Ten years ago, the Municipal Solid Wastes (MSW) generated by 2.9 billion urban residents was about 0.64 kg per person per day (0.68 billion tons per year). But today, it has shot up to about 3 billion residents generating 1.2 kg per person per day (1.3 billion tons per year). By 2025, it will be 4.3 billion urban residents generating about 1.42 kg/capita/day (2.2 billion tons per year). According to the World Bank, environmental impact assessment is a process of analysis that depends on the scale, nature and environmental impact of the project proposed.
1. Legal and administrative frameworks of EIA
For every EIA, the system of preparation and follow-up are unique and is the consequence of particular sets of administrative, legal and political circumstances. There are a number of ways and formal arrangements through which EIA processes are applied to decision-making. Certain countries like USA, CANADA, Egypt and other institutions like European Union and World Bank have formal requirements for EIAs.
2. Air pollution
Air pollution may be defined as substances present in the atmosphere in concentrations great enough to interfere directly or indirectly with man`s comfort, safety or health or with full use or enjoyment of his property, or injurious to other living creatures or plants. The two types of air pollutants are: 1) Primary: emitted directly to atmosphere and stay there in the same form; sulfur oxides, nitrogen oxides, hydrocarbons. 2) Secondary: formed in the atmosphere by oxidation or photochemical reaction; ozone and Acyl peroxy nitrates.
3. Mitigation measures of air pollutants
The best measure to mitigate air pollutants are reduction of pollutant discharge at the source by the application of control equipment. For instance reduction at the source could be achieved through raw material changes, operational changes, modification, or by replacement of process equipment.
4. Water pollution
Water pollution may be defined as: contamination of water or such alteration of the physical, chemical or biological properties of water or such discharge of any sewage or industrial effluent of any other liquid, gaseous or solid substance into water, that is likely to create a nuisance or injurious to public health or to the life and health of animals or plants or of aquatic life.
5. Sources of water pollution
The main Water pollution sources are: sewage and other wastes which contain decomposing organic matter; Industrial waste, which contains toxic agents ranging from metal salts to complex synthetic organic chemicals; Agriculture waste, which comprises fertilizers, pesticides and biocides; and Thermal pollution due to increase in water temperatures.
6. Mitigation measures of water pollution
1) Use of Treatment Process Equipment: Proper operation and monitoring of the equipment is essential for the success of any process treatment. 2) Control of Hazardous Wastes: Control of hazardous wastes, especially spills, both within the project area or on access routes, is crucial for success of water pollution prevention.3) Plant Area Drainage: The plant surface drainage system should be carefully designed to prevent flooding of the plant area. Plant drainage water can contain considerable oil from plant machinery so that a separator is needed prior to discharge. 4) Cooling Water Systems: to prevent thermal pollution and disturbance of water ecology, high temperature water may need to be reduced by some heat transfer processes.
7. Environmental risks of pollution
Environmental risk is an uncertain event or condition that on occurrence has a positive or a negative effect on an environmental impact assessment study and whole project objectives. The objectives of environmental Risk Management are to increase the probability and impact of positive events, and reduce the probability and impact of negative events in the project.
8. The Key Stages in EIA Process
The key stages in EIA process are public participation and consultation: They are important sources of information on EIA for e.g. the identification of impacts, potential mitigation measures and the establishment of alternatives. Public participation and consultation make the EIA process open and transparent.
9. Step To Conduct an Environmental Risk Management
The first step to conduct an environmental risk management is environmental hazard identification; there are different environmental hazards which could be present during the execution of different development project. Examples of environmental hazards are: Soil pollution, toxic wastes generation, water pollution, noise pollution, radiation…etc.