We all want the best that money can buy, and that equally applies to municipalities and cities.
But when it comes to key aspects of solid waste management, experience clearly dictates that spending more to access the best available technology or treatment facility can result in failure.
Reasons for this failure are numerous, but typically it relates to municipalities either underestimating the required operations and maintenance budget or overestimating the technical skills of their staff to operate the state-of-the-art facility or process.
Best budget utilization for solid waste management
All municipalities have a certain budget under which they must operate. There is no such thing as unlimited funds for any aspect of socio-environmental programs or management. Therefore expenditure must give the best bang for the buck. In solid waste management, unless a waste disposal facility is very large and in a particularly sensitive area, then perhaps adopting an appropriate technology rather than the absolute best available technology is the better option. This allows savings or remaining socio-environmental dollars to be better spent on other programs and activities that can achieve the greatest impact and improvement overall.
Sustainable options for waste processing are rapidly evolving
In terms of waste reduction, reuse, and recycling (the 3Rs), as well as waste collection, there are a number of standard approaches that continue to serve the community well. There are always minor iterations and upgrades but major stepwise changes in these aspects are uncommon in the developing country context.
Waste processing, however, is undergoing major changes, particularly as it relates to waste-to-energy facilities. This has now become part of mainstream waste management and is termed the fourth “R”. Higher efficiency incineration processes together with clever waste drying technologies are making waste-to-energy facilities more economically and environmentally sustainable, even for smaller cities. Previously, only relatively dry waste from cities of more than a million people could be converted to energy, but now, small to mid-size cities have this option to consider.
Still, not all waste can be incinerated and some of the resulting ash can be hazardous and requires appropriate disposal. Overall, this development direction is very encouraging and reduces the quantity of waste going to landfill and achieves some productive use of the waste.
Controlled landfill versus fully engineered sanitary landfills
Even with greater emphasis on the 4Rs, there is almost always residual waste requiring final disposal. It is this last disposal stage where many municipalities and cities fail to achieve the socio-environmental sustainable outcomes that are possible by adopting appropriate technology—rather than the most expensive options.
The main difference between the two relates to the standard of the disposal facility to be developed. Sadly many legislators mandate the use of full sanitary landfills, which involves specific types of artificial liners to protect groundwater resources locally, treatment plants for managing the contaminated liquid formed within the landfill called leachate, and other social interventions such as banning waste scavengers from the landfill site. So aside from high cost implications and several components for implementation, even when operated correctly, this does not achieve significantly improved socio-environmental protection compared with a less complex controlled landfill facility, which is far less capital expensive and cheaper and easier to operate.
Save for the very largest cities, all others can often provide a higher level of social and environmental protection by adopting a simpler disposal facility. They then have sufficient funds and technical skills to operate and maintain this correctly.
For example, leachate can be simply intercepted and then sprayed on previously worked or future development areas during dry periods to maintain good grass cover or reinjected back into the landfill mound during protracted wet periods. Such a system is low-cost and simple to operate, and achieves far better environmental protection than an expensive leachate treatment plant which is often improperly operated, harming the environment.
Furthermore, artificial liners are easily damaged and often burn at poorly managed facilities. If the landfill is sited within an area with extensive low permeability clays, there is no need for an artificial liner and these savings can be directed to other aspects of the disposal facility.
Regardless of reports suggesting otherwise, most waste being hauled in developing countries is mixed waste and is not segregated. As a result, higher technology mechanized materials recovery facilities frequently fail due to equipment blockages and damage. Many of these facilities have also failed due to lack of maintenance, high operating costs, and/or have been abandoned. So although it seems socially inappropriate, manual segregation of mixed waste stream has been and continues to be the most efficient approach for recovering recyclables and other high-value products.
Experience from many countries indicate that following suitable health education for the waste pickers, provision of appropriate personal protective equipment, and sometimes shelter and the registration of scavengers (to prevent children working on the site) have proved sustainable. In some cases, where scavengers have been provided with livelihood training to enter the alternative workforce, they eventually returned to waste picking because of better pay, ability to work longer hours if extra funds are required, and because they can save more by not needing to pay for transport to the alternative employment, and so on.
Being resourceful with less resources
Providing the biggest and highest technology or the most complicated facility is often seen as the pinnacle by most municipalities and cities. However, given the finite limit on funds, it is often far better to adopt the best available treatment or technology that is economically achievable rather than the absolute best available. Sometimes less is indeed more.
An environmental engineering consultant, Lyndsay has worked in solid waste management for more than 3 decades. His expertise covers all aspects of solid waste management, ranging from environmental assessments to detailed design of facilities. His passion is developing site-specific solutions that are pragmatic and sustainable.
“Unless a waste disposal facility is very large and in a particularly sensitive area, then adopting an appropriate technology rather than the absolute best available technology is the better option.”
*For more practical waste management solutions, read Integrated Solid Waste Management for Local Governments: A Practical Guide.