| Business | Phone |
| Industrial Systems Engineering 869 Nelson St, Oshawa L1H 5N7 | (905) 725-1555 |
| Blenkhorn & Sawle Ltd 350 Wentworth St E, Oshawa L1H 7R7 | (905) 436-0859 |
| D G Biddle & Assoc Ltd 96 King St E, Oshawa L1H 1B6 | (905) 576-8500 |
| Durham Engineers Inc 676 Drake St, Oshawa L1H 6L3 | (905) 576-7782 |