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HomeMy WebLinkAboutSolid Waste Alternative Study-HERTFORD COUNTY SOLID WASTE ALTERNATIVE STUDY r rDCM COPY,. Vlease do not , to ulkity Division of Coastal Managementsioctric power r -- o . _..-� - r owwator cans I�tewn drum electrostatic precipitator ' ��•.wT i•..` � G� is r o o 0 r Hertford County Solid Waste Alternative Study Prepared for. Hertford County Commissioners Howard Hunter, Jr., Chairman Claude M. Odom Ronald G. Baker Stanley E. Dixon Donald C. Craft Thomas Lynn, County Manager Prepared by: Mid -East Commission Robert J. Paciocco, Planner -In -Charge Connie Ray Price, Planner Lou Valenti, Cartographer Linda Roberts, Secretary This document was financed in part through a grant provided by the North Carolina Coastal Management Program, through funds provided by the Coastal Zone Management Act of 1972, as amended, which is administered by the Office of Ocean and Coastal Resource Management, National Oceanic and Atmospheric Administration. Hertford County Solid Waste Alternatives Study o Page I. Introduction_ 1 II. Data Base Amount of Solid Waste :....................... 5 Composition of Solid Waste ................... 6 Landfill Location ............................ 7 Future Conditions ............................ 7 Toxic Material ............................... 8 III. Analysis of Disposal Alternatives Recycling .................................... 11 Resource Recovery ............................ 13 Baling......... ............................ 15 Shredding.............. ....................... 16 Composting....... .......................... 18 Refuse Derived Fuel .......................... 19 Ocean Dumping ................................ 20 Incineration ................................. 21 IV. Analysis of Energy Market Current Usage ................................ 22 Expected Demands ............................. 24 V. Analysis of Environmental Consequences Current System ............................... 25. Future System Effects ........................ 29 IV. Implementation Financing and operation .......... ........... 32 Citizen Participation ........................ 34 Recommendations .............................. 38 Hertford County Solid Waste Alternatives Study INTRODUCTION Solid waste disposal is a growing problem in all North Carolina counties. The amount of waste is increasing on a yearly basis. Problems in waste disposal are increased by the rising cost of maintaining landfills, regulations and a high water table. All of these have made obtaining a landfill permit a U difficult task. As the volume of waste increases, counties must find a way to adequately dispose'of the trash. Solid waste is defined by the State of North Carolina as "any hazardous or non -hazardous garbage, refuse, sludge from a waste treatment plant, water supply treatment plant, or air apollution control facility" (General Statutes 1969). This report will consider the disposal of what is -known as garbage or refuse. aThe State has defined garbage as "all putrescible waste, including animal offal and carcasses, and recognizable industrial by-products;" refuse is "all non-putrescible waste" (General aStatutes, 1969). The handling of hazardous waste, which counties are not required to handle, will only be considered briefly. This report provides for Hertford County a review of the aNeuse River Waste to Energy Feasibility Study and offers imple- mentation strategies for the alternatives. The engineers study was prepared by Malcolm Pirnie, Inc. for eight counties within the Mid -East Commission and Neuse River Council of Governments. The Malcolm Pirnie document offered a description of existing solid waste disposal systems, quantity projections and composi- tion estimates for the eight County area and is an attachment to this report. 2 I 1 f H E R T ORD C 0 U N Soled Was te Alte rnativ es St ud Y LANDFILL W I N T 0 N • AHOSKIE THE PREPARATION OF THIS MAP WAS FINANCED IN PART THROUGH A GRANT_ PROVIDED BY. THE NORTH CAROLINA COASTAL MANAGEMENT PROGRAM, 4 THROUGH FUNDS PROVIDED BY THE COASTAL ZONE MANAGEMENT ACT OF 1972, AS AMENDED, WHICH 1S ADMINISTERED BY THE OFFICE OF OCEAN AND COASTAL RESOURCE MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC , - ADMINISTRATION. - CtIICD¢A04 DATA BASE Amount of Solid Waste The determination of the amount of solid waste requiring disposal is the first step in any waste disposal project. The waste generated in the County was determined by making use of generation rates developed by other units of government. A generation rate is an indicator of the amount of solid waste produced per capita. The estimated rate within the'County is 3.5 pounds per capita. This rate is`a compilation of typical rates in rural and urban areas. Also included in the rate determina- tion was the actual rate used in Craven County, which regularly weighs trucks entering the landfill. The use of a generation factor in determining solid waste disposal needs is used in conjunction with population estimates provided by the North Carolina State Data Center. Waste quantity projections are: Tons Per Day County 1987 1992 1997 2002 2007 2012 Hertford 43 44 44 44 44 44 aBefore a final determination is made on a disposal alternative a ri provision should be made to weigh actual waste quantities at the a 5 landfill to -insure the accuracy of the projections. Scales should be used for several months to establish accurate weight records. Composition of Solid Waste Equally important as the amount of solid waste generated in the County is the composition of the waste. The Malcolm Pirnie study attempted to determine the composition through a survey of landfill operators. Incomplete information and limited study time prevented an accurate assessment of waste composition. The engineers study used information gathered for other counties and communities. An examination of waste composition looks at waste genera- tors and types of waste. Waste generation includes residential, commercial and industrial sources. The County residential waste comprises approximately 70% of the disposal needs, commercial waste is approximately 25% and industrial waste:is approximately 5%. The volume of residential waste is important as it could �7 become part of a recycling program. 11 The type of waste may include paper, plastics, textiles, aconstruction material, organic and other material. The type of waste generated in the County must be considered when making a adecision on a disposal alternative, especially since the effici- ency of many disposal technologies is dependent upon prior removal of noncombustible and recyclable material. The amount of 2 paper and wood products will determine the level of success in an incineration process. Landfill Location The location of the Hertford County landfill is on the east side of.S. R. 1174 in Winton Township. The closest surface water nis Mill Branch, which flows into the south side of the Chowan River and is approximately 1200 feet away. The site is ap- proximat 50 acres. Approximately 40-45 acres is used for solid waste disposal.- The remaining 5-10 acres is used as a buffer for adjoining property. Three wells are currently on the site to monitor leachate flow. The County plans to replace the three wells with five new wells as part of a new permit: aThe County is attempting to receive a five year permit for extending the use of the landfill. The permit allows the County ato dispose waste on top of the existing site. This will add ,., approximately ten years to the landfill life. Reduction in the amount of waste as a result of changes in disposal methods could extend the landfill life by several years. Future Conditions In preparing for the future of solid waste disposal Hertford County must project needs for the immediate future and long range future. Projections must consider changes in federal and state regulations, size of population, level of recycling and VA 9 paper and wood products will determine the level of success in an incineration process. (� Landfill Location lJ The location of the Hertford County landfill is on the east Dside of S. R. 1174 in Winton Township. The closest surface water ri is Mill Branch, which flows into the south side of the Chowan River and is approximately 1200 feet away. The site is ap- proximat 50 acres. Approximately 40-45 acres is used for solid waste disposal.- The remaining 5-10 acres is used as a buffer for adjoining property. Three wells are currently on the site to monitor leachate flow. The County plans to replace the three wells with five new wells as part of a new permit: The County is attempting to receive a five year permit for extending the use of the landfill. The permit allows the County to dispose waste on top of the existing site. This will add approximately ten years to the landfill life. Reduction in the amount of waste as a result of changes in disposal methods could extend the landfill life by several years. Future Conditions In preparing for the future of solid waste disposal Hertford County must project needs for the immediate future and long range future. Projections must consider changes in federal and state regulations, size of population, level of recycling and 7 amount of disposable waste. In addition changes in the economy P , g Y and technology must be predicted. The previous section on amount of solid waste in the County included a prediction of 1.2 tons per year increase over the next 25 years. The steady growth in the tonnage of solid waste orequiring disposal will be the result of increasing population and disposable material. Population projections for the County as provided by the N. aC. Office of State Budget and Management is as follows: Estimated �j Year Population 1990 24,833 a 1995 25,280 2000 25,390 2010 25,279 Toxic Material The generation, transportation, treatment, storage and disposal of toxic waste within the County are currently monitored Qby field representatives from the N., C. Department of Human Resources, -,Hazardous Waste Management Branch. The facilities athat create.the waste are divided into small and large genera- ators. Small generators are facilities that create less than n 1000.kilograms per month. In Hertford County the facilities are !I classified as follows: o e 0 Small Generator Generator Transporter Brittenham's X CF Industries X Charles H. Jenkins & Co. X Dixon Quality X Easco Aluminum X Facet Enterprises X Freeman Metal Products X Georgia-Pacific X Kerr Glass Mfg. X Larry Freeman Chevrolet -Olds X NC Dept. of Transporation X NCNG-OMS #19 X Perdue Farms X Tulloss Industrial X VEPCO Ahoskie District X West Point Pepperell X Each of the generators must properly dispose of any waste. The County is not prepared to accept toxic waste at its landfill. This creates a need to dispose of the waste at sites outside the County. The current regulations do not require facilities that generate less than 100 kilograms per month to report their disposal needs. They must dispose of any toxic waste in a proper manner, but the method is not traced. The acceptance of household waste at the County landfill will normally include small amounts of toxic waste. Items such as cleaning fluids, batteries, and paint may accumulate in sufficient quantities to create a problem. The mixture of the E toxic waste with putrescible waste at individual homes makes sep- aration at the disposal site difficult, if not impossible. The easiest way to remove household toxic wastes from the waste stream is to not let it in at the start. The education of the general public on source separation should be part of a disposal plan. 10 ANALYSIS OF DISPOSAL ALTERNATIVES The continued generation of'solid waste has created a need aby the County to examine alternative disposal methods. A successful solid waste disposal plan can include recycling, incineration and landfilling. In addition the plan could include baling, shredding, composting, refuse derived fuel and ocean dumping. Installation and operation costs, reliability, and environmental soundness will be the determining factors in deciding on the type of disposal system. Financial considerations have led the County to seek out disposal methods that reduce operation expenses through energy recovery. Each of the methods of energy recovery have had varying degrees of success. The II methods include biological, chemical, biochemical and combustion. Recycling In suburban areas, programs for point of generation recovery of recyclable material have been demonstrated to be capable of achieving upwards of 60% compliance levels. These levels, typi- cally drop to below 20% for both rural and inner city waste streams. This will be a major problem for the County in developing solid waste management programs, especially since the efficiency of many disposal technologies is dependent upon the prior removal of non combustible and recyclable material. Two ways to address these difficulties include: a) Where feasible, the utilization of manned collection stations at disposal sites. Pitt County has initiated this at one site using workers from Eastern Carolina Vocational Center. The best way to insure success of this method is to offer a monetary incentive. For example, a 15-30o reduction in dumping fees for individuals bringing some pre-set amount, such as 5 lb.,) of sorted recyclables. This method could be used if the County began charging a dumping fee. At unmanned facilities, some voluntary compliance can be attained through the use of drop boxes. b) In communities where pick-up is offered, programs involving monthly -or bi-monthly collection of sorted recyclables are often successful. This type of program would require the cooperation of the County and the towns. Mecklenburg County has recently begun a voluntary program offering curbside pick-up (Ogg, 1987). The program began in 1977 with a few drop off points. 'The'County now has a network of seven drop off points including one at the landfill. The County is currently recovering about one percent of the total waste stream with about 9,100 homes involved in the program. They have a goal of 30 percent by 1994. The idea of recycling plastic soft drink bottles was instigated by the Mecklenburg County bottlers of Coca-Cola and Pepsi -Cola. Both companies provided money for services to research such a project. In addition, Coca-Cola guaranteed that it would buy back all plastic containers collected in the recycling program. Participating households receive plastic 0 1 containers for storing recycled items. These are collected at curbside with regular trash pick-up. 0 12 Mecklenburg County also distributes public information materials to its residents, and monitors public participation, material recovery rates, adequacy of the recycling containers received, variables affecting the efficiency of collection, the efficiency of truck operating costs, and the size of collection routes. The data has helped the County fine -tune -the program. Hertford County would need to develop a cooperative agreement with the towns for this type of program to work, as the collec- tion of solid waste at curbside has been a municipal respon- sibility. A recycling program can only be as successful as the public will support. The dependency upon local citizens to recycle 100% of all available material is unrealistic and cannot be expected. The implementation of resource recovery at a disposal site can be the next step in a solid waste management plan. Resource Recovery Resource recovery for the purpose of this study will be limited to the separation of recyclable material at the disposal site. This is refuse that should have been separated at point of generation. Plastics, paper, glass, and metal all may be used again if properly handled. At present there are two primary types of systems available to accomplish this task. The first type of system is referred to as Air Density Separation (ADS). With ADS bulk refuse is 13 a conveyed into a rotating conical bin.which is connected to an air ablower. Low density materials (primarily lightweight paper and plastic products, fabric and food wastes) are suspended in the air stream and moved directly into an incinerator. Denser materials fall to the bottom on the bin where they are recovered and then sorted both electromagnetically and by hand, to remove non-combustible and recyclable materials. Any combustibles remainingafter the sortie process are then incinerate g P d. A more technologically sophisticated method is found in the recently developed wet processing systems.' In these systems, the refuse is finely shredded, suspended in water and then separated and automatically recovered, according to density, by centrifuga- tion. Some of the advantages to this kind of system include: g Y a) The recovered by-products are cleaned by this process, which should facilitate handling and enhance their resale value. b) The homogeneous nature of the product and will create RDF or mass burn fuel that promotes more complete combustion. c) Many of these systems include the capacity to con- tinuously monitor the processed waste stream for the presence of hazardous materials. These materials can then be diverted from the incinerator and processed for alternative disposal. d) Demineralizers are incorporated into many of these systems which help to reduce heavy metal contamination of the residual incinerator ash. Because water is added to the waste, this type of processing usually includes a pre -combustion pyrolysis stage. The water is utilized to drive oxygen from the waste, which is then heated to 14 generate burnable gases. These gases are piped into the incinerator where they are utilized as supplemental fuel, offsetting any combustion efficiency reductions attributable to the added moisture in the refuse. The resource recovery phase should be followed by a process that will result in the final disposal of the waste. A number Dof alternatives such as Baling or Incineration can be chosen by the County with each having its own pluses and minuses. Baling - One alternative for disposal is baling. Solid waste can be baled in a manner similar to the process farmers use in baling their straw and grain products. 'In 1986 there were about 40 baling operations in North America (Robinson, 1986). During baling, the refuse is compacted, usually into a block, by.ram compression. Depending on pressure exerted on this block and moisture content of the waste, the block may be tied or wired during the process. In a multi -county disposal system baling can be a major advantage due to the process of condensing several truck loads into a form that could be easily handled by a larger truck. �J The use of baling after a resource recovery process would help in the reduction of odor, dust, blowing litter, birds, rats,flies, and disease transmission. It is also conceivable n that the need for daily cover material could be eliminated due to �J these factors. While the potential for leachate generation is a 15 o not eliminated by baling, the increased density reduces the velocity with which water may percolate through the bales, leading to amore diluted leachate strength. However the aproduction of this diluted leachate will continue for a longer period of time. aThe major reason the County may consider baling as an alternative is the reduction in necessary landfill "floor space". The reduction in original space requirements is a factor of pressure exerted upon the refuse during compaction, leading to more or less dense bales. The increased density of bales will result in higher operation costs. However, higher density, bales will reduce the amount of leachate. Low to medium density baling may offer a 20 to 40% extension of landfill life. Higher density bales would result in further extension of landfill life. Shredding - An alternative for baling is shredding, also known as milling. The shredding of solid waste involves mechanical pulverization of waste, either by grinding, shearing or beating. The shredding of waste may be used alone as a means to decrease the void space within the waste stream, or as a first step in composting, mass -burn incineration, creation of Refuse -Derived Fuel (RDF), or applications like pyrolysis. The result of shredding is generally a homogeneous mass of approximately the same size particles, unrecognizable from original waste. The shredded waste stream is conveniently handled by means of 16 aconveyor or truck to the landfill site. At the landfill site, the material is easily dumped, spread and graded. Other advantages include a large decrease in nuisance caused by blowing paper and dust, the risk of fire is lessened, and disease carrying inspects and rodents are reduced (Robinson, 1986). The ashredded waste is also generally more aesthetically acceptable to local residents (Pavoni, 1975). .The primary interest of the County in this process will be II the reduction in volume and the amount of landfill space required. While shredders are available which can handle bulky appliances and even demolition rubble, the most appropriate application for MSW is a standard top feed unit. These units normally produce particles in the 3 to 6 inch range, though glass and similar material may shatter to a much smaller particle size. This will cut down on maintenance and repair time for landfill vehicles. The decrease in particle size exposes more waste to surface action of leachate forming agents. Therefore, a more concentrated strength leachate may be expected initially, but a lower degree of contamination potential is present for the long term. After shredding, the material compacts to a greater density ,and in less time than unprocessed waste. In -place densities in the range of 27% greater than unshredded waste are obtainable in as little as 70% of the compaction time (Pavoni, 1975). Also, a . 17 though cover material should still be used, the requirement for daily cover should be less. The major disadvantage of shredding is the capital cost of the unit and its required facilities, such as cover building, conveyors, and site work. High operating costs may also be a factor as electrical consumption may be high, and hammers, shears, and grinders may jam and need replacing on a fairly regular basis. The cumulative costs may be used to extend the life of the landfill by approximately 35-50% over unprocessed or uncompacted waste. Both baling and shredding have a similar disadvantage from the view point of the County. The both continue to rely heavily on landfills as the primary source of disposal. Additional alternatives dispose nearly 80-90% of the MSW to locations other than the landfill. one such alternative is composting. Composting - Though sometimes viewed as an ideal alternative for arural areas where land availability is not a major concern, the aeconomic success of composting may well depend on the marketabil- ity of the product. This primary biological treatment process can result in a humus -like, non -offensive soil tilth conditioner (Robinson, 1986). Composting may be either aerobic or anaerobic ain design, and the MSW may be combined with sewage treatment aplant sludge in the same process (General Electric, 1986). The moisture, nutrients and physical characteristics added by the a a 18 sludge aid in the microbial decomposition process and result in an equal or superior quality product in possibly a shorter period of time. Historically, efforts to establish cost-effective composting plants in the United States have been unsuccessful (Pavoni, 1975). The economics of past attempts have.been largely based on partial cost recovery through the sale of the composted product. Contrary to.m any areas in Europe where composting has been more successful, arable land is much more readily available in the United States. Therefore, as the fertilizing nutrient value of compost is generally low, the United States demand for large amounts has not been great enough to support large scale opera- tions. a Refuse Derived Fuel - The lack of an available market for the acompost in the United States has led to the adoption of processes associated with producing refuse -derived fuels (RDF). This is a Dprocess which will remove non-combustible matter from the waste astream, and increase the combustion potential of the product. This involves metals removal and continued shredding or grinding to finer size particles: plus, for fuels with higher value, removal of glass, dirt, and inorganic material. Finally, high grades of RDF may be processed into a solid brick or pellet form, ashredded into a fluff or ground into a powder, for ease in handling and transportation. 19 0 The RDF can be fired in either a boiler specifically dedicated to RDF combustion or co -fired with another fuel. This D , will affect the firing technology used and the extent of the RDF aprocessing required. The fuel may be sold to outside parties or burned in-house. By-products such as ferrous metals, aluminum, and glass may be recovered, but the primary intent of the preprocessing is to improve fuel quality. Another benefit is overall ash reduction. The type of preprocessing equipment used in RDF facilities varies considerably according to the purpose of the process equipment. If the intent is for improving fuel quality then a Dparticular process train will be'used.If the intent is for materials recovery, a multitude of options are available depending on what product is being recovered. However, some similarities exist in all RDF process trains. Ocean Dumping - The alternatives described previously have not included a final resting place the MSW. One choice for the end of the waste stream is in the ocean. In the past, for extreme cases of limited disposal options, barging could be utilized for aocean dumping of MSW, providing proper permits were obtained from astate and federal regulatory agencies. Ocean dumping has been regulated by EPA since 1972. Prior to ocean dumping it is likely athat high -density baling would be necessary to bring the refuse to densities greater than sea water. 20 Problems with obtaining permits, finding firms to handle the waste, future regulatory problems and locating adequate sites prevent ocean dumping from being a viable alternative. Incineration - The alternative receiving the,most attention from county governments, state and federal regulatory agencies and private vendors is incineration. The process of burning waste has been used for many years. However, controlled burning with the result of energy recovery is a relatively new idea in this country and is receiving increasing support. Incineration may be divided into two major areas: burning of Refuse Derived Fuel and n Mass Burning. As previously described, the creation of RDF allows the waste to be burned on site or transported to another site. RDF boilers are available in three major types: spreader stoker boiler, fluidized bed incineration, acid co -firing in utility suspension boiler. The Malcolm Pirnie study gives a complete description for each of these types. In addition to solid waste disposal through the RDF process, mass burning may be used when little or no preprocessing is described. Mass burning, when combined with energy recovery, is currently a well developed and widely practiced disposal technique. Various types of boilers are examined in the Malcolm Pirnie study. 21 0 ANALYSIS OF ENERGY MARKET The economic success of any waste to energy system requires the participation of an energy buyer. Energy products include steam or electricity. Primary users of the energy include. industry, military installations and electrical' utility com- panies. Current Usage The final product of the waste to energy facility would be - a partial determinant in locating a disposal site. The genera- tion of steam would require location of the facility generally within two miles of a buyer. The buyer could be an industry, such as National Spinning Company in Washington, or military installations, such as Cherry Point MCAS and Camp Lejune MCB. The purchase of steam would allow the buyer to avoid the repair or replacement of boilers. The generation of electricity for sale to an electrical utility company, a municipality or an industry will require an extensive set of agreements. Utility companies, such as North Carolina Power or CP&L, are required by federal guidelines to purchase electricity generated from waste to energy facilities. a The minimum rate paid by the power companies is set by the North Carolina Utilities Commission. This rate may not be satisfactory to the local governments as it is designed to protect the power 22 companies. Waste to energy plant operators should attempt to generate electricity at times that are most favorable to the power companies. The generation of electricity at peak hours will permit the negotiation of more favorable rates for local governments. (_J The purchase of supplemental electricity by a municipality will require a special agreement with their base load supplier. The supplier normally demands an extended notice for any anticipated change in the purchase of electricity. The North Carolina Eastern Municipal Power Agency and CP&L require an eight year notice for any change in power supply agreements. The municipality must -be very certain that a new source of power will abe available on a constant basis. A reversal of plans could be a costly mistake. Industry and other major users may also purchase electricity from a waste to energy facility. The purchaser will require assurances that electricity,will be available when needed. The revision of any existing agreement between a user and supplier amay result in a higher rate for the user. The County should remember that entering the electricity business is not a temporary function. Rates paid by utility companies will be based on regular availability and amount of electricity generated. Municipalities and industry will rely on �j the County for all or part of their electricity. This may ll require the County to use fossil fuels to generate electricity at 23 times when the available solid waste is not sufficient to meet contracted demand. Expected Demands Population variation within the County and the surrounding area can be expected to create a change in the demand for energy. An increase in the cost or availability of traditional sources of energy may lead to the use of alternative sources. One source of additional energy could be from RDF. This process will involve the creation of a product that can be delivered to another site for burning. RDF products are in a form,.such as pellets, that are easily transportable. This will eliminate siting restrictions caused by cogeneration. RDF will also eliminate the County's responsibility for ash disposal. Recycling is an integral part of RDF processing. This can also provide additional income for the County. However, RDF facilities are not the perfect solution to a county's disposal problems. A market for the RDF must be found. Buyer's may require a BTU level that will be difficult to obtain. Pricing of the RDF must be low enough that it will be an attractive substitution for conventional fuels. Recycling may not be a complete success due to fluctuations in the scrap market. 24 ENVIRONMENTAL CONSEQUENCES Hertford County must consider the environmental consequences of continuing to use the existing disposal system or any future system. The disposal methods will have varying effects upon water quality. Ground water and surface water, could be adversely affected by a poor choice. The approval by the Division of Health Services and Environmental Management Division of any -change in disposal method will require a review of the effect on water quality. Current System The environmental integrity of the area surrounding land- fills is closely watched by the Division of Health Services representatives within the N. C. Department of Human Resources. The field representatives monitor leachate filtration throughout the area surrounding the landfill. The primary impetus behind the trust in re-evaluation of landfill.practice is the potential for groundwater contamination. by .the products created by the decomposition of MSW, though control. of waste -generated methane gas is also a concern in some areas. The products of aerobic and anerobic biochemical degradation may be picked up by water from precipitation as it apercolates downward, or by water in the existing water table. This solution may then contaminate adjacent groundwater and sur- 25 face water supplies. The characteristics of this resulting solution, or leachate, are dependent on many factors. The net composition of.the refuse is a principal determinant of leachate biochemistry. Perhaps equally important is the chemical character of the water which comes into contact with the decomposing waste. Soil parameters such as clay content, hydrous oxides, organic matter and pH may determine what products are leached, their rate of generation and degree of mobility. Additionally, factors such as in -place refuse density and quantity of leaching fluid have a great effect on leachate strength and consequently, the amount of time and travel distance necessary for the leachate contaminant levels to approach natural concentrations. Many of the chemical constituents of leachate are present in naturally occurring groundwater and may be considered "polluting" only by virtue of their increased concentration�in leachate. Notable examples of this are iron, sodium, calcium, various metals and their salts, and chemical specifies of nitrogen and phosphorous known to be necessary for plan utilization. The most significant pollutants in MSW leachate are reported to be BOD, COD, chloride and nitrate (General Electric, 1976). Concentration levels of these potential contaminants and other constituents present in leachate have been investigated for many years, and as one might suspect, there is great variation in methodology and reported results. Procedures vary from on -site 26 L sampling at existing fill sites to packing lab and field scale containers with selected refuse and collecting leachate for several years. Characterization of'leachate is made even more difficult due to seasonal changes in waste composition, and variations as the decomposing material approaches stabilization. A number of investigations have been performed on leachate quality of existing landfills, and the, range of values reported is great. However, in the vast majority of cases, either the landfill had accepted industrial and chemical wastes, or the composition of.the refuse was simply unknown. The literature associated with these and other studies show a trend in the production and release of individual contaminants. Very generally, after an initial period of low concentration, levels appeared to increased over a period of several months to a year, and then begin a gradual decline or remain at a plateau as the decomposing material approached stabilization: The trends, rates and concentrations will vary from site to site depending on refuse type, infiltrating water quantity, quality, and velocity, and adsorption/absorption potential of each constituent. Since 1915, several instances and allegations of groundwater degradation have occurred. Notable examples are.the contamina- tion of the drinking water aquifer in New Castle County, Delaware (4 years after landfill closure) and the 2 mile migration of selenium from a site on Long Island, New York (Griffin, 1978). Closer to the County, there are also allegations of leachate 27 contaminated water in the Flemington area near Wilmington, North aCarolina. There are however, many confounding factors in the form of potential local industrial sources which are preventing absolute determination of pollutant origin. New Hanover County remains involved in legal action seven years after the original acomplaint was filed. rl As a means to control leachate migration, a landfill area may be lined prior to the disposal of waste materials. The choice of lining mechanism is dependent on many factors. Double - layer impermeable polymeric membranes, or rigid construction linings may be used for industrial disposal sites or fills accepting chemical waste, while for MSW sites a greater flexibil- ity in choice may exist. Here a liner may be composed of admixed cements or soil conditions which chemically treat the leachate as it passes through; sprayed -on material and applied substances such as asphalt and soil sealant; or a membrane composed.of rubber, plastic, poly -vinyl chloride (PVC) or polyethylene. In some cases, a liner of compacted clays, generally constructed in a series of small compacted layers or "lifts", may be utilized. The choice of lining method is a function of expected leachate chemistry, necessary structural requirements, final permeability desired, and economics. Liners are subject to chemical interaction with the leachate. For example, gasoline and lower -weight hydrocarbons 28 0 D may break down asphaltic surfaces, and acetone (not generally found in MSW fills) can attack the plasticizer of fillers in a PVC material. Other lining membranes may absorb liquids or even ionic chemical species and swell - thus affecting both chemical and structural stability. The lining material and especially the seams from sheet connection must also be strong enough to withstand stresses from installation, the final weight of refuse, cover and compaction, and potential punctures from tree roots, arocks, sharp objects, and vehicular traffic. In the event that lining of a new landfill site becomes necessary, this new expense may dictate the responsible agency to review methods of solid waste volume reduction. The alternatives are many and varied, and while some associated factors may be generalized, ultimate cost -efficiency must be determined on a site specific basis. a Future Systems) The disposal method recommended by Malcolm Pirnie includes incineration of the waste by one of several facility types. The types include waterwall, rotary waterwall and modular. The disposal facility chosen will require an ultimate location for athe ash residue. One of the alternatives includes an incinerator in Beaufort County. The incinerator could be located in Washington near the National Spinning Company plant. National Spinning has expressed n , 29 an interest in buying steam that would be generated by the incineration plant. The use of an incinerator in Beaufort County could leave the County with responsibility for ash disposal, which will be a byproduct of any incinerator. Regulations under consideration by the Environmental Protection Agency may designate ash produced by a.solid.waste incinerator as hazardous. This change could place an additional burden on Beaufort County if it retains ash disposal responsibility. The location of an incinerator in Beaufort County would not mean that the County must dispose of 100% of the ash. The operator of the incinerator would very likely be under contract with surrounding counties. This would leave Hertford County Uresponsible for their share of the ash. The environmental integrity of the area surrounding the DHertford County landfill and the incinerator site should not be affected by the change in use. The landfill is monitored now afor the leaching of both non -toxic and toxic wastes. The Dacceptance of ash would not require a change in landfill opera- tions unless the classification of the ash is revised. EPA aofficials anticipate a release of revised regulations soon for _enforcement in 1992. The use of an incinerator may create additional problems afor the County through air pollution. Revised regulations -may 30 place an additional burden on operators and owners of solid waste incinerators. The ash disposal and air pollution problem can be partially avoided by an active recycling program. Incinerator boiler efficiency can be increased and gas emissions reduced by the removal of noncombustibles. This is believed to be due to more even and complete combustion. In addition the removal of noncombustibles will reduce the volume of final ash (through the removal of its own weight and volume, as -well as the increased combustion efficiencies) that must be processed for disposal. This information suggests that it is imperative for the County to implement a means to also provide point of disposal segregation and collection of recyclable and noncombustible material. The ADS system and the wet processing system described earlier are two mechanical means to accomplish this task. 31 IMPLEMENTATION STRATEGIES The adoption of a particular strategy by Hertford County will involve the commitment of staff, time, money, equipment and resources such as land and water. The alternative chosen will require the County to decide on construction, ownership and operation of the disposal facility. Financing and Operation Construction of an alternative disposal facility may be paid for by one county, several counties, or the private sector. aHertford County may choose to construct a facility by itself. This would make the County responsible for any financing package. The money could be obtained from locally generated revenue, or combinations of State and Federal money. Local revenue could include funding from a capital reserve fund and general obliga- tion or revenue bonds. The capital reserve fund would probably not be usable due to the large amount of money (perhaps as much as $30 million) necessary for construction. In 1983, the General Assembly authorized unitb of government to issue revenue bonds for the collection, treatment and disposal of solid waste. State or Federal money may come in the form of grants or loans. Grants are the ideal source of money, but they are difficult to obtain. Loans will require a repayment method. The most logical choice of repayment funding for a disposal facility is the use of tipping fees These fees may be charged to 32 haulers bringing waste to the facility. Both private and public haulers may be charged a fee based on weight. A tipping fee by itself may not generate sufficient revenue to cover the cost of operating and capital expenses. The . various types of energy buyers discussed earlier will be an additional source of revenue. One other source of revenue is property tax, which could be increased to provide revenue for the facility. All of the combined revenue sources may not generate sufficient revenue if one county,attempts to construct a waste disposal facility. The ability to assume several million dollars of debt may be more than a county can financially or politically afford. This may require the creation of a regional sanitary district. A sanitary district could combine several counties into a group that could affordably operate a facility. The district acould be held responsible for construction and operation financ- ing. One other implementation strategy could be the use of private sector money in the development of the project. Private industry may participate in the construction or operation of a facility if the economic benefits are high enough. The General Assembly permits counties to contract with private firms for the development of a solid waste disposal facility. The contract may be based on factors other than cost, such as a o33 facility design, operational experience, system reliability, aenergy production efficiency, long-term operational costs, compatibility with source separation and other recycling systems, environmental impact and operational guarantees. Citizen Participation aA final non -technical consideration in the development of a waste to energy is the probability of public opposition. Much of the hold-up in constructing solid waste disposal facilities is the result of well organized public resistance campaigns. Public opposition is often the result of two primary factors: (a) Although armed with a considerable number of facts, most lay people do not have the technical training to use these facts in forming an objective opinion. They are easily swayed by emotionally charged arguments which are based upon either technical impossibilities or worst case scenarios. (b) Many.in the general public believe that public offic- ials will promote projects that do not necessarily serve the public interest. The failure of the federal government, until recently, to protect the public from chemical hazards has given support to this argument. The County should implement immediately an effective public relations and information program if a disposal facility is to be completed in a timely fashion. A well informed public will probably be a supportive public. One major mistake in other parts of the country was -the exclusion of the public,from the planning, siting and development process. In many cases, all significant decisions were made behind closed doors with politi- 0 34 L cal decisions overriding public service ones. The public n hearings were held after all the major decisions had been reached. This attitude has tied up many units of government in litigation over siting and construction. Private individuals should be encouraged to serve on committees and participate in all phases of the development process. A consensus among opinion leaders on the criteria for selecting a site long before a site is even unofficially chosen can play an important part in the success of the project. The involvement of citizens in the planning process should include representatives of environmental action groups. These groups have proven themselves to•be formidable opponents to refuse disposal facilities. If'carefully cultivated these same groups could become strong proponents of a disposal system. This will involve approaching them early in the planning process and asking for their opinions and creative input. Their techno- phobia can be overcome by showing a project -package that includes U a certain technological overkill in areas of air.and water quality. A note.of caution is that the groups should not be used unless their opinions will be listened to in the planning process. Simply paying lip service to the groups could create problems at a later date. All citizens of the County cannot be on a planning commit- tee. The soundest environmentally safe plan is.useless if proposals and progress on a disposal facility are not communi- 35 cated to the public periodically from day one. Newsletters, slide shows, media coverage and newspaper inserts can be used to develop an informed public and vividly portray the good neighbor aspects.of a disposal facility. The particular method of communicating is not as important_ as its style. It must be straight forward and demystify high technology solutions. It must not be a slick sell. Going to people at their regularly scheduled meeting can'head off the venting of.frustrations at a public hearing. The public information program must be personalized and dialogue must be continual. The public should be able to feelthey know the county person.responsible for the project. The crucial characteristic of acceptance of information has been found to be the credibility of the source, -of which the two most important ingredients are expertise and trustworthiness. It is much easier to,trust individuals than institutions. For most citizens, the press account of a public meeting is its reality. A reporters decision to give balanced coverage to all points of view or to sensationalize the events by giving disproportionate space to opponents charges can make or break a project. The role of supportive editorials is important, but not nearly so much as what is on news pages and on television broadcasts. The person in charge of the project for the County should'be accessible and have clear, knowledgeable answers to any 36 questions. Successful projects come after many hours spent in educating reporters about the issue. Public information and participation should be built into environmental and engineering contracts. The key is a conscious effort to earn the public trust. If the effort is serious from the beginning of the project, then knowing how to overcome opposition to waste disposal facilities may -become an unnecessary skill. The County must get the message across that it has the ability to supervise the design and operation of a solid waste disposal facility; that the added risk is unmeasurable and insignificant in comparison to risks we readily accept in modern life; and that these are the conclusions of people both with expertise to make such judgments and those with a long commit- ment to public interest. Most of all the County should take the whole process of public acceptance as seriously as financing and vendor selection, for without it their will be no project. The County should be sure that the engineers involved in the project make their findings relevant and intelligible to people outside their discipline and to call on those who can help them do so. Finally, there is a need to,acknowledge the benefit of citizens participation. Without it, many facilities would not be as carefully designed, would not be as well equipped with monitoring and reporting systems, would not have rigorous training programs for operators,would not have the scrubbers 37 which provide acid gas control or fly ash removal systems. In aaddition, citizen support is required to implement a recycling program which reduces the overall disposal burden and will ultimately reduce the cost of waste disposal and the depletion of natural resources. Recommendations The conditions and alternatives resented previously have P P Y covered a wide range of technology. The choices for Hertford County must be based on sound financial and environmental planning. The type of system selected should be cost efficient as well as a'protector of the environment. All possible disposal plans should begin with recycling. g• One type of an incineration system would begin with a wet refuse processor and pre -combustion pyrolysis stage. Pyrolysis is used, as discussed before, to overcome reductions in combustion efficiency due to the wetted fuel. In addition, the ammonia produced during pyrolysis is useful in extracting hydrogen chloride (and other haloacids) which participate in particles of incomplete combustion formation. The pyrolysis chamber should be followed by a rotary kiln. The capacity of most rotary kilns is limited to about 160 tons/day. It would be possible to increase athis capacity by using multiple furnaces tied into a single secondary combustion unit. The secondary combustion chamber containing limestone grates'(limestone absorbs haloacid gases) a 38 ensures the almost complete destruction of combustion gases. The secondary combustion chamber would be followed by the boiler a which -would generate steam. Next is a wet scrubber system used g y to control.gaseous emissions. Finally, a bag house and electro- static precipitator to reduce fly ash levels. Bag houses are asuitable for the removal of larger particles, whereas a precipit- ator is very efficient, once the large particles are gone at D removing smaller, more respirable articles. The performance of P P this, or a similarly configured system, should be substantially greater than what could ever be attained with a mass burn incinerator. Before any system can be implemented the County should gain control over the waste system. A weighing program should be aconducted to verify waste quantities. This program should consist of at least six (6) months of weighing at the existing landfill. The incineration system should be privately owned. The County is without the expertise on its staff to implement a n sophisticated disposal system. Private ownership would release the County of a possible financial burden. Discussions among surrounding counties should begin im- mediately to firm up possible regional disposal alternatives. Tentative agreements regarding commitments of interest should be drafted which include project roles. These agreements will later be superseded as waste supply and energy market contracts are Uformally drafted and approved. y 39 REFERENCES General Statutes of North Carolina, Chapter 130 Article 13B Solid Waste Management, 1969. 2. General Electric Company; Solid Waste Management Technolo Assessment. Van Nostrand Reinhold -General Electric Series, New York, N.Y. 1976. 3. R. A. Griffin and N. F. Shimp; Alteration of Pollutants in Municipal Landfill Leachate by Clay Minerals. EPA 600/2-78- 157, Municipal Environmental Research Laboratory, Cincinnati, Ohio. 1978. 4. Jolie Ogg. "Recycling: Does It Work? Is It Worth It?" Solid Waste and Power, October 1987. 5. Malcolm Pirnie, Inc. Neuse River Waste to Energy Feasibility Study 1988. 6. Joseph L. Pavoni, John E. Heer, Jr., Joseph Hagety. Handbook of Solid Waste Disposal. Van Nostrand Reinhold Environmental Engineering Services. Van Nostrand Reinhold Co. New York, N.Y. 1975. 0 7. William D: Robinson ed.; Solid Waste Handbook - A Practical Guide. John Wiley and Sons, New York, N.Y. 1986. 40