A removable drain filter apparatus (20) with an housing (22) connectable with upstream and downstream drain pipes (40, 46) has a filtering chamber wider than the drain pipes and divided into an upstream portion (78) and a downstream portion (82) by a generally planer filter element (50). A hatch cover (32) carries a downwardly extending central core (76) with an O-ring seal (84), a filter securement member (86) for pressing the filter element (50) against an underlying support ledge (29) and a drain hole plug (88). The location of the O-ring (84) relative to the filter element (50) and the plug (88) being tapered enables the filter housing (22) to be drained of any water during removal of the hatch cover and before the watertight seal is broken to eliminate leakage of drain water out of the housing (22) when the hatch (31) is completely opened. The filter (50) bends out of the way of a plumber's auger (96).