55 gal drum humanure composting question

Hi there! I’m looking to build an outhouse where the waste goes directly into a 55gal drum that I can remove once full, and leave to compost. I’ve seen two designs.. one (actually with a wheelie bin, not drum) that has half pvc pipes running vertically in the corners of the bin, with slits down the sides of the pipe for ventilation. The other is just a drum with a screen over the top, and no internal ventilation. Of course, I’d prefer the latter. Seems like a lot less work. Just concerned that there won’t be enough airflow. Any opinions? Thanks!

Josh, there appears to be some correlation between amount of aeration and pathogen kill at cold composting temperatures.  For example, the manually aerated Omick Barrell Toilet was certified to reliably kill pathogens in only 4 months, but most designs I've seen recommend a conservative 2yrs with no aeration (e.g. Joe Jenkins).  The passively aerated Geoff Lawton Wheelie Bin design supposedly takes 6-10months, but I don't know if that was even formally tested.  This hybrid eco-toilet uses a fan during the aging period and still requires at least a year.  The temperature vs pathogen kill curve for hot composting is independent of aeration, but I think a 55 gallon drum or wheely bin would be too small to achieve that without help.  If you're letting it age for 2 years to be conservative anyways it may not matter.

What designs are you looking into?  For awareness, there is also a Toilet Alternatives forum under the Building group.

Hmm. I see the omick design isn’t well suited for cold climates, unless indoors. I’m at 8000ft in Northern New Mexico. Now I’m wondering if maybe cold composting isn’t the way to go. I was looking into Geoff lawtons wheelie bin system. I stumbled across the other design just searching around on google. I’d have to dig around to find it again. It appears that with the omick design, they only tested for salmonella. I wonder how capable it is of killing other pathogens. So far I haven’t stumbled across anything that suggests (by way of proper studies) that cold composting will eliminate all pathogens. Im now leaning towards the classic bucket to hot compost pile method. Not exactly excited to have to deal with the buckets. I’ve definitely got some more research to do. Thanks for the response!

josh ober wrote:So far I haven’t stumbled across anything that suggests (by way of proper studies) that cold composting will eliminate all pathogens.

Josh, glad you're doing research!  How cold does it get there?  The use of worms to kill pathogens in a flush toilet setup called a vermifilter has quite a bit of research done on it.  See resources.  The effectiveness declines as the temperature drops lower, so it may require some strategy to keep at a reasonable temperature for the worms.

By chance, do you know if NSF Standard 41 includes more than just fecal coliform testing as far as pathogens?  The Clivus Multrum design is NSF 41 certified and works at mesophilic temperatures.

You should check out this video featuring the willow candy warehouse at Wheaton Labs.  They use drums for their humanure.

Watch it here:  

The original blue print submitted to U.C. Davis submitted in about 2002 way more simple than you realize. Remember you're taking billions of your hard earned cash back from the gas and electric company. This easy most of you will figure it out. Home Depot - 3 55 locking drums 3 1/2 in. Metal pipes one2"round drill bit. Eight washers, one pressure regulator and release valve -----35 gallons water and any sent you like you have all you need, because of copyright law and obtained during a degree program that is as far as I can tell you. I will say this, imagine you're a fith grader putting this together and you got it