First, Harness the Flying Toilet
An attempt at an integrated solution for urban sanitation – maximize use of surplus nutrients to create prosperity and health
-Please see recent additions and refinements
Ditches and canals used as open sewers present special problems and opportunities for a sanitation solution. The problems are all too obvious. It's dirty dangerous work fishing plastic and metal garbage out of sewage filled ditches.
First, Harness the Flying Toilet
First, Harness the Flying Toilet
To see the opportunities here takes a little effort. You basically have water in some amount, and lots and lots of surplus nutrients.You also have all the surface area the ditch and its verge takes up.
Even when the flying toilets are completely under control, the waterways will carry plenty of nutrients. How can all this potential fertility be put to use? Marsh plants thrive on nutrient heavy water, purifying, shading and cooling wet areas and providing cool breezes to the areas around them. You have the surface area, the "real estate", to catch a lot of water before it flows into the ditch.
You also have a place where lots of people already go to relieve themselves. Banks of public toilets with roof top rainwater catchment could line the verges of canals and ditches in areas where there was no other space to site them. Water could be released slowly during the dry season for irrigation of plantings.
Additions and refinements-
1. As Johan so astutely pointed out in his comment on the ponds concept for waste treatment, aquaculture (raising fish) is often a part of integrated waste solutions in systems that can temporarily spare enough water. The water that fish are raised in is much improved for crop irrigation because of the nutrients the fish add.The fish provide a low input cost source of protein for the community. Would people in Kumasi eat fish if they had access to them? If so, what species would they prefer? Is there a species they would prefer that is suitable for aquaculture? I've heard that in China ducks and fish feed from ponds with raw human waste in them. This may not be culturally acceptable in Ghana or elsewhere.
2. Integrated systems for waste solutions and food production have many potential inputs and outputs. With expert help, it should be possible to design a system that is accessible for local people to manage, and provides the crops they prefer along with revenue generated from sales of energy.
3. Over time, a percentage of biofuel revenues can be used to finance sustainable water infrastructure in poor urban areas.
The job of living one's daily life in the situation that faces Kumasi is a very difficult one. This deserves a huge amount of respect, and requires of us a certain reluctance to mess with what already works. Buckets and chamber pots, overused and dirty public restrooms and even flying toilets have served to keep millions of people alive and functioning as a society. From the people who drive the vacuum trucks, to the people who run public toilet businesses, all are solution providers in a system that reduces the spread of disease and already keeps most people alive in a very crowded environment.
People don't easily abandon what works for them, even when opportunities for improvement are presented. To make such changes attractive, they must affect the daily bottom line of family prosperity. Even then, the changes must not be too large, and must be introduced in a culturally sensitive way.
The truly poor who struggle to get enough food, clean water and a safe place to sleep, are very easily motivated to help with sanitation. Simply provide the means for safe recycling of their wastes and pay them to collect wastes for processing. Extra points if you also provide them with access to tools and means to improve their situation in life. Motivating people with the means but not the inclination to purchase a sanitation solution (even through a supported loan program) is tougher, but possible.
In order for changes to be adopted and maintained, people must be able to see clear benefit to themselves in areas they care about. Ask people what they want in life, and use a sanitation system as a way to deliver that to them.
How is this possible? Respect the value of these surplus nutrients known as human waste as a resource. The resulting prosperity will give the community the means to make the improvements they want, not the ones we choose for them.
First, Harness the Flying Toilet: An attempt at an integrated solution for urban sanitation
1. Make sanitation products such as peepoo available without monetary cost, so they will be widely adopted. People could have them for free or nearly free if they participate in learning how to use the product effectively and distributing them to others.
2. Work on producing bags and sanitary pads locally out of banana leaf or local equivalent. Design system to keep bags and pads from clogging vacuum trucks etc.(could include separate pickup for waste bags and pads not even involving vacuum trucks)
3. Pay public toilet owners for collecting waste bags, so their business will be augmented rather than disrupted. Facilities can earn bonuses for best/cleanest toilet as voted on by user community (cell phone connection)
4. Pay people to collect flying toilets for deposit at public toilets.
5. Create water harvesting infrastructure at waste processing location.
6. Process waste for biogas at landfill or other appropriate location. Generate electricity and/or sell as gas. Actively source minimum levels of livestock manure to optimize biogas generation until step 11 is in place.
7. Use nutrients (compost) leftover from biogas production to fertilize an ethanol feedstock
8. Distill and sell alcohol as clean cooking fuel and facilitate availability of alcohol stoves
9. Compost fermented leftovers from ethanol production and food waste from the community to fertilize and water grass. Biogas and ethanol both produce water as a byproduct, plus any rainwater than has been collected in the water harvesting system.
10. Graze livestock on grass. Dry and sell hay if there's a surplus. If there's no room or infrastructure for livestock, simply produce hay and straw for sale.
11. Pay people who buy hay for animal fodder to deliver their livestock manure to wherever it can be picked up for transfer to the central facility.
12. Use livestock manure to optimize biogas production levels and enrich the compost.
13. Produce “cleaner”, community acceptable gardening compost from the results of steps 9, 10 and 11 without including any human bodily waste. Sell this soil for urban container gardening along with community sourced containers.
14. Expand to multiple digesters, so you can designate one or more for biogas from 9, 10 and 11 only, so you won't have to waste its energy potential to make “cleaner” compost people will be comfortable using in gardens..
15. Pay people to bring gardening and food waste to a collection point for the central facility.
16. Process that waste on the 9,10,11 side of the biofuel plant as well, to optimize garden soil production. If there is surplus cleaner garden compost, then use it to make food parks and gardens at community institutions such as schools.
17. Begin to branch out and decentralize, adding more water harvesting/biogas/ethanol/waste processing facilities as the community is ready to operate them.
Who could implement this?