| OIO&g Industries INC | Harwinton | CT | — | ◇ UNVERIFIED |
| OCO'hare Concrete Plant | Chicago | IL | — | ◇ UNVERIFIED |
| OCOhio County Road Department | Hartford | KY | — | ◇ UNVERIFIED |
| OVOhio Valley Asphalt INC | Carrollton | KY | — | ◇ UNVERIFIED |
| OSOil Spill (blacklidge Emulsions,, Inc.) | Gulfport | MS | — | ◇ UNVERIFIED |
| OLOilstone LLC / Shady Point Plant | Shady Point | OK | — | ◇ UNVERIFIED |
| OCOkanogan CO Public Works Midland Pu | Okanogan | WA | — | ◇ UNVERIFIED |
| OAOlathe Aggregate Facilities (stormwater) | Olathe | KS | — | ◇ UNVERIFIED |
| OMOldcastle Materials, INC. | Schenectady | NY | — | ◇ UNVERIFIED |
| OSOldcastle Sw Group - Cugnini Pit | Durango | CO | — | ◇ UNVERIFIED |
| OSOldcastle Sw Group Dba B&b Excavating | Eagle | CO | — | ◇ UNVERIFIED |
| OSOldcastle Sw Group Dba Four Conrners | Durango 2.5 Mi Se of | CO | — | ◇ UNVERIFIED |
| OSOldcastle Sw Group Dba United CO of Mesa | Gunnison 2.6 Mi. E of | CO | — | ◇ UNVERIFIED |
| OSOldcastle Sw Group Dba United CO of Mesa | Rifle | CO | — | ◇ UNVERIFIED |
| OSOldcastle Sw Group Dba United CO of Mesa | Montrose | CO | — | ◇ UNVERIFIED |
| OSOldcastle Sw Group Dba United CO of Mesa | Grand Junction | CO | — | ◇ UNVERIFIED |
| OSOldcastle Sw Group, INC. - Asphalt Plant | Mancos Area | CO | — | ◇ UNVERIFIED |
| OSOldcastle Sw Group- Tri County Pit | Hotchkiss | CO | — | ◇ UNVERIFIED |
| OSOldcastle Sw Group - Wattenberg West | Brighton, 2.0 Mi Nw of | CO | — | ◇ UNVERIFIED |
| OSOldcastle Sw - Trinidad Hma Gen | Trinidad | CO | — | ◇ UNVERIFIED |
| OBOmann Brothers INC - St Michael | Saint Michael | MN | — | ◇ UNVERIFIED |
| OCOmans Contracting INC | Hesperia | MI | — | ◇ UNVERIFIED |
| OMOmg Midwest | Omaha | NE | — | ◇ UNVERIFIED |
| OMOmg Midwest Dba Cessford Construction CO | Burlington | IA | — | ◇ UNVERIFIED |
| OMOmg Midwest, INC. | Stanton | TN | — | ◇ UNVERIFIED |
| OEOmni Engineering INC | Omaha | NE | — | ◇ UNVERIFIED |
| OEOmni Engineering Plant 02 | Omaha | NE | — | ◇ UNVERIFIED |
| OEOmni Engineering Plant 02 | Omaha | NE | — | ◇ UNVERIFIED |
| OCOneida County Highway Department | Rhinelander | WI | — | ◇ UNVERIFIED |
| OGOnslow Grading & Paving, INC. | Hubert | NC | — | ◇ UNVERIFIED |
| OPOnyx Paving Company | Seymour | IN | — | ◇ UNVERIFIED |
| OROpen Road Asphalt CO LLC | Marshall | IL | — | ◇ UNVERIFIED |
| OROpen Road Asphalt CO. LLC - Fairmount | Fairmount | IL | — | ◇ UNVERIFIED |
| OROpen Road Asphalt Company LLC | Paxton | IL | — | ◇ UNVERIFIED |
| OCOrange Crush LLC | Skokie | IL | — | ◇ UNVERIFIED |
| OCOrange Crush LLC | East Dundee | IL | — | ◇ UNVERIFIED |
| OCOrange Crush LLC | Des Plaines | IL | — | ◇ UNVERIFIED |
| OCOrange Crush LLC | Wheeling | IL | — | ◇ UNVERIFIED |
| OPOrlando Paving Company | Orlando | FL | — | ◇ UNVERIFIED |
| OPOrlando Paving Company | Winter Garden | FL | — | ◇ UNVERIFIED |
| OPOrlando Paving Company | Apopka | FL | — | ◇ UNVERIFIED |
| OPOrlando Paving Company | Oviedo | FL | — | ◇ UNVERIFIED |
| OBOsage Beach, Mo Stockpile | Kaiser | MO | — | ◇ UNVERIFIED |
| OPOscar Pit | Gnesen Township | MN | — | ◇ UNVERIFIED |
| OAOsuna Asphalt Plant | Albuquerque | NM | — | ◇ UNVERIFIED |
| OMOverland Material and Manufacturing INC / Astec 4 | Ada | OK | — | ◇ UNVERIFIED |
| OMOverland Material and Manufacturing INC / Astec 6 | Ada | OK | — | ◇ UNVERIFIED |
| OMOverland Material and Manufacturing INC / Ommi Astec 5 | Antlers | OK | — | ◇ UNVERIFIED |
| OPOverstreet Paving CO | Spring Hill | FL | — | ◇ UNVERIFIED |
| OCOwens Corning Fiberglass CORP | Compton | CA | — | ◇ UNVERIFIED |