PlainEnviro

Big Horn, WY

Low Risk (26/100)

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 Big Horn in Wyoming · Population: 11,737

Big Horn, WY is tracked across three EPA datasets covering 3 Toxics Release Inventory (TRI) facilities, 15 Safe Drinking Water Act systems, and 0 Superfund National Priorities List sites. Together these generate an environmental burden score of 26/100 (Low Risk), calibrated against national distributions for facility density, chemical release volume, Superfund concentration, and water-system health violations.

Industrial disclosures inside the county total 116.6K lbs of reported toxic releases under EPCRA Section 313, while 3 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 119 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
11,737
TRI Facilities
3
Water Systems
15
Superfund Sites
0
Total Releases
116.6K 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) Max AQI
2024 315 (89%) 36 2 119
2023 335 (93%) 24 0 77
2022 356 (98%) 6 0 64
2021 324 (89%) 39 1 101
2020 349 (97%) 8 2 126
2024 Good Air Quality: 89% of days
Unhealthy days: 2
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 Wyoming, see the EPA's AirNow.gov.

Water Systems (15)

System Population Violations
GREYBULL, TOWN OF 3,260 0
LOVELL, TOWN OF 2,360 0
BASIN, TOWN OF 1,250 0
COWLEY, TOWN OF 800 2
BYRON, TOWN OF 593 0
BURLINGTON, TOWN OF 348 7
DEAVER MUNICIPAL WATER SYSTEM 176 0
FRANNIE, TOWN OF 160 0
SOUTH END WATER USERS S&I DISTRICT 150 0
SHELL TOWN WATER IMPROVEMENT DISTRICT 120 0
MANDERSON, TOWN OF 110 1
GREYBULL HEIGHTS WATER USERS 84 0
HYATTVILLE S&I DISTRICT 66 0
SCHAREN SUBDIVISION 50 0
SHOSHONE MUNICIPAL PIPELINE 25 0

TRI Facilities (3)

# Facility Total Releases
1 Western Sugar Cooperative Lovell Factory 116.4K lbs
2 Georgia-Pacific Gypsum LLC - Lovell Plant 159 lbs
3 Cetco 0 lbs

Cities in Big Horn (1)

Lovell
Pop: -
3 facilities · 2 water

Frequently Asked Questions

What is the environmental risk level in Big Horn, Wyoming? ▼
Big Horn, WY has an environmental risk score of 26/100 (Low Risk), based on 3 TRI facilities, 0 Superfund sites, and 15 water systems on record. 3 water systems have health-based violations. Source: EPA TRI, SDWIS, and Superfund NPL.
Are there Superfund sites in Big Horn? ▼
No Superfund National Priorities List (NPL) sites are currently registered in Big Horn, WY in the EPA database.
How many toxic release facilities are in Big Horn? ▼
Big Horn, WY has 3 TRI-reporting facilities on record with the EPA Toxic Release Inventory, with a combined total of 116.6K lbs in reported toxic releases. TRI facilities self-report annual chemical release data to the EPA.
What is the air quality in Big Horn? ▼
In 2024, Big Horn, WY recorded a median AQI of 39 and a peak AQI of 119. 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 Big Horn? ▼
Big Horn, WY has 15 EPA-regulated water systems. 3 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 Big Horn? ▼
Environmental compliance in Big Horn, Wyoming is overseen by the U.S. Environmental Protection Agency (EPA) at the federal level and the Wyoming 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.

Related Guides

Understanding EPA Data
How EPA collects and publishes environmental data
Environmental Justice
Who lives near polluters and environmental hazards
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