Thought i would write this up since it seems more people are asking about it.
There are many methods to collect but i chose the easiest and least messy method. Theres a learning curve involved to decide which method is best for you and you will likely end up trying a few different methods before you settle on whats best fr you.
I have pumped it from a dumpster before and that proved to be no fun at all but some people still prefer it. First of all its steeling. The contents of a grease dumpster is the property of the rendering company who owns the dumpster...so don't get caught doing it. Chances are the restaurant won't care if you do this but if the renderer drives up while your there, you may end up in the bottom of his truck vat and listed later as a missing person.
Seriously, these guys are kinda like junk yard dogs.
And then after i filled my barrels (3-4 55 gal. drums) I had to pump it back off the truck as these barrels now weighed around 440 lbs each. This was a time consuming ordeal and it was messy.
So, now i have found what seems to be two of the easiest methods i can think of with no mess at all.
1) i collect from some restaurants using the 5 gallon cubies that the oil comes in when its new. The cooks save these empty cubies and when its time to change the oil in their vats, they are able to drain the grease back into these jugs. they then set them by the back door and i drop by once a week and open the back door, grab them and go. There will be 3-9 jugs of oil each time i collect it. I never know what i will find until i get there, it all depends on how busy they were during the week and how fast the oil gets dirty...they may change It once that week or they may change it 2 times that week.
This will only work IF the restaurant has a cooker with a valve and drain system that will allow them to fit the cubie under it and drain it in. Some restaurants do not have a set up that will allow them to do this...so in that case, heres an easy alternative solution.
I made a barrel to put outside there back door to put the oil in. The have a device for draining the oil into that has wheels on it. They can roll this thing outside and easily pour it into the barrel. The barrel has a half moon cutout of the top - or you could cut the whole top out - and i bought a barrel lid and chained it to the barrel so it won't disappear. The lid will keep rain water out of the barrel-very important. the barrel is sitting on a wooden stand i made out of 2x4 material. It also has a drain welded into the side down low. I used a 3/4" NPT coupling in which i used to screw in a 3/4" NPT nipple and then a locking ball valve with a 90 degree turn down. The drain is welded to the side of the barrel about 4 inches off the bottom. Theres a reason for this and i will touch on that later.
Between the stand and the 4 inch height of the drain valve, i have about 16" (cant remember exactly) from the ground up to the 90* turn down which allows me to place an empty cubie under the valve and open it to fill the cubie. Easy as pie! Now the 4" i refereed to earlier...if there is any water that does get into the barrel, maybe from the cooks leaving the lid off your barrel, you want it to settle to the bottom and not end up draining it into your jugs. 4" will allow this water and any other crud to settle and not get in your jugs. Once in a while (once a year maybe) you will want to drain this crud out by tilting the barrel to allow it to come out the drain into an empty jug that you can discard.
This barrel method is easy but there will be some cost involved. First, find a barrel that you can clean out well. Next if you don't have a MIG welder, you may have to pay a welder to weld a fitting on it. Then a barrel lid will cost you. I found some lids on the internet - just google "barrel lid" or "drum lids". I used a metal lid so i could bolt a chain to it and attach it to the barrel to keep someone from stealing it. It fits over the top of the barrel with a 3" lip around the edge to overlap the top of the barrel. Heres a link
to find the metal one i used.
Then a 3/4" locking ball valve found here
...part number 4629K14
. I used a locking valve because i had this nightmare that my barrel was full (55 gallons) and a drunk vagrant was messing around behind the restaurant and turned the valve just before he passes out...recreating the Exxon Valdez incedent...then the restaurant called me the next day to come and bring a HAZMAT team to clean it up. So i sleep better with a lock on it.
Make a stand however you can engineer one but make it so the barrel isn't easily turned over - again, nightmares of the Exxon Valdez. Use a can of spray paint and some stencils to label the barrel :Waste cooking oil" Put your name and phone number on it with a Sharpie and call it good.
These are definitely the easiest ways to collect oil to carry it home. It should be mess free, IF you don't overfill a jug when using the barrel method and be sure to put the lids on the jugs tight...i had one turn over in the truck and the lid was loose, and it leaked about a quart of the nasty stuff in the bed of my truck.
Hint: Dawn dish washing soap and hot water is the BEST way to get it off when you need to clean up a spill. I have tryed several soaps and Dawn far outperformed the rest.