From Cheryl Hillier, Cribyn, Dyfed, UK
Graham Lawton’s article on the recovery of useful chemicals from sewage was excellent. I have long advocated for mainstream use of – which can make use of our waste in situ – so it is helpful to put a value on the commodities we flush away (29 March, p 22).
Extracting chemicals at the source using composting toilets could cut water-treatment costs and domestic water use, making us more resilient to drought, as well as preventing sewage spills into rivers and flood water. Commodify the resources in sewage and you also potentially create emissions from their transport, which is a really strong argument to localise the process of dealing with them.
