US Patent 7546850 Controlled access vent for water storage unit

A vented water storage system (16) is disclosed. A vent (62) is disposed within an elbow (38). A riser pipe (26) extends from the elbow (38) to a containment (18) having water (22) stored therein. The vent (62) includes an open end (66) that fluidly communicates with the riser pipe (26), and a closed end (70) that is located between a distally located open end (42) of the elbow (38) and the open end (66) of the vent (62). An access port (74) is included on a sidewall (64) of the vent (62) at a location within the elbow (38) that reduces the potential for being able to introduce a liquid into the open end (42) of the elbow (38) in a manner such that this liquid will reach the containment (18).