Detection of Oil in Water Column, Final Report: Detection Prototype Tests

This report summarizes the results of Phase II Detection Prototype Tests of an RDC effort to develop a readily deployable system for the in-situ detection, identification, and characterization of submerged oil in the water column. The first phase of the project involved initial development and testing of three technologies to address the detection problem. This second phase involved testing two of the prototypes at the Ohmsett facility in Leonardo, New Jersey. A system developed by NORBIT US Ltd. addresses the detection of hydrocarbons using the backscatter from acoustic signals from a Wide Band Multibeam Sonar WBMS. A system developed by WET Labs, named Wide-angle-scattering Inversion to Detect Oil in Water WINDOW, uses the scattering and refraction of light to determine the mass and volume concentration, droplet size and density of the entrained oil. Both systems demonstrated the qualitative ability to detect andor map oil suspended in the water column with high levels of confidence as well as provide the data quickly and efficiently. Testing of the systems quantitative ability to characterize the oil plume, however, was not possible due to difficulties with correlating and validating the submerged plumes specific droplet size and concentration characteristics with the equipment currently available at the Ohmsett facility. It is recommended that both prototypes be further developed and tested in field tests that eliminate the limitations seen in tank testing. It is also recommended that Ohmsett continue to develop its capability to create suspended oil plumes as well as investigate additional procedures for confirming particle size distribution and concentration during testing.