This document examines the negative externalities of sachet water consumption in Nigeria, specifically in Kwara State. It traces the origins of sachet water production to 1990 due to governments' inability to provide adequate clean water. The non-biodegradable plastic packaging of sachet water leads to pollution when disposed, harming both consumers and non-consumers. The study aims to identify the most appropriate policy to control these externalities, such as a deposit-refund system given sachet water's recyclable packaging. Weather is a key determinant of sachet water demand in Nigeria.