Methodologies for Surveying and Assessing Deep-Water Munitions Disposal Sites

The Hawaii Undersea Military Munitions Assessment (HUMMA) was designed to develop methodologies for surveying and assessing a historic deep-water munitions sea disposal site to determine the potential impact of the ocean environment on seadisposed munitions and of sea-disposed munitions on the ocean environment and those that use it. HUMMA is the most comprehensive deep-water investigation conducted in the United States to look at both chemical and conventional munitions. Recognizingthateachsea-disposedmunitionssiteposesuniquelogisticalandenvironmental challenges, the HUMMA approach emphasizes adaptability. Here, we describe the techniques used to determine the spatial extent and distribution of munitions, evaluate theintegrity of munitions casings,andsamplesediments andseawaternearmunitions present at water depths ranging from 330 to 550 m. We discuss integration and management of the diverse and voluminous datasets that the program produced. Notable results from HUMMA include demonstrating that reconnaissance-style mapping effectively locates distinctive trails of disposed munitions in sandy environments and that visual observations, in combination with acoustic data, constrain the poorly documented historical disposal process. Based on our findings, we conclude with several suggested future avenues of research for evaluating sea-disposed munitions sites.