In September 2017, a Paramount resident spoke at a Paramount City Council meeting about witnessing a metal forging company in the southern industrial region of town performing pressure washing on its rooftop. The resident was concerned about possible contamination of streets and stormwater drains by the water runoff. The City looked into the incident.
Two metal forging companies – Press Forge and Weber Metals – related that they had both recently conducted pressure washing of their rooftops. They stated, however, that this was done to fulfill housekeeping requirements set forth in the South Coast Air Quality Management District’s (SCAQMD) Rule 1430. The Rule states:
The owner or operator of a metal forging facility that is conducting metal grinding or metal cutting operations shall conduct semi-annual wet cleaning or HEPA vacuuming, no more than 6 calendar months apart, of roof tops for total enclosures that house areas associated with metal grinding or metal cutting operations.
The City contacted SCAQMD officials and they confirmed that this practice is in line with Rule 1430.
Additionally, according to the “California Stormwater Quality Association (CASQA): Stormwater Best Management Practice Handbook,” rooftop pressure washing is a widely accepted industry best management practice for stormwater pollution prevention and reduction.
In the case of Weber Metals, the pressure washing was performed by a licensed environmental services company, T&R Environmental Services. The waste water from the pressure washing was collected and disposed of at an appropriate disposal facility. Press Forge stated that they took similar precautionary measures, using a vacuum water recovery system while conducting the rooftop pressure washing.