Back to our regularly scheduled program of regulatory how-to.Â One of the problems that I mentioned in my last post that you may encounter is the potential that the Underground Storage Tank (UST) that you were planning to remove leaked during it’s former use.Â Let’s assume again that the tank held automotive gasoline.Â Let’s also assume that the tank is located in Los Angeles County and therefore all work will be overseen by the Site Mitigation Unit of the Health and Hazardous Materials Division of the Los Angeles County Fire Department.
You went ahead and filed the permits to remove your tank, paid the fees and got approval.Â You also scheduled with your contractor to excavate the tank and remove the tank in the presence of the inspector.Â The inspector also required you to have a marine chemist on site during the tank pull, so she shows up and runs her tests, fills out her forms and now you are good to go.Â Until the tank is pulled and exposes a small rust holeÂ and a relatively largeÂ patch of stained soil beneath the tank.
Now you have a site investigation on your hands.Â You will still collect samples from the sidewalls and the base of the excavation, but the samples you collect from the base of the excavation will be impacted with gasoline.
The County Fire Department will require an investigationÂ whether you backfill or not, so let’s just say that in this case you need to backfill because you have other redevelopment contractors that need to be able to drive over the area.Â Go ahead and order your 1 sack slurry from your local cement supplier and fill that excavation up.Â You will also have to dispose of the pea gravel or sand that was around the tank so call your favorite trucking company and find a place that will accept the material.
Call a drilling company and plan on collecting soil samples and installing a soil vapor extraction system.Â We’re into remediation now, hold tight for the next installment in the process.