This volume presents a critical analysis and timely synthesis of the past decade of intensive research, development, and demonstrations on the in situ bioremediation of perchlorate in groundwater. The intended audiences include the decision makers, practicing engineers and hydrogeologists who will select, design, and operate these remedial systems, as well as researchers seeking to improve the current state-of-the-art. Our hope is that this volume will serve as a useful resource to assist remediation professionals in applying and developing the technology as effectively as possible. An overview of the current state-of-understanding of perchlorate remediation is followed by a discussion of basic principles of microbial and abiotic processes, and of the engineering and implementation issues underlying the technologies described. Characterization of both anthropogenic and natural sources of perchlorate, including isotopic analysis to distinguish between differing sources, precedes discussions of the advantages, performance, and relative costs of applying a range of remedial technologies. Active, semi-passive, and passive in situ bioremediation are fully described and compared with emphasis on field application. Cost information for each technology, using case studies and analyses of several template sites, covers capital costs, as well as costs for laboratory testing, pilot-scale demonstration, design, system operation, monitoring and maintenance during operations, and demolition and restoration after remediation. In addition, analogous cost data are presented for pump-and-treat systems for each template site to illustrate the potential cost savings associated with the use of alternative approaches. Emerging technologies such as monitored natural attenuation, phytoremediation, and vadose zone bioremediation are described, and field demonstrations are used to illustrate the current stage of maturity and the potential applicability of these approaches for specific situations. Each chapter in this volume has been thoroughly reviewed for technical content by one or more experts in each subject area covered.

This book is open access under a CC BY-NC 2.5 license. The Gulf of Mexico is an open and dynamic marine ecosystem rich in natural resources but heavily impacted by human activities, including agricultural, industrial, commercial and coastal development. The Gulf of Mexico has been continuously exposed to petroleum hydrocarbons for millions of years from natural oil and gas seeps on the sea floor, and more recently from oil drilling and production activities located in the water near and far from shore. Major accidental oil spills in the Gulf are infrequent; two of the most significant include the Ixtoc I blowout in the Bay of Campeche in 1979 and the Deepwater Horizon Oil Spill in 2010. Unfortunately, baseline assessments of the status of habitats and biota in the Gulf of Mexico before these spills either were not available, or the data had not been systematically compiled in a way that would help scientists assess the potential short-term and long-term effects of such events. This 2-volume series compiles and summarizes thousands of data sets showing the status of habitats and biota in the Gulf of Mexico before the Deepwater Horizon Oil Spill. Volume 1 covers: water and sediment quality and contaminants in the Gulf; natural oil and gas seeps in the Gulf of Mexico; coastal habitats, including flora and fauna and coastal geology; offshore benthos and plankton, with an analysis of current knowledge on energy capture and energy flows in the Gulf; and shellfish and finfish resources that provide the basis for commercial and recreational fisheries.

This book is open access under a CC BY-NC 2.5 license. The Gulf of Mexico is an open and dynamic marine ecosystem rich in natural resources but heavily impacted by human activities, including agricultural, industrial, commercial and coastal development. The Gulf of Mexico has been continuously exposed to petroleum hydrocarbons for millions of years from natural oil and gas seeps on the sea floor, and more recently from oil drilling and production activities located in the water near and far from shore. Major accidental oil spills in the Gulf are infrequent; two of the most significant include the Ixtoc I blowout in the Bay of Campeche in 1979 and the Deepwater Horizon Oil Spill in 2010. Unfortunately, baseline assessments of the status of habitats and biota in the Gulf of Mexico before these spills either were not available, or the data had not been systematically compiled in a way that would help scientists assess the potential short-term and long-term effects of such events. This 2-volume series compiles and summarizes thousands of data sets showing the status of habitats and biota in the Gulf of Mexico before the Deepwater Horizon Oil Spill. Volume 2 covers historical data on commercial and recreational fisheries, with an analysis of marketing trends and drivers; ecology, populations and risks to birds, sea turtles and marine mammals in the Gulf; and diseases and mortalities of fish and other animals that inhabit the Gulf of Mexico.

This volume presents a critical analysis and timely synthesis of the past decade of intensive research, development, and demonstrations on the in situ bioremediation of perchlorate in groundwater. The intended audiences include the decision makers, practicing engineers and hydrogeologists who will select, design, and operate these remedial systems, as well as researchers seeking to improve the current state-of-the-art. Our hope is that this volume will serve as a useful resource to assist remediation professionals in applying and developing the technology as effectively as possible. An overview of the current state-of-understanding of perchlorate remediation is followed by a discussion of basic principles of microbial and abiotic processes, and of the engineering and implementation issues underlying the technologies described. Characterization of both anthropogenic and natural sources of perchlorate, including isotopic analysis to distinguish between differing sources, precedes discussions of the advantages, performance, and relative costs of applying a range of remedial technologies. Active, semi-passive, and passive in situ bioremediation are fully described and compared with emphasis on field application. Cost information for each technology, using case studies and analyses of several template sites, covers capital costs, as well as costs for laboratory testing, pilot-scale demonstration, design, system operation, monitoring and maintenance during operations, and demolition and restoration after remediation. In addition, analogous cost data are presented for pump-and-treat systems for each template site to illustrate the potential cost savings associated with the use of alternative approaches. Emerging technologies such as monitored natural attenuation, phytoremediation, and vadose zone bioremediation are described, and field demonstrations are used to illustrate the current stage of maturity and the potential applicability of these approaches for specific situations. Each chapter in this volume has been thoroughly reviewed for technical content by one or more experts in each subject area covered.