Table 1 shows an excellent example of monitoring of the quantity of the different waste fractions collected in a German county (Aschaffenburg) from 1989 to 2013 (Aschaffenburg, 2013). A total of 17 recyclable streams and 4 unrecyclable, bulky, hazardous and commercial waste streams have been systematically recorded over the last 20 years.
Such detailed waste monitoring reveals the drastic change in the waste management system of the county in the last 20 years. The quantity of residual waste decreased considerably and the quantities of recyclables sharply increased. The county introduced a weight-based pay-as-you-throw system for residual waste, biowaste and paper/cardboard. At the same time, the waste management infrastructure was significantly improved in order to drastically increase the recycling rates. Thus, today the percentage of recyclables is more than 85 % and the specific quantity of mixed household waste is about 50 kg/capita per year. These analyses and the successfulness of the implemented waste management system would not have been recognised and improved without such detailed waste monitoring.
With respect to evaluation of data, specific circumstances may have to be taken into account, such as the influence of tourism, and the collection of paper and cardboard by third-party organisations such as clubs of a municipality, etc.
In connection with the PAYT BEMP, it is easily possible to monitor which citizens have individual bins and which use common bins. Then it can be investigated where the collection and capture rates can be optimised most. The same is true for the collection frequency for citizens' waste as each collection is recorded and documented for all citizens. In this case, the data is available very quickly, practically just-in-time, and an evaluation and assessment is possible within a few weeks or months (Aschaffenburg, 2014).
