Natural Attenuation for Ground Water Remediation

• ISBN13: 9780309069328
• ISBN10: 0309069327
• Format: Hardcover
• Copyright: 2000-07-01
• Publisher: Natl Academy Pr

Summary

In the past decade, officials responsible for clean-up of contaminated groundwater have increasingly turned to natural attenuation-essentially allowing naturally occurring processes to reduce the toxic potential of contaminants-versus engineered solutions. This saves both money and headaches. To the people in surrounding communities, though, it can appear that clean-up officials are simply walking away from contaminated sites. When is natural attenuation the appropriate approach to a clean-up? This book presents the consensus of a diverse committee, informed by the views of researchers, regulators, and community activists. The committee reviews the likely effectiveness of natural attenuation with different classes of contaminants-and describes how to evaluate the "footprints" of natural attenuation at a site to determine whether natural processes will provide adequate clean-up. Included are recommendations for regulatory change. The committee emphasizes the importance of the public's belief and attitudes toward remediation and provides guidance on involving community stakeholders throughout the clean-up process. The book explores how contamination occurs, explaining concepts and terms, and includes case studies from the Hanford nuclear site, military bases, as well as other sites. It provides historical background and important data on clean-up processes and goes on to offer critical reviews of 14 published protocols for evaluating natural attenuation.

Table of Contents

Executive Summary	1	(19)
Introduction: Using Natural Processes in Groundwater Restoration	20	(17)
Historical Role of Natural Cleanup Processes	25	(1)
Limitations of Engineered Remediation Systems	25	(1)
Increasing Reliance on Natural Attenuation	26	(5)
Increasing Variety of Contaminants Considered for Natural Attenuation	31	(1)
Increasing Number of Natural Attenuation Protocols	32	(1)
Increasing Public Concerns	33	(1)
Focus of This Report	34	(1)
Summary	34	(1)
References	35	(2)
Community Concerns About Natural Attenuation	37	(28)
Specific Community Concerns	38	(3)
Basis for Community Concerns	41	(7)
Principles of Community Involvement	48	(5)
Mechanisms for Involving the Community	53	(5)
Conclusions	58	(2)
Recommendations	60	(1)
References	61	(4)
Scientific Basis for Natural Attenuation	65	(85)
Contaminants and Hydrogeologic Settings	66	(3)
Removal of Contaminant Sources	69	(9)
Movement of Contaminants in the Subsurface	78	(4)
Transformation of Contaminants in the Subsurface	82	(1)
Transformation by Microorganisms	82	(24)
Transformation by Chemical Reactions	106	(7)
Integration of the Mechanisms That Affect Subsurface Contaminants	113	(2)
Case Studies of Natural Attenuation	115	(20)
Summary: Appropriate Circumstances for Considering Natural Attenuation	135	(5)
Conclusions	140	(1)
References	141	(9)
Approaches for Evaluating Natural Attenuation	150	(62)
Footprints of Natural Attenuation Processes	151	(3)
Creating a Conceptual Model	154	(18)
Analyzing Site Data	172	(31)
Monitoring the Site	203	(1)
Conclusions	204	(3)
Recommendations	207	(2)
References	209	(3)
Protocols for Documenting Natural Attenuation	212	(53)
Criteria for a Good Protocol	213	(6)
Overview of Protocols	219	(12)
Adequacy of Protocols	231	(10)
Adequacy of Decision-Making Tools	241	(3)
Adequacy of Training	244	(4)
Adequacy of Policies Concerning Use of Protocols	248	(2)
Conclusions	250	(2)
Recommendations	252	(1)
References	253	(2)
APPENDIXES
A Acronyms	255	(2)
B Presenters at the Committee's Information-Gathering Meetings	257	(2)
C Biographical Sketches of Committee Members and Staff	259	(6)
Index	265