If a malfunctioning chemical storage tank in Garden Grove ends up resulting in a fiery explosion, a map released by the Orange County Fire Authority on Saturday afternoon provided a potential preview of the areas that could see the most severe damage.
An evacuation zone centered at the GKN Aerospace plant on Western Avenue in Garden Grove and extending out to encompass portions of six cities has been in place for more than a day, as crews sought to clear the area to protect residents from a potential explosion and chemical fallout.
If an explosion does occur, the resulting “severe damage blaze zone” would most directly impact a largely industrial and business zone to the west, north and south of the plant, according to an OCFA map.
However, what appears to be around 100 homes is also included in the “severe damage” zone to the east of the plant, along with what appears to be around 100 more residences — and portions of an elementary school campus — in the “moderate damage blast zone.”
OCFA Division Chief Nick Freeman, in a video about the map, explained that “severe damage” zone — the innermost circle of the map — represents areas where they would expect “severe structural damage and significant harm.”
Similarly, in the “moderate” zone, Freeman said, “structural damage and harm to those within the zone” would be expected.
A little further out, the map includes a “light damage blast zone” where “we might see some structural damage, but it would be limited.”
The map also includes an area, extending from the plant past West Chapman Avenue, where they may see “fire or flash fire,” along with areas where the amount of chemical released in an explosion would pose a serious risk to people, and a much larger area where people would be able to smell the chemicals but not be impacted.
Also see: Why experts, emergency crews haven’t been able to find a solution to Garden Grove chemical threat
The exact nature of the damage — and what contingencies are in place to deal with it — has not been made clear.
Authorities say an explosion is not necessarily a foregone conclusion.
In a comparatively less dangerous scenario, the tank could crack, leading 7,000 gallons of chemicals to pour out instead.
Also see: Map shows Garden Grove chemical emergency and evacuation near GKN Aerospace plant
And officials on Saturday outlined a third, more optimistic potential scenario, where the cooling deluge of water from fire crews slows down the rate of the chemical reactions inside the tank, reducing the overpressure as the liquid chemicals turn to solid.
But until the fate of the damaged tank is clear, authorities urged residents to steer clear of the evacuation zone.
Newsom declares state of emergency as chemical tank in Garden Grove under threat of exploding