They still need to mitigate against the soil contaminants. It's not as if developers have free rein with non-residential uses. The theory behind provincial guidelines treating some non-residential uses differently than sensitive land uses such as residential uses is due to the fact that people at work are less likely to have their children with them playing and rolling around on the grass on a constant basis (as compared to a back yard) and people at work are unlikely to be digging around in the soil the way they do at home (gardening, etc.). And while office and retail workers might be spending long days at their places of work, people with greater sensitivities (children, seniors) tend not to spend long hours at such workplaces. In any event, that's the theory. It is, as you point out, arbitrary and subjective, but most environmental regulations are.
