Specifications include, but are not limited to: Professional engineering firms to perform engineering design and construction administration services for improvements to the City’s Water Treatment Plant (WTP) Filtration System. The City of Great Falls operates a surface water treatment facility to treat water drawn from the Missouri River. The current filtration configuration consists of four filter basins, each basin containing four filter beds, the first constructed in 1916 (filters 1-4) then in 1932 (filters 5-8), 1952 (filters 9-12), and the last in 1959 (filters 13- 16). The filtration process is described as conventional rapid rate filters with granular media. Filters constructed in 1916 are a mono-media filters (sand with a two inch anthracite cap) and those constructed later are comprised of dual media (sand and anthracite).