posted 2 weeks ago
Marta, my hot Humanure compost piles sit for 2 years, but they also cook at 155F in the center and 132F on the edges. I'm not sure letting them rest for more than 2 years buys you anything unless perhaps if the piles are moist, never get hot, and can't breath.
In your original post you mentioned separating urine, what was the goal with doing that? To utilize the nutrient directly, or reduce the risk of contaminating the well? I tried for months to come up with a reliable urine diverter, but it always seemed to clog. Keeping the urine with the poop also reduces the added labor of adding more water and even more green material or manures if your goal is to get the pile hot. I've collected urine in a bucket, tried to heat it for added safety, and then distribute it, but it's not a pleasant task, and I wouldn't want to have guests around while doing it.
The question about building modifications was to see if there were any design constraints you might have there. The Humanure Handbook method requires no plumbing. Other solutions may require standard plumbing or just an electrical outlet, and still others would require a direct chute to a lower level or under the house (e.g. Clivus Multrum style).
You mentioned wanting to have a system others could learn from. While I've shown the Humanure Handbook method, I've grown increasingly discouraged by not just the workload (given the size of my family), but I haven't felt successful at making good compost from it. I mostly have kiln dried pine sawdust available, which definitely takes more than 2 years to break down, and composting it so hot dehydrates the pile to the point it becomes hydrophilic and won't grow anything. I've tried screening aged mulch to get hydrated biologically advice sawdust like what is recommended in the Humanure Handbook, but it was a lot of work, and I don't have the indoor space to store enough of it to last 8 people for 5 months of freezing moist (I can store kiln dried sawdust outdoors).
I'm definitely excited to share our vermicomposting toilet when we get it installed. I think I'll be happier with the output and the low maintenance. I live in a dry climate, and establishing trees takes a lot of work, so our design also includes a way to automatically sub-irrigate trees from the vermifilter output, which will be so nice. Other designs I think I would be excited to share include Clivus Multrum and
Wastewater Gardens. The Clivus Multrum design manages moisture, is a cold composting process that doesn't cook the soil food web, is very low maintenance, and has a shelf stable liquid output. Wastewater Gardens use lots of plants, have very low regular maintenance, but may require cleaning the gravel every 20 years, and the output isn't quite as clean as vermifilter when coupled with plants.