St. Mary's, MD
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 St. Mary's in Maryland · Population: 114,372
TRI sites such as US Naval Air Station Patuxent River; Smo Mechanicsville Plant; SDWIS systems such as LEXINGTON PARK; PATUXENT NAVAL AIR STATION (NAVFAC-WASH); TOWN OF LEONARDTOWN; NPL sites such as Patuxent River Naval Air Station; Southern Maryland Wood Treating anchor St. Mary's, MD's EPA extract. Derived burden score 34/100 (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 St. Mary's include TOWN OF LEONARDTOWN; LORD CALVERT TRAILER PARK; CHRISTMAS TREE FARM TRAILER PARK, while US Naval Air Station Patuxent River leads reported TRI pounds among local Form R filers. No AQS county monitors report here.
Burden score 34/100 (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 St. Mary's -- 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 St. Mary's, MD: EPA TRI 2023 reporting year
Same facilities, both years
-78.1%
2 facilities that filed in 2022 and 2023
Whole inventory
-78.1%
66 lb → 14 lb, every facility that filed
- St. Mary's, MD's total reported releases fell from 66 lb in 2022 to 14 lb in 2023, based on EPA TRI filings.
- St. Mary's, MD's off-site transfers fell from 66 lb in 2022 to 14 lb in 2023, based on EPA TRI filings.
Water Systems (32)
| System | System pop (SDWIS) | Violations |
|---|---|---|
| LEXINGTON PARK | 43,030 | 0 |
| PATUXENT NAVAL AIR STATION (NAVFAC-WASH) | 22,000 | 0 |
| TOWN OF LEONARDTOWN | 5,000 | 2 |
| COUNTRY LAKES | 3,016 | 0 |
| CEDAR COVE | 2,728 | 0 |
| WICOMICO SHORES | 1,262 | 0 |
| GREENBRIER | 1,161 | 0 |
| BRETON BAY | 1,012 | 0 |
| LORD CALVERT TRAILER PARK | 892 | 1 |
| HUNTING QUARTERS | 715 | 0 |
| ROLLING ACRES | 699 | 0 |
| PINEY POINT | 672 | 0 |
| ST. CLEMENTS SHORES | 620 | 0 |
| CHARLOTTE HALL | 615 | 0 |
| FORREST FARM SUBDIVISION | 577 | 0 |
| LAUREL RIDGE | 560 | 0 |
| PERSIMMON HILLS | 514 | 0 |
| WILDERNESS RUN | 511 | 0 |
| BIRCH MANOR | 272 | 0 |
| GRANDVIEW HAVEN | 269 | 0 |
| PINEY POINT LANDINGS | 239 | 0 |
| VILLAGES AT LEONARDTOWN | 239 | 0 |
| FENWICK MANOR | 234 | 0 |
| LEONARDTOWN FARM | 193 | 0 |
| SOUTHGATE | 188 | 0 |
| KING & KENNEDY | 169 | 0 |
| HOLLAND FOREST | 139 | 0 |
| FOX MEADOW | 128 | 0 |
| CHRISTMAS TREE FARM TRAILER PARK | 100 | 5 |
| MULBERRY SOUTH | 65 | 0 |
| HEARTS DESIRE | 65 | 0 |
| WILD GOOSE CREST SUBDIVISION | 65 | 0 |
TRI Facilities (2)
| # | Facility | Total Releases |
|---|---|---|
| 1 | US Naval Air Station Patuxent River | 37.0K lbs |
| 2 | Smo Mechanicsville Plant | 0 lbs |
Superfund Sites (2)
| Site Name | Status | HRS Score |
|---|---|---|
| Patuxent River Naval Air Station | NPL Site | 50.00 |
| Southern Maryland Wood Treating | Deleted NPL Site | 34.21 |
Cities in St. Mary's (7)
Frequently Asked Questions
What is the environmental risk level in St. Mary's, Maryland? ▼
Are there Superfund sites in St. Mary's? ▼
How many toxic release facilities are in St. Mary's? ▼
What is the air quality in St. Mary's? ▼
Is the drinking water safe in St. Mary's? ▼
What environmental agencies cover St. Mary's? ▼
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.