Home Podcasts THMG073 – Leaking Tanks 2.0

THMG073 – Leaking Tanks 2.0


In this episode, we revisit our discussion of leaking fuel tanks and how to handle them.

Complete Show Notes

6:45 Review of Scene Size-Up

  • Vehicle type – car, truck, boat, plane, locomotive, heavy equipment, etc.
  • Is the scene safe? Safety is always paramount
  • Product type – most are gasoline or diesel, but you might also be dealing with CNG (compressed natural gas) or propane
  • Where is the leak coming from? Can be the engine compartment, the fuel tank, or anywhere in between
  • What was the cause of the leak? Can be collision, age, equipment failure, rust, improper repair, etc.
  • In some cases, the vehicle isn’t upright or they drove over an object in the road – if it’s a train, they may have encountered something in the rail bed
  • What’s the total amount of fuel in question? Do you have the resources on scene to contain and overpack?
  • How will we access the leaking tank? Most modern gas tanks are very well packaged into the vehicle and not particularly easy to access under normal conditions
  • Is the vehicle on its wheels, overturned, or somewhere in between?
  • is the vehicle on the roadway or somewhere else?
  • Are there other scene hazards present? This can include traffic, manholes, sewers, storm drains, waterways, railroads, live wires, elevated roadways, etc.

14:35 Leaking Tank Example Scenario

  • You’re preparing to remove an unknown amount of gasoline from the fuel tank of a passenger car that’s upright and leaking slowly from damage to its undercarriage. Until now, you considered the pros and cons of either puncturing or drilling, but there’s a third option – disassembly
  • Most modern cars have tanks mounted towards the vehicle’s geographic center and are molded to utilize the space under the rear seat and floorboard
  • Luckily for us, the in-tank fuel pump is accessible without removing the entire tank from the vehicle – allows us to remove fuel from the tank with simple hand tools and without further damage to the vehicle
  • Make sure the vehicle key has been removed from the ignition – if the car has an electronic-style key, disconnect the battery
  • Lift the lower portion of the back seat to see whether there’s a flap of carpet or padding that could be covering an access point
  • Lift the carpet/padding and look for a metal cover of some kind that’s secured in place with sheet metal screws – there should be a wire harness running through this cover and into the tank below
  • Have your resource offer Google the make and model of the vehicle, along with the words “fuel pump replacement” – you’ll probably be able to find video tutorials that reveal whether the car has any kind of access
  • Remove the metal cover, and you should be looking directly at the top of the fuel tank – the wiring harness and several small hoses will be connected to the tank inside a circular port that’s maybe 6-8″ in diameter – this is the top of the fuel pump assembly
  • Most pumps are held in by a metal ring held down by 6-8 nuts – it can also be a plastic ring that unscrews like a large jar lid – remove this, and the pump assembly will lift straight up
  • There will likely not be enough slack in the wires and hoses to completely remove the pump, but there will be enough room to slip a narrow stinger inside the tank
  • Directly below the fuel pump is likely the best place to pull the fuel from, as it’s designed to be the low point in the tank
  • Open gas tanks produce flammable vapors, so all of the vehicle doors should be open prior to opening the tank – the member inside the vehicle should have full PPE and SCBA
  • In general, passenger cars can hold 20 gallons of fuel or less – most pickups are in the 32-35 gallon range

24:35 Tractor Trailer and Heavy Truck Saddle Tanks

  • Piercing isn’t really an option with saddle tanks
  • Modern heavy trucks have at least 2 different types of tanks hanging on the outside of their frame rails – some have 3
  • Diesel fuel – is usually in an aluminum barrel that’s D-shaped
  • Diesel exhaust fluid (DEF) – poly (plastic), and possibly stainless steel and various shapes
  • Hydraulic fluid reservoir – made of steel in a rectangular shape
  • DEF tanks are very common, while hydraulic tanks are found on trucks with other equipment on board – garbage trucks, crane trucks, dump trucks, roll-offs, etc.
  • If the truck is on its wheels, the fuel can easily be removed through the fuel port – the only hindrance may be a screen-type insert, but they’re easy to pull out or pushed into the tank
  • If the fill port isn’t an option, it’s time to drill – you’ll want to drill into the vapor space rather than the liquid space, though
  • Truck tanks are much larger than cars and pickups – each tank can hold up to 150 gallons
  • There can be multiple fuel tanks, and they may be connected
  • DEF is corrosive and must be handled appropriately – there’s also considerably less of it on board when compared to the fuel capacity
  • Hydraulic steel tanks are pretty tough and much harder to drill
  • If the liquid level is difficult or impossible to see, a thermal imaging camera (TIC) is a good option

35:45 Tank Interconnection and Transfer Valves

  • Dual saddle tanks are both connected to the engine (and sometimes to each other)
  • This is important to know – if you’re draining one side, the system might start to equalize as you empty one tank – in reality, you’re emptying both at the same time
  • You need to be prepared to contain the total amount of fuel – there are no set standards for these interconnections, and the driver may or may not know about it
  • Sometimes, the tanks can be mechanically isolated via a shut transfer valve
  • If there’s no connection (or if they don’t equalize on their own), there’s the option of removing the fuel from the damaged tank and pumping it into the tank on the opposite side (if there’s room)

38:10 Leaks and Heavy Equipment

  • Keep the following in mind if you’re dealing with leaks from heavy equipment (bulldozers, backhoes, wheel loaders, etc.):
    • You’ll probably be dealing with diesel fuel and tanks with considerable capacity
    • There will also probably be a large capacity for hydraulic fluid
    • The tanks will be well protected
    • Leaks are more likely to be from equipment failure, rather than tank damage
    • If the vehicle is upright, fluid removal happens via the tank fill pipe

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