At that time, SCAQMD was investigating only Carlton Forge Works, and for elevated levels of nickel and cadmium. The City was kept informed of that investigation. In the summer of 2016, SCAQMD did present data to the City and the community-at-large of hexavalent chromium readings that were above background levels around Carlton Forge but expressed no immediate concerns about this information. Never during this time did SCAQMD identify Aerocraft or Press Forge as being responsible for elevated levels of hexavalent chromium. SCAQMD also presented a plan to expand their air monitoring to other parts of the industrial sector, leading the City to hire a consultant to help staff understand the science behind the investigation. SCAQMD then discovered very high levels of hexavalent chromium in late October 2016. This was the first time the City learned about these very high levels. In late November of 2016, SCAQMD identified Aerocraft as one source of these levels and began its process of forcing the company to comply with air quality regulations and laws.