Groundwater systems quality assessment

Technical Guidance Document and Water Framework Directive approaches EU member state, North American, and other international approaches) and the way in which they are implemented (e.g., mandatory pass or fail probabilistic, e.g., 95th percentiles or tiered risk assessment frameworks). Soil and water standards were considered, as were values for the protection of human health and the natural environment. The focus was on European regulatory frameworks, although expert input was sought from other jurisdictions internationally. Chemical standards for aquatic (water and sediment) and terrestrial (soil and groundwater) systems were the main focus for the meeting. This workshop built on, and included some participants from, a 1998 SETAC workshop Re-evaluation of the State of the Science for Water-Quality Criteria Development (Reiley et al. 2003). 

For a better comprehension of the chemistry of a groundwater system the redox status needs to be well-defined. Until recently, most efforts have relied solely upon Ej.j or pE, intensity factors, as the master variable. However, it is apparent that these intensity factors do not truly represent the redox status of a system because some pertinent redox couples are not electroactive and redox reactions are generally slow and are not at equilibrium. In this paper, the oxidative capacity, a capacity factor, is operationally defined and shown to be a better descriptive parameter of the redox status. Determination of the OXC of an aqueous system allows investigators to cla.ssify the system in terms of well-defined geochemical and microbial parameters. This classification combined with other predictive tools, such as a redox titration, allows one to predict the identity and assess the role of chemical reactions and microbial populations within a specific groundwater system. As such, the capacity factor OXC should be determined in water quality assessment. 

CPE XI returned to Cairo, Egypt in 1997, and papers and posters were presented on adsorption, analytical methods, chemical/biological/treatment, groundwater studies, ion exchange, modeling, risk assessment, waste minimization and treatment, and for the first time, ISO 14001, which focuses on environmental management and quality systems. 

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