Environmental Impacts and Monitoring: A Historical Perspective on the Use of Natural Attenuation for Subsurface Remediation

摘要

The collective processes that constitute the broadly used term "natural attenuation," as it relates to subsurface remediation of contaminants, refer to the physical, chemical, and biological interactions that, without human intervention, reduce or contain contaminants in the subsurface environment. Knowledge of these processes has been used successfully to control water quality in surface water. However, the understanding of the impact of the same processes in the subsurface environment has improved fundamentally and dramatically over the course of the last three decades. It is now known that chemicals are capable of moving deep into the subsoil and sediments and are subject to a wide variety of complex chemical reactions, water/solid interactions, and microbial degradation. This chapter discusses the evolution in our understanding of these processes, how they relate to current philosophies concerning subsurface contaminant cleanup standards, and the issues pertaining to public acceptance of natural attenuation as an important component of remediation strategy.