Feasibility Studies for Water and Waste Water Solution

Hello All, I am working on a proposal Methodology to conduct feasibility studies FOR WATER AND WASTE WATER MANAGEMENT STRATEGY FOR A 1,000-HECTARE. The permanent water and waste water solutions must be capable of producing 10,000 m3 to 15,000 m3 of potable water per day and handling about 7,000 m3 to 12,000 m3 of waste water per day.  Please, anyone with useful information or with past experience should kindly help. I need to come up with the best Technical Proposal. Location is Lekki Island Lagos Nigeria. Thank you