Door to door selective waste collection and the effects on waste prevention

Municipalities that have implemented the door to door (DtD) selective waste collection experience a significant waste reduction: Waste generation per capita in the Catalan cities and towns shows an average decrease of 15.3% (weighted by population) comparing the generation before and after the implantation of the DtD waste collection scheme, according to a study conducted by the Association and ENT Foundation in 2013.

The results of waste reduction achieved with the introduction of door to door schemes are listed below.

Table 1. Waste reduction achieved after the implementation of door to door waste collection schemes.

Per capita waste generation: weighted average
(kg / inhabitant per day)
% Waste prevention
Year before implementation 1,572
Year of implementation 1,438 -8,5%
1 year later 1,341 -6,8%
2 years later 1,317 -1,7%
3 years later 1,338 1,6%
4 years later 1,371 2,4%
5 years later 1,307 -4,6%
Total -17,6%

1 Only experiences where DtD collection applies to more than 90% of the population have been included.

Figure 1. Waste reduction achieved after the implementation of door to door waste collection schemes.

Waste prevention achieved during the first two years after the implementation reaches 15.3% of waste prevention. Then this tends to stabilize.

When comparing the prevention achieved between the different types of door to door waste collection schemes, results obtained are lower in the case of 2-fractions DtD schemes than those obtained in schemes in which more fractions are collected door to door (Figure 2).

Figure 2. Waste reduction achieved after implementing different door to door waste collection schemes, depending on the number of fractions collected door-to-door.

No other schemes achieve this reduction in waste generation. These are some of the main causes:

1) Avoided collection of non-municipal waste. This is considered one of the most important reasons that explain the achieved waste reduction. With the implementation of DtD collection, most street containers are removeds, and so it ceases the collection of non-municipal waste that were irregularly disposed of in them, such as some industrial waste, green waste from professional gardeners, construction waste, etc. Once the street containers are removed, these forms of illegal disposal become more visible and thus easier detect and prevent.

2)"Waste tourism" waste tourism is responsible for a small part of the total waste reduction that occurs when a DtD scheme is implemented. This phenomenon appears when a small percentage of people disagree with the waste collection scheme in their neighbourhood or town, and they irregularly dispose of their household waste in street containers located in bordering towns or just dump it illegally on the environment (close to roads, water streams, etc). These are negligible in weight, but potentially very visible.

Factors that may influence "waste tourism" could be mainly:

  • 1. High presence of tourism and second homes
  • 2. Effects related to dormitory towns
  • 3. DtD towns very close to towns with waste collection by means of street containers
  • 4. Waste street containers in bordering towns located in accessible places
  • 5. Inadequate communication and information campaign. Insufficient monitoring and control.

Waste tourism is difficult to control. The complicity of the bordering municipalities is necessary and may be punishable if regulated in the local ordinances.

Under the "waste tourists" point of view, moving their waste around and avoiding waste separation may seem easy and comfortable at the beginning, but tends to be not sustainable in the long term.

3) Change of habits in the population. The introduction of a DtD selective waste collection scheme require important information and awareness campaigns that must reach the entire population. This will include a variety of meetings with the population, sectorial talks to businesses, associations, communities, door-to-door, etc. Besides, once DtD is implemented, it requires communicative monitoring through civic agents, inspectors and informants. This big effort on communication at the beginning allows people to be very informed and aware. This translates into higher environmental concerns, and ultimately in better results.

Making the people responsible of the management of their own wastes, makes them more aware of their own production and the environmental consequences of an unsustainable waste management. This leads to changes in their household's habits in relation to waste generation.

In DtD municipalities it is easy to see people incorporating new habits into their daily behaviour, such as shopping with basket, using lunchbox, buying products in bulk or with minimal packaging, avoiding single-use products, using tap water, refusing advertising in the mailbox, etc.

4) The use of aerated bins. The use of compostable bag for the biowaste collection is established as mandatory in some DtD municipalities; and many others promote it.

A characteristic feature of the compostable bags is is "breathability". The combined use of compostable bags and aerated bins reduces much of the moisture in the biowaste, achieving a 3% to 4% weight loss due to water evaporation (Martin, P. (2010) "Impacts of compostable bag use in managing Biowaste").

Furthermore, this continuous exchange of air between the waste and the environment reduces anaerobic fermentation (putrefaction), which is a clear advantatge for the user, due to the reduction of odours, mould, flies or accumulations of water condensation in the bin. This encourages greater citizen participation in the correct separation of biowaste.

5) Home composting becomes an important tool regarding waste prevention. On average, a composter manages annually 200 to 250 kg of biowaste and green waste. Managing this organic matter at the source reduces the amount of waste to be collected, transported and handled in biowaste processing facilities. Many of the DtD municipalities strongly promote home composting as a complementary element to the waste collection scheme.

6) DtD waste collection applied together with Pay-as-you-throw schemes encourages further participation in the separate waste collection and achieves a even higher waste reduction. In a Pay-as-you-through (PAYT) scheme every home and business pay their waste charge according to the type and amount of waste they generate, unlike the usual flat waste charges where every citizen pay the same no matter if they recycle or not.

This scheme creates a strong incentive to waste prevention and separate waste collection: the less waste you produce or the more you recicle, the less you pay for it. Most of these PAYT schemes need a DtD waste collection scheme implemented: a DtD allows the individualization and the waste producer identification. Nowadays, three Catalan municipalities apply a PAYT scheme: Argentona, Miravet and Rasquera.

For more information on PAYT, see theGuidelines for the implementation of Pay-as-you-through schemes for municipal waste generation.

Due to the waste reduction produced when introducing a DtD waste collection scheme, this system can be considered an effective way of preventing waste, fully conforming to the current legislative framework.

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