tailieunhanh - Groundwater contamination by organic chemicals in industrializing countries: the unseen threat

The number of certified organic farms in Canada has also been on the rise, increasing 60% between 2001 and 2006. In 2006, there were about 3,500 certified organic farms, representing of all farms in Canada [6]. Nearly half (45%) of these farms are situated in the Prairie Provinces, with Saskatchewan accounting for about one-third of the nationwide total. Like their conventional counterparts, most (95%) organic producers on the Prairies are engaged in the production of hay or field crops, primarily wheat and barley, but also including a variety of other grains, pulses | 23 Impacts of Urban Growth ơn Surface Water and Groundwater Quality Proceedings of UGG 99 Symposium HS5 Birmingham July Ỉ999 . IAHS Publ. no. 259 1999. Groundwater contamination by organic chemicals in industrializing countries the unseen threat OLIVER T. N. SILILO Cape Water Programme Environmentek CSIR PO Box 320 Stellenbosch 7599 South Africa e-mail osililo@ Abstract Industrialization brings with it a high production of wastes. Many of these are disposed of in the environment and can have a serious impact on groundwater. In developed industrialized countries hierarchical approaches to investigating contamination problems are generally well established. In many instances individual organic chemicals have been identified as being critical in pollution plumes. On the other hand in many industrializing countries individual organic contaminants are rarely determined during groundwater pollution investigations. The reasons for this include low level of awareness lack of analytical facilities and cost constraints. Three case studies are presented from the Western Cape South Africa where although organic contaminants were suspected the investigation concentrated on inorganic contaminants. It is concluded that there is need for increased awareness of the potential impact of organic contaminants on groundwater and ultimately guidelines need to be developed for principal organic contaminants that should be analysed for at contaminated sites. INTRODUCTION Human settlement and industrial development have an inevitable impact on groundwater resources. With industrialization a wide range of inorganic and organic chemicals are manufactured used and disposed of. Many of these chemicals if not well managed can pollute groundwater. Friesel 1987 estimated that there were some 100 000 chemical substances of potential concern for the environment the vast majority of which are organic chemicals. In Germany and the United States for example approximately 1200 organic .