Request for Expression of Interest for Manufacturing, Marketing and Distribution of Waterguard at PSI Kenya 2013   Request for Expression of Interest for Manufacturing, Marketing and Distribution of Waterguard Population Services International, Kenya (PSI/Kenya) is searching for a private sector firm that has the capability to manage the manufacture, marketing and distribution of the WaterGuard brand. WaterGuard is a successful point of use household water treatment proven to purify untreated water to drinking standards and dramatically reduce the incidence ...