Many dams that are no longer serving an economic purpose and are no longer being maintained are being removed to reduce liability, to ensure public safety, and to restore river ecology. The management of impounded sediments is one of the greatest challenges to the removal of dams, presenting a potentially costly and complicated situation. A comparison of multiple dam removal projects across the northeastern US reveals that (1) many impoundments, regardless of size or geographic location, have low concentrations of contamination that represent potential ecological effects according to established ecological screening criteria, and that (2) the wide-spread low-level contamination, which may eclipse the most protective ecological screening criteria (i.e. threshold effect levels), appears to represent ambient or background conditions. Regulatory concerns have also focused on sediment quantity and minimizing potential impacts to wetlands on-site. Response and guidance from agencies regarding sediment quality, quantity, and wetland impacts has varied widely among states and agencies. Balancing these concerns has produced dam removals that involved passive sediment release, re-location of sediment on-site, or, less frequently, excavation and off-site disposal of impounded sediment. These trends within the region based on the varied regulatory responses and resulting sediment management approaches provides valuable insight and guidance to dam owners, regulators, and dam removal practitioners when analyzing alternatives for a dam, and developing engineering designs for permitting a dam removal project.

Paul is the primary fluvial geomorphologist at Princeton Hydro and applies his expertise to a range of projects involving the assessment, management and restoration of streams, large rivers, floodplains, and wetlands. As of 2015, Paul has been involved with over 50 barrier removals while at Princeton Hydro. He has completed detailed studies that demonstrate dam removal feasibility and identify project constraints and special considerations for engineering designs including bank erosion and infrastructure protection. In the planning and design phases, Paul assesses and anticipates channel adjustment processes, samples substrates and impounded sediments, conducts topographic survey of channels, and supports bathymetric survey of impoundments. Paul applies field data, geomorphologic principles, analytical techniques and hydraulic modeling to assess and design for sediment stability and mobility, and the potential for channel adjustments (degradation, aggradation) following dam removal or other significant disturbances.