Once upon a time... long, long ago (ok, maybe not that long ago)... spill containment for fuel tanks often went ignored or was a hole in the ground lined with plastic sheeting. But operators have become wiser and/or more environmentally conscious and enforcement has been stepped up.
But when you consider the options, the Ultra-Containment Sump really does seem like a "no-brainer". Yes, it costs more than a sheet of plastic and some man hours, but if there's a spill onsite, it's going to outperform that "home made" containment every time. Not only that but when you need to move to another area of the site or to another site completely, the Containment Sump is a completely portable solution.