Johnston, OK
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.
Environmental data for Johnston in Oklahoma · Population: 10,334
SDWIS systems such as TISHOMINGO MUNICIPAL AUTHORITY; JOHNSTON CO RWD #3; MURRAY STATE COLLEGE anchor Johnston, OK's EPA extract. Derived burden score 15/100 (Low Risk) uses fixed national caps on density, log release volume, Superfund count, and health-flagged systems - not an official EPA rating.
No TRI Form R facilities sit in Johnston in this extract; water coverage still lists TISHOMINGO MUNICIPAL AUTHORITY; JOHNSTON CO RWD #3; MURRAY STATE COLLEGE. AQS monitors logged median AQI 44 / peak 119 in 2024.
Burden score 15/100 (Low 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 Johnston -- 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.
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 | 192 (75%) | 62 | 3 | 119 |
| 2023 | 166 (67%) | 75 | 4 | 161 |
| 2020 | 267 (92%) | 22 | 0 | 97 |
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 Oklahoma, see the EPA's AirNow.gov.
Water Systems (11)
| System | System pop (SDWIS) | Violations |
|---|---|---|
| TISHOMINGO MUNICIPAL AUTHORITY | 3,000 | 50 |
| JOHNSTON CO RWD #3 | 2,783 | 2 |
| MURRAY STATE COLLEGE | 1,150 | 7 |
| JOHNSTON CO RWS& SWMD #4 | 600 | 2 |
| MANNSVILLE PUBLIC WORKS AUTHORITY | 587 | 6 |
| RAVIA | 459 | 8 |
| WAPANUCKA | 420 | 6 |
| MILBURN PUBLIC WORKS AUTHORITY | 317 | 5 |
| MILL CREEK | 310 | 11 |
| KENEFIC | 165 | 15 |
| BROMIDE | 163 | 6 |
Cities in Johnston (9)
Frequently Asked Questions
What is the environmental risk level in Johnston, Oklahoma? ▼
Are there Superfund sites in Johnston? ▼
How many toxic release facilities are in Johnston? ▼
What is the air quality in Johnston? ▼
Is the drinking water safe in Johnston? ▼
What environmental agencies cover Johnston? ▼
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.