| AMAllan Myers Md, INC. -- Elk Mills Rap Plant | Elk Mills | — | ◇ UNVERIFIED |
| AOAnchor (an Oldcastle Company)-white Marsh Plant | White Marsh | — | ◇ UNVERIFIED |
| BCBeavercreek Concrete Plant | Beaver Creek | — | ◇ UNVERIFIED |
| BSBetco Supreme INC | Odenton | — | ◇ UNVERIFIED |
| BMBluegrass Materials Marriottsville Quarry | Marriottsville | — | ◇ UNVERIFIED |
| BMBluegrass Materials Rockdale Quarry | Clear Spring | — | ◇ UNVERIFIED |
| BMBluegrass Materials Texas Quarry | Cockeysville | — | ◇ UNVERIFIED |
| CRCentral Ready Mix Cambridge Plant | Cambridge | — | ◇ UNVERIFIED |
| CEChaney Enterprises | Upper Marlboro | — | ◇ UNVERIFIED |
| CIChaney Industries | Annapolis | — | ◇ UNVERIFIED |
| CNClayburn - New Savage Works | Grantsville | — | ◇ UNVERIFIED |
| CPConcrete Pipe and Precast, LLC | Jessup | — | ◇ UNVERIFIED |
| CCCrouse Construction CO INC | Aberdeen | — | ◇ UNVERIFIED |
| DGDaniel G. Schuster Concrete/h | Hagerstown | — | ◇ UNVERIFIED |
| ECEquality Concrete - Seat Pleasant | Seat Pleasant | — | ◇ UNVERIFIED |
| GEGardner, E.l.,inc. - Pasadena Plant | Pasadena | — | ◇ UNVERIFIED |
| JRJessup Ready Mix Concrete | Jessup | — | ◇ UNVERIFIED |
| KAKeymar Aggregates Engineering | Keymar | — | ◇ UNVERIFIED |
| LALafarge Aggregates & Concrete | Frederick | — | ◇ UNVERIFIED |
| LJLafarge Joppa Concrete Batch Plant | Joppa | — | ◇ UNVERIFIED |
| LMLafarge Mid-atlantic, LLC - Jessup Plant | Jessup | — | ◇ UNVERIFIED |
| LMLaney Materials LLC - Laney Recycling and Aggregates | Laurel | — | ◇ UNVERIFIED |
| LILocke Insulators INC | Baltimore | — | ◇ UNVERIFIED |
| MEMaier, Ernst, INC. | Bladensburg | — | ◇ UNVERIFIED |
| MCMaryland Concrete Septic Tank INC. | Maryland Line | — | ◇ UNVERIFIED |
| MPMaryland Paving Churchville | Bel Air | — | ◇ UNVERIFIED |
| MSMt Savage Firebrick | Frostburg | — | ◇ UNVERIFIED |
| MSMt Savage Specialty Refractories | Mount Savage | — | ◇ UNVERIFIED |
| NNNew Ngc INC (dba National Gypsum Co) | Belcamp | — | ◇ UNVERIFIED |
| OAOldcastle Apg Mid-atlantic Crofton, Md | Odenton | — | ◇ UNVERIFIED |
| OPOldcastle Precast INC. | Edgewood | — | ◇ UNVERIFIED |
| OMOpta Minerals | Baltimore | — | ◇ UNVERIFIED |
| PBPrice Brothers Company | Perryman | — | ◇ UNVERIFIED |
| QHQuikrete - Hagerstown, Md Plant | Hagerstown | — | ◇ UNVERIFIED |
| RBRedland Brick | Rocky Ridge | — | ◇ UNVERIFIED |
| RMRinker Materials Hydro Conduit- Frederick | Frederick | — | ◇ UNVERIFIED |
| RFRockville Fuel and Feed | Rockville | — | ◇ UNVERIFIED |
| SCSchuster Concrete Ready Mix Llc-guilford Rd | Jessup | — | ◇ UNVERIFIED |
| SCSchuster Concrete Ready Mix Llc-hobbs Rd | Denton | — | ◇ UNVERIFIED |
| SCSchuster Concrete Ready Mix Llc-southlawn Ln | Rockville | — | ◇ UNVERIFIED |
| SDSchuster, Daniel, INC. | Owings Mills | — | ◇ UNVERIFIED |
| SCS&g Concrete Company | Odenton | — | ◇ UNVERIFIED |
| SCS&g Concrete Edgewood | Edgewood | — | ◇ UNVERIFIED |
| WPWaldorf Plant | Waldorf | — | ◇ UNVERIFIED |
| WCWaugh Chapel Plant | Gambrills | — | ◇ UNVERIFIED |
| WCWicomico County Airport | Salisbury | — | ◇ UNVERIFIED |
| WGWienerberger Group (general Shale) | Beltsville | — | ◇ UNVERIFIED |
| YBYork Building Products - Cockeysville | Cockeysville | — | ◇ UNVERIFIED |
| AIAmerican Insulated Glass LLC - Baltimore | Ijamsville | 20–99 | ◐ LIKELY ACTIVE |
| BRBay Ready Mix of Maryland Llc | Baltimore | 20–99 | ◐ LIKELY ACTIVE |
