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To provide a review of the problems pertaining to solid wastes and disposal thereof.
The solid waste problem is fundamentally a health problem. Major changes in recent years have greatly affected our environment and have complicated the waste handling picture.
Public awareness and interest in the mounting problems of solid waste storage, collection, and disposal have lagged.
A. Insects and rodents resulting from improper refuse handling are vectors of human disease:
B. Accidental injuries are direct consequence of improper refuse handling practices:
C. Air pollution through the open burning of solid wastes creates hazards:
A. Decreases property values are a certain consequence of poor operating practices including:
B. Economic losses due to poor service are perhaps more common and more often tolerated, than is the case with other municipal services:
A. Nuisances resulting from improper refuse handling are increasingly serious with crowding, and intensified use of our backyards for cookouts and parties. Some of the problems encountered are:
B. Blighting of the natural scenery with scattered refuse is now too evident to ignore. This "visual pollution" now reaches out to spoil our dwindling beauty sites. Some examples are:
C. Air pollution as a result of attempts at salvage and makeshift incinerators
D. Water pollution as a result of open dumping or improper landfill
site selection or design. We are just beginning to realize the implications of ground water contamination, for example, which may result from transfer of decomposition gases, direct horizontal leaching of refuse by ground water, or vertical leaching by percolating water.
In 1979, it was revealed by the House Commerce Oversight Committee that hazardous wastes in Love Canal in Niagara Falls, New York, were slowly seeping into the ecosystem. Following this report similar incidences were reported in Islip School in New York, Aurora, MD and Youngstown, PA on the leakage of industrial chemicals buried in dumpsites. In Alabama the Environmental Protection Agency (EPA) has identified three sites as: Anniston acid waste disposal Southern Metal Processing Company; Decatur creosote dumped into barge unloading area and Huntsville DDT contaminants, U.S. Army and Olin Chemical Corp. In addition, chemical waste management has a dumpsite for harmful chemicals at Emelle, AL. It is estimated that there are more than 32,000 dumps in the U.S. and they may contain harmful chemicals in varying amounts. The chemical dump sites range from sludge pits that slowly leak harmful chemicals into water supplier to collections of metal drums that eventually leak harmful chemicals into water supplies to collections of metal drums that eventually leak and spill their dangerous contents into the environment. According to the EPA, each year a total of 750,000 industrial plant in the U.S. generate some 57 million tons of hazardous waste.
The dangerous discarded substances include lead, arsenic, asbestos, benzene, cadmium, mercury PCB's (polychlorinated biphenyls). TCE (trichloroethylene). TCDD (tetrachlorodibenzoparadioxin) which can cause ulcers, liver damage, birth defects and miscarriages; some of these are known carcinogens. Just about everyone, including the chemical industry, agrees that deterioration at the nation's dump sites and storage facilities must be halted and that the bad habits that cause the problem should be corrected. But these measures are expensive, for example, it is estimated that the cost of the Love Canal disaster alone to be above $300 million. The administration has asked for a $1.6 billion "superfund" provided mainly by the chemical companies to start dealing with such problems. This is a serious emerging problem which needs our attention. The waste doesn't go away just because you take it out of the air and water.
In the development of the comprehensive solid waste management program there are four basic categories of criteria on which decisions are made; these are costs, environmental factors, resource conservation, and institutional factors. The key points in each of these categories are:
In designing the solid waste collection system, one of the first decisions to be made is storage where the waste will be picked up, the curb or the backyard. Another key decision is frequency of collection. Both the points of collection and the frequency of collection need to be evaluated in terms of health factors and their impact on collection costs. Collection once a week is mandatory from a health standpoint. That is the time frame that breaks up the breeding cycle of flies. Factors regarding more frequent collection, the point of collection and of solid waste storage containers must be evaluated. Another factor to be considered in recycling. Perhaps one of the greatest problems in this area has been and will for sometime continue to be one of new and innovative systems that appeal to the fancy of men. If we were required at home and at business to separate our waste products into four simple categories such as paper, metals, glass and garbage, we could reuse much of the first three categories and dispose of the last. In addition to the separation at the point of generation, a separate collection mechanism would have to be developed. One approach would be to have a small, low powered motor vehicle pulling four to eight small open body cars where they could pick up the waste in separate categories and carry it to a master system. There are over 125 cities in these are financially successful and will continue to be so as long as a reasonably adequate price for the wastepaper is maintained.
The distance between the collection points and the disposal site will usually determine the advisability of including a transfer station in a transportation system. If you exclude some very questionable alternatives such as ocean dumping and rocketing waste into outerspace, there is only one acceptable method for the final disposal of solid waste and that is burial via the sanitary landfill. However, there are three basic alternatives with sub- alternatives in handling the waste prior to final disposal. They are:
Direct haul to a sanitary landfill is usually the cheapest disposal alternative in terms of both operating and capital costs. However, it may not be the best alternative in the long run because of the inherent wastefulness of land and resources that goes with direct disposal. With the second alternative, that is processing prior to burial, the primary objective of the processing is to reduce the volume of waste. The third category for disposal alternatives is processing with the recovery of energy or materials. In terms of economics there are significant capital and operating costs associated with all of these energy and/or materials recovery system. However, if sufficient markets are available, both energy and material can be sold to reduce the net cost of the recovery.
The processes are aimed at recovering useful material and/or reducing the volume of waste that must be finally disposed off. In the normal procedure of collecting solid waste in a compactor truck and delivering the waste directly to a landfill, the waste is ultimately reduced in volume by a factor of 3 to 5 with a resulting density in the neighborhood of 1,000 pounds per cubic yard. In a conventional landfill, densities in excess of 2,000 pounds per cubic yard can be obtained which results in an additional volume reduction of about 50 percent. This in itself can double the life of a sanitary landfill. Shredding is a volume reduction process in which the solid waste is shredded into a relatively homogeneous material that in turn may be further processed. Shredding can also be used in conjunction with incineration. Incineration itself can reduce the volume of refuse to be disposed of by around 80 percent. This, of course, leads to extended sanitary landfill life. However, incinerator does have several environmental difficulties.
All of the comments made regarding energy recovery are applicable to materials recovery systems. In fact, almost all resource recovery systems being developed include the recovery of both materials and energy. Generally, the preferred approach is to recover as many of the materials as technology and the market can justify and then to recover the energy values in the solid waste. However, it cannot be emphasized too much that the major deterrent today to recycling, resource recovery or energy recovery is not technology, but the lack of profitable markets.
A sanitary landfill is not obnoxious and does not create public health hazards or nuisances. This does not mean that there are no adverse environmental impacts from sanitary landfills. The selection of a site for a sanitary landfill is perhaps the most difficult problem in the development of a sanitary landfill. Because of opposition by local citizens a public information campaign is essential in the early part of site selection. In addition to public opinion the location of landfills should take the following variables into consideration:
Consideration must also be given any special or hazardous waste that may be brought to the landfill. The two basic sanitary landfill designs are known as the area method and the trench method. In either case the landfill consist of cells of compacted refuse. In the area method the solid wastes are placed on the land a bulldozer or similar piece of equipment spreads and compacts the waste. Then the wastes are covered with a layer of earth and finally the earth is compacted. The area method is best suited for sloping land and is also used to fill in quarries, strip mines, valleys or other suitable land depressions. Obtaining adequate cover material may often be a problem in area landfill operations. In the trench method a trench is cut in the ground and the solid wastes are placed in it. The waste is then spread in thin layers and compacted and covered with the earth that was excavated from the trench. This method is best suited for flat land where the water table is not near the ground surface. The main advantage is that the material excavated from the trench can be used for the cover material without importing additional materials. In any case it is recommended that the depth of each cell be no more than 8 feet as a deeper cell can usually result in fill that have excessive settlement and surface cracking. However, the number of cells which can be placed on top of each other is considerable and there are many landfills that are in excess of 60 feet deep.
Solid waste - All discarded materials, except sewage and liquid wastes. Since this encompasses nearly everything we use, its accumulation is continuous and rapid. Its rate of generation increases with population, affluence and as of late, convenience packaging. In fact, the rate of generation of solid waste is increasing more rapidly than our population. In the past twenty years, for example, the population has risen somewhere in the neighborhood of 30 percent while the volume of solid waste has risen approximately 60 percent.
Garbage - Is usually considered putrescible decay animal and vegetable waste.
Rubbish - Is usually defined as non-putrescible solid wastes, such as paper, rags, cartoons, wood, rubber, plastic, leaves, and like materials.
Refuse - Is a mixture of garbage and rubbish and as far as the handling of refuse is concerned, it is nearly always treated the same as garbage.
Hazardous Waste - Include such things as the waste resulting from the manufacture of pesticides and drugs, pathological waste, explosives, radioactive materials and similar dangerous or toxic materials.
Sanitary Landfill - Is defined as a controlled area of land upon which solid waste is deposited, compacted and then covered with earth each day with minimum impact on the environment.
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Source: Nine separate studies (approximately 300 samples) carried out by USPHS, APHA, and university personnel throughout the United States over the past decade.
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Source: Based on studies carried out by New York University, Dr. Elmer Kaiser et al. over the past four years. The figures represent averages of data which exhibit large ranges with regards to time, place, technique. There is no assurance that this information is applicable elsewhere than in the metropolitan east.
Figure 1. Jefferson County Health Department - Solid Waste Disposal Site Evaluation
Site: Date:
Location: Total Rating Points:
Classification:
Comments:
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garbage, rubbish, refuse, and
hazardous waste 2. What is a sanitary
landfill? 3. What is the
purpose/limitation of a sanitary landfill? 4. What are some problems of
solid waste management? 5. What is meant by the phrase:
"a comprehensive solid waste management program" as it
relates to public health?
1. Define the following
terms:
