Section 450.10 - Applicability(a) This part applies to discharges associated with construction activity required to obtain NPDES permit coverage pursuant to 40 CFR 122.26(b)(14)(x) and (b)(15) .(b) The provisions of § 450.22(a) do not apply to discharges associated with interstate natural gas pipeline construction activity.(c) The New Source Performance Standards at § 450.24 apply to all new sources and are effective February 1, 2010.(d) The BPT, BCT and BAT effluent limitations at § 450.21 through 450.23 apply to all sources not otherwise covered by paragraph (c) of this section and are effective February 1, 2010.