The purpose of this paper is to describe the solution that is currently being developed in response to a water treatment capacity shortage in a First Nation (Indigenous) community in northwestern Ontario, Canada. Due to a variety of reasons, the slow sand filtration plant at Lac La Croix First Nation, constructed in 1994, has prematurely reached capacity. The expansion options available to the First Nation are limited due to current fiscal constraints. In the early 1990s, during the original design process, slow sand filtration technology had been considered somewhat unproven in small scale applications in cold water conditions. As a result, a conservative filter rate of 0.12 m/hr was adopted for the Lac La Croix design to allow for sufficient contact time. This paper discusses the optimization study currently being undertaken by the Project Team to determine the effectiveness and benefit of increasing the hydraulic loading rate (HLR) of the existing slow sand filtration process. By deferring the major capital expenditure that would normally occur as a result of treatment facility expansion, it is anticipated that this optimization project will result in significant cost savings. Includes 6 references, table, figure.