Ash depth filter sanitation eliminates all bacteria and makes source-separated urine waste sterile

Remote houses cannot use sewerage systems and so they must make their own arrangements for waste disposal. A solution is the use of ash depth filters which simultaneously trap nitrogen and phosphorus from human waste streams and all bacteria during long periods (750 ml per day for more than 6 weeks) of operation by filtration under gravity. Bacteria entering the filtration system, those trapped by the filter and the living material which eventually emerges if the system is operated till it eventually fails, are characterized. Reduction of bacterial numbers is achieved by two mechanisms: physical filtration and chemical sanitation.