I disagree with your reasoning. Your use of the word 'someones' sounds rather sinister, the _Someones_ involved in building and running chemical plants aren't going to choose to pay extra to inconvenience minorities, I assure you. I am absolutely certain however that building such industrial development in lower socio-economic areas is advantageous for the companies, as local residents are less likely to be able to litigate, or less integrated within the democratic process overall. I'm not being unsympathetic to the victims of this issue, I'm just not going to attribute this process to outright malice or racism. I think you're putting the cart before the horse. Is the plant really there _because_ it's a black area? Or is it there because it's a poor area, and is it also a predominantly black area because it's a poor area? What economic impact has the introduction of the chemical plant had on the community, did it make it poorer? Correlation does not imply causation, I think there's other explanations for the plight of the area that aren't predicated entirely upon racism.

Building somewhere because the residents have bad access to the law and government is malicious.

In some specific decisions the racial bias is all incidental. But that's still exacerbating past racism, and if even a little bit of current racism slips in it can be massively magnified. It's not cheap or unfair to highlight these effects. Decisions don't happen in a vacuum.