The project targets the citizens of Hernani. Currently, there are around 700 family units that self-compost at home and around 1,100 that participate in community composting.

The people who participate in the project are especially beneficiaries, since, due to the regulation of community composting that the Basque Country government made by decree, they are the only ones who can use the compost.

The entities involved in the project are, on the one hand, City Council of Hernani through the Waste Office, which belongs to the Environment Unit, and, on the other, the citizens of Hernani as participants in the composting process.

The governance of the project is carried out from the City Council of Hernani through the Waste Office, which belongs to the Environment Unit. The City Council, through the municipal company Garbitania Zero Zabor, has a contracted person who controls the composting process with periodic actions such as controlling the temperature, traceability and possible incidents.

On the other hand, the external company that manages the municipal gardening is responsible for transporting the compost from the composters to a municipal space where it has just matured, and, subsequently, to another space where, once ready, it is collected by the people participating in the project.

The City Council uses pruning residues, leaf litter and other plant remains as structuring material and deposits them in a compartment of the composters for the people participating in the project to use.

To encourage family units to self-compost their organic waste fraction, City Council provided composters free of charge to all those who signed up for the program, in addition to offering them a composting course.

One of the main actions developed, the "door-to-door" waste collection system, has allowed Hernani to go from a household waste separation rate of 32 to 78%.

Hernani's City Council established differentiated municipal waste rates, with a 40% reduction for people who participate in community composting.

In the beginning, the community composting system did not work properly. There were responsible people who cared about each part of the process, while others simply poured organic matter into the composter. Therefore, there were soon problems with flies, odors, etc.

Due to the high cost involved in outsourcing waste management and with the desire to close cycles internally, the possibility of creating a municipal composting plant was considered. However, the Guipúzcoa Provincial Council refused to obtain the necessary permits, arguing that the municipality of Hernani could not have the competence to decide on the implementation of this infrastructure.

The Basque Government regulated community composting through a decree in 2019, which poses a threat to the project, in that it requires strict conditions to be able to carry out the activity that are difficult to comply with despite the fact that there is professional control of composting. Specifically, it only allows people who participate in the composting process to collect compost, and they can only use it in gardening. This decree has been appealed to the courts, but so far there has been no resolution in this regard. This inconvenience means that the project is at a point where, despite more people being interested in participating, it has been decided not to increase its size.

Since at the beginning it was possible to verify that the self-management of composting by citizens was not entirely effective, the need was observed to hire a person to control the entire process: turning the compost, controlling the temperature, pH and humidity, etc.

The initial composting tanks were replaced by larger ones, as it was necessary to expand the project. These tanks are wooden houses that have been integrated into the landscape and have a larger capacity. They also have several compartments to pour the organic fraction, to start the composting process and to deposit the structuring material.

It has been found that using the concept of bonus to refer to the reduction in waste rates for people participating in the community composting process is not the most appropriate, since it is considered that it may have caused some people to participate in the project for economic benefit and then not be sufficiently involved in the composting process. It is considered more appropriate, therefore, to speak of differentiated rates , since the fact of composting implies work for the person participating in the process and a job saving for the municipality.

To facilitate the task of waste separation, any organic waste is allowed to be dumped into the composter, even if it is slow-decomposing. It has also been found that bags, even if they are biodegradable, negatively influence the purity of the compost, which is why composting is not allowed. Thanks to these practices, a compost purity of 99.76% has currently been achieved.

• Composting manual
• Guide to the correct classification of waste