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Draft Skeleton of a Solid Waste Mangement System Description for a County or Town Comprehensive Plan

Overview

In 1982 Bob Giles worked with a group of students on designing and developing a prototype for a system he called Dynaplan. At the time, he was serving on a planning commission and realized the need for information on hundreds of major environmental and other city/town/county problems. At the time, every county was required to have a comprehensive plan. Many resisted; many developed excellent plans. They all looked very much alike. Most were zoning or land-use plans. He had a much larger concept than land use of what a plan should be to meet the needs of people and resources for the longrun. He, with students, began to put on the coumpter a format for a plan and the main text (typically that which was in common for all counties in the state). He anticipated a computer branching to text that was relevant only to different regions within the state.

Herein is the text prepared (with minor recent revisions) and at one time available to any county. It was another project never used because there was no marketing or structure for delivering it (among other reasons). Giles preserved the text and has made it available herein. Systems must have a physical, stable" home." He now feels that with only minor modifications and editing, the text can still serve as the basis for a draft solid waste plan for a town or county. Selection of waste disposal processes and sites are critical to quality of life in rural areas. A regional plan reduces the amount of dispersed, often unknown and potentially dangerous waste sites on farms, forests, mined areas,and wetlands. Urban demands for disposal sites often exceed rural residents' ability to withstand them. The text allows, he suggests, for the work at the local level (with staff and consultants) to be concentrated on local problems and special needs. He believes that the text here provides a beginning that, on average, will save time in developing a superior to the average text on the topic in plans, and that the material such as found here will be better than omitting solid waste issues from comprehensive plans or the planning effort.

He also believes that this website offers the opportunity, in the spirit and concept of Dynaplan and The Trevey, to evolve rapidly (and continue to evolve) to become a superior aid to planners. Each county does not have to "start from scratch." The same text and research does not have to be done 100 times for each of the counties of the state ... and re-done every 5 years. By having this material on a web site, citizens can have access to it. The plan does not have to be "that dusty book over there on the shelf", out-of-date before it was delivered.

This document was initially authored by John P. Harvin (1976), graduate research assistant in the then Division of Environmental and Urban Systems, VPI and SU . Editors and contributors have been Robert H. Giles, Jr. (1982) and David Mistick (1976) and Fortran Programmers were Edward Okie(1976) and Ashraful Huq(1982). Transcribers were Cathy Miller(1977) and Leslie Mehring (1982). The participation of all of the above is gratefully acknowledged. The pattern seen in the text is that of a systems approach to solid waste management. Management implies operating and controlling a system to to achieve stated objectives. The text started in 1976 may seem old and potentially out of date. Unfortunately most of the problem remains the same or have grown and the suggestions for solutions have changed little. Suggestions for updates, additions, and improvements are continually sought and authors will be listed. Faculty members are encourage to assist in getting student help in improving the text for this chapter of the former Dynaplan. It will be used within Rural System. GIS capabilities enable good selection of waste disposal sites ... at least the least bad regions for the difficult decision. Recent facts, figures and notes are available for use.

With or without a plan, litter prevention and control are needed.

Duncan, A.P. 1999 What is source reduction? A critique and comparative analysis of Polish and American Students. Env. Management Vol 23:4:495-505 . Source reduction was seen as a preventative activity (reduces number and extent of actions; prevents resource consumption and pollution generation, its a producer and consumer activity, and includes frugal (less conserving) as well as efficient strategies.

Littering can be a part of vandalism as can purposeful dumping and related action. Vandalism prevention and control needs to be part of wast management.

RHG, August 27,2000

Outline

SOLID WASTE MANAGEMENT FOR _____COUNTY

Planning for dealing effectively with solid waste is one of the most pressing of county problems. On the average, solid waste disposal is the third largest county expense (schools and roads are first and second). It is a problem now increasing. It will never be solved, but it can be held in check or reduced, then managed in an orderly, cost-effective way. Increasingly, waste becomes a meaningless term. It is a negative word for materials that are in an intermediate state between their first and second uses. Much material that comes from homes and industries is raw material for some process. There is not much difference between coal mined to fire a town's boiler and paper boxes extracted to fire a boiler. There is money to be made, losses and costs to be reduced by active operation of a comprehensive solid waste management system.

How big is the problem and how big will it be if present trends continue? The answers for ______ County are in the following table (based on 43, 44, 45, 46).

Table 1. Solid wastes produced by average county residents under present policies and trends.

Insert table here in subsequent work.

The 1920 data suggest the rate at which the problem increases. The economist will translate this into a simple interest rate of about 6 percent. There are many reasons for the waste increases. Knowledge of these may suggest future trends, suggest points at which the problem can be attacked, and help justify public expenditures and management efforts. The reasons are:

  1. Urbanization concentrates waste-generating activities.
  2. Packaging costs are decreasing, allowing the amount of packaging used (and discarded) to increase.
  3. Income and per capita consumption of goods are increasing.
  4. Consumers are increasing.
  5. Quantity of scrap has reduced and market price has depressed recycling or caused it to vary widely.
  6. The weight and volumes of solid wastes are impressive as they increase, interactively, with populations and per capita consumption. Costs now increase for:
    • collection
    • transportation
    • disposal, and
    • their interactions.
  7. Fuel, labor, land, buildings, and road maintenance costs increase. Inflation reduces buying power of the tax dollar or the private waste disposal dollar.
  8. Older disposal techniques, once suitable for the waste volumes that were being generated, are no longer suitable due to changes in population densities and knowledge of pollution risks. Traditional solid waste disposal practices, while relatively inexpensive, are no longer legal or acceptable due to their potential danger to the health, safety, and welfare of the human community and the potential hazards to the ecological community. Ocean dumping is illegal (1972 Marine Protection, Research, and Sanctuaries Act) and has been drastically reduced since 1975. The Resource Conservation and Recovery Act (PL-94-580) requires open dumping of all solid wastes to be stopped nationwide by1983.

Former practices, if continued at present costs, inflation rates, and dollars adjusted to 19 will result as shown in the following table.

Table. Average costs of solid waste disposal for the county under the present policies and trends

Insert table here in subsequent work.

No county can afford to spend so much money or time on waste disposal when there are so many other pressing needs. No city or county can afford not to plan for meeting the solid waste management needs of its jurisdiction in the future. Cities can no longer simply dump their garbage in a nearby field, or industry hire a collector to take their garbage to his pigs. Out-of-sight is no longer out of mind. Solid waste disposal is becoming increasingly subject to rigid Environmental Protection Agency (EPA), state regulations, and strict local ordinances. The problem of solid waste control must be faced squarely, without fail. The problem will not disappear, unaided.

In some areas, solid waste represents an unexploited resource that can provide benefits for citizens and industry rather than a source of proliferating costs and problems. Many industries now recycle their own waste, therefore industrial solid wastes are not included in this analysis. Wherever these wastes must be included in county planning, volume estimates can be multiplied by a factor of about 1.4.

Solid Waste Management

Solid waste is such a complex problem that it will not be overcome by simple solutions. Any short-term ploys will only create larger problems later - for the children and grandchildren of citizens of the county. Because of the complexity, a solid waste management system is proposed. Such systems include the major components of the context, objectives, inputs, processes, feedback, and feedforward.

The Context

A solid waste management system usually must be operated for a county, but occasionally regional approaches are taken, occasionally a planning district will attempt to coordinate or provide aids in such management. While local and quite personal, the system is very much a function of national advertising and product use, attitudes, and of course national and state laws. Can and bottle recycling may be a local, regional, state or even national issue and will drastically effect the waste disposal problems locally. It is best to see the context of the system to be just as broad as possible for it will justify and encourage system managers to work on state level educational efforts, legislative issues, and regional coordination among counties.

A statistical technique (cluster analysis) is available for forming regions of optimal size, either sub-county or multi-county, that can most cost-effectively achieve the following set of weighted objectives. Clustering is a means of gaining economies from large scale operations not otherwise possible with independent community action. Those in the regional system should initiate state or regional coordination of (a) information, (b) accounting, (c) legal support, (d) research, and (e) financial support for small communities.

In many areas it will be expeditious to employ a solid waste system manager, perhaps jointly among counties and communities, to design, put into action, and manage a system to achieve the following set of objectives.

Objectives

Objectives of a community solid waste management system are (link for comparison):

  1. To minimize solid waste generated per unit time
  2. To minimize litter
  3. To maximize solid waste separation at the source
  4. To maximize recycling of solid waste
  5. To maximize usable energy generated from solid waste
  6. To minimize secondary undesirable effects of solid waste disposal, e.g. as to health, air, ground water, wildlife, and from pest populations and odors
  7. To minimize public costs of solid waste disposal
  8. To minimize the area required for solid waste disposal
  9. To maximize the use of sewer plant wastes and industrial chemical wastes

These should be weighted as to their relative importance. A weight of 100 is assigned the most important objective and others are weighted relative to this one. An effort must be made to achieve all of them simultaneously as one set. After weighting them, estimates need to be made of the relative risk of failing to achieve each objective. (K is the probability of a bad outcome if the objective is not substantially achieved. it ranges from 1.0 ("really bad!" and life threatening) to 0.1 which implies" unfortunate" but conditions tolerable for a short time if there is failure ). Tradeoffs and continual re-allocations among them may be based on the relative benefits (the weights x (1.0- K)) achieved for all objectives per unit of investment.

Inputs to the System

Budgets

Solid waste management is usually financed by:

In 1964 (as in all cases, updates will be supplied as they become available or as they are collected for a locatity)

The trend is toward service charges, though there are optional systems.

One source of income to operate the system is a product-category solid waste tax which has the following characteristics:

  1. It is limited by EPA standards on disposal and reclamation.
  2. It may be local, district, or state operated.
  3. It is a tax (like that on gasoline) that is to be used only for solid waste system operation purposes.
  4. It is computed as follows:
    The total annual costs are estimated. About 12 percent is added for recycling. The total annual overhead cost ,T, is computed. The total tax from each product category (e.g., containers, paper) t, is set equal to T multiplied by the percentage P for that waste in samples properly taken (or by national or regional averages.)

    t=T(P)

    P may be obtained from dividing the weight of a product waste by the weight of the total solid waste last year. Materials that produce special handling or disposal problems should have their tax appropriately increased. Rigid containers, for example, should have a unit tax rather than a weight tax determined by dividing t by the number of containers in public solid waste systems. Since the percentages are computed every 2 years, an incentive to reduce the weight is provided as well as an incentive to use larger containers. Annual costs are re-estimated and the computations repeated.

  5. Reused containers are not taxed, thus another incentive is provided.
  6. Credits against the tax are given to companies that accept salvaged material of their product from publicly-funded reclamation facilities.
  7. Incentives are provided which bring individual and social interests in line with each other.
  8. The tax does not constrain, restrict, or prohibit individuals or corporations. It provides inducement to constructive behavior of all parties.
  9. Homeowner waste collection charges based on weight may be used.

Energy recovery systems necessitate large capital outlays from county governments. The implications for financing such systems are (53):

  1. Solid waste collection and disposal will require much more capital in the future than it has traditionally
  2. The capital will tend to be concentrated in fewer and larger facilities
  3. The revenue potential of resource recovery systems will introduce a new element of entrepreneurial risk and reward not previously contemplated by traditional lenders
  4. Capital will have to be amortized over a longer term than allowed by traditional bank lenders.

The major types of resource recovery finance being utilized at the present time are:

  1. General Obligation Bonds (tax exempt) - backed by the full faith and credit of the issuing municipality
  2. Revenue bonds with additional security pledge (tax exempt) - backed by revenues from the project and pledge of debt service back-up from the general funds of a municipality
  3. Revenue bonds secured by pledge of controllable revenues (tax exempt) - backed by promise of municipality to charge rates sufficient to cover debt service
  4. Industrial Revenue Bonds (tax exempt) - promise of corporation to make lease or sale payments sufficient to cover debt service on the bonds
  5. Corporate Bonds (taxable) - full faith and credit of the private corporation

Conducting appropriate cost accounting of solid waste disposal is needed, including:

A facility-acquisition plan and capital budget are needed for 50 years to provide phased financial resources and appropriate space to carry on essential, diverse components of a successful solid waste management system.

Employment

Of the 337,000 workers involved in waste collection, 53% are employed by public agencies, while the remaining 47% are privately employed. Moreover, there is one employee for every 590 persons, 1 compactor truck per 2,100 persons, and 1 non-compactor truck per 1,100 ( a total of 179,000 vehicles). Furthermore, 80% of the non-compactor trucks are privately owned and only 10% of these are used for residential collection.

Knowledge

Solid waste issues involve many disciplines. There are few agencies having complete responsibility for the problem. Legislative responsibility centers on the Solid Waste Commission (changed?), General Assembly of Virginia.

Advice can be gained from:

The Department of Health has final approval of all proposed landfill sites. Graduates of various univeristy programs in industrial research, operations research, and environmental sciences may be employed. Multi-county solid waste authorities may profitably evolve to secure the full time professional advice, education, coordination, and systems operation knowledge of such people.

University programs in civil and environmental engineering and urban and regional studies may be contacted for advice and study programs. Many sites on the Internet provide sources of information.

Analyses are needed of solid waste production by type, amount (volume and weight), per capita production, energy content, costs of recycling or processing, energy use efficienies, transportation cost, sorting or processing costs, end products, and re-sale or re-use opportunities. Rates of change in the above are needed to predict and guide the system.

A rational, longterm approach, as many-factored and complex as the problem itself, needs to be developed to achieve the stated goals. The action options include inputs from the system itself, supported by taxes and fees, to the citizens (both individual and corporate). They may be educated to

A key source of inputs to a system is research. Although much has been done, there are needs to conduct local studies and support state and national research on the problems of the system. These may be directed to producing less waste-producing items and practices, and improving sorting, collection, recycling, processing, reuse, financing, accounting, and reporting. These answers may be developed and designed as subsystems that will fit well into management systems over large areas.

Several consulting firms offer advice, plans, and operate entire systems.

Waste

In your county the solid waste output per capita per day is w___________

The annual solid waste weight is (A2 + B2) tons. If > 500 tons. If < 500 tons, omit.

Where disposal charges are $1 .00 or more per ton (typically) a sorting and reclamation plant is likely to be profitable with incinerators.

In your county, _____________ and contiguous counties of

The total annual estimated volume is _______ tons.

Processes in the System

Collection

Solid waste disposal is a step that occurs quite late in the practice of solid waste management. Solid waste collection is just as important and in almost all cases more expensive than the disposal of the waste. Of the total solid waste budget, $0.80 out of every $1.00 goes to collection, and $0.60 of the collection cost is paid to labor.

A waste management system provides collection services appropriate in amount and schedule for the type of solid waste (based on volume, health, and other criteria, and costs).

The type of equipment used in collection is important. Since collection equipment represents a large capital investment, special care should be taken in selecting equipment, with special emphasis on utility. For example, side-loaders are more convenient for curbside pickup and alley collection than rear-loaders due to the increase walking time to the rear of rear-loaders. In large urban residential areas, small highly maneuverable collection vehicles can reduce time and increase efficiency in collection.

Maintenance and repair costs represent the largest single operating expense for a piece of refuse collection equipment. The expense is highlighted by the fact that the owner of a properly maintained piece of refuse collection equipment can expect to spend 100 percent of the purchase price of the piece of equipment within 5 years, or between 3 and 4 years if not properly maintained (33). In order to reduce this expense, many counties and cities are attempting to either reduce the number of pieces of equipment or reduce the operating time of the piece of equipment.

The city of Bellaire, Texas adopted a new bag retriver mechanism on an existing collection vehicle. The bag retriver has drastically reduced collection time and it is operated by one person (34). The city of Tolleson, Arizona has modified a single rear-loader to pick up barrels. The collection cycle of Tolleson has been reduced from 4.5 to 3 days and it only requires one man to operate it. The savings for the town of only 4,000 is significant (35).

In reducing the frequency of collection, it is advised that the size of the container be maximized so that the frequency of collection may be minimized. The container capacity should account for a 25 percent seasonal variation in solid waste production (33).

The best way to increase labor productivity is to optimize the equipment-to-person ratio. For example, one-person crews are more efficient and less costly than multi-person crews for curbside collection. The following table summarizes some of the costs differences among size of collection crews. Labor costs can be further reduced by re-routing collection routes in order to minimize such things as left turns across traffic and to reduce dead time spent in overlapping routes.

Waste collection costs comparisons

Insert table here in subsequent work.

Separation of refuse either requires collection vehicles with multiple compartments or multiple pickups. The latter are preferred and should be used on a schedule determined by the volume and hazards of temporary storage. Waste would not have to be picked up weekly, for example.

On the average, it requires one truck operating 8 hours per day per 2000 residents. By working two shifts and Saturdays, one truck per 4800 residents is required. A minimum fleet size for your county would be

X. =Total Population/4800.

This will decrease somewhat as volumes decline from conservation and other practices, but the gains may be offset by the needs for multiple pickups. An operations research specialist can determine a minimum-cost solution to most county and urban waste collection and transfer problems, but to date, this must be done at the county level.

Significant savings can be obtained from curbside collection in residential areas as opposed to backyard collection. In some cases a 40 to 55 percent reduction in collection costs has accompanied the switch from backyard to curbside collection. Subsidies, incentives, and education can be used to encourage appropriate storage and collection places. Collection containers can also have an effect on the efficiency of collection operations. Collection containers should be of a strong, lightweight material which is secured in a fashion that it cannot be overturned by wind or animals. Significant savings can also be made in curbside collection by using plastic or heavy paper bag containers. These containers are easily and quickly loaded by one-person crews. In rural areas, centrally located collection containers have proved to be highly efficient in solid waste collection.

In Connecticut (1976) there is a curbside pickup and recycling of newspapers, and a separate pickup of a mixture of cans and glass. Regular crews make the pickups. As much as 20 percent of residential waste is diverted from other disposal systems. The method reduces transportation and disposal costs and provides financial returns to the communities.

Transfer stations can be used to increase the efficiency of solid waste disposal systems. A transfer station is a centrally located collection center where solid waste is compacted and then transported by truck or rail to disposal site. Transfer stations separate collection and transfer costs and therefore avoid labor time consumed by collectors in traveling long distances to the disposal sites. If total costs of collection, transfer, and disposal are less than the present collection and disposal costs, a transfer station is obviously a desirable economical practice. If convenient disposal sites are not available, it can be economical to construct a transfer station if the disposal is at least 50 miles away from the center of the collection service.

Computers can be used to optimize (in terms of time, cost, energy) collection routes. GPS can map out routes and efficiencies discovered.

In small communities (but greater than 6000 people) the annual residential refuse collection cost was $15.60 in 1953. Considering inflation, the average costs are now likely to be over $30 per residence.

Refuse collection often has high noise levels. These can be minimized. (See Noise Chapter.)

Who Should Make Collections?

Who the appropriate solid waste collectors are is an often debated issue. While some localities have left such collection up to private enterprise, it is generally accepted that the disposal of refuse is a proper governmental function in the interest of the publicvs health, safety, and welfare. Further, the courts have held that "in disposing of its garbage and in letting a contract therefore, a municipality acts in its governmental capacity and not in its corporate or private capacity." In other words, as servants of the people, local governments must insure an adequate and sanitary system of solid waste collection, regardless of what form that collection takes.

The cost and quality of solid waste collection has come under increased criticism by both local officials and the public in general. The wide-spread dissatisfaction with existing services, demands for increased services, and general "agitation" caused by spiraling cost of collection services, has created a great deal of pressure on public officials to enact some form of change in existing collection policies.

In general, local officials have three alternative forms of solid waste collection from which to choose. These forms are municipal collection, contract collection and private collection. A municipality may also choose a combination of any of the three forms. Under the municipal form of collection, city employees and equipment, directly supervised by a municipal department or official, perform the actual collection of refuse. The costs of operating the services are paid from general revenues or from other fees. Contract collection is the establishment by a city of a private collection firm, under a formal and binding agreement, to collect and dispose of municipal refuse. Contract costs are financed through general revenues or the collection of service fees by the municipality. Under the private collection form, refuse collection is performed by an individual or company under an agreement directly between producer and collector. The private collector charges a service fee to the producer for whom he makes collections.

No formula has been developed which can decide for a municipality which form of collection is most appropriate. In general, the most appropriate form of collection will depend on the specific and unique conditions of a particular municipality. The decision is made to achieve these objectives:

  1. regular collection
  2. minimal inconvenience to citizens
  3. enforced conditions of sanitation and safety
  4. minimum traffic disruption
  5. minimum cost.

The advantages and disadvantages of the three forms of collection will next be discussed as they might tend to achieve these objectives.

Municipal Collection

It has been argued that under sound, non-political management, municipal operation is economical, satisfactory to households and citizens, beneficial from a public health standpoint, and a credit to the community. Municipal collection has several desirable characteristics which are not common to the other forms of collection. Probably, the most desirable characteristic is that its basic source of motivation is sanitary conditions, not obtaining a profit. Because it is motivated to place the community 5 health, sanitation and attractiveness over economy of service," municipal collection should be desirable to the public. Another potential advantage of municipal collection is in terms of costs. A municipal service benefits from two factors in its ability to operate at lower costs than other forms of collection. Obviously, a municipal service is not required to earn a profit for the municipality. Further, such a non-profit service does not have to pay state or federal income taxes as do private collectors. A municipal service also benefits from economies of scale. As a municipal service, it can benefit from municipal central facilities, such as garages, accounting and billing services, as well as personnel and payroll administration services.

Municipal collection not only benefits from economies of scale in buying gasoline, oil, parts, etc., but it also enjoys a bargaining superiority over other forms of collection. That is, as part of a governmental body, a municipal collection agency has behind it the policies and powers of the local government. Such power and status gives a municipal collection agency political leverage in such things as rate structures, role of the citizen in the collection operations, and in union negotiations.

The city of Tucson, Arizona, annexed over 57 square miles of residential areas over a 4 year period. These areas were being serviced by a private collection firm at the average rate of $1.31 per unit per month. After phasing out the private collection agencies, Tucson was able to provide municipal collection to those same areas at an average cost of $0.68 per unit per month.

Municipal collection also benefits in terms of community relations. Usually, municipal collectors repsond to citizens' complaints in a courteous and prompt fashion and further, citizens are generally more readily cooperative with a public collection agency than to a private agency. Such cooperation is deemed critical to a successful collection operation. Municipal collection employees are also under the constant eye of the public. Further, municipal collection allows for long range planning, has the ability to provide equipment and personnel for other municipal functions (such as snow removal) and is readily adaptive to technological and managerial improvements over a long period.

Municipal collection suffers from a variety of disadvantages when compared to other forms of collection. The primary complaint against municipal collection is that the "lack of business competition can lead to administrative and labor inefficiencies not associated with a profit motivated firm". Municipal monopolies, such as a refuse collection firm, tend in general, toward inefficiency. The public is more or less at the mercy of its servants, who, under such monopoly conditions, are generally unmotivated and inherently unreliable because of their vulnerability to strikes and slowdowns, especially in the larger cities. Improved feedback mechanisms can substantially reduce these problems. Municipal collection is also very susceptible to political interference which often translates into the appointment of unqualified and inexperienced people to positions of management in the refuse collection agency. Municipal agencies are also expected to provide large employee benefits which add to labor costs.

Other factors contributing to the problems of municipal collection focus on budget constraints. Because expenditures are controlled by the general budget, continued efforts to economize may reduce the level and quality of service. Further, because budgets are made to control spending and rarely "to make rational allocations of resources", budgets afford no incentives for efficiency. Municipal services also require high capital investments which may exceed budget limitations.

Contract Service

Contract collection is becoming an increasingly common practice. Under contract collection, a municipality engages a private collector in a binding legal agreement to provide collection services. The private collector is paid out of general revenues or through the collection of service fees. Contracts are awarded to private collection firms or individuals on a competitive-bid basis, with the firm offering the lowest bid usually receiving the contract. The contracts typically specify exactly the quality and frequency of service as well as the form that payments to the contractor are to take. Usually, collection contracts run from 1 to 15 years.

The most appealing aspect of contract collection is that it allows a municipality to retain control over refuse collection without having actually to operate the collection service. It has been argued that private collection is less costly due to superior management policies and methods. Because private firms are profit motivated, good management and efficient uses of personnel and equipment are essential. Further, private contractors are less subject to political interference which has resulted in some of the management problems in minicipal collection. Also, because contractors are competing for contracts, bids will represent the lowest possible charge under which a contractor can operate and still receive a profit.

Contract collection has several other advantages over municipal collection. One of these advantages is that a minicipality's fiscal responsibility is predetermined for the entire operating year and not subject to budget revisions during that time. Once the contract becomes binding, the collection agency will not have to fear budget cuts or other governmental changes which can affect municipal operations. Contract operations also reduce the burden of large capital investments for collection facilities and equipment by a minicipality. Finally, private collectors are more likely to take advantage of salvage and recycling opportunities in order to increase their profits while municipal agencies may not be motivated to earn such profits.

Contract collection, as the other methods, presents several signigicant problems for a municipality. One problem, especially for small cities, is that there may be only a few private contractors submitting bids for municipal contracts. In such a case, the municipality may have to accept a higher bid than expected. Further, if a private contractor has severely under-bid, or if the contractor experiences unusual operating expenses, he may default on his contract and leave the city without service. In the same context of uncertainty, a private contractor is not obligated to renew a contract. Such action could cause severe problems to the municipality as it attempts to plan for the collection needs of the future.

Another problem relating to costs, is the variation in costs between different private operators. A 1969 report on Boston1s contracts with private collectors submitting bids to provide services to any of 11 Designated collection districts, found a great variation in the lowest and highest bids granted. The bids, which represented the lowest bid submitted in each district, ran from a high of $10.30 per person per year to a low of $4.35 per person per year. While no immediate trends were determined to account for the discrepancy, potential factors include collection frequency, population density and distance from collection site to disposal site. Further, contract services must be inspected by city employees which adds to the total costs of the service.

Another common complaint of private contractors is the tendency to sacrifice sanitation and public health concerns for profits. Private contractors are also less likely to respond adequately to citizens1 complaints. In some municipalities, contracts have been granted under the cloud of corruption and political favoritism. Private contractors do not enjoy the backing of local police powers in enforcing citizen's rights. Finally, if technological or managerial improvements are made available to the private contractor, he will usually absorb these advancements as greater profits instead of reducing costs to the municipality.

Private Collection

Private collection is the only form of collection for many small communities. Further, almost all municipalities allow private collection of commercial, institutional, and industrial establishments. Under private collection, the private collector and the individual producer of refuse enter into a contractual agreement. A municipality will usually exercise a limited degree of control over private collection in the form of a license or franchise requirements. A franchise is a legal agreement in which one private firm is given exicusive right to provide a service in a certain area. In return for these monopoly privileges, a municipality is in a good position to demand exceptionally high operational standards. Franchise contracts are determined by competitive bidding with the highest bid receiving the contract or franchise. In larger cities, there is less tendency to provide this degree of control. In such cases, city Health Departments or Public Works Departments may only provide license requirements and minimal sanitation standards. A compromise between unrestricted competition and franchise arrangements is the assignment of specific routes to private collectors.

The main advantage to private collection is that free competition insures lower prices, service quality, and more efficient service. The assumption is that a private firm will attempt to increase its volume of business or reduce its volume of waste in order to increase its profits. Under municipal or contract collection, there is, under conventional systems, no incentive to increase volume or quality after the budget or contract has been finalized.

The greatest area of savings for private collection is in terms of labor. Municipal collection crews usually work on an hourly basis and there is seldom any incentive to collect more than some predetermined quota from the route. Further, private collection firms do not have to offer the extent of employee benefits required in many cities. A New York City study revealed that in 1972, city supported collection of refuse averaged $49.00 per ton while private collection averaged $17.50 per ton. Similarly, private collection in San Francisco averaged $30.00 per ton and $18.00 per ton in Boston during 1972.

Private collection also has the advantage of being divorced from political influence, except in the cases of granting licenses and franchises. Private collection shares with contract services the advantage of reducing excessively high capital investment cost to the municipality. Finally, private collection obviously reduces the fiscal responsibility of collection from the municipality, except for the administrative costs of licensing and inspections.

There are problems associated with private collection which a municipality must address. The primary objection to private collection is the lack of control a community has over the level and quality of service. If there is free competition between collectors, there is a distinct possibility that some unprofitable areas may not receive service, especially if such areas are faced with excessive fees. Further, becuase profit is the only motivating concern of a private collector, a community's appearance, health and safety may be jeopardized. Private collectors, like contract collectors, offer a municipality no guarantees for future services. Finally, the granting of collection franchises and licenses has drawn criticism as being politically controlled and riddled with corruption.

Solid Waste Collection in U.S. (1968) From Hagerty et al.
Type Percent of
of Population
I Industrial Wastes
  individual-self 30
private 57
public 13
II Commercial Wastes
  individual-self 13
private 62
public 25
III Domestic Wastes
 : individual-self 12
private 32
public 56
There is a growing trend in the United Stated toward more contract and private collection systems. In 1955, over 55 percent of municipal solid waste was collected by a municipal collection agency while in 1964, that figure had dropped below 45 percent. Further, in terms of all collected wastes, private collection in 1975 accounted for 73 percent. This figure represents 51 percent of residential collection, 91 percent of all commercial collection and 94 percent of industrial collection.

Most communities now offer some combination of the various forms of solid waste collection. As was noted previously, there is no formula to derive the optimal form of operation for a municipality. Under the most ideal conditions of management and administration, municipal collection is most efficient and least costly to the other forms of collection. Unfortunately, few cities have such ideal conditions to offer. In general, it has been found that "municipal solid waste systems cost more to operate than private or contract systems".

A significant problem in making just comparisons between the various forms of solid waste collection, is in determining an equitable basis for costs estimates. If a municipality accepts its general obligation to the public as was outlined earlier, merely selecting the form which appears least costly is not enough. Costs must include social and environmental costs to the municipality.

Further, due to the variation of quality and level of service between the various forms of collection, average costs may not represent an equitable basis for dollar commparisons. In this context, all costs to the municipality, including inspection, license administration, reporting, etc., should be included in some form of annual or total cost estimate. Also, a municipality should decide how much control is necessary to insure the public's health, safety and welfare in the collection of solid wastes.

Solid waste management does offer municipalities with an excellent opportunity to further the present emphasis on "good government." That is, the savings and potential improvements in service, achieved through well planned and managed solid waste collection systems, would go far in giving credibility to local government reorganizations and administrative changes. This motivation should prompt municipal government to look more closely at solid waste management.

There are no singular solutions to the solid waste collection problem. There is no one way to reduce it. The topic is not pleasant, and neither are any of the alternatives. The collection subsystems proposed (1) are capable of being improved systematically with experience, and (2) are adaptable to other changes in the community.

Other Processes

There are many other processes that may become a part of the management system. These include:

  1. Providing building codes and standards that encourage waste separation.
  2. Requiring building permit provisions that protect existing collection and sorting spaces and encourage others.
  3. Providing incentives for individual, neighborhood, and commercial spaces and methods for proper waste storage and sorting prior to its collection.
  4. Encouraging private enterprise or public cooperatives to form waste processing or recycling industries.

Organic Solid Wastes and Energy Recovery

Organic solid waste can be categorized into two basic groups:

  1. animal wastes (primarily manure), and
  2. general organic residues (forest residues, grass clippings, tree prunings, etc.)

Animal waste and other organic waste make up approximately 58 percent of the total amount of all combustible waste produced yearly (36). These two groups of waste decompose rather rapidly and therefore present only minimal problems if they do not require transport. That is, if waste can be allowed to decompose on the site where it originates, it does not present any significant problems except, perhaps, odor and water pollution. Often, however, these wastes must be removed and transported to landfills or other disposal areas. These types of solid wastes do provide excellent sources of energy. Energy can be produced by combustion of organic materials in fossil fuel generators or used to produce methane gas. Already the yearly production of animal wastes on the four largest feedlots in Kansas equals the amount of sewage produced by the entire state's population (37).

Operating a solid waste management system results in four areas of potential energy conservation (42):

  1. Source Reduction - using less energy to collect and dispose of solid waste.
  2. Energy Recovery - using solid waste as a fuel for energy production in place of (or along with) coal, oil, or gas.
  3. Recycling - using recycled materials that consume less energy than virgin materials in manufacturing.
  4. Improved Collection - using waste collection trucks more efficiently and thus reducing fuel consumption.

Source reduction, recycling, and improved collection techniques are means for conserving energy, primarily through sound management policies. Success in these areas will depend largely on the cooperation and education of public and private sectors. Techniques for success are generally socio-political rather than technical.

Energy recovery is a rapidly developing field in solid waste management. Energy recovery systems generate energy directly or by producing gas or oil. The ever-increasing rate of solid waste production and demand for energy coupled with decreasing supplies of low-cost fossil fuels makes this area of conservation very promising. Numerous energy recovery systems are presently available and new systems are being rapidly developed. Some of the potential advantages of energy recovery systems are (42):

Insert table here in subsequent work.

Some of the additional conditions and trends which make energy recovery systems more favorable are (53):

  1. an interested, willing and cooperative consumer
  2. heavily populated areas can insure a large, steady volume of combustible material
  3. there is a desire or need for additional low-sulfur fuel sources, and
  4. land for other disposal systems is at a premium.

Energy recovery systems are now best suited to heavily populated areas due to the above conditions. This condition is, however, dictated primarily by technology. New and improved systems of energy recovery are likely to make smaller scale operations economically possible.

The most promising solid waste disposal process is to convert it into energy. The first step is to remove non-combustible materials from the waste. A sorting and reclamation plant is required and is profitable at above 500 tons per year which is (is not) achieved in your county and is (is not) achieved in your county and contiguous ones.

Potential disadvantages for energy recovery systems include:

  1. markets are needed for the energy produced
  2. most systems will not accept all types of wastes and therefore require sorting
  3. specific needs of the energy market may dictate parameters of the system design
  4. they are complex processes requiring sophisticated management
  5. relatively long periods for planning and construction are needed between approval of funding and full-capacity operation
  6. technology for some operations are new and not yet fully tested most systems require large capital outlays which may require forms of public financing and lending services not now available.

Much has been said about reusing and recycling solid waste materials. The most promising reuse of solid waste is as fuel for energy. This process of energy recovery has been briefly discussed. Other materials, however, may also be recycled. Paper makes up 50 percent of all solid waste collected. Technically, recycling paper is not a complex operation and large facilities already exist in such localities as Roanoke. Further, approximately 17 trees are saved for each ton of paper recycled. If one half of the paper presently being disposed of were recycled, demands for some 30 million cords of wood annually could be reduced. However, unlike other materials in solid waste, paper originates from a renewable resource, namely the forests. Paper also biodegrades very rapidly. A newspaper, for example will decompose in about a year (32). Further, in order to make such a recycling operation profitable, a processing plant must be located near the collection site. Transportation costs, whether by highway or rail, are the most restricitve costs in paper recycling (4). Paper is also being developed as a possible source of protein. When, or if, this process is perfected, recycling of paper for protein may be more beneficial and profitable than recycling for paper alone (29).

After sorting, refuse may be used as energy in several ways, the most widely used of which is burning it with coal in an electricity-generating or steam plant. Sorted refuse has 5000 BTU (_____ k cal) per pound (half the energy in coal). A good fuel ratio is 1:10, refuse-to-coal. Given your county's combustible waste resource of _____ tons and a generator using the 1:10 ratio, you could operate a utility with a capacity of about _____ k watts per year. The resulting fuel produces far less pollution, is more economical than fuel of purely coal, and it does not adversely effect the boiler in fossil fuel systems (49).

It is unlikely all combustibles will be used in the above manner. In St. Louis, half is so used. Making the same assumption as for their operation, you have the potential for a _____ k watt generating capability at present rates of $_____ per kwh, this is equivalent, at this date, to $_____ Total county electrical usage is _____. The solid waste contributi6n could be _____ or _____ percent.

Frankfurt, Germany, now gets 7 percent of its energy from garbage. There are advantages to using refuse as fuel. They include:

  1. Power production costs are reduced.. System costs become more favorable as fossil fuel costs rise.
  2. Refuse-coal combinations are less expensive than central refuse incineration.
  3. Solid waste as fuel contains less sulfur than most coals and thereby reduces air pollution. Total pollution is reduced when compared to conventional fossil fuel plant plus incinerator.
  4. Coal reserves are extended.
  5. Additional revenues (or savings) may beprovided to the community.
  6. The life of landfills can be extended.
  7. Existing generator equipment can usually be used. A sorting and reclamation plant may be needed.
One way of determining the economic feasibility of an energy recovery system is to compare the costs of processing, transportation and firing of refuse minus the savings of fossil fuel consumption with the costs of existing solid waste management system. In considering this comparison, local decision-makers should evaluate:
  1. inflation costs
  2. increasing fuel costs
  3. sorting and reclamation costs and revenues
  4. market outlets
  5. potential of new technological breakthroughs
  6. capital outlay
  7. type of financing.

The most thoroughly-proven system of energy recovery is the Waterwall Combustion System. Basically, this system involves the combustion of solid waste on a mechanical grate in a waterwall furnace to produce steam. The steam is then used to drive directly turbines which produce electricity. Depending on the design and operation of the waterwall system, one pound of solid waste will produce from 1 to 3 pounds of steam (42-A). The city of Atlanta, Georgia is presently selling steam from such a system at the rate of $140,000 a year. The revenue from these sales paid for the entire cost of the waterwall incinerator in 12 years (50).

Landfill Evaluation Program For Methane Recovery

Only outlined here is a scheme for evaluating the potentials of existing landfills for gas recovery for use as fuel:

Phase I - Background search

Phase II - Landfill investigation and analysis

  1. Refuse characterization
    1. Recover representative sample by boring
    2. Conduct laboratory analysis of samples
      • - Moisture content profile
      • - Volatile solids profile
      • - Biodegradability profile
  2. Gas production and recoverability
    1. Install test wells and probe network
    2. Observe landfill response to various extraction rates
      • Well head gas composition
      • Landfill pressure field
      • Gas movement through cover
  3. Data anaylsis
    • - Reduce and correlate data
    • - Predict deliverability of the fill
    • - Estimate kinetics of production
    • - Design well field configuration
    • - Specify operation of withdrawal system

Phase III - Processing and marketing

Pyrolysis

Another system of energy recovery using garbage is through a process known as pyrolysis. Pyrolysis is the chemical reaction by which heated garbage under pressure and in the absence of oxygen will produce methane gas. Methane can also be produced from bacterial action on garbage. Methane can then be used as a synthesized fuel in oil- and gas-fired generators. In some land fills this process is occurring naturally and the fill may be tapped for gas or oil.

In the landfill, methane gas is produced as a by-product of the degradation of susceptible organic materials by methogenic bacteria under limited environmental conditions. These environmental conditions are basically (53):

  1. the absence of oxygen
  2. a pH level of between 6.5 and 8
  3. the presence of moisture.

Under normal conditions, the natural process of methane production will produce from 1 to 3 cubic feet of methane gas per pound of refuse. The gas can be extracted from the landfill by wells and pumps, similar to ground water wells. A landfill of 1,000,000 tons of refuse can be expected to produce a recoverable 1 to 5 billion cubic feet of methane gas at an energy level of 1 to 5 trillion BTUs (53). Obviously, different types of refuse decompose at different rates. This must be considered along with the size and environmental conditions of the landfill before this source of energy can be economically tapped. Reference 53 offers an evaluation procedure for the practicability of methane recovery from a landfill. While such a recovery system is best suited to large metropolitan area landfills, the recovery of even small amounts of methane gas will undoubtedly become more promising in the future. It was expected that natural gas demand would exceed production by 10 trillion cubic feet by 1980 (53). De- regulation and development of resource has expended the production estimate. The resource is limited, however highly valuable as a chemical feedstock, and some people argue it is too valuable to burn. Local production from wastes will probably produce gas that is cost-effective and will extend the usefulness of natural reserves.

Mechanically controlled systems of pyrolysis appear to be one of the upcoming stars in the energy-recovery field. The mechanical system is extremely clean, uses almost all types of domestic waste, and produces a very small amount of residue. Further, such systems require relatively small amounts of space. For example, a 1000 ton-per-day refuse pyrolysis system can operate on a 3 acre site (50). Most pyrolysis systems do require large capital outlays and in some cases the systems have not been tested on a large scale. However, recent innovations and modifications of the pyrolysis systems are making such systems a great deal more efficient as well as economical. One offshoot of this process is the Wallace/Atkins Destructive Distillation Process. In this process, refuse is first heated and the gas produced is then passed through a series of reactors and recovery tanks. Each recovery tank collects a different grade of high quality oil. The oil obtained through this process ranges from crude oil to gasoline to light alcohol with the left-over gas being pipeline-quality methane gas. The residue from the original firing of the refuse is commercial quality charcoal (54). The system runs on its own energy once the system is operating, and its only pollutant is from water condensation which can be easily treated on the site. The system, while not completely tested, is an example of new and improved methods of energy recovery which are rapidly being developed.

Pyrolysis not only produces a usable gas; it reduces the volume of garbage. Anaerobic digestion in bacterial pyrolysis can reduce the original volume up to 90 percent. Animal manure is used to produce methane on small farms in England. A single hog will generate waste to produce 7 cubic feet of methane a year.

Composting

Another system of solid waste disposal which has had widespread success in Europe is composting. Composting is the biochemical degradation of organic materials to a sanitary, nuisance-free, humus-like material. The material produced is a highly saleable source of fertlizer. The material is high in nitrogen, other minerals, and humus. Such an operation may or may not involve a high capital investment, depending primarily on the type of operation to be used. Composting can be accomplished in outdoor composting bins or in mechanical digestion tanks. Composting does have high operation and distribution costs. A large scale operation has about the same operation costs as a central incinerator. The financial feasibility of such an operation is limited by the distance between composting site and the user of the by-product. In other words, if the market for the by-product is at a great distance, the cost of transporting the materials will make the method economically unsound. On the other hand, composting does recycle minerals and nutrients to the soil as fertilizer which would have otherwise been buried or burned.

New systems of composting are now being developed which take place in large digestion tanks and are therefore limited, as are outdoor methods, by bad weather. The following table shows the relative costs of three composting operations. Composting is probably best suited for individual practices. Methods have been developed by which a family can develop a compost bin without serious odor, offensive appearance, or without attracting pests. Residential organic waste such as grass clippings, leaves, coffee rinds, etc., provide excellent compost material. On a larger scale, compost markets include truck farms, home gardens, and landscaping. Problems attributed to compost operations are disease vectors, flies, rodents, as well as odor and visual nuisances. With the ever-increasing cost of fertilizer, composting is likely to become an increasingly widespread practice.

There are several supplementary practices which can benefit these different methods of waste disposal. Grinding of materials helps increase compaction and decomposition in landfills. Grinding is also helpful in composting and in incineration. Compaction involves subjecting wastes to extreme pressure and thus reducing the volume of the solid wastes. On-site compaction can reduce the volume of solid wastes up to 60 percent. Compacted garbage is easier to handle, requires less storage space and reduces the need for further compaction. Disadvantages for compaction include high equipment costs, added energy use! no reduction in weight and the requirement that compacted wastes must be tightly secured.

Hazardous Wastes

Hazardous wastes are by-products of human activities which present special health or safety hazards for their disposal. Traditional methods of solid waste disposal are therefore not suited. The three potential sources of hazardous waste are (39):

  1. Industrial Operations - which produce a hazardous residual as part of their process, or handle hazardous materials, a portion of which is wastes.
  2. State and Federal Activities - which handle hazardous materials. Also included under this heading are public utilities.
  3. Agricultural Operations - which handle large quantities of pesticides.

The first concern of planners will be in determining the sources and quantities of hazardous wastes within the county. The second major concern will be in determining who is fiscally responsible for treating or disposing of

Table Average capital costs and manpower needs for urban composting (4)

Insert table here in subsequent work.

the hazardous wastes. Even if governmental agencies are not responsible for the actual physical disposal of such wastes, they will play a vital role in controlling the disposal, due to the potential hazards to the public. Without governmental intervention, economics will dictate the type of disposal which may well be unsafe. Further, the county may provide financial incentives to the private sectors to provide adequate and safe disposal through such means as grants, loans, loans guarantees, and preferential taxation or public bonding (40).

In dealing with the actual hazardous wastes, three factors should be considered (41):

  1. Segregating hazardous wastes from all other wastes
  2. Keeping various kinds of hazardous wastes separated from each other
  3. Processing the hazardous materials to produce environmentally acceptable end products when there is no opportunity to recycle the materials.

Each hazardous waste will have its own special requirements for treatment and disposal. Further, it is a good idea to rate the extent of hazards presented by the particular waste. Rating systems should involve the four following factors (42):

  1. Health
  2. Flammability
  3. Stability
  4. Reactivity

Locating facilities to handle hazardous wastes is a critical problem. Public reaction to any waste disposal facility is apt to be negative if the location is in a populated area. This problem is further complicated if the facility must deal with "hazardous wastes." It should be kept in mind that citizen acceptance of the location and method of disposal is critical to the viability of the entire solid waste management program. In order to handle the socio-political aspects of siting hazardous waste treatment and disposal facilities the following factors should be considered (40):

  1. The public must know the facts and dimensions of the problem and how the facility will handle the problems
  2. The public must be assured of safety
  3. The public must know the alternatives and the resulting tradeoffs of economic and environmental cost vs. benefits.

Further, in formulating a policy for the siting of hazardous waste treatment and disposal facilities, the following factors should be addressed (40):

  1. The policy should be based on scientific facts, not politics
  2. The policy should be well documented and defensible
  3. The policy should be realistic and not unnecessarily severe
  4. The policy should be based on an accurate interpretation of trends.

Actual methods of hazardous waste disposal and treatment vary greatly depending on the type and quanity of hazardous wastes. There are methods for utilizing a modified landfill approach for disposal of some hazardous wastes. The chemical waste landfill is, however, very costly and environmentally delicate. Before considering this particular approach, the following factors should be addressed (42):

  1. Large available volume and long operating life of the chemical waste landfill
  2. Proximity - closeness to source
  3. Protection against uncontrolled leaching and excessive rain
  4. Protection of personnel involved with the actual operation of the chemical landfill
  5. Avoidance of fire and odor.

The experience of such an operation in West Virginia (42) provides an operational cost comparison between a chemical waste landfill and conventional methods. This comparison assumes that conventional methods could safely deal with such wastes (which they obviously cannot).

Waste Anaylsis

The general waste sources influencing disposal are:

The type of solid waste being collected should be analyzed. The type of waste being collected will identify special needs in disposal, such as disease prevention. Qualitative analysis should also reveal amounts of potentially recyclable and reusable waste products. Such analyses are generally not being done but some general figures are available. For example, about 50 percent of municipal waste is paper. Paper is recyclable, can be used in composting, and can be used as an energy source. Paper is also biodegradeable. Such information can reduce costs for solid waste management as well as serve as an environmentally sound energy recovery-strategy.

Chemical Waste Landfill West Virginia Operation (1971 Dollars)

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Disposal

There exists today a great number of acceptable disposal practices, with new practices being developed continually. Each practice varies in initial costs, maintenance costs, effectiveness, and longevity. It is beyond the scope of this Dynaplan chapter to describe and evaluate every possible disposal method. The major methods will be described and some additional information presented about supplementary practices associated with the methods.

A bulletin prepared by the Virginia Management Series, Solid Waste Management Planning for Localities in Virginia (1), lists ten critical features in evaluating a solid waste disposal method. These features are:

  1. safety hazards
  2. incidence of disease
  3. pest and disease vector propagation
  4. other physically disagreeable or harmful effects
  5. convenience to the waste producer
  6. system reliability
  7. adapatability to changing regulations
  8. production of a saleable by-product
  9. conservation of land resources
  10. salvage of resources for return to the economy.

These factors must be weighed against financial limitations, spatial limitations, magnitude of the problem, desired degree of efficiency, and public sentiment.

Sanitary Landfill

The most widely used disposal method is the sanitary landfill.

The sanitary landfill is a method for disposing of refuse on land without creating nuisances or hazards to public health or safety, by utilizing the principles of engineering to confine the refuse to the smallest practical area, to reduce it to the smallest practical volume, and to cover it with a layer of earth at the conclusion of a day of operation or at as frequent intervals as may be necessary. (1) An open dump is an unacceptable disposal method which poses health and safety problems as well as aesthetic degradation of the landscape. The open dump should in no way be confused with a sanitary landfill. The sanitary landfill is a carefully engineered and maintained sanitary system for disposing of waste by burial which minimizes health, safety and environmental problems.

Today, sanitary landfills account for over 50 percent of solid waste disposal methods used. The principle reason for such widespread use is the relatively low initial costs as well as relatively low maintenance costs. However, in 1970, less than 6 percent of all landfills in operation were adequate and not in direct violation of sanitation rules and regulations. (5) Ninety-four percent failed to meet 3 simple criteria:

  1. daily cover
  2. no open burning
  3. no water pollution

Sanitary landfills are, however, considered presently the "best alternative for most Virginia localities." (1)

The sanitary landfill has many advantages when compared to other disposal methods. It has a low capital investment cost especially when compared to an incinerating or composting plant. Initial costs of a sanitary landfill will be typically 25 to 50 percent less than a central incinerator. (1) The sanitary landfill will also have 33 to 50 percent less maintenance costs than a central incinerator. (1)

The sanitary landfill has the advantage of being able to handle almost all types of solid waste and, further, it can handle peak loads. The sanitary landfill, unlike other methods, does not require extensive sorting. Due to compaction, sanitary landfills use less land than open dumps. Typically, compaction will reduce the original volume of solid waste between 40 and 50 percent. The operation of a landfill can begin almost immediately without a lengthy delay in building time and it can be terminated without a great loss in equipment or land usage. Also, landfills usually improve the value of marginal lands and provide sites for parks, playgrounds, baseball fields and parking lots.

There are numerous disadvantages in sanitary landfills which must be considered. The most critical disadvantage concerns the large amount of land required. In urban areas the cost and availibilty of land may greatly limit the feasibility of a landfill. Further, the location of landfills outside of large urban areas may cause large transportation costs. Winter operation of landfills can be limited without special maintenance due to the freezing of soils to be used as cover material.

Another problem is the almost inevitable leachate produced by landfills. These waterborne substances pose a potential threat to ground water contamination. Not only does the landfill produce a leachate pollutant, but it will also produce methane gas, under the right pressure and temperature. This methane gas may, however, be tapped for energy. Another problem is that the sanitary landfill is only temporary and therefore it offers only a temporary solution. Lastly, there exists a widespread misconception by the public that a sanitary landfill will invariably be odorous and unsightly (9).

There are two broad types of landfill disposal methods; area and depression. An area landfill involves the excavation of relatively flat land in order to provide the depression for the landfill. Area landfills are further grouped into types of excavation and use of fill material. Progressive excavation is the practice of excavating cover and fill material from an area directly in front of the working face. A trench method of operation excavates a large narrow strip and stores the excavated material to be used as cover and fill material. Excess cover material from this type of landfill may be used as fill material or sold as borrow material. A third type of area landfill involves importing cover and fill material when the excavated material is unsuited for cover material. This type of landfill is used when it is desirable to change the terrain of the landfill area. However, the practice of importing cover and fill material is very costly (1).

A depression landfill uses a constructed or naturally occurring depression. A constructed depression may be an abandoned clay pit, stone quarry, etc. A natural depression includes such things as canyons and ravines. Depression fills usually require cover material equaling 25 percent of the volume of the depression. The use of any such depression will depend largely on soil conditions and the slope of the site. It should be noted that if no such suitable cover and fill material is on or near the perimeter of the landfill, importing such materials will greatly increase the costs of operation (1).

In Virginia, the State Health Department has final approval of all proposed landfill sites. In order to comply with the departments standards, several features must be further considered:

  1. Topographic features--slope should be between 3 and 25 percent to allow drainage but not induce erosion. They may not be on karst topography (i.e. with limestone caverns) (7).
  2. General soil types--sandy soils may be too porous and thus promote ground water contamination. Clays, silts and shales provide low permeability (6).
  3. Ground water--landfills should not be located directly over aquifer recharge areas.
  4. Landfills cannot be located in flood plains.
  5. Oil, gas, and coal resources should be considered as well as any other unique or significant rock or mineral deposits.
  6. Existing vegetation, especially the removal of large amounts of timber.
  7. Climate--severe winters may cause problems in utilizing the landfill when the earth is frozen.

The size of a landfill needed can be determined by using a general formula developed by the American Public Works Association Research Foundation (9). This formula (see Appendix Ill) predicts the volume in cubic yards per capita required for a landfill based on a yearly per capita waste production (9). Generally 1 .25 acre feet of land cover material is needed per 1,000 persons per year in Virginia (1). Thus, your county may need _____ acres of such sites. Further, a landfill requires one part earth fill for every four parts refuse at a 6-inch cover layer minimum (1). Other considerations and requirements for the operation of a sanitary landfill include, a semi-permanent all-weather access road, an earth berm or fence for aesthetic purposes, a barrier or fence to control wind blown paper, scales to weigh solid waste for analysis and when user fees are being charged, and finally, utilities such as electricity may also be needed (1). It should be reemphasized that the hauling distance from collection to the landfill will greatly affect the operational costs of the landfill.

Costs for the operation of a landfill involve three major categories:

  1. Land acquisition costs (note that landfills will usually increase the value of the land)
  2. Site development, including the initial excavation and, if needed, the installation of an impermeable base layer
  3. Operating and maintenance costs which include labor and equipment costs.

Generally these costs when taken together, vary between $0.80 and $1.50 per ton of solid waste. The national average is $1.05 per ton at a 27,000-ton yearly capacity. Both equipment and labor costs increase with increases in the amount of refuse collected. The following table shows the average equipment and labor needs for the operation of a sanitary landfill.

Landfill equipment and personnel requirements

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However, it is important to note in the next table costs per ton of solid waste decreases as the volume of solid waste increases.

Landfill operation costs

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Generally, one large landfill can operate cheaper than can two small ones. In some cases the reduction in operating costs in a jointly operated landfill may reduce previous operating costs by as much as 50 percent (1). A reduction in collection costs per household will also occur as the population increases (or as more houses are serviced). This trend is summarized in the following table (25):

Collection and disposal for the small community

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A sanitary landfill should be constructed to serve for at least 30 years (4). It should also be kept out of swamps, marshlands, and wetlands (see Wetland Chapter of Dynaplan (being restored)). While it has been often used to fill swamps and marshlands in the past, the importance of these areas for wildlife and as traps for flood waters warrant their protection. The sanitary landfill can also be used as a supplementary disposal method or in conjunction with other methods. It is important to note that the landfill is not the only method of solid waste disposal available and with the ever growing premium on land and energy, alternatives will become increasingly important.

Incineration

Incineration is the second most widely used method of solid disposal. Incineration can be defined as the "thermal reduction of wastes to a small volume of inert solids and the conversion of the rest of the material to innocuous gases" (9). Incineration is concerned only with reducing the volume and weight of solid wastes which are collected. There remains a small amount of residue for disposal. This process usually takes place in a centrally located plant, although onsite incineration in apartment house complexes and within some industry is being developed. There are numerous advantages to incineration, especially when compared to the sanitary landfill. A central incineration system uses far less land than the landfill and usually less than any other method. The operation of the incineration plant is not affected by weather conditions. Central incineration can also produce saleable by-products and when operated in conjunction with a salvage process during sorting, a wide variety of saleable reusable and recyclable materials can be obtained such as steel and aluminum. Perhaps the most attractive aspect of central incineration is that it may be located in heavily populated areas; saving a tremendous amount of money in transportation costs.

There are disadvantages with incineration. The primary one is the high initial capital investment (4). In 1967 the average capital investment per ton capacity, excluding land acquisition, ranged between $6,000.00 and $9,000.00. About 50 percent of this cost goes to the furnace alone. The costs of operation are equally high. Operation costs average about $5.00 per ton of solid waste processed. Another problem with incineration is air pollution. An adequate pollution control system will generally account for 10 percent of the total building cost of a central incinerator. If a 5 percent cut is taken from this figure for pollution control, a six fold increase in emmisions rates can be expected. It should be noted that technology is steadily improving pollution control systems and the high cost of such systems will in all probability be reduced (3). Another problem is the residue left after incineration. While this residue is a saleable by-product in some cases, it must be disposed. This residue can amount to as much as 25 percent of the original volume of the solid waste1 however, the range is between 5 and 25 percent.

There are numerous supplementary practices which can reduce the costs of central incineration. It has been found that where disposal charges are at least $1 .00 per ton and where there is at least 500 tons of solid waste being incinerated, a sorting and a reclamation plant should prove profitable (3). A sorting and reclamation plant separates the solid waste before incineration, (note that there is some sorting already taking place as a necessary step in the incineration process). After extensive sorting, saleable materials such as aluminum and steel can be removed and sold as scrap materials. The sale of these reuseable materials will make the costs of such reclamation plants profitable if they are in operation at the above magnitude.

Perhaps more pressing than recycling paper is the need to recycle and reuse metals. Unlike trees, minerals are non-renewable. The recycling of metals also takes far less energy than the processing of raw materials, and therefore energy can be saved. Steel takes 25 percent less energy in production when the materials come from recycling while aluminum takes 95 percent less energy in production (22). A recent publication by the Environmental Protection Agency indicates a potential savings of 6,000 tons of aluminum, 24,000 tons of steel, 80,000 tons of glass with an energy savings of 2,000 barrels of oil per day (23). Further, many private industries have found that by recycling potentially pollution oriented waste, such as chemicals, increased profits can be made. For example, Dow-Corning Corporation is now saving $900,000.00 per year after a $2.7 million investment in waste recovery (21).

Ferrous metals can be rather easily separated by magnets in sorting and grinding plants. Aluminum is perhaps the most promising of recycleable metals. The method of recycling aluminum is financially profitable and not extremely complicated. In 1973, payments were averaging $200.00 per ton or about one half cent per aluminum can (4). Tin and steel are less economically promising due to high collection, shipping and bailing costs. Junked cars contain between 150 and 190 pounds of non ferrous metals (29). Due to the large costs of automobile shredders, ($600,000.00 to $6 million), and the high transporting costs of junked cars (4), private collection services are usually more successful than municipal operations (1) Further, the market for recyclable materials is very unstable, therefore making cost-benefit analysis elusive. A principle advantage of any reclamation operation is its reduction of the weight and volume of solid waste collected, thus making existing disposal methods more efficient and having greater life.

Public cooperation is a key component in maximizing the efficiency of solid waste management. Composting is both desirable in reducing the volume of refuse collected and for providing a cheap source of fertilizer for residential families. Wastes can be used to produce energy. Recycling campaigns help preserve natural resources and can be profitable both on a private and public scale. Money spent on education and publicity for such projects can only help the individual and the community. A State-wide clean up program in Kentucky resulted in an increase of 7 million dollars in tourists spending while in West Virginia, a State-wide clean up campaign helped attract 46 new industries and consequently provided 5,000 new jobs (29).

Solid wastes are a big problem. When approached as a resource and not as a problem, they can be managed to reduce costs and risks and to increase the wellbeing of citizens throughout the Commonwealth.

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