Book excerpt: Despite nearly three decades of efforts intended to protect the nation's waters, and some success against certain forms of chemical and organic contamination, many of our nation's waterways continue to be seriously degraded. The call of the 1972 Clean Water Act -- "to restore and maintain the chemical, physical, and biological integrity of the Nation's waters" -- remains unanswered. Restoring Life in Running Waters discusses freshwater ecosystems in the United States and the need for using biology to understand their present condition. The book makes a case for using indexes that integrate measurements of many biological attributes to assess and communicate environmental health. In a unique and innovative format, the authors present 37 premises and 7 myths that explore the theory and practice of biological monitoring and the use of multimetric indexes. The book explains: why biological monitoring and assessment are needed the historical evolution of biological monitoring how and why living systems give the best signals for diagnosing environmental degradation what multimetric indexes do and why they are effective how multimetric indexes can be used and common pitfalls to avoid in using them why many criticisms of biological indexes are not valid how the principles of biological monitoring and multimetric indexes can be expanded beyond aquatic systems to other environments how information from indexes can be integrated into the regulatory and policy framework Restoring Life in Running Waters provides practical and effective tools for managers and scientists seeking to understand the impact of human activities on natural systems and to determine proper action to remedy problems. It is an essential handbook for conservation biologists; agency personnel at all levels, including technical staff, policymakers, and program managers; and for anyone working to protect and restore the health of the nation's waters.