Table 1.

Advantages and disadvantages of selected on-site wastewater treatment systems

Sanitation system	Water requirements	Advantages	Disadvantages
Simple pit latrine	Dry	Inexpensive, limited expertise needed for construction	Significant fly and odor problems, concerns by users over safety
Pour flush latrine	Wet, with low-volume water use	Low-volume water use, fly and odor problem controlled, convenient for users, easily upgraded	Increased cost compared to pit latrine, reliable water supply needed
Composting latrine	Dry	Humus produced as fertilizer/soil conditioner	Requires expertise to operate, sludge requires careful handling, some systems require urine separation, ash and vegetable matter must be added regularly
Urine separation	Dry, with urine collected separately	Provides humus used for fertilizer, urine can be used as fertilizer, low-cost systems available, reduces hydraulic load	Desludging requires careful handling, pathogens may not be inactivated in sludge pile, user education required, significant time spent in operation and maintenance
Septic tank	Wet, with high-volume water use	Convenient, limited fly and odor problems, wastes removed rapidly	High cost; in-house piped water generally required, large space requirement, regular desludging required, permeable soil required

Source: Franceys R, Pickford J, and Reed R (1992) A Guide to the development of on-site sanitation. Geneva: WHO.