CBS for flood prone areas in Zambia

An initiative that fosters circularity and stimulates local economic development by piloting an innovative solution using black soldier flies for treatment and reuse of human waste within a CBS service model.

In the flood-prone, low-lying Overspill and Zambia compounds in Choma, residents predominantly rely on unlined pit latrines. These regularly overflow, collapse, and contaminate the living environment. The area currently lacks a faecal sludge treatment facility and remains to be served by a professional, regulated system of emptying services. Consequently, waste is often disposed of in drains and open fields, leading to the pollution of local water sources.

To support government objectives for water, sanitation, and public health, SNV has been engaged by BMZ—through KFW—to introduce a climate-resilient, market-driven business model for human waste management using Container Based Sanitation (CBS), addressing the complete sanitation chain with Black Soldier Flies as the preferred treatment/reuse option. The project (2025-2029) is part of the broader Management of Water Resources and Sanitation in Medium-Sized cities, managed by Posh & Partners, NIRAS, and MACs, with KFW and EU funding.

Key elements of this approach include:

●       Piloting a CBS sanitation service model utilising BSF, which reduces sludge volume by up to 70%, lowers greenhouse gas emissions, and produces safe bio-fertilisers for local industry and farmers.

●       Promoting the benefits of bamboo and hydraform bricks for durable toilet superstructure construction, reducing reliance on deforestation-linked burnt bricks.

●       Enhancing CBS service delivery by institutionalising occupational health and safety standards for sanitation workers.

This project builds on the success of the Chambeshi-Lukanga sanitation programme—a WASH SDG partnership between SNV, Plan International, and the WASH Alliance International (2017-2022), which succeeded in pioneering scheduled desludging in Zambia and contributed to the development of the statutory instruments for on-site sanitation and the climate change risk screening guidelines.

In Choma, SNV is providing technical assistance to the Southern Water and Sanitation Company and training masons and emptiers, while ensuring close engagement with local leaders and representatives of women and people with disabilities for more inclusive and responsive services. At the same time, drainage and solid waste management are addressed as interconnected factors influencing the long-term sustainability of sanitation—aligned with SNV’s Sustainable Urban Water Cycles approach.

1. Ensure access to safe, flood-proof sanitation for 12,000 people

2. Support the local water utility to manage CBS services, with private sector

3. Validate BSF as a safe and viable sludge reuse solution