The most commonly used form of general permit is the nationwide permit (NWP). Like all general permits, NWPs are issued for classes of activities that should result in only minimal individual and cumulative adverse effects to the aquatic environment (Long et al. 1992). The Corps publishes proposed NWPs for public comment in the Federal Register and considers input from the public before deciding to issue an NWP. Initially, the Corps published a list of current NWPs in an appendix to 33 CFR Part 330 but no longer does so. Instead, current NWPs are available at the Corps district offices and may be found on the Corps website at www.usace.army.mil. Figure 4–3 illustrates how the NWP process operates.
The term “minimal,” as it is used in the CWA and regulations, is not quantified, leaving the determination of what constitutes a minimal impact to the interpretation of the Corps regulatory staff. The thresholds in the NWP program provide some guidance as to what level of impact the Corps considers acceptable, and this threshold has become increasingly lower since the program was first authorized. For example, NWPs authorized on November 22, 1991, included NWP 26, which authorized the filling of up to 10 acres of nontidal wetlands. In 1996 the threshold for use of NWP 26 was reduced to 3 acres (Fed. Regist. 61(Dec. 13):65874 –65922). More recently, the Corps eliminated NWP 26 and replaced it with NWPs for which the impact threshold does not generally exceed 0.5 acres of discharge into nontidal waters.
As noted earlier, NWPs may authorize activities to occur in wetlands with little agency oversight. Indeed, some activities authorized by general permit allow the permittee to proceed without notifying the Corps. These are commonly referred to as “nonreporting” NWPs and include activities for which the notification impact thresholds are not exceeded. If a project's impacts fall below the notification impact threshold, the project is automatically authorized and the Corps does not require that the applicant provide written documentation. No mitigation is required for impacts authorized by nonreporting NWPs. Nonreporting NWPs make it difficult for the Corps to determine overall program impacts.
Many NWPs now require a prospective permittee to provide the Corps with a preconstruction notification (PCN). For NWPs that trigger a PCN, the Corps may now require compensatory mitigation (Fed. Regist. 65(Mar. 9):47). Table 4–1 lists current NWPs and notes whether they are nonreporting NWPs or ones that require a PCN.