Many water purveyors in the Okanagan use a groundwater source. Manganese is a common water quality problem from an aesthetic perspective. Nuisance conditions associated with Manganese include black sediments in the water, stains on plumbing fixtures and laundry and black deposits in the water distribution system. The objective of this project was to assess the feasibility of Manganese removal using a biological treatment system. Developed in the 1980's by Degremont Ltd., the Mangazur is described as a biological water treatment process where bacteria naturally present in the well water adhere to a filter media and produce a biofilm that biologically oxidize metals to form compact precipitates. There are currently over 120 biological iron and manganese removal plants around the world, including a number in Canada. In 2001, the City of Waterloo received the 'Technological Innovation Award for Infrastructure' for adopting the Mangazur and solving its manganese problems in an efficient and ecological fashion, without additional taxes. The Town of Osoyoos engaged TRUE Consulting to pilot test a biological filtration technology that could address the elevated concentrations of dissolved manganese in the groundwater extracted from Well #6 and Well #8. In the final report, the biological filtration technology is described and the results of the pilot study are analyzed.