tailieunhanh - ENVIRONMENTAL IMPACT STATEMENTS - CHAPTER 8

Man-Made Môi trường: nước ngầm Trong những năm gần đây, sự cần thiết phải bảo vệ nước ngầm đã trở thành một phần quan trọng của tất cả các dự án xây dựng mới. Nhấn mạnh ngày càng tăng này là do việc sử dụng phát triển nhanh chóng của nước ngầm là nguồn nước uống. Theo Briggs (1976), hơn 97% nước ngọt chất lỏng của thế giới dưới lòng đất. Rõ ràng, số tiền này của nước là không phải tất cả có sẵn như là một nguồn nước uống trong tương lai, nhưng cường độ của nó xác định. | 8 The Man-Made Environment Groundwater In recent years the need to protect groundwater has become a critical part of all new construction projects. This increasing emphasis is because of the rapidly growing use of groundwater as a source of drinking water. According to Briggs 1976 more than 97 percent of the world s fluid fresh water is underground. Obviously this amount of water is not all available as a source of future drinking water but its magnitude defines underground water as a precious resource to be husbanded for future needs. The use of groundwater for all purposes in the United States was estimated by the . Geological Survey Salley 1997 to be as shown in Exhibit 4 for the year 1995. In contrast to rapidly moving freshwater streams underground water moves very slowly and does not have ready access to oxygen supplies. This means that contaminated underground water tends to remain in that condition. The result all too often is the loss of a major source of water supply for public or industrial purposes. REGULATORY BACKGROUND Recognizing the need to keep underground water from becoming contaminated the . Congress the EPA and a number of states have taken various protective actions. There are a number of different federal and state laws and regulations that are designed to protect groundwater. In contrast to other media groundwater protection is a function of several laws. The most common ones place emphasis on three areas Contamination by buried hazardous wastes. Maintenance of the purity of sole-source aquifers. Underground injection of wastes. The first contamination of groundwater by buried hazardous wastes is regulated by RCRA CERCLA and the Safe Drinking Water Act which are discussed elsewhere in this book. Of particular concern is the possible contamination of groundwater by leachates from landfills. Existing landfills are covered by RCRA and abandoned ones by CERCLA. Over the years toxic chemicals have accumulated in landfills and are .