7.3 Government and laws on the environment  (Page 2/7)

The CWA aims to provide a system of national effluent standards for each industry, a set of water quality standards, an enforceable discharge permit program, provisions for special wastes such as toxic chemicals and oil spills, and a construction program for publicly owned treatment works (POTWs). Municipal wastewater treatment plants are examples of POTWs. The NPDES permits are issued according to the effluent limitations required by the Federal Water Pollution Control Act and the Clean Water Act. Because of higher costs associated with treatment of industrial effluents before discharge into natural waters which requires an NPDES permit, many industries discharge to a municipal sewer and have their wastes treated at the POTW following pretreatment regulations overseen by the POTW. In addition, the CWA provides permits for stormwater and other non-point source (see definition in Module "Sustainable Stormwater Management") pollution to prevent stormwater runoff over contaminated land and paved areas from polluting surface waters such as rivers and lakes. Stormwater pollution prevention plans and stormwater treatment facilities have to be implemented to avoid contamination of clean water.

Safe drinking water act (sdwa)

The Safe Drinking Water Act (SDWA) of 1974 was established to prevent potential contamination of groundwater, which may serve as a source of drinking water. The SDWA amendments of 1986 and 1996 established standards for water quality, which apply to drinking water as supplied by the public water supply systems. The groundwater standards are also used to determine groundwater protection regulations under a number of other statutes. The EPA has established a set of standards for unhealthful contaminants in drinking water referred to as the National Primary Drinking Water Regulations (NPDWRs) as required by the SDWA amendment of 1986. The list of regulated contaminants includes synthetic organic compounds, inorganic species such as heavy metals, radionuclides, and pathogenic microorganisms. The NPDWR standards include both enforceable Maximum Contaminant Levels (MCLs) and nonenforceable Maximum Contaminant Level Goals (MCLGs) used as health goals. The MCLs are achieved in the drinking water treatment plant using the Best Available Technology (BAT) for removal of the contaminants from water. Many of the drinking water MCLGs have also become the working standards for organic and inorganic chemical contaminants as "Superfund" regulations for hazardous waste site cleanups; Superfund regulations deal with the cleanup of abandoned sites containing hazardous wastes. Table Example Drinking Water Standards lists the MCLs and MCLGs for several chemical contaminants. The Safe Drinking Water Act amendment of 1986 also introduced Secondary Maximum Contaminant Levels (SMCLs) that act as recommended maximum levels for contaminants, which do not have an adverse health effect but are mostly related to esthetics of water (such as color and odor). The use of sound science and risk-based standard setting for the NPDWRs is included in the SDWA amendment of 1996; new contaminants may be added in the future using a list of candidate contaminants. In addition, the SDWA amendment of 1996 provides guidance to individual states and industry toward protection of source water and well-head areas used for public water supply.