Section 116.15 - Preliminary investigation(a) During the Preliminary Investigation, the District Commander will prepare a written report containing all pertinent information and submit the report, together with a recommendation for or against the necessity of a Detailed Investigation, to the Chief, Office of Bridge Programs.(b) The Preliminary Investigation Report will include a description of the nature and extent of the obstruction, the alterations to the bridge believed necessary to meet the reasonable needs of existing and future navigation, the type and volume of waterway traffic, and a calculation of the benefits to navigation which would result from the proposed bridge alterations.(c) The Chief, Office of Bridge Programs will review the Preliminary Investigation Report and make a Preliminary Decision whether or not to undertake a Detailed Investigation and a Public Meeting.(d) If after reviewing the Preliminary Investigation Report, the Chief, Office of Bridge Programs decides that further investigation is not warranted, the complainant will be notified of the decision. This notification will include a brief summary of information on which the decision was based and details of the appeal process described in § 116.55 .CGD 91-063, 60 FR 20902, Apr. 28, 1995, as amended by CGD 96-026, 61 FR 33663, June 28, 1996; USCG-2012-0306, 77 FR 37314 , June 21, 2012; USCG-2013-0397, 78 FR 39174 , July 1, 2013; USCG-2014-0410, 79 FR 38433 , July 7, 2014