Abstract: A storm water injection well incorporating a precast settling chamber having an overflow pipe extending upwardly into the chamber. The top of the overflow pipe is covered with a debris screen which in turn is covered by a debris shield. The shield is supported above the open end of the pipe and extends downwardly over the pipe end displaced radially from the surface of the pipe to form an annular passageway between the shield and the pipe to permit storm water to flow upwardly in the passageway into the pipe. An anti-siphon vent is provided in the debris shield. The precast settling chamber includes a plurality of weep holes sloped upwardly from the inside to the outside of the chamber. A drainage pipe is connected to the overflow pipe and delivers water from in the pipe to backfill in a ground hole through an injection screen.