Note, I am not a lawyer or anyone who could professionally give an opinion on this.*
The most egregious violation the author purports Apple did is the illegal venting of hazardous chemicals.
IMHO, the most plausible evidence supporting the author's claim can be found in the (redacted) EPA report in observation #11.[1]
My understanding is that waste streams (hazardous materials being vented into the environment) must be accounted for in order to accurately calculate how often you must change carbon filters (called breakthrough time in the report) and that carbon filters lose efficacy as hazardous gasses are passed through it.
Anyways, the report found that Apple did not account for all the waste they were putting through the filters and thus could not accurately assess the "breakthrough time" of the filters. There is a plausible case that could be made that a filter had reached its "breakthrough time" -- potentially leaking hazardous gases into the environment. This reportedly has been occurring since atleast* Dec 2020, which could be around the time the author moved in which was also 2020 (unspecified range). Note, this neither confirms nor denies the claim that hazardous chemicals did leech into the air.
1. https://www.dropbox.com/scl/fo/312oqvretg7yyhfx0ohx4/AGZduVX...
More discussion: https://news.ycombinator.com/item?id=40772224