Solid waste treatment and recycling

weekly in one centre. When the sufficient amount of waste is collected, it is sold to nearby junk shops and total amount is shared among the labourers who are involved. On a rough estimate it was found that municipal labourers spend about 20% of their time in sorting recyclables for sale.

In addition to the municipal efforts in promoting separated waste and recycling activities in the city, the informal recycling sector in Colombo is played a historical role. It is largely comprised by the waste recycling activities of junk dealers including junk shops and their network of junk collectors locally called Botal Pattaray. Junk dealers have been very common features in the chain of waste recycling in Colombo for several decades, though they were hardly noticed by the society, in general, or the government and business sector, in particular. They provide primary collection and processing of collected materials into intermediate or final products, using creativity and innovation to respond cost effectively to market needs. They are involved at the very first point of collection from households, before the municipal council collects waste from them.

Botal Pattaray often goes to house to house by riding the bicycle, collect sorted recyclable materials from households, which they usually buy and then transport to the junk shops. Each junk shop has a network of about 15-20 Botal Pattaray who operate in particular area [31]. The junk shops then add value to them by sorting, cleaning, altering the physical shape to facilitate transport or by aggregating materials into a commercially viable quantity, and sell to larger recycling firms. According to the city officials, there are around 200 Botal Pattaray in the streets of Colombo at any one time. From household’s point of view, this is

preferable to the separated waste being collected by municipal labourers, for which no payment would be received.

Figure 7: Junkshop dealer in Thibirigasyaya area Source: Premakumara, IGES

Through the informal discussion with two Botal Pattaray and a junk shop dealer in the city, it was identified that even though, Botal Pattaray is generally known to originate from under-served settlements in Colombo, their activities are also largely operated in high and middle-income areas of Colombo. Due to high security, there is no Botal Pattaray however in the most luxury residential areas in the city. From selling the collected recyclable materials, they can earn between SLR 100 – 1,000 per day, while the daily wage of the unskilled labourer is around SLR 500 per day. The normal prices for recyclable materials are as follows (SLR/kg); cardboard (20), bottle (10), plastic (35), metal (45), paper (20). However, Botal

Pattary have facing the following problems; competition from municipal labourers and private collection firms operating in these areas, some people are prefer to municipal staff though it is free, because of security concern, negative social status attached to their work, lack of resources and equipment, directly taking recyclable materials to collection centres and junk shops, and difficulties in their daily operation and insecurity, such as sickness and rainy season etc.

Even though, scavenging activity is not largely widespread in Colombo, when compared to some other larger cities in neighbouring countries in Asia, it is found that there are some poor people, especially from the under-served settlements who collect the materials from the secondary collection points and from final dumping site. They are also sold the recovered materials to junk shops and getting daily income between SLR 400 – 700 [24].

In 2006, CMC has started the Eco-school Project aiming to creation of environment friendly attitudes among school children and educate them about importance of waste separation and recycling. The ultimate idea of the project is to bring the 3R (reduce, reuse and recycling) message from school children to their parents and neighbourhoods. For this purpose, a team of environmental facilitators was established at each school and those students are educated to serve as the coordinators of the environmental activities proposed by the CMC. At present 47 schools, including both public and private, are involved in this project. CMC staff along with the environmental coordinators appointed in each school organise education and awareness campaigns using the electronic and printed media, distributing printed materials, organising street-dramas, and initiating practical projects to introduce composting and waste recycling centres. According to the city officials, the participation of student in these programmes is limited only to junior levels. High-school student show the least interest for these programmes. Further, a level of interest of the school to participate in these programme are mostly based on the commitment of the principle and the teachers. For motivating, both teachers and student, CMC is planned to start an award system for identifying the best school involved in the programme as an incentive.

Figure 8: Recovered recyclable materials from dumpsite and prepared for selling Source: Premakumara, IGES

Promotion of organic waste recycling through composting

While about 83% of municipal solid waste in Colombo is compostable materials, CMC has taken several attempts to introduce composting at household, community and centralised level. According to the municipal officials, a several composting technologies have been proposed by at least 15 studies done by both local and foreign researchers over the past years. [32] However, it was become practical when CMC contracted with Burns Environmental and Technologies (Pvt) Ltd. (BETL) in 2002 to establish a composting plant for a period of 25 years.

Based on the contract agreement, BETL has agreed to implement composting plant and invested more than SLR 654 million in compost equipment and operations at the Bloemendal Road Site. The composting system applied by the BETL in its Bloemendal Road Site plant included the following process; collection of solid waste without any separation at source, transport them to the composting plant and store on to a concrete sorting floor that is covered with a full roof to give protection from the rains. The recyclables are then separated into different types mechanically and graded them again to the followings by manually, such as metal, cardboard, paper, plastic bottles and glass. The compostable materials are later put into static piles with 50-100 meters long, 3-5 meter wide, and 2-3 meters high. The temperature of the heap controls between 65-70C to kills pathogens and ensures proper fermentation. The required moisture level is maintained during the fermentation cycle. Frequent aeration is done for accelerated fermentation, i.e. the rapid multiplication of microorganisms. It is done by turning the piles through front-end loaders or compost turning machines. The temperatures are taken at three locations in each pile, each 8 hour shift and recorded. [33] [14][32]

After 4 to 21 days, the piles are moved to another location where the material is put into windrows on a concrete floor. The piles are again monitored carefully for temperature, moisture and free air space. Further, piles are mixed and moved every 14 to 28 days. After a total of 60 to 120 days, materials in the piles are screened and sorted to remove any plastic and other contaminates. Next the compost is processed through separating, grading, sieving, and air classification by a series of trammels at the processing site to recover the enriched organic soil. Quality control tests are done randomly for physical, chemical, and biological parameters as per standards recommended by the Sri Lanka Standards Institution. At the final stage, the finished product is packed in 5, 20 and 50 kg bags and arranged for selling to use in agricultural and horticultural crops, while recyclable materials are sold to local recycle ventures.

According to the city officials, the BETL composting plant was operated only in three years (2002-2004). During this period, BETL collected, sorted recyclables and composted from 130 to 750 tons of solid waste a day. It was provided job opportunities for about 200 poor people who are living around the factory area. The capacity of the composting plant was 80-100 tons per day. By using the 100 tons of organic waste, plant produced 40-50 tons of compost, while the rest end up as moisture. BETL has developed six compost products designed for specific crops and uses. However, the sustainability of the plant was come to question with its sudden stop in 2005. It was identified that a main reason for this sudden stop was a contract dispute between BETL and the CMC. Both parties are blamed each other on this issue. CMC complained that BETL was failed to maintain the requirements on

environmental quality control in the process, while BETL was complained that CMC was not paid according to the contract. Further, Auditor General’s recommendation on the contract was that the CMC had not acted in the best interests of the municipality and did not take necessary approvals from the Cabinet as well as the Attorney General under the Financial Regulations of 702. [34]

However, it can be identified several other reasons for this sudden stopped, such as the cost of production was

higher than the revenues. The total sale of compost products and recyclable materials was sufficient to cover only 10%-15% of total cost of the plant. The cost of compost products is higher than the market price, because of government subsidies for chemical fertiliser. Though, BETL obtained about SLR 500 per tonne tipping fee from the CMC, about 60% - 70% of them is used for waste collection and transportation purposes. Therefore, efforts

Figure 11: A process of compost production in Bloemendal site Source: Aheeyar (no date)

need to be taken to separate waste at source with citizen cooperation to reduce both labour and equipment cost for removal of contaminates at the plant, introduction of combination of collection fees, tipping fees, processing fees and sales of recyclables and compost, and supportive policy and institutional environment will be needed if this type of operation is to be economically sustainable.

After the failure of centralised composting approach, CMC started a pilot project in 2004 to encourage home-based composting in 4,500 households in Kirulapone and Pamankada East wards. It was aimed to promote waste separation at source, recycling of organic waste, and collection of recyclable materials separately reducing waste to be collected and dumped by the city. A local Non Governmental Organisation (NGO) called Sevanatha was contracted for four years to carry out the community mobilisation, distribution of compost barrels, and carryout the follow-up monitoring. The Sevanatha was selected considering its good relationship with both city officials and the residents in the project area. Based on the past experiences in implementing a community-based solid waste management programmes, Sevanatha adopted the following activities, such as identification of households for distribution of home compost bins, raise community awareness, arranging the distribution of compost barrel and three bags to each household free of charge, monitoring and evaluation.

After a one year of the project implementation, a sample survey was carried out by the Sevanatha and CMC officials covering about 300 households to monitor the progress. The results identified that only 40% of the households use the compost bin as required by the project. According to the staff of Sevanatha, the biggest challenge is continuing the use of compost bin by the households. Even though, they carried out a massive awareness and education programme covering all households in the area using community meetings, distribution of printed materials and regular announcement through loud speakers, it was difficult to obtaining 100%

cooperation from the communities. Some households raised the legal issues and asked the responsibility of the municipality to collect and dispose the city’s waste, while certain household made excuse in telling that they do not have sufficient space to place a compost bin. Moreover, the compost bins need to be carefully operated at the households to minimise the bad effects. It was found that many households stopped the use when the compost bin may not work properly. This required a proper system in place for monitoring and follow-up after distribution of the compost bins.