7.3 Government and laws on the environment  (Page 4/7)

The CAA aims to reduce emissions from mobile sources such as cars and other vehicles, and to develop cleaner fuels. To maintain higher octane ranking in unleaded gasoline, the refiners have used more volatile fractions in unleaded gasoline formulas, leading to release of volatile organic compounds (VOCs). Under the CAA amendments of 1990, gasoline fuels are required to contain less volatile fractions, to contain oxyfuel compounds (such as alcohol-based oxygenated compounds) for reduced production of carbon monoxide in cold weather, to contain detergents for smoother running of engines, and to contain less sulfur in diesel fuel. The production of cars capable of burning cleaner fuels such as natural gas or alcohol is mandated by the CAA amendments of 1990.

Emission of sulfur dioxide (SO ₂ ) and nitrogen oxides (NO _x ) from combustion processes contribute to the formation of acid rain. Most of the sulfur dioxide emitted annually in the United States is produced from the burning of high-sulfur coal by electric utilities, resulting in acid rain with adverse impacts on the environment and public health. Reduction of sulfur dioxide emissions is mandated by the CAA. Pollution allowances (up to prescribed thresholds by EPA) for sulfur dioxide have been established by the EPA for each utility, where allowances may be traded between utilities or within a company. Companies with emissions less than the EPA allowance may trade their excess allowance with companies with allowance deficits, preventing severe hardships to those utilities that that are dependent on high-sulfur coal. The CAA has also set provisions for reduction of NO _x emissions. A market-based approach is employed by the 1990 CAA amendments to eliminate ozone-destroying chemical substances (such as chlorofluorocarbons) that deplete the ozone layer using a phasing-out schedule by terminating the production of these chemicals in accordance with the Montreal Protocol (1989). The recycling of chlorofluorocarbons (CFCs) and the labeling of ozone-friendly substitute chemicals are mandated by the CAA.

Hazardous wastes

Hazardous wastes are wastes that pose a health and safety risk to humans and to the environment. The EPA designates hazardous wastes as wastes which contain components that have one of the four general characteristics of reactivity, corrosivity, ignitability and toxicity, in addition to other EPA classifications of hazardous wastes. The laws and regulations governing the management of hazardous wastes and materials may be divided into two categories: present and future hazardous materials and wastes are regulated under the Resource Conservation and Recovery Act (RCRA), while past and usually abandoned hazardous waste sites are managed under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA).

Resource conservation and recovery act (rcra)

The RCRA (1976) aims to achieve environmentally sound management of both hazardous and nonhazardous wastes. As required by RCRA, the EPA established a cradle-to-grave (see Module Life Cycle Assessment ) hazardous material management system in an attempt to track hazardous material or waste from its point of generation to its ultimate point of disposal, where the generators of hazardous materials have to attach a "manifest" form to their hazardous materials shipments. The management of hazardous wastes including the transport, treatment, storage and disposal of hazardous wastes is regulated under the RCRA. For hazardous wastes disposal, this procedure will result in the shipment and arrival of those wastes at a permitted disposal site. The RCRA also promotes the concept of resource recovery to decrease the generation of waste materials. The RCRA, as amended, contains 10 subtitles. Subtitle C, for example, authorizes regulations for management of hazardous wastes and Subtitle I deals with regulation of Underground Storage Tanks (USTs).