Marathon, WI
Transparent derived index from EPA TRI / SDWIS / Superfund extracts: not an official EPA rating. Fixed caps: facilities ≤25 pts (50+ = max), log10 releases ≤25 pts, Superfund ≤25 pts (5/site), health-violation systems ≤15 pts (3/system), high-chemical facilities ≤10 pts. Bands: High ≥60, Moderate ≥30. See methodology. This is a different measure than the EJ Screening score for this county, which ranks it by percentile against other tracked counties rather than against these fixed caps.
Environmental data for Marathon in Wisconsin · Population: 138,067
TRI sites such as Mullins Cheese Inc; Weston Power Plant; Mullins Cheese Inc; SDWIS systems such as KRONENWETTER WATER & SEWER UTILITY; RIB MOUNTAIN WATER UTILITY; ABBOTSFORD WATERWORKS; NPL sites such as Mid-State Disposal, Inc. Landfill; Spickler Landfill; Unity Auto Mart anchor Marathon, WI's EPA extract. Derived burden score 86/100 (High Risk) uses fixed national caps on density, log release volume, Superfund count, and health-flagged systems - not an official EPA rating.
Health-flagged SDWIS rows in Marathon include KRONENWETTER WATER & SEWER UTILITY; ABBOTSFORD WATERWORKS; SCHOFIELD WATERWORKS, while Mullins Cheese Inc leads reported TRI pounds among local Form R filers. AQS median AQI 37 / peak 151 in 2024.
Burden score 86/100 (High Risk) is the only weighted composite on this page. The tables below list every TRI facility, SDWIS system, and Superfund site EPA has on record for Marathon -- not just the names called out above -- reproducing the disclosure history as filed, not a current-safety verdict. Extract current as of 2026-08-25.
Release-over-release change
What changed for Marathon, WI: EPA TRI 2023 reporting year
Same facilities, both years
-17.8%
34 facilities that filed in 2022 and 2023
Whole inventory
-17.8%
5.1 million lb → 4.2 million lb, every facility that filed
Between the two reporting years, 1 facility filed for the first time and 0 stopped filing. Facilities entering or leaving the inventory are excluded from the same-facility comparison above.
- Marathon, WI's total reported releases fell from 5.1 million lb in 2022 to 4.2 million lb in 2023, based on EPA TRI filings.
- Marathon, WI's land releases fell from 3.7 million lb in 2022 to 2.9 million lb in 2023, based on EPA TRI filings.
- Marathon, WI's off-site transfers fell from 987.7 thousand lb in 2022 to 847.4 thousand lb in 2023, based on EPA TRI filings.
- Marathon, WI's air releases fell from 349.7 thousand lb in 2022 to 329.0 thousand lb in 2023, based on EPA TRI filings.
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) | Max AQI |
|---|---|---|---|---|
| 2024 | 311 (85%) | 54 | 0 | 151 |
| 2023 | 168 (78%) | 39 | 8 | 166 |
| 2022 | 197 (96%) | 8 | 0 | 64 |
| 2021 | 191 (96%) | 9 | 0 | 87 |
| 2020 | 193 (97%) | 6 | 0 | 74 |
Source: 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 | System pop (SDWIS) | Violations |
|---|---|---|
| KRONENWETTER WATER & SEWER UTILITY | 6,931 | 1 |
| RIB MOUNTAIN WATER UTILITY | 6,398 | 0 |
| ABBOTSFORD WATERWORKS | 2,502 | 2 |
| SCHOFIELD WATERWORKS | 2,205 | 1 |
| MARATHON CITY WATERWORKS | 1,695 | 3 |
| ATHENS WATERWORKS | 1,025 | 1 |
| HATLEY WATERWORKS | 550 | 0 |
| DEER TRAIL VILLAGE | 120 | 1 |
TRI Facilities (37)
Superfund Sites (4)
| Site Name | Status | HRS Score |
|---|---|---|
| Mid-State Disposal, Inc. Landfill | NPL Site | 35.23 |
| Spickler Landfill | NPL Site | 44.24 |
| Unity Auto Mart | NPL Site | 50.00 |
| Wausau Ground Water Contamination | NPL Site | 28.91 |
Cities in Marathon (13)
Frequently Asked Questions
What is the environmental risk level in Marathon, Wisconsin? ▼
Are there Superfund sites in Marathon? ▼
How many toxic release facilities are in Marathon? ▼
What is the air quality in Marathon? ▼
Is the drinking water safe in Marathon? ▼
What environmental agencies cover Marathon? ▼
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.
Read our methodology - how this data is sourced, computed, and verified.