**3.1 Efficiency indicators**

In order to determine the level of efficiency of a separate collection system, it is necessary to define some indicators. This efficiency has been defined in terms of the level of recovery of clean materials at source, deposited in the container, which is in turn expressed in terms of a series of indicators (Gallardo *et al*. 2010):

 *Fractioning Rate* (*FRi*): the ratio between the amount by weight of the raw material separated and the total amount of urban waste. This rate is used to measure the various collection streams.

$$FR\_i = \frac{Gross\,amount\,\,of\,\,waste\, collected\,\,in\,container\,\,for\,\,i}{\text{Total\,amount\,\,of\,\,urban\,\,waste}}\,\text{100(\%)}$$

Separate Collection Systems for Urban Waste (UW) 121

 *Number of fractions*. The level of participation falls as the number of fractions into which urban household waste is divided increases. Noehammer *et al*. (1997) studied the influence of the number of separations on the degree of participation in 104 separate collection programmes and found that for a separation into two fractions, participation is between 75-95%, while for more than four fractions the range was 49 -92%. Another conclusion they obtained was that in mandatory programmes, there was no clear correlation between the level of participation and the number of separations. However, when the programme was voluntary, the level of participation declined as the number

 *Distance to the deposit point.* Participation falls as the distance to the deposit point increases. In Spain, the *SR* for glass in kerbside collection was 40% (distance to container 50 m), while at drop-off points, with a range of between 100-160 m, the

 *Compulsory separate collection.* Compulsory separate collection programmes have a higher level of participation than voluntary programmes, providing that they are accompanied by certain incentives. Noehammer *et al*. (1997) found in their study that in compulsory programmes the level of participation had a range of 49-100%, while in voluntary collection it ranged between 11% and 92%, and concluded, as did the other authors that they cite, that compulsory programmes are more successful provided that they are accompanied by a high level of information, financial incentives, an adequate

 *Socioeconomic level.* Gandy (1994) and Belton *et al*. (1994), in two studies on the relationship between socioeconomic level and the degree of participation in the dropoff points, found that there was participation clearly increased among people with a higher socioeconomic level. However, Lober (1996) in a study of reduction at source and recycling, found that in the various recycling programmes he studied, the socioeconomic factor was not significantly correlated with the degree of participation. *Education and promotion*. The level of information received by the public influences the degree of participation and quality of the separated materials. Gallardo (2000) showed that in Spain the *SR* of glass and paper-cardboard at the drop-off point level was higher

 *Sociodemographic characteristics.* These characteristics have become a basic tool for many researchers when evaluating the profiles of a participatory individual compared to another person who does not participate in collection programmes. This classification also makes it possible to take education and awareness-raising action among groups with low participation (Rojas *et al*. 2008). Nationality, socioeconomic status, age and gender, among other factors, correlate strongly with separation behaviour (Rojas *et al*., 2008). In Preston (England), Perry & Williams (2006) conducted research on participation in separate collection programmes, including the factor of nationality, because ethnic minorities now constitute a significant proportion of the town's

in cities where citizens were better informed, for the same range.

occupants of tall buildings are more reluctant to participate (White *et al*., 1995). *Frequency of collection*. If collection is infrequent, citizens' motivation declines, while if frequency is appropriate and in line with the rate containers are filled, participation

increases (White *et al*., 1995).

of fractions increased.

average is 22% (Gallardo *et al*., 1999).

collection frequency, free containers, etc.

easier to monitor who is participating in separation in the latter, while in a block of flats this is more difficult. Following this argument, in the Netherlands it has shown that

Where *i* is *p, g, lp*, *o* or *uw* depending on whether the *FR* is for paper, glass, packaging, organic waste or household waste, respectively. Raw material refers to material contaminated to a greater or lesser extent by other unwanted materials (also called improper materials).

 *Separation Rate (SRi):* the ratio between the amount by weight of raw material separated and the total amount of material in the urban waste.

$$SR\_i = \frac{\text{Gross amount of waste collected in container for i}}{\text{Total amount of i wasste generated}} \cdot 100 \text{(\%)}$$

For example, to find out the *SR* of the paper-cardboard in the paper container, we divide the amount of separated paper by the total paper in the waste.

 *Quality in Container Rate* (*QCRi*): the ratio between the amount of net recyclable materials deposited in a container and the gross amount deposited in them.

$$\text{QCR}\_i = \frac{\text{Amount of waste collected correctly in container for i}}{\text{Gross amount of waste collected in container for i}} \text{-100(\%)}$$

A good system would be one with a high *SR* with high quality materials, i.e. a low proportion of improper materials. These indicators are a necessary tool for evaluating the efficiency of the infrastructure of the separate collection system implemented. They provide direct information on the total quantities and products obtained in each type, in comparison with the potential amount of recyclable materials present in urban wastes. They are also useful for a diagnosis of the situation of the separate collection programme implemented and for finding out whether the poor quality of the materials collected separately is due to low participation, poor performance in collection or a lack of public information, for example.

#### **3.1.1 Factors affecting the separation rate**

The *SR* is directly related to the public's participation in separate collection programmes. This participation depends on several factors, which Wang *et al.* (1997), grouped into two categories: factors related to the citizen's attitude and factors associated with the characteristics of the collection programme. Few studies have been carried out in this area (Noehammer *et al*., 1997), although some researchers have found interesting results that relate the *SR* to various factors:


*Separation Rate (SRi):* the ratio between the amount by weight of raw material separated

·100(%) *<sup>i</sup>*

For example, to find out the *SR* of the paper-cardboard in the paper container, we

·100(%) *<sup>i</sup>*

*Quality in Container Rate* (*QCRi*): the ratio between the amount of net recyclable

A good system would be one with a high *SR* with high quality materials, i.e. a low proportion of improper materials. These indicators are a necessary tool for evaluating the efficiency of the infrastructure of the separate collection system implemented. They provide direct information on the total quantities and products obtained in each type, in comparison with the potential amount of recyclable materials present in urban wastes. They are also useful for a diagnosis of the situation of the separate collection programme implemented and for finding out whether the poor quality of the materials collected separately is due to low participation, poor performance in collection or a lack of public information, for

The *SR* is directly related to the public's participation in separate collection programmes. This participation depends on several factors, which Wang *et al.* (1997), grouped into two categories: factors related to the citizen's attitude and factors associated with the characteristics of the collection programme. Few studies have been carried out in this area (Noehammer *et al*., 1997), although some researchers have found interesting results that

 *The economic factor*. Noehammer *et al.* (1997), in a study on the impact of free separate collection bins on the degree of participation, concluded that providing bins in voluntary programmes has a positive effect. However, they were unable to confirm anything for compulsory programmes. They also showed that if the fee paid directly for the collection of municipal waste falls, the level of participation increases. Gilnreiner (1994) presents the results of a survey conducted in Vienna in which "reward systems" are clearly preferred by consumers over "punitive systems" such as ecotaxes and packaging taxes. Another way to increase the degree of participation is through the introduction of tax benefits (Bolaane,

 *Size of housing*. Participation in high-rise housing, which is usually small in area, is lower than in single-family homes, which are generally larger. On the other hand, it is

2006) or by lowering the fees paid for collection (Harder & Woodard, 2007)

*Gross amount of wastecollected incontainer for i SR Total amount of i waste generated*

materials deposited in a container and the gross amount deposited in them.

*Amount of wastecollectedcorrectly incontainer for i QCR Gross amount of wastecollected incontainer for i*

divide the amount of separated paper by the total paper in the waste.

and the total amount of material in the urban waste.

improper materials).

example.

**3.1.1 Factors affecting the separation rate** 

relate the *SR* to various factors:

Where *i* is *p, g, lp*, *o* or *uw* depending on whether the *FR* is for paper, glass, packaging, organic waste or household waste, respectively. Raw material refers to material contaminated to a greater or lesser extent by other unwanted materials (also called easier to monitor who is participating in separation in the latter, while in a block of flats this is more difficult. Following this argument, in the Netherlands it has shown that occupants of tall buildings are more reluctant to participate (White *et al*., 1995).


Separate Collection Systems for Urban Waste (UW) 123

Since there are new European standards that must be complied with in terms of recycling targets, local authorities in countries belonging to the European Union have hastened to develop new collection models. As a result, a wide variety of separate collection systems can be found throughout Europe. This has given rise to their study and comparison in the different countries where they have been implemented. For example, in Sweden, Dahlén *et al*. (2007) conducted a study that compared 3 systems. The first consists of kerbside collection of recyclables and organic waste, including a specific case in which fees are paid for the collection of mixed waste. The second involves kerbside collection of recyclables, and the third the collection of recyclables at drop-off points. After the study, it was concluded that in municipalities with a kerbside collection system for recyclables, the mixed waste container has a higher *QCR* due to the proximity of the containers to the public. The introduction of the fee payment system for the collection of mixed waste led to this waste from many homes being burnt or dumped in the wrong place. In fact, in the municipality where this system was in place, the level of improper materials was 12% compared to 4% in

Mattsson *et al*. (2003) produced a study that compared separate collection systems in both single family and multifamily property close areas in Sweden and England. They used 6 Swedish examples and one recently introduced case in the United Kingdom as examples. The cases analysed showed that although the technical details were almost identical, they differed in terms of how they had been developed. The aspects taken into account for their different developments were: cooperation between the municipality and producers, the efficiency in collection using appropriate vehicles, the quality of the materials collected,

In the United Kingdom, Woodard *et al*. (2001) analysed waste collection in a district before and after the introduction of a new plan. Under the old system, mixed waste was collected in black bins and recyclables (paper, cardboard and metal) in a box, every week in both cases. The new plan (CROWN: Composting and Recycling our Waste Now) added a green container for the collection of biowaste every two weeks. The frequency of mixed waste collection declined and became fortnightly, like biowaste. The container volumes and satisfaction of citizens was noted in a sample of households in a residential area. The result was a 55% reduction in waste sent to landfill sites, an increase from 5.5 to 17.7 liters in the average amount of deposited recyclables per household per week, and a rise in participation from 40% to 78%. Wilson and Williams (2007) subsequently analysed the implementation of a new collection system in a northern town in the United Kingdom. Two samples with different collection frequencies were used to see which system worked better: in one the mixed waste and recyclables were collected in alternate weeks, and in the other the mixed waste was collected weekly and the recyclables fortnightly. The proportion of containers brought to the street for collection compared to the total number of containers available was analysed in each sample, as was the level of material recovery in each sample. Both

is possible that not all members will collaborate in separate collection.

one of the municipalities where this model was not implemented.

Agenda 21 and environmental awareness.

calculations produced better results in the first sample.

**4. Separate collection systems in Europe** 

designed specifically for them, this had increased to 64%. According to Kimrey (1996), the information-education programme must be targeted at the entire family as if not, it

population. The study found that nationality that anticipated most in the recycling programme was the Indian-British minority (95.2%), followed by the British (78%) and the category of "other ethnic groups" (56.3%). The authors note that the reasons for the differences shown are unclear and require further investigation.
