Apparatus for treating storm water

A separation tank for treating a flowing stream of water, said separation tank comprising:

• a container having a bottom, sidewalls and a cover and having formed therein a low flow treatment path and a high flow treatment path,
• an inlet formed in one of said sidewalls of said container to allow water to enter said container,
• an outlet formed in another of said sidewalls of said container to allow water to be discharged from said container;
• said low flow treatment path and said high flow treatment path extending from said inlet to said outlet,
• a low flow treatment means in said low flow treatment path to prevent non-floatable materials from passing through the low flow path to said outlet,
• a low flow treatment means in said low flow treatment path to prevent floatable materials from passing through the low flow path to said outlet,
• an opening located at a predetermined height between said low flow treatment path and said high flow treatment path to allow water exceeding a predetermined flow rate to flow over said opening to pass said water from said low flow treatment path into said high flow treatment path when the height of the water exceeds the predetermined height;
• a treatment means in said high flow treatment path to prevent non-floatable materials and floatable materials from passing through the high flow path to said outlet,
• a filter/recharge chamber formed in said low flow treatment path, said filter/recharge chamber having a filter, said filter having an upstream side receiving the water and discharging the water at a downstream side after passing through the filter.

A method of treating a stream of water by means of a separation tank, said method comprising the steps of:

• providing a container having a bottom, side walls, a cover, an inlet for allowing water to enter the container and an outlet for discharging water from the container, said container having a low flow treatment path for water to pass from the inlet to the outlet and a high flow treatment path for water to pass from the inlet to the outlet;
• conveying water through the inlet into the container;
• treating the water passing through the low flow treatment path to remove floatable and non-floatable materials;
• conveying the water that exceeds a predetermined flow rate from the low flow treatment path into the high flow treatment path by passing the water over an opening located at a predetermined height;
• treating the water passing through the high flow treatment path to remove floatable and non-floatable materials, and
• discharging the water from the container through the outlet.