Environmental impacts of waste management in Dar es Salaam

Image Courtesy of www.Recycler.co.tz

The waste generation in Dar es Salaam (DSM) has been tripled during the past 16 years; the city generates 4,252 tonnes of MSW per day, with a per capita waste generation of 356 kg/year/person. About 60% of waste generated in DSM remains uncollected and may end up in storm water drains, contributing to pollution of runoff water, rivers and coastal waters and exacerbating annual flooding events and the spread of disease and uncontrolled methane generation.

The high organic composition of DSM’s solid waste is a driver of water quality degradation. Studies confirm that about 40-45% of the wastes are organics from kitchens and 10% are yard wastes, while the rest of the wastes are less organic materials such as plastics (2%), metals (1.7%) and ceramics / stone (0.3%). Landfills are the single largest man-made methane emitter sources. Methane poses a risk not only through its high reaction potential with ambient air, which could lead to explosions on the landfill, but also through its greenhouse gas (GHG) potential. In tropical climates, the degradation rate and thus methane and carbon dioxide production is higher.

Climate and Clean Air Coalition work

The City of Dar es Salaam has joined the Municipal Solid Waste Initiative (MSWI) of the Climate and Clean Air Coalition (CCAC) in 2014 in order to receive assistance to reduce Short Lived Climate Pollutants (SLCPs) resulting from its current solid waste management activities.

The Phase 1 scoping missions started in December 2014 and was concluded with an Action Plan in April 2015, focusing on improving the status of solid waste management in the city of DSM. Elements of the workplan are considered below.

Pugu Kinyamwezi landfill capacity building event

In August 2016, the International Solid Waste Association (ISWA) conducted a 2.5-day capacity building event which focused on potential upgrades of the operations at the Pugu Kinyamwezi dumpsite and on basic principles for the construction of sanitary landfills. The following observations were made:

• Although waste is spread out all over the site and the compaction density is very low, Pugu has sufficient capacity to be the final disposal option for the waste generated in Dar es Salaam for the next 5 to 10 years.
• The situation on the landfill site can most accurately be described as disastrous with regard to waste management operations as well as living and working conditions.
• The site is located in the outskirts of Ilala, west of the international airport, and measures 65 hectares.
• The site has no infrastructure for environmental protection. There is no bottom liner and no catchment system for landfill gas and leachate. The waste is dumped in a thin layer, not exceeding six meters. It is not compacted and not covered. Six pieces of equipment are available (bulldozers, compactors and cranes) but only one is in operation due to lack of maintenance, spare parts and fuel.
• There is almost no physical barrier between the waste and the surrounding settlements. A brick wall fencing is under construction (40%) but works only proceed when money is available. A weighing bridge is available and in operation.
• A pilot landfill cell with drainage and a leachate pond has been constructed, equipped with a very thin plastic bottom liner, unfit for this purpose.
• Waste is all around, inside and outside the site’s boundaries. Light plastics are lifted by turbulent winds and transported up to the clouds (and airplanes) through thermals and transported over long distances.
• Waste is floating in surface water, leading to the formation of leachate. These are optimized reproduction conditions for flies and mosquitos.
• The internal roads are accessible in the dry season. Conditions in the rainy seasons will be much worse bringing operations to a halt and leading to reduced capacity.
• Several hundred scavengers are working, eating and living on the site under inhuman conditions.
• The tipping fee is 1,500 Tzs (€0.60) per ton, with all municipal waste being exempted from payment. The average daily tonnage reaching the dump site is said to be 1,000 tons. Assuming 50% of the waste at Pugu is of municipal origin, this leads to an annual turnover of ± €100,000. This is indeed barely enough to cover some salaries and limited expenditures for fuel and repairs.

Establishing a sorting facility at the Pugu dumpsite

Another strand of the work found that incoming waste treated by sieving, sorting and composting could be carried out at Pugu landfill in order to reduce the overall “consumption” of landfill space.

Composting workshop

Composting is a way of reducing the costs of the solid waste management system, by reducing the amount of organic waste that has to be transported to the dumpsite and be disposed of. An additional reason can be to reduce the emissions of greenhouse gases and short-lived climate pollutants generated through open dumping and burning of waste. A workshop carried out in December 2016 focused on household composting, community composting and centralized composting at a large scale. Composting is a way of producing a valuable product that can be sold and set up as a feasible business with marketing being one of the main activities.

Hamburg composting facility

A large-scale composting facility in Kinondoni is due to be constructed and operational by end of 2017, supported by the City of Hamburg and the German Federal Ministry for Economic Cooperation and Development (BMZ). Organic waste will be collected from two of the larger fruit and vegetable markets (Tandale, Tegeta) and will be located in the North of DSM (Mabwepande). In the future, the facility would like to accept segregated organic waste from households. If this project succeeds, Dar es Salaam will be the second city to have large scale composting plant in the developing world, next to Dhaka.

Cleanest Mtaa program

This part of the workplan aimed at awareness creation in communities about solid waste management. Mtaa is Swahili for neighbourhood or in this case sub wards. It was carried in Makuburi and Mabibo, two of the thirty-four wards of Kinondoni municipality in DSM city.

Study found there is generally not much solid waste separation at household level, partially more than 80% of respondents are not separating their solid waste. If separation is done, it is most often plastic bottles as they are collected by scavengers that make money from it. Organic waste is sometimes separated for feeding animals. Glass is also separated in a few places and collected to be recycled, like with plastic bottles the middle men get money for that. Paper is not separated very often and the market is not big yet. When collected, it can be used for briquette making. More than 50% of the respondents the major reason for not separating solid waste at source is really just not seeing the importance of it. Solid waste is burnt, buried and collected by formal/informal waste collectors, the extent of collection dependent on accessibility.

The exercise shows that two big fractions alone make up ¾ of the waste, namely organic waste and sand from sweeping. Separating these would reduce the amount of waste drastically and, with organics removed, would also make waste a less dirty business. Here awareness creation and user education can help a lot to increase understanding of the matter. Survey found a willingness to separate waste at household level mainly driven by financial or environmental reasons.

International Solid Waste Association scope for intervention

The initial assessment report of the Dutch Delegation of three experts on integrated solid waste management was presented to the Dar es Salaam City Council and other stakeholders during the Final Conference of the CCAC Work Plan project on 27 April 2017 includes detailed planning to upgrade the Pugu landfill within the next 3-4 years.

References

• BreAd Apr 2017 Separation, sorting and composting of MSW at the Pugu dumpsite in Dar es Salaam
• Climate & Clean Air Coalition 2017 A green City is our home: Strategy for Organic Waste Management in Dar es Salaam 2017-2020
• Climate & Clean Air Coalition Workplan for Dar es Salaam: Final Trip Report April 2017
• International Solid Waste Association 2016 Support to Improve Waste Disposal Practices at Pugu Dumpsite and Assistance for Planning of the Construction of New Landfills
• International Solid Waste Association 2016 Findings from Baseline Survey on Solid Waste Generation and Management in Mabibo And Makuburi Wards
• International Solid Waste Association 2016 Workshop on Organic Waste Management December 2016