DAILY OPERATIONS AT THE OTI ENGINEERED LANDFILLby | 20-07-2016 00:28 |
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     Zoomlion, Sakim, The waste are classified by the vehicle used for collecting and the source of the waste- they are door to door, heap, communal and the industrial collection. These companies are paid for the waste they collect to the site on ton basis. Every ton of waste cost 15 Ghana cedi / 3.9 USD.
A 'pay- as – you – dump' system has being introduced to consumers so that people will able to handle waste wisely. A private contractor is currently working on the site in the waste managing and they are being supervised by the Metropolitan Assembly. 12cedis (3 USD) a ton is also paid to the private company that manages the waste at the landfill site. 28cedis (7USD) is the total cost in managing a ton of waste. Charges collected on waste is based on the volume of waste produced at a particular time In other to ensure effectiveness and keep track of performance, information of waste received and other details are kept in the control room.
This also allow assessment of performance of waste collecting companies and also to check waste coming from each Sub Metro and municipal assembly. Oti landfill management also allow scavengers to come in and pick plastics, aluminum, copper and other materials to sell. They have about 18 registered scavengers.
The Oti landfill site is the only landfill site that merges landfilling and stabilization pond. Waste brought to the landfill is tipped into a cell, a bulldozer spreads the waste over the cell before compaction which is done by a compactor. This is done to compress the waste and to create space for more waste. Apart from the current cell surface, all other surfaces are supposed to be covered with laterite to prevent rodents, flies and stink emanating from the site to nearby communities. However, at a time of visit not all cells were covered with laterite as said. There are five rounded wire mesh packed with big stones called the gas vents in the cell. The purpose of the gas vent is to absorb methane and other gases that emanate from the cell during decomposition of the waste.
The landfill site has 9 stabilization ponds comprising of 6 anaerobic ponds, 1 facultative pond and 3 maturation or aerobic ponds. Each pond connects to the other through a pipe system. Processes in the stabilization pond has no chemicals- It is solely biological. The anaerobic ponds are about 3m deep and they do not use oxygen. Bacteria, and other substances in all the fecal matter and leachates- from the cell decomposes in the anaerobic pond without oxygen. This produces gases such as methane, ammonia and hydrogen sulphate which may kill some of the bacteria in the pond.
It takes about 60 days for the liquid substance to move from one stabilization pond to the other. This is done to ensure better quality. Bacteria or particles in the liquid waste are expected to be decomposed after being moved through all the 6 anaerobic ponds before it gets to the facultative pond.
The facultative pond is less shallow and allows Ultraviolet (UV) rays to penetrate and kill some of the bacteria still present and also allow oxygen to get through.
The last pond is the maturation pond where organisms like toads, alligators, and snakes exists in these ponds. Presence of life in the pond serves as an indication that it is safe to discharge the liquid from these ponds into streams. The liquid at this stage of treatment can be used for irrigation and has proven to be good for croplands, however, liquid from the maturation ponds at the landfill are discharged into the Oda River – a river closer to the Oti landfill.
To conclude, the Oti landfill serves a greater purpose but the financial and bureaucratic challenges makes operations more challenging each passing day. Also, segregation of waste at household level will be another advantage and benefit to the landfill management and all inhabitants of the 9 sub-metro and the municipality of the Metropolitan Assembly as this will help reduce the amount of waste needed to be treated.
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