adjusted, weighted, or forecast. A past violation or elevated score does not itself indicate current unsafe conditions; it documents the regulatory and disclosure history publicly filed with the U.S. Environmental Protection Agency through the most recent reporting cycle.

Population

85,867

TRI Facilities

Water Systems

Superfund Sites

Total Releases

2.8M lbs

Air Quality History (2020–2024)

EPA Air Quality Index (AQI) data showing how many days per year fall into each air quality category.

Year	Good	Moderate	Unhealthy (SG)	Median AQI	Max AQI
2024	183 (89%)	22	0	39	93
2023	145 (71%)	43	15	44	140
2022	185 (93%)	15	0	38	87
2021	178 (86%)	29	1	40	101
2020	189 (90%)	17	4	38	136

2024 Good Air Quality: 89% of days

Median AQI: 39

Source: EPA Air Quality System (AQS) Annual AQI by County EPA Air Quality System (AQS) Annual AQI by County AQI categories: Good (0-50), Moderate (51-100), Unhealthy for Sensitive Groups (101-150), Unhealthy (151-200), Very Unhealthy (201-300), Hazardous (301+)

For real-time air quality readings and pollutant breakdowns in Wisconsin, see the EPA's AirNow.gov.

Water Systems (8)

System	City	Source	Population	Violations	Health
WATERTOWN WATERWORKS	Watertown	Groundwater	23,945	0	–
FORT ATKINSON WATERWORKS	Fort Atkinson	Groundwater	12,390	0	–
LAKE MILLS WATERWORKS	Lake Mills	Groundwater	6,211	8	Yes
WATERLOO WATERWORKS	Waterloo	Groundwater	3,520	6	Yes
JOHNSON CREEK WATERWORKS	Johnson Creek	Groundwater	3,318	1	Yes
PALMYRA WATERWORKS	Palmyra	Groundwater	1,756	0	–
AUTUMN RIDGE WATER SYSTEM LLC	Ixonia	Groundwater	575	1	Yes
ROCK RIVER MOBILE HOME PARK	Fort Atkinson	Groundwater	30	0	–

TRI Facilities (21)

#	Facility	City	Industry	Total Releases
1	Fisher Barton Blades	Watertown	Fabricated Metals	1.3M lbs
2	Fisher-Barton Specialty Products	Watertown	Fabricated Metals	629.6K lbs
3	Ball Container LLC	Fort Atkinson	Fabricated Metals	389.9K lbs
4	Fiberdome Products LLC Plant 2	Lake Mills	Plastics and Rubber	163.1K lbs
5	Whitewater Generating Station	Whitewater	Electric Utilities	117.2K lbs
6	Mastermold LLC	Johnson Creek	Plastics and Rubber	80.9K lbs
7	Generac Power Systems Inc-Whitewater	Whitewater	Electrical Equipment	27.0K lbs
8	Milkrite Interpuls Inc	Johnson Creek	Plastics and Rubber	22.4K lbs
9	Diversey Inc.	Watertown	Chemicals	19.5K lbs
10	Valero Renewable Fuels	Jefferson	Chemicals	11.9K lbs
11	Aztalan Bio	Johnson Creek	Chemicals	3.1K lbs
12	Nestle Purina Petcare	Jefferson	Food	1.4K lbs
13	Wisconsin Investcast	Watertown	Primary Metals	1.0K lbs
14	Hoppe N.a.	Fort Atkinson	Fabricated Metals	898 lbs
15	Osi Industries LLC	Fort Atkinson	Food	10 lbs
16	Epic Resins	Palmyra	Chemicals	7 lbs
17	East West Wisconsin	Whitewater	Computers and Electronic Products	0 lbs
18	Electronic Technologies International Inc	Fort Atkinson	Computers and Electronic Products	0 lbs
19	Jones Dairy Farm	Fort Atkinson	Food	0 lbs
20	Jones Dairy Farm South	Fort Atkinson	Food	0 lbs
21	Generac Power Systems Inc-Jefferson	Jefferson	Electrical Equipment	0 lbs

Cities in Jefferson (7)

Johnson Creek

Pop: -

3 facilities · 1 water

Watertown

Pop: -

6 facilities · 2 water

Palmyra

Pop: -

1 facilities · 1 water

Whitewater

Pop: -

5 facilities · 3 water

Fort Atkinson

Pop: -

6 facilities · 2 water

Jefferson

Pop: -

3 facilities · 1 water

Lake Mills

Pop: -

1 facilities · 1 water

Frequently Asked Questions

What is the environmental risk level in Jefferson, Wisconsin? ▼

Jefferson, WI has an environmental risk score of 51/100 (Moderate Risk), based on 21 TRI facilities, 0 Superfund sites, and 8 water systems on record. 4 water systems have health-based violations. Source: EPA TRI, SDWIS, and Superfund NPL.

Are there Superfund sites in Jefferson? ▼

No Superfund National Priorities List (NPL) sites are currently registered in Jefferson, WI in the EPA database.

How many toxic release facilities are in Jefferson? ▼

Jefferson, WI has 21 TRI-reporting facilities on record with the EPA Toxic Release Inventory, with a combined total of 2.8M lbs in reported toxic releases. TRI facilities self-report annual chemical release data to the EPA.

What is the air quality in Jefferson? ▼

In 2024, Jefferson, WI recorded a median AQI of 39 and a peak AQI of 93. 89% of monitored days had "Good" air quality (AQI 0–50). Source: EPA Air Quality System (AQS) Annual AQI by County.

Is the drinking water safe in Jefferson? ▼

Jefferson, WI has 8 EPA-regulated water systems. 4 systems have reported health-based violations (MCL exceedances). A past violation does not necessarily mean water is currently unsafe. For current water quality, contact your local water utility. Source: EPA SDWIS.

What environmental agencies cover Jefferson? ▼

Environmental compliance in Jefferson, Wisconsin is overseen by the U.S. Environmental Protection Agency (EPA) at the federal level and the Wisconsin state environmental agency. Facilities report to the EPA Toxic Release Inventory, water systems are regulated under the Safe Drinking Water Act, and contaminated sites are managed under the Superfund program. Contact your state environmental agency for local concerns.

What does this county environmental profile show?

This county environmental profile rolls up EPA Toxics Release Inventory facility reports, Safe Drinking Water Information System public-water-system filings, and Superfund National Priorities List sites for the county boundary defined by the U.S. Census Bureau. Facility counts reflect facilities with a reporting address inside the county, not where downstream environmental effects may be observed. Population figures are from the most recent Census ACS 5-year estimate. The county detail page is updated whenever the upstream EPA programs publish revised data; see the methodology page for the documented ingest cadence and the editorial choices governing how aggregations are computed.

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How to Check Environmental Quality

Step-by-step guide to checking your local environment

Read our methodology - how this data is sourced, computed, and verified.

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Data sourced from U.S. EPA environmental datasets. See our methodology for details. Retrieved and formatted by PlainEnviro Editorial