Knowledge base

Small-Scale Wastewater Treatment Technologies for Challenging Environments

One in every three people globally still lack access to appropriate sanitation, those without sanitation are increasingly those who reside in remote, temporary, or challenging environments. In order to achieve full coverage by 2030 will require a significant shift in technology development and marketing (UN, 2016). Recognising this, the Engineers Without Borders (EWB) Sanitation in Challenging Environments (SCE) Project takes a sector-wide collaborative approach to improve awareness, funding, technology options and action on SCE in Cambodia. Challenging environments defined as rural locations where it is either difficult to construct conventional pit latrines or where they would risk contamination of the environment, particularly groundwater and surface-water resources.

Through collaborative partnerships EWB has been working to expand, test and monitor sanitation technology options available in challenging environments. This paper examines three technologies adapted to challenging environments that demonstrate innovative and novel approaches to a largely under-resourced issue, these include:

i. ATEC* Biodigester – a combined environmental sanitation and energy production technology. The biodigester treats household toilet waste, provides renewable bio-gas for cooking, and produces nutrient rich fertiliser. The ATEC* biodigester is uniquely suited to flood prone and high groundwater environments.

ii. The 3C pit – a simple, cost effective adaption to the widely used pit-latrine for areas of high-groundwater and minor flooding. The design uses three chambers to improve effluent treatment compared to a standard pit-latrine before the effluent leaches into surrounding soil.

iii. HandyPod by Wetlands Work! – a unique sanitation technology using local materials for floating communities who have no alternative but to defecate into the water-body they live on.

Early results indicate a two to three log-order reduction in pathogen levels before effluent enters the surrounding environment. This is a significant improvement on existing latrine technologies for these environments. To reach all affected communities, will require continued investment in research and development, manufacturing, supply chain enhancement, demand creation and marketing.