Subcontractors

R: Refer to 05-CU drawings and Specification Section 40 27 00.Pipes are booted into structure.22. Q: (TDC) Chemical Manholes. Is there a detail for them?R: There is no detail. Refer to drawing 05-CU-25 for dimensions23. Q: (TDC) Electrical Manhole/Vaults. Is there a detail for these?R: Refer to details 2605-443a and 2605-443b for details on electrical manholes.24. Q: (WT) SECTION 44 42 24.03 - SECONDARY CLARIFIER MECHANISM2.03 MANUFACTURED UNITSD.2 Please revise this section to read as follows, "Drive Mechanism: Easyremoval of internal bearing balls, and strip liners (if used) without walkwaybridge removal."R: See subsequent addenda.25. Q: (WT) SECTION 44 42 24.03 - SECONDARY CLARIFIER MECHANISM2.06 FLOCCULATION WELLB.1 Please revise this sentence to read as follows, "Rigidly supported fromwalkway bridge and influent column. Flocculation wells supported from belowby the rake arms are also acceptable."For flocculation wells over 30' in diameter, WesTech believes that it isstructurally better to support the well from below using the two long rake armsand two stub arms.R: See subsequent addenda.26. Q: (WT) SECTION 44 42 24.03 - SECONDARY CLARIFIER MECHANISM2.10 RAKE ARMSE. 1: Please review the deflection requirement for the rake arms.Considering a span of half the clarifier diameter the vertical deflectionrequirement would be L/2880, this is excessive and unrealistic for a clarifiermechanism. The industry standard is that a deflection requirement between1/100 and L/400 would result in a truss that would provide adequate support fora suction header mechanism.R: See subsequent addenda.27. 0: (WT) SECTION 44 42 24.03 - SECONDARY CLARIFIER MECHANISM2.10 RAKE ARMSE.2: Please review the deflection requirement for the rake arms.Considering a span of half the clarifier diameter the horizontal deflectionrequirement would be L/5760, this is excessive and unrealistic for a clarifiermechanism. The industry standard is that a deflection requirement between1/1100 and 11400 would result in a truss that would provide adequate support fora suction header mechanism.05114/08 02001-158A QR 4-9