Pits, pipes, ponds – And me

My life in low-cost sanitation and low-cost wastewater treatment and the use of treated wastewater in agriculture and aquaculture really has been ‘pits, pipes and ponds’ – ‘pits’ are low-cost sanitation technologies (LCST) such as VIP latrines and pour-flush toilets; ‘pipes’ are low-cost sewerage, principally condominial (simplified) sewerage; and ‘ponds’ are low-cost wastewater treatment systems, especially waste stabilization ponds, and the use of treated wastewater in agriculture and aquaculture. ‘Pits’ were mainly working on World Bank LCST research projects, with fieldwork principally in Zimbabwe, ‘pipes’ were working on condominial sewerage projects in Brazil and disseminating this LCST to a wider global audience, and ‘ponds’ were waste stabilization ponds, with fieldwork mainly in Brazil, Colombia, Portugal and the United Kingdom, the development of aerated rock filters to polish facultative-pond effluents, and the human-health aspects of treated wastewater use in agriculture and aquaculture, with fieldwork in Brazil and the UK, and the application of quantitative microbial risk analysis. The paper provides a professional perspective and lessons from historical developments and gives recommended future directions based on my career working on low-cost sanitation technologies and treated wastewater use in agriculture and aquaculture.

► Pits: sanitation technologies such as VIP latrines in rural areas.
► Pipes: simplified sewerage using 100-mm diameter sewer laid at 1 in 200.
► Ponds: waste stabilization ponds and safe effluent reuse in agriculture.