Waste the Greek and Cypriot way

Greece and Cyprus have a very high dependence on landfill for the disposal of their waste.

Greece and Cyprus have a very high dependence on landfill for the disposal of their waste. These landfills, which operate around the clock, have to deal with more leachate run-off and methane treatment issues than fellow EU countries. We look at four such sites at Kefalonia, Corfu, Rhodes and Cyprus

by Tim Byrne

There is wide variation in waste disposal throughout Europe, despite the existence of stringent EU regulations, i.e. the European Directive on Landfill. For example, in Germany, Holland, Belgium and France there are few landfill sites as these countries have opted to construct waste-to-energy facilities. They supply combined heat and power (CHP) to the national grid and turn solid waste into an energy source. This is the most environmentally friendly way of dealing with waste and the one which best fits the EU Landfill Directive.

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Other countries, however, are not so far advanced, or are meeting opposition to this greener route from their citizens. Such countries include Greece and Cyprus as well as the Balkan States. Here, people depend on controlled and sanitary landfill sites. Before the European Landfill Directive, Greece and Cyprus used landfill sites for the disposal of their solid waste and the resulting dependence on landfill now can cause problems. For six to eight months of the year, Greece and Cyprus experience a hot, Mediterranean climate. For the benefit of both operatives and the public, most of the refuse collection is carried out from midnight in the early hours of the morning. Greek and Cypriot landfills work to a 24-hours-a-day, seven-days-a-week operation, through a rotation of three shift patterns for staff.

Since both Greece and Cyprus have many miles of coastline, which encourages a vast tourist industry, there is a great amount of municipal solid waste (MSW). Due to this, the refuse collection vehicle (RCV) may have to travel to the landfill two or three times through the duration of its round.

The Greek and Cypriot governments, when designing and constructing their individual landfills, ordered high-specification street lighting to surround the landfill sites and line the roads from the weighbridge to the tip face. Risk assessments were carried, taking into account that drivers of the RCVs would need good visibility at night, so for health and safety reasons, machinery operating on the site at night (mainly bulldozers and landfill compactors) are fitted with high strength lights.

Dealing with leachate

The hot Mediterranean climate is an advantage, as the heat causes evaporation of leachate and thus reduces the size of the problem.

The size of each landfill and the annual tonnage of solid waste determine how leachate and methane generation are treated. In a small landfill site, leachate can be treated via a collection of pipes buried beneath the base of the landfill, with the layers of waste on top. The leachate is collected by a collection tank.

Large landfill sites, receiving an annual 300,000 tonnes (330, 693 US tons) of waste, such as those in Thessaloniki and Athens, deal with this problem with a leachate treatment plant.

Landfills which have been built since the EU Landfill Directive was implemented in 1999 have state-of-the-art leachate treatment plants where the leachate is drained off the landfill and into one of four purifiers. The purification of leachate normally takes place on a daily basis. Prior to purification, any debris which has blown into the leachate is cleared. Once the leachate has been treated it is diverted into the sewer systems for final water purification.

When the European Landfill Directive was first implemented, both Greece and Cyprus began to construct landfill sites where the leachate is drained off and treated by purification. The majority of sites in Greece and Cyprus now meet the European Landfill Directive using this method.

Methane treatment

The Mediterranean climate has an effect on the production of methane as there is a quicker rate of decomposition of solid waste than in the more temperate climates of the UK and northern Europe. The diet of the Greek and Cypriots also has an impact they consume a greater amount of fruit and vegetables in their diet and since this has a higher calorific content, it decomposes quicker.

On some of the smaller Greek islands, where high MSW production is only a problem in the tourist season, methane is treated by venting. The methane produces anaerobic reactions which take place in the waste. The treatment process consists of a methane collection system through vertical gas wells, which have external perforated concrete pipes. From these wells, the methane is released in a controlled manner into the atmosphere.

Larger landfills use the central torch method to burn off methane. Tests are carried out twice a week, using meteorological data, to measure the amount of methane being produced and it is then burnt off by a torch. Of these two methods for treating the methane, this is the most environmentally friendly. Methane is burnt off at various intervals, and the process also gives the possibility of producing electricity.

Landfill design

The fact each EU member state, including Greece and Cyprus, has to comply with the same legislation has an impact on landfill design.

A permeable layer of material has to be laid prior to the landfill liner being fitted. This prevents the seepage of leachate through the liner once solid waste is offloaded at the site. If this permeable layer was not implemented in the design stage of the landfill it could have a disastrous effect on the water table.

The landfill liner is placed on top of the permeable layer it is a requirement that this permeable layer should be at least 2 mm thick so the liner can retain all leachate throughout the life of the landfill and prior to further treatment through purification.

It is also the requirement of the EU Landfill Directive that no waste water is to be delivered to a landfill. Pre-treated sewage, which has become solid matter, can be accepted at the landfills.

Other waste systems in Greece and Cyprus

The reason that so few waste-to-energy plants have come to fruition in this region, is largely due to public opposition:

There is a natural dislike of having a waste site visible from homes, taking into account the ‘proximity principle’ Fear of the impact on tourists which many residents’ incomes rely upon Emissions fear of pollution and personal health Impact on tourism

Recycling in Greece and Cyprus

Communal collection points have been set up in the main towns using 1100 litre containers for glass, paper, cardboard and plastic. These are then emptied by an RCV, in co-mingled form, and delivered to a materials recovery facility (MRF) for segregation.

The system is poor at present as the infrastructure is not in place for regular collection from villages and rural areas. More government promotion is needed to encourage the wider population to recycle, e.g. posters, campaigns, education etc.

Conclusion

The Greeks and Cypriots are well on their way to meeting the requirements of the EU Landfill Directive, they have reduced the amount of biodegradable solid waste from the waste stream by 35% and will continue to press ahead with their recycling targets and reduction of biodegradable waste from landfill, once alternative infrastructure has been constructed such as new anaerobic digestion (AD) and mechanical biological treatment (MBT) plants. Much needs to be done on encouraging the local population to recycle, but given time and education, there is the potential for good progress.

Tim Byrne is a Refuse Collection Operative in the West Midlands, UK
e-mail: timthebin2005@yahoo.co.uk

Northern Rhodes sanitary landfill site

The sanitary landfill site on northern Rhodes caters for four municipalities and the busiest tourist areas of Rhodes Island, encompassing Kalithea the municipality that serves Faliraki and the City of Rhodes.

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The site is owned and operated by the Municipal Solid Waste Company of Rhodes which is a subsidiary of DEKR, the Greek abbreviation for City Of Rhodes.

Like the other examples, the site is operational around the clock. Equipment is fitted with spotlights for night time operation and there are streetlights fitted throughout the perimeter of the facility.

Delivery of MSW is 24-hours a day, to cater for the deliveries from the City of Rhodes and other municipalities that operate night time collections. There are also deliveries of MSW via RCVs from 5am to 2pm, and throughout the day there are deliveries of C&I waste from the private sector.

Waste is deposited at the designated area of the tip face, as instructed by the machine driver, and once delivered is compacted and covered.

There is a state-of-the-art leachate treatment plant operational on-site, consisting of four purifiers that are cleaned out on a daily basis by removing loose material that has blown from the tip face e.g. plastic bags, paper, cardboard etc. Purification is then carried out. Netting catching debris blown off the landfill is also cleared on a daily basis and bagged up for subsequent disposal in the landfill.

Methane is extracted from the site and burnt off in a central torch, similar to the Tembloni landfill of Corfu. There is a separate area laid out to retain WEEE items, used tyres, and waste wood, following the EU waste diversion and pre-treatment guidelines.

Paphos, Cyprus sanitary landfill site

Cyprus and its old dumping sites were subject to a lot of bad publicity three years ago. A viability study was carried out on their existing means of disposal for MSW and any requirements that would need to be implemented to meet the EU Landfill Directive (at this time Cyprus had not joined the EU).

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Studies were carried out on their operations and concluded that existing sites did not have a deep membrane fitted, nor did they have leachate management implemented prior to MSW being delivered and subsequently covered. This had an adverse affect on the water table and Enviroplan AE were brought in to design, construct and operate the new sanitary landfills.

Paphos has subcontracted out the collection of C&I waste to private contractors. A feasibility study was carried out to look at the previous partial collection of C&I waste using 1100 litre containers and a RCV or by utilizing a compactor skip giving a net capacity of five tonnes, the latter has become standard for hotels. The compaction skip, supplied by Bergmann, proved to be less costly than collection by RCV with multiple 1100 litre containers. The compactor skips are collected via standard skip vehicle once or twice a week and transported to the sanitary landfill of Paphos to be emptied.

This landfill also operates a leachate treatment plant and methane extraction is via a flare torch.

On my visit there three years ago there was a MBT and AD plant being built on site, as well as a MRF.

Tembloni, Corfu sanitary landfill site

The Tembloni sanitary landfill site of Corfu is situated in the centre of the island. All RCVs, operated by local municipalities, deliver their MSW straight to the site, while there are two roll-on-roll-off drawbar vehicles that transport the MSW to Tembloni from the north and south of the island.

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Operation of machinery at the tip face is only carried out during the day, but there is open access for RCVs to enter the weighbridge and proceed to the tip face from midnight. The Greeks, when going through the design and construction phase, had streetlights fitted around the perimeters to aid the drivers at night.

The loads delivered are compacted via a machine and covered. There are also two deliveries of pre-treated sewerage to this site on a daily basis which is deposited in the same area as the MSW and C&I waste.

The site encompasses a state-of-the-art leachate treatment plant and also a methane collection system, which is understood to be flared off via a central torch.

There is a separate area adjacent to the landfill for waste electrical and electronic equipment (WEEE) material as well as reusable items of a wood origin. The site also boasts a MRF, operated by the Recycling Company of Greece which has its own collection vehicles for recyclables, e.g. paper, cardboard, glass and plastic this material is collected in a co-mingled form, 24-hours a day.

The Tembloni landfill is nearly full to capacity and has been subject to wide spread publicity the village in close proximity to the site has protested and blocked the entrance to the site every couple months during the summer season due to the odours given off. This causes major problems for Corfu as there is no other viable alternative site that has been engineered as a sanitary landfill to accept MSW and C&I waste.

There is a new landfill site designed and engineered to the sanitary landfill specification in Lefkimi, to the south of the island, but this has also been subject to great opposition and protests. Prior to these outbursts, the mayor of Lefkimi would not pay the high transport costs of delivering MSW to Tembloni and was utilizing existing dumping sites that did not meet any EU Landfill criteria.

Pallosti, Kefalonia controlled landfill site

Refuse collection and disposal at Pallosti is controlled by Kefalonia Intermunicipal Enterprise for Waste Management and Environmental Protection. This company is responsible for the collection and disposal of MSW and commercial and industrial (C&I) waste from all of the municipalities and districts that make up the island of Kefalonia. It also has the responsibility to collect and dispose of MSW and C&I produced on the island of Ithaca a delivery takes place daily via a roll-on-roll-off vehicle which transports the solid waste to the Pallosti landfill (via compaction container, a small waste transfer station in Ithaca and the daily ferry).

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Refuse collection vehicles commence operation from 3am due to high temperatures. Waste collected, which is generally co-mingled MSW and C&I, is transported to the controlled landfill of Pallosti where deliveries are concentrated between the hours of 8am and 8pm, although the operating license is 24/7.

Upon arrival, waste is weighed and deposited at the tip face where it is compacted and covered by soil excavated from the area.

Leachate produced is treated via holed pipes in the bottom of the waste basin (membrane) and the leachate collection tank. Once the tank has collected the leachate it is re-dispersed through the waste via the pump station.

Methane is collected in a system that consists of vertical gas wells with perforated concrete pipes filled with coarse grained material and a smaller perforated PVC pipe. From these wells the methane is released into the atmosphere in a controlled manner. It was considered in the design stage that a central torch would not be required as the expected methane quantity produced would not be sufficient.

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