tailieunhanh - Environmental Risk Assessment Reports - Chapter 26

Xử lý ô nhiễm các hóa chất đánh giá rủi ro cụ thể tính toán hiệu suất bằng số Những Must Be đạt được tiêu chuẩn cho một Cơ quan Điều tiết để tìm Điều đó vừa vàng trang web chấp nhận được sạch sẽ. Họ là Tiến hành xác định bao nhiêu của một hoặc nhiều chất gây ô nhiễm môi trường phải được loại bỏ từ một trang web hoặc từ trung bình đến Đạt Mức độ rủi ro chấp nhận được đầy đủ để bảo vệ sức khỏe con người và môi trường | CHAPTER 26 Remediation Risk Assessment William Phillips CONTENTS I. II. Technical Review of Remediation Risk A. Evaluation of Remedial B. Residual III. I. INTRODUCTION Remediation risk assessments calculate chemical specific numerical performance standards which must be achieved for a regulatory agency to find that medium or site acceptably clean. They are conducted to determine how much of one or more environmental contaminants must be removed from a site or medium to achieve acceptable risk levels sufficient to protect human and environmental health. Cleanup decisions are not solely based on calculated risk levels and acceptable risk criteria. Risk managers are not captives of risk findings and must weigh several factors to arrive at a final equitable cleanup decision. For example when formulating a cleanup decision for contaminated wetland sediments risk managers must weigh reduced ecological risks against habitat destruction. Risk managers must balance the costs and benefits of chemical risk reduction and not rely solely on achieving a numerical performance standard. Site or medium remediation efforts are often hampered by technological and financial constraints. Currently available technologies may not be able to reduce site contamination levels to regulatory agency numerical performance standards. As a remediation technology reaches its removal limits its ability to efficiently and 497 2001 by CRC Press LLC 498 A PRACTICAL GUIDE TO ENVIRONMENTAL RISK ASSESSMENT REPORTS economically remove contaminants decreases. At the limits of remediation technology each increment of pollutant removal increases cleanup costs steeply. For example removal of a substance to 10 ppm could cost 1 million 5 ppm 10 million and 1 ppm 100 million. In an age of limited financial resources risk managers must balance the need to achieve calculated acceptable risk levels with real economic and .