AIRPORTS DESK REFERENCE
contain information on the status of the airport sponsor’s efforts in getting any necessary permits.
b. NPDES storm water permit for construction. EPA notes excavating 1 acre or more often requires the operation of equipment (i.e., bulldozers, cranes, dump trucks, etc.) disturbing or removing trees or ground cover or filling or leveling land. According to EPA, these disturbances cause sediment runoff rates typically 10 to 20 times those of agricultural areas and 1,000 to 2,000 times the rates of forested areas.1 As a result, substantial adverse water quality impacts could occur when airport construction disturbs 1 acre or more. The storm water regulation (found at 40 CFR Section 122.26) has two provisions regarding construction activity. One provision addresses a construction activity that would disturb 5 or more acres. Another provision addresses a “small construction activity,” that is, a project disturbing 1 acre or more but less than 5 acres.
(1) In either instance, an airport sponsor must obtain an NPDES storm water discharge permit as outlined in 40 CFR Section 122.26(c).
(2) For a “small construction activity,” compliance with NPDES requirements is not necessary if:
(a) the rainfall erosivity factor2 is less than 5 during the period of construction
(b) stormwater controls are not needed based on an EPA approved “total maximum daily load” or an equivalent analysis that determines that such allocations are not needed to protect water quality. See 40 CFR Sections 122.26(b)(15)(i)(A) and (B).
(3) FAA does not require an airport sponsor to have an NPDES permit when it approves a project, when it accepts a sponsor’s EA, or when it completes an EIS. However, if the sponsor receives the permit before the EA or EIS is finished, the EA or EIS should include a copy of the permit. In all cases, EAs and EISs should explain what the airport sponsor has done to obtain the permit and the status of the sponsor’s NPDES storm water permit application. Provide letters from the permitting agency that indicate if there are any pending issues regarding permitting.
EPA Stormwater Phase 2 Final Rule, Construction Site Runoff Control, Minimum Control Measure, EPA Fact Sheet 2.6, January 2000; http://rvcog.org/pdf/rainstorming/subsection1.1.5.pdf 1
Erosivity factor (“R” in the Revised Universal Soil Loss Equation): The rainfall erosivity factor is determined per Chapter 2 of Agriculture Handbook Number 703, Predicting Soil Erosion by Water: A Guide to Conservation Planning With the Revised Universal Soil Loss Equation (RUSLE), pages 21–64, dated January 1997. 2