Aerocraft Heat Treating Co., Inc. – a metal-finishing facility in Paramount — has been ordered to shut down all metal processing equipment and operations with the potential to emit the toxic compound hexavalent chromium. This is the third time since the order was adopted that Aerocraft has had to curtail operations due to exceeding the threshold in the order. Prior curtailments occurred from Jan. 19 to Jan. 27 and Feb. 14 to Feb. 21.
Aerocraft, at 15701 Minnesota Ave., was ordered late yesterday to curtail operations by midnight last night because South Coast Air Quality Management District air monitoring data found levels of the compound above a trigger threshold of 1.0 nanograms per cubic meter.
The level is an average of three samples collected over a period of about a week. The threshold, agreed to by Aerocraft, was specified in an administrative order adopted by the independent SCAQMD Hearing Board on Dec. 16, 2016.
In response to this announcement, Mayor Daryl Hofmeyer from the City of Paramount issued the following statement:
I remain troubled that Aerocraft continues to struggle to comply with the abatement order from SCAQMD. I hope Aerocraft is equally concerned and frustrated and that they are working doubly hard to achieve compliance. The closure announcement marks the third time that Aerocraft has suspended parts of its operations as a result of non-compliance. SCAQMD remains vigilant in its monitoring and enforcement efforts to protect our community, and this announced closure demonstrates that the regulatory process is working as expected.
The following table shows recent levels of hexavalent chromium at a SCAQMD monitor just outside of Aerocraft:
Aerocraft will not be able to resume operations of any equipment with the potential to emit hexavalent chromium until SCAQMD determines that the average of the three most recent samples, collected over about one week, are below 1.0 nanograms per cubic meter.
Hexavalent chromium is a potent human carcinogen associated with lung cancer when inhaled over long periods of time, typically years to decades.