(1) Kitchen and animal waste because biogas for energy saving is needed --> But the organic load is to high for the wastewater treatment
(2) Treated domestic wastewater for irrigating food garden is needed
--> But not so much and not all the time
(3) Water temperature goes down to 9°C in winter time. -->Actually to cold for biological treatment processes
(4) Can the construction not be done cheaper?
--> On-site sanitation may not cost much, shall be repaid within few years, shall bring clean water and much biogas
Those are the 4 major challenges facing the BORDA partner TED (Technologies for Economic Development) in Lesotho. But on the other hand, Lesotho is an ideal place for DEWATS application. Septic tanks with soak-away are either not allowed by authorities or do not work due to the ground texture. Regular empting of the septic tanks is expensive and the commercial utility can hardly serve the demand. Thus many private households, landlords of rental houses and institutions invest in a Biogas/DEWATS system provided by TED in cooperation with BORDA.