I'm planning to build a system that will use 1000lt IBC tanks. im told that the outlet from the first tank,
when this turns 90 degrees and goes vertical, the height you go vertical before turning 90 degrees into the second
tank is important. So does anybody have experience with this? the tanks are 1 meter in height and the finish height
of the sand in the first tank will be 150mm/6inches from the top of tank. the out let from the bottom of the first tank
will be within a couple of inches of the bottom of tank.
I would imagine that once the capacity in the first tank is enough to take the volume of grey water form cabin without over flowing the tank would be the way to go... anyone got an idea as to how long a system like this would take to
process grey water?
forgive my ignorance but i would like to build this once and not be going back to dig it up an redo it!
Stan, all you're talking about is grey water? Not black water? Just the sink, bathtub, shower, washing machine?
Not sure where you are, but since you're asking here, and not the building department where you are, this is not a permit issue? I'm assuming you want to have this water "cleaned up" before you use it in a garden?
Assuming you will be using soap, hopefully not detergent, bar soap, dish soap, the first tank could be half filled with bark chips and compost and worms, and then the overflow can go into a bark chip trench in the ground via PVC Lines. Some people send it straight into bark chip trenches, which then will seep through the soil to a tree/landscape planting (not food production) of your choice that is downhill from those bark chip trenches.
There is a black water version of this bark chip/compost/ worms mix with about 5,000 worms per 500 gallon tank. The worms work it over, it overflows into a second tank with plants or ground trench with bark chips and used for landscape.
There are reed beds you could run it into straight from the house. I designed mine on this picture, using pond plants, and it works really well. We do not have a frozen winter, so the reed beds are open. But there are municipalities in Canada that use reed beds, and those must freeze, so you can search on those.
An important distinction: Permaculture is not the same kind of gardening as organic gardening.
Mediterranean climate hugel trenches, fabuluous clay soil high in nutrients, self-watering containers with hugel layers, keyhole composting with low hugel raised beds, thick Back to Eden Wood chips mulch (distinguished from Bark chips), using as many native plants as possible....all drought tolerant.
Hi Stan, I've seen IBC reed beds here in Ireland, but haven't got much experience using them for reed beds. Generally I like to design my reed bed systems large enough to filter all the usual gunk that makes its way down the drains - including a flush toilet, dish washer, washing machine, shower, sinks etc. So the size is a lot larger than a few IBCs. When you're careful with what you put down the drain, you can afford to go a lot smaller with your reed bed size.
Here's what I'd do if I were using IBC tanks:
Saw the IBC in half, so that you get two 500mm deep tanks out of each unit. Fill these with pea gravel and use grey water piping (PVC, eco-disaster) or 1" water mains piping (PP, much friendlier) as a connector between the two. Plumb the tanks so that you have a finished water level 100mm below the top lip of each tank.
If you're using the first one as a vertical flow reed bed rather than a horizontal flow reed bed I'd use a www.ribbit.ie splitter unit to get a good distribution of effluent across the top surface; or build a syphon dosing unit to do a similar job. Then the outlet can be from the base part of the IBC, with an open tap dropping to the next IBC.
In terms of the time taken to process the grey water, that will depend on the amount of water you use. Here in Ireland the typical water usage is 150 litres/p/d (officially anyway, it's actually a bit less), and a typical grey water reed bed would usually be about 20m2 to get the water good and clean prior to the percolation area into the soil.
Check out solviva.com and oasisdesign.net for more background. Or of course wetlandsystems.ie/watertips.html, but I'm biased... :-)