Abstract: A mobile water filtration apparatus and method for on-site removal of contaminants from raw water comprising a portable platform and a first settling tank secured with respect to the platform. The settling tank includes flocculating agent and a lower portion into which sediment settles. A sloped trough is secured with respect to the platform and has an upper end which receives the flocculating-agent-containing water, a lower end, a plurality of spaced-apart walls between upper and lower ends which define a serpentine flow path, and a plurality of agitators between the walls. A terminal settling tank receives water from the trough lower end and includes a lower portion into which sediment settles and an outlet along an upper portion through which treated water flows. An exemplary apparatus includes a gate corresponding to each wall and defining an opening through which water flows.