A plate is positioned across an inlet to a catch basin and a filter strainer is inserted through an opening through the plate and into the basin. A tertiary filter completely surrounds the strainer and is suspended below the plate. Surface water flows through a primary grate that covers the catch basin, through the strainer and through the tertiary filter. The tertiary filter comprising fibrous filter media retained in a non-woven mesh fabric enclosure and the filter media is selected according to the type of contaminants that are to be removed.