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NFPA 31 2020 Secondary Containment

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.



  • STEVEusaPA
    STEVEusaPA Member Posts: 5,328
    edited November 2020
    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 Member Posts: 10,374
    And I believe all single wall tanks are bottom draw, don't think they make side outlet anymore