House in the country… Old house,single story,so everything went through to the ground…
something like 30-50 gallons of canola oil. forklifting mishap. 5 gal jugs raining from 20ft up, landing a few feet in front of me. I think around 10 broke. took the rest of the day to clean up. the floor was nice and polished. there is probably still a stain going 10 ft up the nearby wall to this day.
Ex-Navy, huh? 
(Well, someone was going to say it)
I dumped a degreasing tank and wash basin once. It was mounted in a dumb location and I managed to be even dumber and hit it with a lift.
Waiting for Joseph Hazelwood or Gregory Cousins to post…
A giant tub of glaze in the clay studio (20-50 gal – I suck at estimating volumes). The tubs are on wheels so you can pull out the one you want, but unbeknownst the me, part of the one I was pulling out was hooked around another one, which I pulled over along with.
At home, a 2 liter of Mountain Dew. My husband had brought it home from the store, it was on the counter, and then he picked it up to put in the fridge and it was like the bottom of the plastic bottle fell clean off. It must have been faulty or damaged somehow (but yet it broke in our kitchen and not the store and not the parking lot and not outside). I probably washed the floor ten times a day for the next two weeks, and we would still find random sticky areas for a long time after.
At work, one of those water cooler jugs of water that you tip upside down to load into the unit.
About 20 gallons of gasoline. Jacked up a car by the rear differential with a large floor jack while the car was parked on a dirt driveway. Took off the rear tires to work on the brakes. Ran to the auto parts store to get the parts and came back half an hour later. The jack had sunk into the dirt and the car slid forward onto the jack ripping a big whole in the gas tank. I had just filled the tank the day before. The gas soaked into the ground, the smell lasted for only a few weeks.
This thread ended up being way more interesting than I would have ever thought possible.
I didn’t spill this but I was there when it happened:
Untold thousands of gallons of sea water.
Hurricane Iwa (Thanksgiving weekend, 1982) in Hawaii did substantial damage to our dolphin research facility in Honolulu. We moved the dolphins to a large sea water tank at another facility across the harbor in order to do repairs at our place. This was on the grounds of some marine fisheries research facility.
The tank had a plexiglas window. There was also a massive floating platform in the tank. (It was one of our dolphins’ “toys” that we put there.) Somehow they managed to smash the platform into the plexiglas window, and umpteen thousand gallons of sea water flooded out all over the facility. Good thing the dolphins didn’t get flooded out along with it.
I fumbled the drainage hose of an automatic floor scrubber. It was completely full of filthy soapy water from scrubbing the concrete floor of a grocery store warehouse room. At least 30 gallons of pitch-black scummy soap-suddy vomit-smelling water. It went everywhere. Including into my mouth and eyes.
I was unhappy.
Another ‘not me, but I was there’…
About 200 litres of gin. We were loading a shipping container at a levelled dock - forklift driver placing pallets of liquor on the tail end; me and several others carrying and stacking it in solid walls at the back.
The driver thought we were done and started to pull away; the stacked cases of liquor came down flat and smashed hundreds of the bottles inside (remarkably, nobody was injured).
Gin cascaded from the back on the container like a waterfall.
Cleanup involved several of us paddling through a mushy layer of gin soaked cardboard, suffused with broken glass. The alcohol fumes were overpowering (particularly because this happened on a hot day and the metal container was like an oven) and we had to keep stopping for air.
Dozed off at a hotel while the tub was filling. The people across the hall notified management when the water came under their door.
God, that was mortifying. :o Especially since I had already undressed when the staff came barging in.
In my defense, I was pregnant with my first and having migraines, so I was pretty narcoleptic.
Two gallons of milk. Back when I was four I tried to ‘help’ my mother by bringing two gallons of milk up the stairs from the basement. This is when milk was bottled in glass. They “tinked” against each other and the milk went flowing back down the stairs.
Two different answers.
The first is “I was there and cleaned it up.” A twenty-five gallon drum of concentrated honey and almond fragrance for shampoo. An idiot supervisor put it on a drum rack(where the drums are on their sides) and put the wrong type of plastic valve in the lid. As a D.O.T. Class 8 corrosive, it ate through the plastic valve. By the time I got it off the rack and upright, about half of it was on the floor. It killed my sense of smell.
The second one was “That was completely my fault.” It was only 3-5 gallons…of battery acid. I stabbed a 55 gallon drum while unloading a trailer. By the time I had the drum on its side with the hole pointed up, some had spilled out. You haven’t had a bad day at work until you’ve had to call a hazmat team to fix your mistake.
As a teenager, I accidentally clipped the side of an above-ground pool with a riding mower.
I don’t exactly, but about half the water came out. 
I used to be a research technician in a wet lab. It’s called a wet lab for a reason, as I quickly found out.
Well, I once took a job as a caretaker of a mountain lodge in Oregon, and had a bit too much to drink, which was strange because I was told there wasn’t a drop of alcohol in the place. After I murdered my entire family, I gathered up all their blood and put it in the elevator, hoping no one would notice.
Needless to say, I had egg on my face when the doors opened. I’m such a klutz.
Over 100 gallons of jet fuel. Fortunately it wasn’t my fault. But standing in that much fuel was scary. I was praying that there wouldn’t be a spark.
I was changing the bottle in the cooler at work one day and the carboy slipped. So, that is 5 gallons of water.