Mastermold LLC
111 Grell Ln, Johnson Creek, WI 53038, Jefferson County
A manufacturing facility in Johnson Creek, Wisconsin, listed in EPA records under all other plastics product manufacturing (NAICS 326199) and also custom compounding of purchased resins. It is one of 2,851 active manufacturing facilities in EPA records in Wisconsin.
- Industry
- Plastics and rubber
- NAICS 326
- TRI reporter
- Yes
- Inspections, 5 yr
- 4
- EPA registry ID
- 110000416327
- Revised
- November 1, 2026
What's made here
- All Other Plastics Product Manufacturing (NAICS 326199)
- Custom Compounding of Purchased Resins (NAICS 325991)
Public EPA records
| Toxics Release Inventory | Reports to the TRI (facility ID 53038MSTRM111GR). |
|---|---|
| Clean Air Act | Listed as a major source of air emissions. |
| Clean Water Act | A non-major water discharge permit (NPDES). |
| Hazardous waste (RCRA) | Listed as a large quantity generator of hazardous waste (1,000 kg or more a month). |
| Inspections | 4 in the last five years; most recent October 17, 2025. |
EPA ECHO, November 1, 2026; not a rating. EPA report · About these records