2611 ROCKEFELLER AVE ROCKEFELLER SQUARE 2 2024-08-12

No. 4—Control Structure/Flow Restrictor Maintenance Defect Condition When Maintenance is Needed Results Expected Component When Maintenance is Performed General Trash and Debris Material exceeds 25%of sump depth or 1 Control structure (Includes Sediment) foot below orifice plate. orifice is not blocked. All trash and debris removed. Structural Damage Structure is not securely attached to Structure securely manhole wall. attached to wall and outlet pipe. Structure is not in upright position (allow up Structure in correct to 10%from plumb). position. Connections to outlet pipe are not watertight Connections to outlet and show signs of rust. pipe are water tight; structure repaired or replaced and works as designed. Any holes--other than designed holes--in the Structure has no structure. holes other than designed holes. Cleanout Gate Damaged or Missing Cleanout gate is not watertight or is missing. Gate is watertight and works as designed. Gate cannot be moved up and down by one Gate moves up and maintenance person. down easily and is watertight. Chain/rod leading to gate is missing or Chain is in place and damaged. works as designed. Gate is rusted over 50%of its surface area. Gate is repaired or replaced to meet design standards. Orifice Plate Damaged or Missing Control device is not working properly due to Plate is in place and missing, out of place, or bent orifice plate. works as designed. Obstructions Any trash, debris, sediment, or vegetation Plate is free of all blocking the plate. obstructions and works as designed. Overflow Pipe Obstructions Any trash or debris blocking (or having the Pipe is free of all potential of blocking)the overflow pipe. obstructions and works as designed. Manhole See"Closed See"Closed Detention Systems" (No. 3). See"Closed Detention Systems" Detention Systems" (No. 3). (No. 3). Catch Basin See"Catch Basins" See"Catch Basins" (No. 5). See"Catch Basins" (No. 5). (No. 5). Volume V—Runoff Treatment BMPs—December 2014 4-37