Cold Composting

Urban Moorings Cold Composting Case study By Jennie Howland Urban Moorings C.I.C.

Cold composting is simply allowing nature to take its course. Hot composting speeds up the natural process. Cold composting takes 9 – 12 months for nature to complete the process of turning a seemingly unusable waste material into a very usable product.

Here at Urban Moorings, we have been composting human manure for quite some time. Before beginning the Urban Moorings project, two of the boats now involved had separating /dry toilets, so we were well experienced in the production of humanure.

From our experience here, I would confidently say that setting up and maintaining a humanure facility can bring benefits, not least saving on the cost of buying in fertiliser and compost for any flower beds, pots or other containers that may be in use for non-food plants and trees.

Getting Started

All you need is space, about one meter square x one meter high x two minimum.  As we have the space, we have built four bins to maintain a rotation of a minimum of three months.

Building materials to construct the bins, we used old, recycled beams and cement made from cement powder and fire ash, plus some 2x2 timbers for the corners of the bins, screws and hinges for the lids.

Or you can buy ready made containers, large dustbins or repurpose old wheelie bins, but do bear in mind that whatever container/bin is used, it will need emptying after an appropriate time. I have seen old wheelie bins with large square access holes cut in the side and then hinged back on with nuts and bolts and taped across the bottom until they need to be emptied. In line with the ethos here at Urban Moorings, we use as much reclaimed/recycled materials as possible and would encourage others to do the same. Apart from any other consideration, utilising recycled materials can often save financially and is good for the environment. 

Whatever design of bin is used, it will need to be sealed at the base to prevent any risk of leakage, although if the material being composted has been covered with an appropriate carbon material there should be little fluid to worry about. Wheelie bins/dustbins make good containers as they are sealed at the base even if side access panels are cut into them.

Last date edited: 20 October 2021