Pitch a Greywater Reuse System for a Lagos Compound House

Compound housing, where multiple households share a single plot, bathrooms, and sometimes a single water source, is one of the most common living arrangements in Lagos, Ibadan, and Kumasi. Residents pay significant amounts for water, then discard greywater from washing, bathing, and cooking with no secondary use. At the same time, gardens go unwatered, toilets are flushed with drinking-quality water, and groundwater tables fall. Design a greywater reuse system appropriate for a compound of 6 to 12 households. Your system should address collection, basic filtration, storage, and redistribution for a secondary use, such as toilet flushing, garden irrigation, or cleaning. It does not need to be an original invention. You should draw on existing low-cost approaches (constructed wetlands, sand filters, drum systems) and adapt them to the compound context. Deliver a pitch deck of 8 to 12 slides that covers the problem, your proposed solution, a rough bill of materials and cost estimate in naira, the implementation process, and the main risks. Include at least one diagram or sketch of the physical setup. The deck should be good enough to present to a community development association or a housing NGO. Strong submissions will show awareness of who actually makes decisions in compound housing, whether that is a landlord, a caretaker, or a tenants' committee, and will address how the system gets maintained once installed.