| Advanced Drainage Systems |
| Aerotek |
| Altorfer, Inc. |
| American Cast Iron Pipe |
| American Commercial, Inc. |
| Assurance Agency |
| ATM Aggregate Logistics Inc. |
| BakerCorp |
| Bluff City Materials, Inc |
| Brown R Cartage |
| Bunker Hill Underwriters |
| Casey Equipment |
| Christofano Equipment |
| Clow Water Systems Co. |
| Cobra Concrete Cutting Services |
| Columbian Agency |
| Concrete Specialties |
| Crissie Insurance Group |
| Daniel G. Suber & Associates |
| Dearborn Companies |
| Deutsch, Levy & Engel Chartered |
| Divane Brothers Electric Co. |
| Dohn & Associates |
| DS&P Insurance Services, Inc. |
| East Jordan Iron Works |
| Elmhurst-Chicago Stone |
| First Midwest Bank |
| Fleetmatics |
| FOCIS Promotions & Incentives |
| Godwin Pumps of America |
| Graber Concrete Pipe Co. |
| Green Pipe & Supply, Inc. |
| Griffin Dewatering, Midwest, L.L.C. |
| Griffin Pipe Products Company |
| Hancor, Inc. |
| Hanson Material Service |
| Hard Rock Concrete Cutters |
| HD Supply Waterworks |
| Heritage Logistics |
| Highway Technologies |
| Holland & Knight LLP |
| HUB International Scheer's Inc. |
| Hydro Exc. Inc. |
| Illinois American Water |
| Illinois Mining Corporation |
| ITT Waste & Wastewater USA, Flygt Products |
| John Sakash Company |
| JULIE, Inc. |
| Kieft Brothers Inc. |
| LBT Trucking |
| Lee Jensen Sales Co., Inc. |
| LoJack Corporation |
| Mackie Consultants, LLC |
| Martin Equipment of IL, Inc. |
| MassMutual Financial Group |
| Maurides Foley & Tabangay LLC |
| McCann Industries, Inc. |
| Merritt Credit Bureau |
| Mersino Dewatering Midwest |
| Meyer Material Company |
| Mid-American Water of Aurora |
| Mid-American Water of Wauconda, Inc. |
| MKMP, LLC |
| Moglia Advisors |
| Mueller Co. |
| National Concrete Pipe Co. |
| Naylor Pipe Company |
| Neenah Foundry Company |
| Ogletree Deakins Nash Smoak & Stewart |
| OSCO Oil, Inc. |
| Ozinga Bros., Inc. |
| Patten Construction Products |
| Pirtek O'Hare |
| Planet Underground |
| Prairie Material |
| Prinsco, Inc. |
| Rabjohns Financial Group |
| Rain For Rent |
| Ritchie Bros Auctioneers |
| Roland Machinery Co. |
| Roughneck Concrete Drilling & Sawing |
| Safety Alliance Ltd. |
| Safety Check, Inc. |
| Sawyer Falduto Asset Management, LLC. |
| Schwartz Bros. Insurance Agency, Inc. |
| SEC Group, Inc. |
| SES, Inc. |
| Sigma Corporation |
| Southern Underground Services, Inc. |
| Standard Equipment Co. |
| StormTrap, LLC |
| StormTrap, LLC |
| Thelen Materials |
| Tonyan Bros., Inc. |
| Trafic Service, Inc. |
| Travelers Insurance |
| Trotter & Associates |
| Truck King Hauling Contractors, Inc. |
| TT Technologies, Inc. |
| Tyler Union |
| U.S. Pipe & Foundry |
| United Rentals Trench Safety |
| Utility Concrete Products, LLC |
| Vermeer Midwest, Inc. |
| Vulcan Materials |
| Water Products Co., Inc. |
| Weible & Cahill |
| Welch Bros. Inc. |
| West Side Tractor Sales |
| Willis |
| Wolf and Company, LLP |
| Ziebell Water Service Products |