Water quality standards groundwater systems

Action levels for decisions related to drinking water quality are the Maximum Contaminants Levels of the Safe Drinking Water Act (SDWA). The MCLs are the maximum permissible contaminant concentrations in the drinking water that is delivered to the user through a public water system. First enacted in the USA in 1974 and reauthorized in 1996, the SDWA protects drinking water and groundwater resources. This law establishes two kinds of standards for drinking water quality primary standards for the contaminants that pose a risk to human health (EPA, 1985), and secondary standards for the contaminants that affect the physical characteristics of water (odor, taste, and appearance). 

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). 

The Safe Drinking Water Act (SDWA) is designed to ensure that public water systems provide water meeting the minimum national standards for protection of public health. The act mandates establishment of uniform federal standards for drinking water quality, and sets up a system to regulate underground injection of wastes and other substances that could contaminate groundwater sources. (Surface water is protected under the Clean Water Act.)... 

The quality of drinking water in relation to public health is an important issue worldwide. Water may come from groundwater sources or surface waters such as lakes, reservoirs, and rivers with a wide variation in water quality. The treatment required to achieve potability depends upon the characteristics of the source, relevant drinking water standards, and the characteristics of the distribution system. Treatment of some supplies consists of disinfection only while others may use several clarification steps prior to disinfection. 

The SDWA was enacted in 1974 to protect the quality of drinking water in the USA. The act authorized the EPA to establish safe health-related drinking water standards, with which all owners and operators of public water systems must comply. The SDWA required the EPA to identify contaminants and rate their potential to harm public health. The wellhead protection provisions of the SDWA are important for groundwater quality protection. 

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