Re-emergence of dry toilets and fecal nutrient reuse in M'zab cities

Abstract

In the M'zab valley, dry toilets represent an ancestral dry sanitation system, serving as a source of fertilizer thanks to human excrement valorization. However, in the 20th century, local populations began to shun these systems. The objective of this article is to illustrate the importance of dry toilets on agricultural and environmental scales in ancient M'Zab, and the renewal of these systems in response to sanitation problems in the oasis after their decline. The hypothesis put forward is that dry toilets can act as a complementary system to conventional sanitation systems. Data were collected through interviews with the local population. Our results show that the use of dry toilets, and the resulting use of human excrement as fertilizer, has gone through three phases. First, a phase of strong recycling dynamics, followed by a second phase of decline in dry toilet use which is linked to the discovery of the Albian aquifer and flush toilet adoption. The third phase is characterized by dry toilet reuse in response to oasis degradation caused by sanitation and environmental problems. Some oasesians have taken the initiative to revert to dry toilets to ensure oasis system sustainability and to revive the practice of recycling human waste.

Reinventing the wheel: adapting a traditional circular irrigation system to ‘modern’ agricultural extensions in Algeria’s Sahara

“…The introduction of electric pumps has contributed to a drop in the piezometric level. Also, due to urbanization of the palm grove and the implementation of a water supply system, the water consumption and the production of waste water of households has increased drastically (Bekaddour et al, 2021). The absence of a sanitation system in most parts of the oasis has resulted in the degradation of groundwater quality.…”

“…They weave different patterns or ways of farming with multiple manifestations of the age-old principles of circularity in their technologies, institutions and practices. First, there is a strong focus on the recycling and reuse of "waste" products, including the age-old use of animal and human manure, the use of vegetable waste for composting and mulching, the use of sediments transported by flash floods, and the more contemporary recycling of plastic and ferrous waste (Bekaddour et al, 2021). Second, most farmers engage also in agroecological practices related to reducing or even eliminating the use of chemical inputs, while favoring short marketing channels for "local" products thus reducing emissions to the environment.…”