Determination of appropriate distance for solid waste transfer stations

Waste collection is very well known activity of municipalities. It is the most important service after supplying water for them. Simply called waste collection by citizens, has a lot of works behind the stage such as detailed schedules, feasebility reports, cost analysis. The work includes; picking up the wastes to collection truck, carrying to transfer station, transferring to semi trailer, transportinf to disposal facility. On the other hand, in another scenario collection truck can directly transport the wastes to disposal facility according to cost analysis. While the environmental awareness developing in Turkey, landfill facilities' numbers are increasing proportionally. Thanks to landfill facilities, solid waste generated from residential areas can be disposed impermeably to the ground water sources. Additionally, composting and recovering facilities are also exist to processing waste. To meet the design conditions, disposal facilities are need to be fed. Also, on the other hand, wastes are must be picked up on time from the streets to prevent infectious desaeses spread and rodent and insect reproduction. Because the time management is so important to manage collecting and transporting business, vehicle capacities and transfer stations distances are need to be selected very carefully. With this thesis study; 7+1 m3, 13+1,5 m3, 15+1,5 m3 ve 20+1,5 m3 collecting truck capacities are considered with the information that the most common used sizes are these ones.The estimated duration of collection while working between the garbage containers for one truck's one full trip is calculated. So, daily collected amount of waste has been calculated by 2 shifts per day. According to different waste generatios amounts per day and distances between the residental area and transfer stations; number of truck requirements are calculated. After finding the daily trip number and haw many trucks are needed, cost analysis was made. Capital costs are consist of purchasing the chassis and the hatch costs multiplying by the demanded truck number. Driver and two pickers are planned for each truck per shift. 2 shifts are planned per day, because of increasing the efficiancy. For calculating fuel costs; truck's time spent at residental area and the distance between the residental area and transfer station are determined and then daily fuel cost is found with the unit price of 5,05 TL/Liter. The maintanance costs are considered and assumpted as the half of the fuel cost. To find the total amount of money that needs to be spent is sum of capital cost, personnel cost, fuel cost and maintenance cost. Then according to daily waste generation amount, unit waste collecting cost can be found as TL/Ton. Secondly, transfer station capital costs and operational costs are found out. Purchasing land and construction phases are considered as the captal cost. Because the project duration is 30 years, yearly cost can be found with yearly amortization charge. For the operational costs; personnel costs, electricity costs, water consumption costs and the unexpected costs are took place. Personnel qualities and quantities are planned to increase proportionally with the size of the facility. A correlation factor has been used to find out the size of transfer stations. The data received from Gaziantep, Trabzon, Konya and Bursa transfer stations and contains daily waste transfer amounts and site area in square meters unit. According to their existing ratio which can be calculated by daily waste transfer amount divided by total site are. After all data checked, to stay at the safe side, the highest factor which is obtained as 0,06 has chosen. Thus, the square meters of the site increase proportionally with the daily waste transfer amount. For daily water consumption 200 L per capita per day assumption is made and also 100 L per truck for cleaning the tires. After all, by adding each prices, the yearly cost has been found and then divided by yearly waste generation to obtain unit price as TL/Ton. Thirdly, the transportation costs have been calculated. 40 m3, 55 m3, 70 m3 semi trailers are taken place for the calculations. Unfortunatelly, with the national highways regulations maximum tonage of a truck is need to be 40 Ton. Furthermore, when the capacity of truck increase, tare weight of it increase also. But the total maximum weight remains same. Hence, 55 m3 and 70 m3 semi trailers cannot be used efficient enough in terms of the density of waste and unit costs are getting hifher and higher for these haul capacities. That's why, 55 m3 and 70 m3 semi trailer capacities are neglected in this thesis. Because, calculating their values also is total loss of time and money. The estimated distance of transportation while working between the transfer station and disposal area for one truck's one full trip is calculated. So, daily transported amount of waste has been calculated by per shift. Like collecting trucks, for transportations trucks 2 shift personnel work is assumpted. According to different waste generatios amounts per day and distances between the transfer stations and disposal areas; number of semi trailer requirements are calculated. After finding the daily trip number and haw many semi trailers are needed, cost analysis was made. Capital costs are consist of purchasing the chassis and the semi trailer costs multiplying by the demanded truck number. Only one driver is planned for each truck with 2 shifts per day. For calculating fuel costs; truck's time spent on the road is determined and then daily fuel cost is found with the unit price of 5,05 TL/Liter. The maintanance costs are considered and assumpted as the half of the fuel cost. To find the total amount of money that needs to be spent is sum of capital cost, personnel cost, fuel cost and maintenance cost. Then according to daily waste generation amount, unit waste collecting cost can be found as TL/Ton. Lastly, the option of transpoting wastes to disposal area by collecting trucks without any transfer stations stops, has been evaluated. Every single steps are applied to this option also. 7+1 m3, 13+1,5 m3, 15+1,5 m3 ve 20+1,5 m3 collecting truck capacities are considered again. The reason why they are chosen the same capacities is to get most crystal clear comparing results. Because the distances are increased per tour, the daily tour numbers of trucks observed as getting lower. On the other hand, there is no transfer stations, nor semi trailers. Because they have both capital costs and operational costs. The additional cost possibilities can be elliminated by this way. At least, to find the total amount of money that needs to be spent is sum of capital cost, personnel cost, fuel cost and maintenance cost. Then according to daily waste generation amount, unit waste collecting cost can be found as TL/Ton. Consequently, by comparing the total unit prices, most feasible alternative can bu determined easily. To make the determination much clear, the daily waste generation projection of the residential area must be handled well. Also, if the city or region is in the developing country, anaylsis must be reviewd twice. Because there might be additional plans for near future and the plans can be changed rapidly. At the end of thesis there is a chart has been came up. With this chart, everybody, especially the municipalities make a decision about where to build a transfer station is more feasible, what capacity of collectiong truck's unit price is cheaper or is there a real need of transfer station. The charts are colorized on purpose for comparing the prices more easy way. Red refers to high price, and the green is low. By using this chart some of the actual transfer station plans' change and cancel possibilities are strengthen.