Expanding a port, deepening a navigation channel or creating new land for development, introduces changes to our physical, social, economic and political environment. Changes may result from events during the construction process, or relate to the nature of the completed structure. Changes can be positive or negative, short-term or long-term, and may affect the immediate vicinity of the project or a larger geographical area. Predicting and assessing all possible effects of a planned dredging activity in a scientifically-sound and reliable manner is essential, so that appropriate control measures can be taken to avoid or mitigate unwelcome impacts. This book provides guidance for a complete holistic environmental evaluation procedure and for the design and implementation of environmental control measures. The book is of particular interest to engineers, government agencies and port authorities, as well as civil engineering consultants and contractors involved in planning and designing dredging, maritime infrastructure and fluvial projects.

The varied use of dredgers has led to the development of a variety of dredger types, from small ones appropriate to modest inshore projects, to very large sea-going dredgers for large-scale projects calling for the storage of dredged material within the ship. This book, which is the first book dedicated to dredging and its environmental impact in the widest sense, contains chapters on dredging operations in the Netherlands, Belgium, the UK, Spain, the US, China and Singapore. Additional chapters discuss more general aspects such as dredging techniques, monitoring of dredging operations, and the prospects of dredging in a changing environment. As well as providing information on dredging activities in different areas, it gives an insight into the activities and problems (environmental or other) involved in modern dredging. It will be of interest to professionals and students alike.

Without proper hydraulic fill and suitable specialised equipment, many major infrastructure projects such as ports, airports, roads, industrial or housing projects could not be realised. Yet comprehensive information about hydraulic fill is difficult to find. This thoroughly researched book, written by noted experts, takes the reader step-by-step through the complex development of a hydraulic fill project. Up-to-date and in-depth, this manual will enable the client and his consultant to understand and properly plan a reclamation project. It provides adequate guidelines for design and quality control and allows the contractor to work within known and generally accepted guidelines and reasonable specifications. The ultimate goal is to create better-designed, more adequately specified and less costly hydraulic fill projects. The Hydraulic Fill Manual covers a range of topics such as: • The development cycle of a hydraulic fill project • How technical data are acquired and applied • The construction methods applicable to a wide variety of equipment and soil conditions, the capabilities of dredging equipment and the techniques of soil improvement • How to assess the potentials of a borrow pit • Essential environment assessment issues • The design of the hydraulic fill mass, including the boundary conditions for the design, effects of the design on its surroundings, the strength and stiffness of the fill mass, density, sensitivity to liquefaction, design considerations for special fill material such as silts, clays and carbonate sands, problematic subsoils and natural hazards • Quality control and monitoring of the fill mass and its behaviour after construction. This manual is of particular interest to clients, consultants, planning and consenting authorities, environmental advisors, contractors and civil, geotechnical, hydraulic and coastal engineers involved in dredging and land reclamation projects.

Some of the nation's estuaries, lakes and other water bodies contain contaminated sediments that can adversely affect fish and wildlife and may then find their way into people's diets. Dredging is one of the few options available for attempting to clean up contaminated sediments, but it can uncover and re-suspend buried contaminants, creating additional exposures for wildlife and people. At the request of Congress, EPA asked the National Research Council (NRC) to evaluate dredging as a cleanup technique. The book finds that, based on a review of available evidence, dredging's ability to decrease environmental and health risks is still an open question. Analysis of pre-dredging and post-dredging at about 20 sites found a wide range of outcomes in terms of surface sediment concentrations of contaminants: some sites showed increases, some no change, and some decreases in concentrations. Evaluating the potential long-term benefits of dredging will require that the U.S. Environmental Protection Agency step up monitoring activities before, during and after individual cleanups to determine whether it is working there and what combinations of techniques are most effective.

Concerns over the potential ecological effects of fishing have increased with the expansion of fisheries throughout the marine waters of the United States. Effects of Trawling and Dredging on Seafloor Habitat describes how assessment of fishing impacts depends on gear type, number and location of bottom tows, and the physical and biological characteristics of seafloor habitats. Many experimental studies have documented acute, gear-specific effects of trawling and dredging on various types of habitat. These studies indicate that low mobility, long-lived species are more vulnerable to towed fishing gear than short-lived species in areas where the seabed is often disturbed by natural phenomena. Trawling and dredging may also change the composition and productivity of fish communities dependent on seafloor habitats for food and refuge. The scale of these impacts depends on the level of fishing effort. This volume presents color maps of fishing effort for all regions with significant bottom trawl or dredge fisheries-the first time that such data has been assembled and analyzed for the entire nation.