Hazardous Waste Management
Hazardous waste management involves reducing the amount of hazardous substances produced, treating hazardous wastes to reduce their toxicity, and applying sound engineering controls to reduce or eliminate exposures to these wastes.
Safety and Occupation Hygiene
Safety and occupational hygiene is ultimate in the maintenance of hazardous waste management facilities. The following safety equipment has to be provided at all strategic points, regular training have to be imparted, and mock drills have to be conducted. Regular health checks of employees have to be made. Training on first aid are to be imparted to the selected staff with qualified faculties.
personal protective equipment
safety shower with eye wash arrangements
relevant fire extinguishes
preferably a fire hydrant system
first aid kits
Prevention of Environmental Hazard Risks
Environmental hazard risks in the disposal sites are mainly from the threat due to the following:
ground and surface water contamination
explosion and earthquakes
Fire in the landfill may arise to due to disposal noncompatible wastes together or wastes having high ignitability calorific value and reactivity with water, air, acids, and bases. High caloric value (say beyond 2500 cal/kg) wastes may accelerate the process and sustain the fire. Every care has to be taken while deciding the pathway of the disposal as landfill. Fire due to other operations is very remote.
Heavy rains or storms are not desirable due to the potential of generation of high amounts of leachate. Depending on the rainfall patterns of the area, landfills have to be completely closed or proper temporary cover arrangements have to be made. The storm water drains have to be constructed and maintained to see that they are operational. It is to discourage logging of water in areas where groundwater levels are high.
Dust is the main problem from the point of air emissions. The other emissions due to volatile organics and unpleasant/obnoxious odors may be very well controlled if the organic content in the wastes is restricted. Proper compaction and daily cover combat the entire problem of dust, odors, and volatile gases effectively. The esthetic appeal of the landfill also improves. Spraying of leachate back to landfill in the summer season not only helps in evaporation of leachate but also suppresses the dust.
Ground, Surface Waste, and Soil Contamination
The worst scenario is due to failure of a landfill liner system and seepage of leachate into the ground, which ultimately spoils the groundwater. To avoid this problem, experience in design, construction, and operation of landfills is desirable. No activity has to be initiated/executed in the landfill or nearby areas that may cause or is likely to cause damage to the liners. Any spillages on the roads have to immediately be collected and disposed into the landfill time to time. All the storage areas and the operations at stabilization have to be properly monitored for effective functioning in mitigating the contact of waste to the soil and generation of leachate.
Explosion and Earthquakes
The possibility of explosion and earthquakes are the ultimate failure cases of the landfills. However, both these possibilities are almost remote. The explosive wastes can be well restricted if proper control on the initial characterization of the wastes and subsequent reactivity tests are conducted for every truck load at the TSD facility. With regard to the earthquakes, the seismologic studies have to be conducted at the stage of site selection itself and landfills have to be developed in non-seismic zones.
List of Potentially Noncompatible Wastes
Many hazardous and toxic wastes, when mixed with other wastes or materials at hazardous waste storage, treatment, or disposal facility, can produce effects that are harmful to human health and the environment:
heat or pressure
fire or explosion
toxic dusts, mists, fumes, or gases
flammable fumes or gases
Next are examples of potentially noncompatible wastes, waste components, and materials, along with the harmful consequences that result from mixing materials in one group with materials in another group. The list is intended as a guide to occupiers and owners or operators of storage, treatment, and/or disposal facilities, and to enforcement and permit granting officials, to indicate the need for special precautions when managing these potentially noncompatible waste materials or components.
An occupier and owner or operator must, as the regulations require, adequately analyze the waste so one can avoid creating uncontrolled substances or reactions of the type listed next, whether they are listed or not.
It is possible for potentially incompatible wastes to be mixed in a way that precludes a reaction (e.g., adding acid to water rather than water to acid) or that neutralize them (e.g. a strong acid mixed with strong base), or that control substances produced (e.g., by generating flammable gases in a closed tank equipped so that ignition cannot occur, and burning the gases in an incinerator).
In the lists following, the mixing of a Group A material with a Group B material may have the potential consequences as mentioned.