EPA-regulated facilities in Mason County, WA
There are 531 EPA-regulated facilities inside Mason County, Washington. The most common kinds are drinking water systems (241), water discharge (167), hazardous waste (131). 25 are currently in significant noncompliance, the EPA's designation for the most serious or persistent violations, and 52 have a violation on record. Penalties over the last five years total $9k across 2 sites.
By category
| Category | Facilities |
|---|---|
| Hazardous waste | 131 |
| Large quantity generators | 1 |
| Small quantity generators | 9 |
| Chemical (RMP/TRI) | 6 |
| Superfund | 1 |
| Air emissions | 12 |
| Major sources | 1 |
| Synthetic minor sources | 3 |
| Minor sources | 3 |
| Water discharge | 167 |
| Major permits | 1 |
| Minor permits | 138 |
| Drinking water systems | 241 |
| Greenhouse gas reporters | 1 |
| Scrap yards | 1 |
| Recycling centers | 2 |
A facility enrolled in several programs counts once in the total and once in each of its categories.
In significant noncompliance
The EPA's designation for its most serious or persistent violations, as of the latest data.
- POTLATCH BEACH MUTUAL WATER SYSTEM Significant noncompliance
- MANZANITA RESERVOIR AND BOOSTER PUMP STATION Significant noncompliance
- ACE PAVING CO MCREAVY PIT PLANT 3 Significant noncompliance
- PORT ORCHARD SANDG MCEWAN PRAIRIE Significant noncompliance
- DAYTON AIRPORT PIT Significant noncompliance
- PAY MORE RECYCLE & SALVAGE Significant noncompliance
- PORT OF SHELTON SANDERSON FIELD BUILDING REPLACEMENT Significant noncompliance
- ACE PAVING CO INC JOHNS PRAIRIE PIT Significant noncompliance
- BAYSIDE REDI MIX Significant noncompliance
- FRONTIER CONSTRUCTION SUPPLY LLC SHELTON PLANT Significant noncompliance
Largest penalties
Penalties assessed over the last five years.
- JENSEN PRECAST $8k in penalties
- SIMPSON TIMBER CO FRONT ST $1k in penalties
Superfund sites
Towns in Mason County
Bordering counties
Reading these numbers
These are regulatory records, not measurements of pollution. Most facilities appear because they hold a permit or file reports, and most of them are compliant; a listing is not a claim that a facility has polluted anything. Compliance status and penalties are the EPA's own determinations in data retrieved Oct 9, 2026. The Data page explains where each record comes from and how it can mislead.