Toilets that make compost : low-cost, sanitary toilets that produces valuable compost for crops in an African context

iii Table of Contents Table of Figures ____________________________________________________ v Acknowledgements _________________________________________________ xi 1. Introduction______________________________________________________ 1 2. Compost-Making Toilets ___________________________________________ 2 2.1 Arborloo - The simplest single pit compost toilet _________________ 3 2.2 Fossa alterna - The double alternating pit compost toilet ___________ 3 3. Arborloo - The Single Pit Compost Toilet_______________________________ 6 3.1 How to build the single pit compost toilet _______________________ 7 3.2 How to make ring beams ___________________________________ 9 3.3 Building the toilet house (superstructure) ______________________ 18 3.4 Making an Arborloo fitted with a pedestal______________________ 19 3.5 Types of superstructure ___________________________________ 22 3.6 How to use the single pit compost toilet _______________________ 24 3.7 Planting trees in a filled organic pit ___________________________ 24 3.8 Growing vegetables on Arborloo pits _________________________ 26 3.9 Making compost in small single shallow pits____________________ 27 4. Fossa alterna - The Double Pit Compost Toilet _________________________ 29 4.1 Managing the double pit compost toilet _______________________ 29 4.2 Examples of double pit composting toilets _____________________ 30 4.3 Building the double pit compost toilet _________________________ 31 4.4 Superstructures with rectangular slabs________________________ 35 5. Low Cost Pedestals for Simple Pit Toilets _____________________________ 39 5.1 Very low cost pedestal ____________________________________ 39 5.2 Low cost pedestal with concrete seat _________________________ 40 5.3 Low cost pedestal with plastic seat___________________________ 41 6. Urine-Diverting Toilets ____________________________________________ 44 6.1 How to build a single vault urine-diverting toilet _________________ 45 6.2 Making the vault, step and lintel _____________________________ 46 6.3 The urine-diverting pedestal ________________________________ 47 6.4 Sequence of making a homemade urine-diverting pedestal with urine outlet pipe above slab level_________________________________ 47 6.5 Making a simple urine-diverting platform ______________________ 53 iv 6.6 Urine-diverting toilet installation details________________________ 53 6.7 Urine-diverting superstructures______________________________ 56 6.8 Use and management of the urine-diverting toilet _______________ 57 6.9 Processing the faeces_____________________________________ 58 6.10 Stages of building a twin pit composter for a single vault urine-diverting toilet___________________________________________________ 60 6.11 Routine maintenance of the urine-diverting toilet ________________ 62 7. Upgrading the Toilet System _______________________________________ 65 7.1 Upgrading using a round slab and ring beam___________________ 65 7.2 Upgrading using a rectangular slab __________________________ 67 8. Odour and Fly Control ____________________________________________ 69 8.1 Odour control ___________________________________________ 69 8.2 Fly control ______________________________________________ 70 9. A Matter of Hygiene and Hand Washing ______________________________ 73 9.1 Simple hand washing devices_______________________________ 73 10. How to Use Toilet Compost in the Garden____________________________ 76 10.1 Testing crops in toilet pit compost____________________________ 77 10.2 Testing compost from a urine-diverting toilet ___________________ 78 10.3 Growing trees in toilet compost______________________________ 79 11. How to Use Urine in the Garden ___________________________________ 81 11.1 Crop trials using urine as a fertiliser __________________________ 81 11.1.1 Rape________________________________________________ 81 11.1.2 Spinach _____________________________________________ 81 11.1.3 Mint and passion fruit ___________________________________ 82 11.1.4 Onion _______________________________________________ 82 11.1.5 Maize _______________________________________________ 83 11.2 Effect of urine use on maize growth on poor sandy soils: A field trial in Epworth near Harare______________________________________ 84 11.3 Effect of urine treatment on trees ____________________________ 87 12. Summary _____________________________________________________ 90 13. Conclusions ___________________________________________________ 94 Bibliography ______________________________________________________ 97