Regulatory Overview and Action Levels

An example of a concentration limit is a cleanup level, which is a type of an action level used in remediation projects. Pollutant concentrations in an environmental medium that are greater than the cleanup levels warrant a remedial action. Cleanup levels are often developed based on site conditions, such as future land use exposure pathways the presence of groundwater and the likelihood of its beneficial use the presence of specific ecological receptors background concentrations. 

The concept of the action level emerges in every environmental project. The action level comes in many different forms, and there are a number of guidance and reference materials available today that allow us to competently establish a basis for choosing an action level. The following discussion provides an overview of various types of action levels that are typically used during implementation of environmental projects in the USA. The EPA summarizes these laws and regulations on its Web Page at http //www.epa.gov and provides the links to their full texts. 

The CWA has established discharge requirements for 129 individual toxic pollutants (VOCs, pesticides, metals and corrosives), known as priority pollutants, and conventional pollutants for 34 industrial categories (EPA, 1998b). Appendix 2 lists these pollutants, which are either individual chemicals or groups of chemicals of a similar nature. Aquatic toxicity testing and temperature measurements also often included into NPDES permits. 

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). 

The SDWA also controls injection of hazardous wastes into underground wells and sets standards for groundwater protection from toxic pollutants, viruses, and bacterial contamination. That is why the drinking water MCLs are used as cleanup for groundwater treatment. 

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A6 Project/task description 2.3 Regulatory overview and action levels... 

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