Waste collection cost is strongly influenced by choices in equipment and by time inefficiencies, like the idle time of this truck waiting for ages to be loaded with waste. In this module, we'll be covering the factors of inefficiency in waste collection and transport, with some suggestions on how to improve on cost efficiency. So hopefully after this module, you will be able to identify the reasons for inefficiencies in waste collection, for instance in your own city, and be able to provide some suggestions on how to improve on efficiency in collection.
One aspect is the placement of the containers or points of collection and the routing in a neighbourhood. Let's take a look at this example of a neighbourhood. If you would want to collect all these yellow bins, you would have to follow a route that for instance takes you this way, which would imply that sometimes, you have to cover the same stretch of road twice.
So how could you improve the routing and placement of bins? For instance, you could place your bins at strategic locations and set them together to decrease the time of stop and go for your truck, as shown here in this example. However, you must check if the bins are not too far away from the houses, as else, the residents will not bring their waste to the bins.
A distance of 200 meters is a good reference as maximum distance. So now, if you circle the area from the bins with a radius of 200 metres, you can see what area these bins can approximately cover. And then, if you do this for all the bin locations, you can see that the whole area is well-covered.
So now, with these new bin locations, you can improve the routing. Try to avoid turns that cross traffic. So if you drive on the left side, that means: Avoid right-hand turns!
A second factor to increase efficiency is to decrease loading time. These three examples show inefficient loading. For example: waiting for the people to bring their waste or manual loading of the waste or finally a very high loading height, which decreases the efficiency.
The examples below show some measures to decrease the loading time. For instance with automatic lifting of the containers, the lifting of a hook container or by kerbside collection, using bags and a very low loading height. A note on containers or collection point: What you see here is a collection point with a hook container with side openings for easier access.
What you also see is a ramp that allows smaller vehicles to easier discharge into the container. But you also see the problem: The container is located at the wrong position. It should actually be here on the side of the ramp - else, the ramp cannot be used.
This example shows that technology is not enough. Although this is an appropriate technology, it is not used correctly. The truck driver has not placed the container at the right location.
So it is important to always include the human factor. Another factor is transport distance. This is the distance from when your truck is full after collection to the point where you need to deliver the waste, be this a disposal site or treatment facility.
When the transport distance increases beyond 20 kilometres, then most often it is advisable to consider a transfer station. Here, the waste is transferred from a smaller vehicle to a larger one. Transporting a larger load with a larger vehicle is more cost-efficient.
Here are some examples of transfer stations: Above using a large truck - in fact some cities might even use train waggons or barges. The example below from India shows a transfer station where the load from the smaller trucks is unloaded into a storage bunker, and then from there transferred to larger trucks with a truck excavator grapple. Once the waste arrives at the disposal point, it will depend on how fast the truck can be unloaded.
A very inefficient example is shown here, where the waste is manually unloaded; in contrast this example with a hydraulic tipping and unloading of the truck body. Another aspect I would like to highlight is the choice of the vehicle used for waste collection. There is a wide variety of vehicles available on the market.
Whatever your choice, I would strongly recommend to check the local market. Choosing a vehicle that is common in your region often also means that it can be serviced more easily. Other criteria that should influence your choice of vehicles are on one hand of course the dimensions - width depends on street conditions, body volume and payload.
These two factors will depend on waste amounts and the route lengths and the number of trips per day that the vehicle should make. Then there is also the number of crew that is needed to operate the vehicle, which impacts on the operational cost of the vehicle through the salaries needed for the crew. Finally, there's also the cost of the vehicle and the cost of its operation such as fuel consumption, maintenance cost etc.
All these factors will reflect on the costs per ton of waste collected. This table shows a comparison of different vehicle types, starting off with the density of 350 kilograms per cubic meter. You can see that the compactor increases the density, but on the other hand, it has less body volume because a part of the volume is taken up by the machinery.
So now, if you multiply body volume by density, what you get is 1200 in this case, 6300 for the open body truck and 5850 for the compactor truck. So you see that the compactor truck under these circumstances of density can actually transport less than an open body truck. If you then compare other factors in terms of performance, you can then calculate the cost per day of the vehicle, compare this with the waste per day you can collect, which then gives you a cost per kilogram or ton of waste collected.
Another aspect of increasing efficiency is to reduce the downtime of vehicles. That means the time that the vehicle is out of service, broken and waiting to be repaired. Relying on locally well-represented brands increases the chances that spare parts can be easily obtained - and that there are skilled mechanics familiar with these brands.
A further aspect is to establish a well-functioning and well-organized mechanic workshop that conducts preventive inspections and maintenance to avoid the truck even breaking down. Also, it is important to simplify procurement rules and regulations so that when spare parts are needed, they can quickly be organized and the truck quickly fixed. Another element to increase efficiency is especially increasing fuel efficiency - and that involves training of the drivers.
Here are some core tips for fuel efficient driving. They can reduce fuel consumption by over 20 percent. Also, training of staff can increase efficiency - on one hand in terms of risks and safety to avoid accidents, but also to speed up the collection process.
One aspect is also the communication with the waste generators. It is important to reduce delays when collecting the waste. Monitoring and supervision is important to always strive for further improvements.
Feedback from the crew and drivers on how things could be improved should be really integrated, and observations might also help in streamlining the collection process. Measuring performance of vehicle and staff is important for various reasons; on one hand to identify bottlenecks, but also to plan for preventive maintenance. GPS trackers and electronic on-board recorders are innovative devices that can help with monitoring.
A weigh bridge at the disposal site will help identify the amount of waste collection. Remember: Monitoring is crucial, as data availability is a step towards improving management. Finally, some last words on communication: Ensuring open communication channels with the beneficiaries, the residents, is important to get their feedback and their suggestions as well as their complaints, and be able to inform them about new developments.
Ensuring communication with the collection team from a central location is also crucial to know if delays are expected or finding ways to solve problems rapidly. GPS trackers can visualise to a central location where the truck is at the moment, giving management an overview of the vehicle fleet. So in summary, in this module, we have looked at different factors that influence efficiency in waste collection: optimization of collection points and routing, decreasing the loading time, longer distance, use transfer stations, decrease vehicle emptying times, choose vehicles appropriately, monitor and supervise performance, train and educate staff, and communicate and cooperate, especially with the waste generators.
As mentioned, I would like to recommend these two excellent books on waste collection in developing countries. They are available for download in the list of key readings, but also on the Internet and they give much more details on all the aspects I have discussed here. Thanks for watching.
