New information and guidance for collapsible bag-type sediment samplers

Answers for many critical water-related issues require solid-phase water-quality data that are representative, accurate, and consistent. Collection of suspended sediment samples for subsequent analyses of solid-phase constituents that represent water-column sediment concentrations requires use of appropriate isokinetic samplers and sampling techniques (Davis, 2005a). Recent review of field and laboratory data indicates that the Federal Interagency Sedimentation Project (FISP) collapsible bag-type sediment samplers may not function isokinetically under certain low velocity and/or low temperature conditions. Updated guidance and operational limits for FISP bag-type samplers were issued in FISP Memorandum 2013.01 (2013). This paper describes new information and guidance for operation of FISP bag-type samplers and ongoing efforts to further characterize the factors that influence bag-type sampler efficiency.