33 C.F.R. § 230.11
A FONSI shall be prepared for a proposed action, not categorically excluded, for which an EIS will not be prepared. The FONSI will be a brief summary document as noted in 40 CFR 1508.13 . In the case of feasibility, continuing authority, or special planning reports and certain planning/engineering reports, the draft FONSI and EA should be included within the draft report and circulated for a minimum 30-day review to concerned agencies, organizations and the interested public ( 40 CFR 1501.4(e)(2) ). In the case of operation and maintenance activities involving the discharge of dredged or fill material requiring a public notice, the notice will indicate the availability of the EA/FONSI. For all other Corps project actions a notice of availability of the FONSI will be sent to concerned agencies, organizations and the interested public ( 40 CFR 1501.4(e)(1) ).
33 C.F.R. § 230.11