- common waste product
- may be available free
- strong, lightweight, durable, good on water quality
Several types of barrels
- can be re-used in many ways (compost turner?)
- rarer around here
- more expensive to buy new
"Closed top" barrels
- used fo the design below
- more common
- cheaper to buy new
- fewer re-use possibilities besides liquid storage
- no removable lid, just two threaded holes:
The best barrels for water storage have only held food products, like cola syrup, grain/baking supplies, juices, sauces, animal feed?
On the other hand, this design calls for many PVC joints (see below), meaning many fittings and much time spent fitting them. The price of the PVC fittings may greatly exceed the cost of the barrels. The time required to plumb more than a few barrels may be prohibitive. Fortunately, the design is fully scalable, all the way down to a single barrel.
This system is intended to be connected to a house gutter to provide rainwater storage, ultimately feeding an irrigation system for a garden plot.
Closed-top barrels usually have two threaded holes, one coarse-threaded, the other fine-threaded.
Coarse thread hole/"bung"
- funky threading: buttress threads
- but: bung cap has an adapter for 3/4" NPT
Fine thread bung
- regular 2" NPT female threads
Bung caps are made to accept a bung wrench for opening and closing
You can buy one or you can make one.
A pair of pliers will work in a pinch.
Weight of water is an important consideration.
Water weighs eight pounds per gallon.
A full 55-gal barrel weighs more than 440 pounds.
Some barrel system designs require the construction of a sturdy timber frame for stacking the barrels. This is a fine idea if you have the necessary time, resources, and expertise. I do not.
Instead: stacked barrels in a pyramid--cheaper, faster to construct, more mobile, less resource-consumptive than timber frame.
- Avoid crushing empty barrels. Full barrels shouldn't sit on top of empty ones.
- Prevent the barrels from rolling away when full. Wire rope wrapped around the barrels like a giant rubber band might work
- Prevent the barrels from blowing away in the wind when empty.
- The higher the barrels are, the greater the pressure at the outlet. Might want to make a base from something sturdy. For more, see this.
Plumbing the Barrels
Scale up/down to suit.
One feature of this design: the nominal distance between any two connected bungs is ~23 inches (diameter of one barrel).
Why is This "Untested"?
We found a local source for IBCs at $20 each, cheaper than plumbing the comparable number of barrels. (2 IBCs = ~600 gallons for $40).
We've had a hard time finding suitable barrels for free in the Richmond area.
Faster to install 2 IBCs than 10 barrels.
But, I couldn't find anything on the intertubes about this.
Art Ludwig, Water Storage: Tanks, Cisterns, Aquifers, and Ponds
Stacy Pettigrew and Scott Kellogg, Toolbox for Sustainable City Living: A Do-it-Ourselves Guide