Stellantis taking multi-pronged approach to fixing odors at Mack plant

Some time ago, neighbors reported strange odors coming from the new Mack Avenue assembly plant, officially named Detroit Assembly Complex – Mack. The state investigated and found that there were indeed odors, from this and one other plant.

Detroit Complex - Mack rendering

Stellantis hired a specialist company to do source sampling, and over 13 days, that company took 152 samples from 42 potential sources. A specialty engineering firm then used dispersion modeling to predict the potential odor impact from various sources and evaluate strategies for ending the problem.

To quote the release, the modeling found some possible fixes in the paint shop:

  • Routing ducting to the existing emissions control system as required in the air permit was completed on Dec. 19, ahead of schedule. Odors generated from the volatile organic compounds (VOCs) in the exhaust will now be reduced by thermal oxidation in the emission control system
  • Installing a completely new and dedicated regenerative thermal oxidizer (RTO) and ducting. The exhaust from two existing stacks will be routed to this new system to destroy odor contributing compounds
  • Routing the clean air exhaust from the existing concentrator to the stack of the new RTO to improve dispersion through increased velocity and height. The concentrator removes VOCs and “concentrates” them into smaller volumes so the RTO can destroy them more efficiently
  • Using odor reducing technologies as needed in specific areas that have been identified as minor odor contributing sources

The timeline depends on discussions with the state and permits. According to the EPA, the odors do not present a health risk to residents.