NFPA 31 2020 Secondary Containment

CSMachineCo

I'm not an HVAC technician, merely just want to be an informed homeowner.

I'm preparing to replace an existing tank and planned on pouring a new pad myself (this is something I am familiar with) since the existing tank is on concrete blocks. While doing my research, I looked at the 2020 NFPA 31 and noticed they added a section to the 2016 version:

"7.8.7 When a steel single-wall aboveground tank is fitted with a side outlet or is installed in a top draw configuration, and is located outside, it shall be installed within a secondary containment large enough to contain 110 percent of the tank's content."

This seems pretty straight forward, if tank is single-wall top-draw then secondary containment is required. But I am a bit confused as why secondary containment is not required for bottom draw (or is it)? I suspect there is a higher likelihood of water sitting in the bottom of the tank with top-draw...

On to my next question. It is my understanding that steel "double-bottom" tanks would be considered single-wall for the purposes of 7.8.7, correct?

The bottom line... If I wish to avoid having to implement a secondary containment system my options are: steel single-wall tank with bottom draw OR a double-wall tank like the Roth series of galvanized DWTs (which appear to only be top-draw). Correct?

Bonus question: I have room in my basement for a Roth DWT, but a couple hundred gallons of fuel in the basement puts me on edge. I've also read a couple of reports of these tanks leaking at the fill port, likely due to poor installation. Oil heat is not terribly prevalent in my area so I am a bit concerned about finding an installer for the basement tank (I've had issues with "techs" servicing my oil furnace in the past). Comments as to basement tanks are welcome.

Thanks

STEVEusaPA

I doubt anyone has adopted 2020 yet. I haven’t received my copy.

The best place for your oil tank is in the basement. A double wall tank would be ideal, and they’re only a little more expensive.
Any oil company should be able to properly install a leak free tank. They do it every day.
And they would have someone checking the connections during the first fill.

EBEBRATT-Ed

And I believe all single wall tanks are bottom draw, don't think they make side outlet anymore