Drain basin filter insert system

A drain basin insert for extracting impurities from drainage water, comprising:

• an outer wall defining a rectangular periphery, said outer wall having a top edge and a bottom edge;
• a concave perforated bottom surface extending across the periphery of the insert;
• filter means resting on the perforated bottom surface;
• an outwardly extending flange depending substantially transverse to the outer wall at the outer wall top edge, the outwardly extending flange having a support surface adapted to rest on a grate-bearing surface of a drain basin;
• and
• a flange inwardly extending from the top edge of the outer wall and out over the outermost portions of the filter means for directing drainage water onto the filter means, whereupon the filter means extracts impurities from the drainage water and filtered drainage water exits through the perforated bottom surface into the drain basin.

A drain basin insert system for extracting impurities from drainage water, comprising:

• a filter cartridge comprising:
• an outer cartridge wall defining a periphery, said outer wall having a top edge and a bottom edge;
• a perforated first surface extending across the periphery of the cartridge;
• a perforated second surface extending across the periphery of the cartridge;
• filter means between the perforated first and second surfaces;
• a flange inwardly extending from the top edge of the outer cartridge wall and out over the periphery of the filter means;
• and
• a flange inwardly extending from the bottom edge of the outer cartridge wall and out over the periphery of the filter means;
• and
• an insert frame comprising:
• an outer frame wall defining a periphery, said outer frame wall having a top edge and a bottom edge;
• support means for retaining the insert frame within the drain basin;
• and
• support means for retaining the filter cartridge within the insert frame.

A filter cartridge for use in a drain basin filter system, comprising:

• an outer cartridge wall defining a periphery, said outer wall having a top edge and a bottom, edge;
• a perforated first surface extending across the periphery of the cartridge;
• a perforated second surface extending across the periphery of the cartridge;
• filter means between the perforated first and second surfaces;
• a flange inwardly extending from the top edge of the outer cartridge wall and out over the periphery of the filter means;
• and
• a flange inwardly extending from the bottom edge of the outer cartridge wall and out over the periphery of the filter means.