Feidhlim Harty wrote:
Sean, I'm not aware off hand of any systems in the UK, but you're probably like me insofar as the extra liquid certainly isn't necessary in the garden. In my case the main hurdle will be convincing the local authorities that our approach is not going to damage the local environment; which essentially means that all effluent will need to be disposed of safely on heavy, rocky soil. In this instance we propose a pump-fed drip irrigation system. Not entirely in line with Permaculture principles, but a compromise to both address pollution concerns and to deal practically with extra liquid in a wet environment.
Feidhlim Harty wrote:Thanks Sean, Second thing first: if it rains, the water will simply add to the overall volume of effluent from your mini reed bed, so no problem there, and no need for it to go in a greenhouse. The Irish wastewater codes call for a minimum of 5m2 per person capacity in the house. Thus for a 3 bedroom house, the equivalent is 5 persons, thus 25m2 minimum reed bed size for secondary treatment (reducing the BOD and suspended solids from 300 to c.20mg/l). An additional 1m2/pe is needed for tertiary treatment to achieve 5-10mg/litre. Clean river water has a BOD of about 1mg/litre.
Feidhlim Harty wrote:Hi Sean, perhaps the easiest way to recoup the nutrients is to use two Solviva brownfilter boxes in series followed by the Solviva green filter planted with a crop of comfrey for nutrient cycling back to your compost heap or willow or ash etc. for a quick growing firewood crop. Easier than aquaponics (but if you'd rather the watery route, then not necessarily as much fun to experiment with either).
Andrew Ray wrote:Do the worms have a preference or aversion to certain species of trees as far as to what I could source for organic matter? Fresh sawdust from a lumber mill is something I already get for the sawdust toilet and to put under the chickens. If sawdust is problematic (since I see mention of "wood chips" and "wood shavings" but not sawdust), this could be the excuse to get a limb shredder. We have a fairly unlimited supply of brush on our property, and if I ran out and started clearing overgrowth on other peoples' land, they wouldn't complain.
Is there a risk of the outlet of the IBC container getting clogged? Should I be putting gravel in the bottom to keep solids from migrating out?
As far as getting air to the worms, I am imagining a pipe extending up along the side of the house to roof level from the top of the IBC container to allow air to exchange, though maybe I would need also an input for air?
Since no one reports needing to remove compost, I plan to just leave the top of the IBC container as is with the large screw cap that comes on them.
What species of worms do y'all use for your worm-tanks? Is there some mail order company that ships them? I've never bought worms! Or are ordinary earthworms fine?
Steve Smyth wrote:I wonder if I could take an IBC tote and cut the top out and place drain rock in the bottom. Cover the drain rock with landscape fabric. Place a bale of straw in the center and surround it with bedding material (wood shavings/chips, shredded leaves & paper etc). Then pump 30+ gallons of effluent onto the straw bale every 10-14 days. Do you think this is a practical application?
My thought is that the straw bale would help disperse and moderate the effluent flow to avoid drowning the worms.
If the liquid discharge from the bottom of the IBC tote is clean enough I could pump it to a raised bed planter. If it is not suitable for that I would continue to store it and have the potty people come out and remove it as I am now just not nearly as often.
What do you all think?
Wendy Howard wrote:
I think you'd be better just to have the effluent go straight to the worm bin. By macerating it with the flush water, you're doing something which then has to be undone again. Better not to do it in the first place. From Anna Edey's figures, the vermicomposting ecosystem will clean the liquid component of the flushings in as little as 10 minutes and remove upwards of 90% of the dissolved nitrogen. The water can be filtered much more efficiently and effectively with a speedier throughput time if it's not been mixed up with the faeces and your system is much less likely to run the risk of becoming too wet for the health of the worms. Drain rock isn't necessary with this set-up either.
It's true worms are used very successfully to compost sewage sludge, but to my way of thinking, a system has greater resilience the closer it is to the way nature intended. Mammals were designed to poop on soil, not water, and worms evolved in the soil to deal with it. Poop + water = disease + smell, so if you're going to use water as a carrier medium, keep it as brief as possible! I think it would be very hard to avoid a stink with 30 gallons of sludge at a time. If there's no option but to do it the way you suggest, then I would feed your worms much smaller amounts much more frequently and fill the tank with a well mixed selection of carbon material, not one type in the middle and another at the edges. I wouldn't really think of it as 'bedding material' so much as feedstock - the whole lot will disappear in a surprisingly short period of time!
Feidhlim Harty wrote:Steve, a client of mine used a marine toilet, which had a combined pump and macerator built in, and then pumped directly to the woodchip bed. That seemed to work ok for him. However, Wendy's comments about flushing directly to the woodchips are very valid and you'll need to consider that in your overall design by factoring in an extra filter stage or equivalent to make sure that the final effluent is good and clean before discharge.
Feidhlim Harty wrote:Steve, the last I heard the client was very happy with that approach. Follow-up is sometimes thin on the ground though. Do you have guidelines for the reed bed design? Just be sure to build it large enough. One of the challenges is systems sized too small. That said, if you're using a vertical flow system then you'll need to be sure that the summer weather where you are won't fry everything in times of low inputs. My website has links to the Irish EPA Code of Practice (www.wetlandsystems.ie) if that's of any help to you. All the best with it.
Wendy Howard wrote:The coarse carbon material provides an almost infinite surface area for bacterial colonisation and is consumed in the process of stabilising the active nitrogen in the effluent. This is as much part of the cleaning system as the worms.