Lewis And Clark, MT
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 Lewis And Clark in Montana · Population: 72,580
TRI sites such as American Chemet Corp; US Army National Guard Fort Harrison Ranges; Helena Sand & Gravel Inc; SDWIS systems such as HELENA WATER SYSTEM; EAST HELENA CITY OF; EASTGATE VILLAGE SEWER AND WATER; NPL sites such as East Helena Site; Upper Tenmile Creek Mining Area anchor Lewis And Clark, MT's EPA extract. Derived burden score 44/100 (Moderate 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 Lewis And Clark include HELENA WATER SYSTEM; EAST HELENA CITY OF; JEFFERSON HILLS WUA, while American Chemet Corp leads reported TRI pounds among local Form R filers. AQS median AQI 46 / peak 160 in 2024.
Burden score 44/100 (Moderate 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 Lewis And Clark -- 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 Lewis And Clark, MT: EPA TRI 2023 reporting year
Same facilities, both years
-11.6%
3 facilities that filed in 2022 and 2023
Whole inventory
-11.6%
21.1 thousand lb → 18.6 thousand lb, every facility that filed
Between the two reporting years, 0 facilities filed for the first time and 1 stopped filing. Facilities entering or leaving the inventory are excluded from the same-facility comparison above.
- Lewis And Clark, MT's total reported releases fell from 21.1 thousand lb in 2022 to 18.6 thousand lb in 2023, based on EPA TRI filings.
- Lewis And Clark, MT's air releases fell from 15.2 thousand lb in 2022 to 12.2 thousand lb in 2023, based on EPA TRI filings.
- Lewis And Clark, MT's land releases rose from 5.9 thousand lb in 2022 to 6.4 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 | 233 (64%) | 127 | 5 | 160 |
| 2023 | 240 (66%) | 120 | 3 | 165 |
| 2022 | 239 (65%) | 119 | 4 | 167 |
| 2021 | 249 (68%) | 99 | 14 | 156 |
| 2020 | 277 (76%) | 84 | 1 | 168 |
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 Montana, see the EPA's AirNow.gov.
Water Systems (51)
| System | System pop (SDWIS) | Violations |
|---|---|---|
| HELENA WATER SYSTEM | 32,091 | 12 |
| EAST HELENA CITY OF | 2,114 | 1 |
| EASTGATE VILLAGE SEWER AND WATER | 2,000 | 0 |
| VA MEDICAL CENTER HELENA | 1,275 | 0 |
| HELENA LEISURE LLC | 1,200 | 0 |
| JEFFERSON HILLS WUA | 780 | 2 |
| NORTH STAR PUD | 715 | 0 |
| WINDSOR ESTATES | 530 | 0 |
| COVERED WAGON MB HM PARK | 500 | 0 |
| LA CASA GRANDE WATER AND SEWER DISTRICT | 404 | 0 |
| SKYVIEW WATER AND SEWER UTILITY | 400 | 3 |
| GOLDEN ESTATES HOMEOWNERS ASSOCIATION | 400 | 0 |
| MOUNTAIN ACRES MB HM PK | 320 | 0 |
| RIDGEWOOD TERRACE MHP | 280 | 0 |
| GRASS LAND ESTATES | 228 | 0 |
| HOLMBERG VILLAGE ESTATES | 225 | 2 |
| GLACIER POINT HO AND WUA | 210 | 1 |
| BRIDGE CREEK ESTATES SUBDIVISION | 205 | 0 |
| PELE PARK | 186 | 0 |
| DAVIS MEADOW VILLAGE | 180 | 0 |
| TOWN VIEW ESTATES WUA INC | 175 | 0 |
| MOUNTAIN HERITAGE WATER SYSTEM | 175 | 0 |
| PRAIRIE MOBILE VILLAGE | 163 | 0 |
| PEBBLE GARDENS MOBILE HOME CT | 125 | 0 |
| HOMESTEAD VALLEY WUA HVHA | 105 | 0 |
| BRYANT NO 3 SUBDIVISION | 100 | 0 |
| NORTH FORESTVALE HOMEOWNERS | 98 | 0 |
| CAMEL MOUNTAIN HOA | 96 | 0 |
| CAMELOT HOA | 96 | 0 |
| BUZZ INN | 95 | 0 |
| TALL TIMBERS MOBILE HOME PARK | 90 | 2 |
| MASONIC HOME OF MONTANA | 90 | 0 |
| APPLEGATE VILLAGE | 85 | 0 |
| ELK CREEK COLONY | 84 | 12 |
| SOUTH FORESTVALE HOA | 82 | 1 |
| MITCHELL COURT APARTMENTS | 80 | 0 |
| RUGER WATER DISTRICT | 79 | 0 |
| MCDONALD TRAILER CT | 75 | 2 |
| BARNETT WATER USERS SYSTEM | 70 | 0 |
| SMITH MCHUGH #2 BLR | 68 | 0 |
| MILFORD COLONY INC | 67 | 12 |
| BLUE CLOUD SUBDIVISION | 60 | 26 |
| SUNNYBROOK ACRES HOA | 50 | 0 |
| GRAND VALLEY ESTATES SUBDIVISION | 50 | 0 |
| MOONLIGHT ESTATES HOA | 44 | 0 |
| BROADWATER ESTATES HOA | 40 | 5 |
| PHOENIX PARK | 36 | 1 |
| TRAILS END TR PARK HELENA | 35 | 0 |
| BAHNY BRAE SUBDIVISION | 35 | 1 |
| ROSEMARYS ADDITION | 30 | 0 |
| SOUTHERN CROSS PUD | 25 | 0 |
TRI Facilities (5)
| # | Facility | Total Releases |
|---|---|---|
| 1 | American Chemet Corp | 110.6K lbs |
| 2 | US Army National Guard Fort Harrison Ranges | 35.6K lbs |
| 3 | Helena Sand & Gravel Inc | 55 lbs |
| 4 | Forterra Concrete Products - Helena | 0 lbs |
| 5 | Boeing Helena Inc | 0 lbs |
Superfund Sites (2)
| Site Name | Status | HRS Score |
|---|---|---|
| East Helena Site | NPL Site | 61.65 |
| Upper Tenmile Creek Mining Area | NPL Site | 50.00 |
Cities in Lewis And Clark (8)
Frequently Asked Questions
What is the environmental risk level in Lewis And Clark, Montana? ▼
Are there Superfund sites in Lewis And Clark? ▼
How many toxic release facilities are in Lewis And Clark? ▼
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Is the drinking water safe in Lewis And Clark? ▼
What environmental agencies cover Lewis And Clark? ▼
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.