The importance of models for calculating the pay as you throw tariff.
Choosing the right model to calculate the pay as you throw tariff is fundamentally important for implementing the “pay as you throw” principle. In fact, while the waste tax (TARI) is calculated according to almost equal parameters everywhere, the pay as you throw tariff system needs specific models.
Waste tax vs pay as you throw tariff
The TARI, introduced starting from 2014 with Act 147 of 27th December 2013, is the tax intended to finance the costs of waste collection and disposal and is charged to the user. “The pre-requisite of the TARI is the possession or holding of premises or uncovered areas, for any reason and for any use, which may be susceptible to producing urban wastes”. This includes, for both residential users and non-residential ones, a fixed share and a variable one; in the residential ones, the calculation is made by taking into account the surface area of the residence expressed in square metres and the number of occupants; in the non-residential ones, – commercial, industrial, professional and production businesses in general, communities – the surface area of the areas occupied and the type of business are considered. This concerns payment criteria that do not reward virtuous behaviour: commercial users and business, for example, pay a disproportionate tax compared to the quantity of RSU (solid urban waste) that they produce, which is generally very reduced.
The regulations based on the pay as you throw tariff (TARIP) is different. These were introduced with the Ministerial Decree of 20th April 2017 and make the cost of disposing of urban waste proportional. The Ministerial Decree “sets out the criteria whereby the municipalities can create pay as you throw measuring systems for the quantity of waste consigned by the users to the public service”, aimed “at implementing an effective tariff model proportional to the service rendered to fully cover the costs for managing urban wastes and similar wastes”. The pay as you throw tariff also consists of a fixed part and a variable part: the first is calculated on the basis of the property’s surfaces area and finances the costs linked with the production of wastes, like street cleaning, cleaning public spaces and investment in works; the second, on the other hand, depends directly on the wastes produced by the user and covers the costs of collection and disposal. It is a system that introduces a principle of fiscal fairness, since the user pays on the basis of the quantity of general wastes produced and consigned.
The models for calculating the pay as you throw tariff
Measurement of the general waste is implemented by using a prepaid bag or complex tariff models, i.e. detection of the weight or volume of the wastes consigned by the user. The latter require the reading of an RFID tag placed on the bag or bin – assigned uniquely to every user – by means of a fixed antenna mounted on the vehicle or wearable technology, i.e. a device that can be worn by the operator.
♦ The prepaid bag
This is standardized volume bag with a print or bar code to identify the user and intended to contain the general dry part; the user buys or receives a specific quantity of them as kit, according to the provisions of its municipality of residence – in the case of purchase, the price is an advance payment on the tariff – in a sufficient quantity to cover a period set by the administration, usually a year. The prepaid bag is a simple model to implement, but it does not take into account the weight or volume and does not allow the pay as you throw system to be applied precisely.
♦ The complex tariff models
A complex tariff model must be adopted in order to implement a tariff that conforms to the regulations, measuring the “quantity of waste consigned through direct weighing, with the weight being detected, or indirectly through detecting the volume of wastes consigned by each user”, as specified by Article 6 of the Ministerial Decree of 20/04/2017.
In particular, the weight is measured by means of approved balances or electronic/computerized weighing systems on the elevators installed on board the collection truck. Weighing, carried out more frequently for large size bins, is the complex tariff model that guarantees by far the greatest precision; nevertheless, fitting out the vehicle to weigh the waste on board is a complex and extremely costly process.
In order to implement the volumetric calculation of wastes, used more often in the door to door collection, the municipality distributes bags or bins with a specific capacity to the users, e.g. a 50 litre bag or 30 litre bin, which corresponds to a fixed quantity of RSU and has a set volumetric coefficient. A container with a certain capacity manages to contain 5, 10, or 15 kg of RSU, to give a few examples. The number of times the tub is emptied or the number of bags assigned by the users is then identified and recorded. Less precise than direct weighing, volumetric calculation however offers the advantage of much reduced costs; moreover, over the long term, small weighing errors are compensated for by even more accurate calculation models and thus similar results are reached at the end of the process.
Deciding which model to adopt is fundamentally important for the municipality considering the pay as you throw tariff:
♦ the tariff model is the last element in the whole pay as you throw process and influences its choice;
♦ every area needs its own collection process and, consequently, the appropriate calculation method: the requirements of large cities, where there are users grouped into numerous residences, are different to those of small municipalities, where the majority of residential users consist of small houses, detached properties or blocks of flats with few residences;
♦ further determining factors are the physical features of the area: narrow roads, inclines or, on the contrary, broad wide roads have a different impact in assessing the process to adopt.