This document includes a study of various nondestructive evaluation (NDE) techniques for composite overwrapped pressure vessels intended for gaseous hydrogen infrastructure applications. The majority of the study focuses on Model Acoustic Emissions (MAE) techniques. Testing was performed on various composite tank designs including small high pressure plastic-lined fully-wrapped composite pressure vessels designed for portable, stationary or vehicular storage and large steel-lined hoop-wrapped pressure vessels designed for bulk transport and stationary storage. MAE testing was performed by Digital Wave Corp. on vessels provided by Lincoln Composites and TransCanada.