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I • ITable 3.5 • Maintenance of Control Structures and Catchbasins -. I . Maintenance Results Expected When Component Defect Condition When Maintenance is Needed Maintenance is Performed Manhole See Table See Table 3..4 See Table 3.4 3.4 ICATCH BASINS . • Greneral• Trash& Trash or debris which is located immediately in No Trash or debris located ' Debris front of the catch beak opening or is blrrlring immediately in front of catch basin or I Wetting capacity of tbe.basin by more than 10%. on grate opening. Trash or debris(in the basin)that exceeds 00 No trash or debris in the catch basin. I percent of the sump depth as measured from the bottom of basin to invert of the lowest pipe into or out of the basin,but in no case lase than a minimum of six inches clearance from the debris surface to the invert of the lowest pipe. I Trash or debris in any inlet or outlet pipe blocking Inlet and outlet pipes free of trash or more than 1l3 of its height debris Dead animals or vegetation that could generate No dead animals or vegetation odors that could cause complaints or dangerous present within the catch basin. gases(e.g.,methane). Sediment Sediment(in the basin)that exceeds 60 percent of No sediment in the catch basin • the sump depth as measured from the bottom of I • basin to invert of the lowest pipe into or out of the basin,but in no case less than a minimum of 6 inches clearance from the sediment surface to the invert of the lowest pipe. • Measured from the bottom of basin to invert of the I lowest pipe into or out of the basin. Structure Top slab has holes larger than 2 square inches or Top slab is free of holes and cracks. .f Damage to cracks wider than 1/4 inch I Frame and/or Top (Intent is to make sure no material is•ranring into • Slab basin). Frame not sitting flush on top slab,i.e., Frame is sitting flush on the riser I I . separation of niore than 3/4 inch of the frame from rings or top slab and firmly attached. the top slab.Frame not securely attached Fractures or Maintenance person judges that structure is Basin replaced or repaired to design • Cracks in. unsound. standards. I Basin Walls/ Bottom Grout fillet has separated or cracked wider than Pipe is regrouted and secure at basin 1/2 inch and longer than 1 Soot at the joint of any wall inlet/outlet pipe or any.evidence of soil particles catch basin through cracks. Ientering Settlement/ If fa ure of basin has created a safety,function,or Basin replaced or repaired to design IVIisaligame design problem standards. • nt Vegetation Vegetation growing across and blocking more than No vegetation blocking opening to 10%of the basin opening basin r t Vegetation growing in inlet/outlet pipe joints that No vegetation or root growth present. is more than six inches tall and less than six Iinches apart. I 3-56 Volume 111—Hydrologic Analysis and Flow Control BMPs February 2005 • I . 1