Humus & Associés





Location: Toulouse

Sector: End of life

Date of creation: 2012

Date of analysis: June 2020

Project maturity: viable

Between prevention and management of local bio-waste, the association is committed to recovering organic matter in the city in the Toulouse region.


The Humus & Associés association was created in 2012, at the initiative of an environmental coordinator who wanted to set up a project to recycle kitchen waste. The association has created a partnership with Toulouse Métropole, a public establishment for inter-municipal cooperation made up of 37 municipalities, in order to propose a solution for collective composting within local authorities. This historic partnership has been renewed from 2020 to 2024, and allows the association to be the supporting actor for the collective composting facilities of Toulouse Métropole.

Map of Toulouse Métropole

– 250 composting sites installed since 2012 with Toulouse Métropole (+ other local authorities)

– 1 residence is between 15 and 20 and up to 40 user households, i.e. 200-300 L and up to 1000 L of compost per year. 

– 1 collective restaurant means up to 1000 meals per day, i.e. 2000 to 3000 L (1 to 2 T) of compost per year.

  • Recycling

Toulouse and its surroundings is a densely urbanized area. Indeed, in 2016, 66.9% of the housing was collective housing (apartment type). [1] An inhabitant in France produces on average 354 kg of household waste per year, of which about half is bio-waste. [2] With more than 760,000 inhabitants in Toulouse Metropole (all types of housing combined), more than 90,000 tons of biowaste is produced each year by all inhabitants living in apartments. [1]

Humus & Associés has partnered with Toulouse Métropole to offer a solution for composting this bio-waste to the residences of all 37 municipalities. By installing composting sites within each residence, the association enables the recovery of local organic matter and shared management. 

For more information on what compost is and how to compost successfully, Humus & Associés has dedicated a page to it on their website.

project operation

To listen to testimonials from residences that have installed composters, you can watch the video at the very bottom of the article ! 

The actions of the association are divided into 3 main areas: awareness & animation, support for the installation of composters and professional training. 

Humus & Associés aims to raise public awareness about environmental issues, including food waste and composting. The association organises a wide variety of events such as information stands, practical workshops, workshop-conferences in companies … 

For example, in November 2019, during the European Week for Waste Reduction, the association intervened at the Banque Postale, at a market and at the Zero Waste Village created by a municipality near Toulouse to present their local composting system and how to make quality composting at home. 

The association also has a bio-waste information space. This resource and information centre allows citizens to learn about the recovery of organic matter.

The main activity of Humus & Associés, thanks to their partnership with Toulouse Métropole, is to set up composting sites within residences. It is a voluntary and civic-minded approach on the part of the residences to call on the association to help them set up a local composting site. Today, 250 residences in Toulouse Métropole have installed composting sites with the help of the association.

The association does not provide the material and does not take charge of the installation of the composter, this is the responsibility of Toulouse Métropole. Once the composter is installed, the association offers training and support to help the residents of the residences to develop good habits to maintain their compost and make the project last in the long term. The good level of the composting process is also guaranteed thanks to a person appointed as a referent, who can follow further training to become familiar with composting methods. 

The compost can only be used within the residences. Indeed, following the decree of April 9 th, 2018, the materials composted in the context of local composting must be used locally for the own use of the managers of this compost. The term “local composting” means composting that brings together individuals and/or associations and/or catering professionals and/or communities, producers of kitchen and table waste. [5] Thus, all kitchen leftovers as well as green waste from gardens can be recycled into compost for residents. On average, 15 to 20 households take part in the maintenance of the composting site, generating between 200 and 300 L of compost per year, which remains easily absorbable. Thus, the compost can be used by the residents of the residence for their own use but also to amend the soil, flower beds, hedges of common green spaces. 

Such an approach has a real social interest. It allows to set up a common project that makes sense and is useful for everyone. It is necessary to set up a certain organization to achieve autonomy within the residence to self-manage the compost. It is a way to recreate a link, a pretext to recreate a dynamic in the residences, and sometimes, the first steps to organize a shared garden.

Residential garden with composter 

The association is extending its approach to collective catering, such as company canteens. It is working with the Pro-portion association upstream to raise staff awareness of food waste and how to reduce it. After assessing the amount of bio-waste thrown away each day and the practices of kitchen staff, Pro-portion proposes an action plan to reduce food waste by at least 10% in the first year. Humus & Associé can then propose a composting site with adapted dimensions, which reduces the company’s investment cost. 

The association generally works with a collective catering canteen for one year, the time it takes to raise awareness of composting, reorganise the kitchen and service chain to limit food waste and set up the composting site. This system is suitable for company canteens that distribute up to 1,000 meals per day, as all the compost generated (between 1 and 2 tonnes per year) can be used internally (by employees and for the company’s green spaces). If the company has green spaces, it can also recover its green waste by incorporating it into the compost. 

Green waste is in fact bio-waste present in very large quantities and cannot be recovered by the waste collection centres. In 2013, 5.9 million tonnes of green waste were accounted for by ADEME in France, 60% of which end up in waste collection centres. [4] Humus & Associés has therefore decided to propose a solution to the region’s waste collection centres to enable them to recycle green waste into compost. The association also wishes to carry out awareness-raising actions among gardeners of public green spaces, in particular so that they can recycle their green waste themselves rather than taking it to a waste collection centre. This allows to reduce the transport of waste and to reduce the quantity of discarded waste that will be incinerated or buried in a waste disposal site. For example, lawn mowing can be used as mulch to protect the soil or grass can be cut less to restore natural meadow areas. An educational garden has been created in a waste disposal site to highlight this type of solution.

The association offers multiple professional training courses: 

– for the referents of collective composting sites (residence or collective catering). The designated person will be able to lead the group in order to respect the composting process and obtain a quality compost. 

– to become a “guide or master composter” and to train others yourself. This training over several days allows you to obtain a recognized diploma. The training covers in particular the technical and practical principles of domestic management of garden and kitchen waste and information for different audiences.  

A maturing compost

Brown (plant matter) providing the carbon resource for the compost

Shared kitchen garden installed in a residence 

A shared garden in a Toulouse residence

sustainable approach

Composting has several environmental virtues including : 

  • the recovery of organic waste that would be incinerated or landfilled
  • improvement of soil quality (nutrient and structural)
  • increasing biodiversity in soils (this encourages the presence of decomposer fauna and flora)
  • substitution of chemical fertilizers


Local composting allows its users to be self-sufficient in their compost supply: no transport, no mechanical composting that consumes energy.

The recovery of green waste by gardeners also limits the quantity of bio-waste thrown away and reduces the number of return trips to the waste collection centre.

According to a recent ADEME study, the average direct cost of raw material losses and wastage is 0.27€/meal. If we add the indirect costs (in particular the time and energy consumed in preparing meals, waste bill), the amount comes to 0.68€/meal. [3] 

Thus, there is a real economic interest in working to reduce food waste and to put a compost to valorize organic waste. The association has determined that the investment required for the composting site, support and training, compared to the collection costs, are 5 to 10 times less in time and money. On average, in 3 years, the cost of joint actions to reduce waste and the installation of the composting site is amortised in relation to the collection costs, whether for local authorities or businesses.

Setting up a composting site makes it possible to revitalize a residence by bringing its inhabitants together around a common long-term project. This often helps to recreate social links since it is necessary to set up an organisation between the residents. 

The association makes the general public and businesses aware of the issues of food waste and composting. 

Within the collective canteens, the composting site makes it possible to free up working time for the staff. The skills acquired are valued and recorded on their job descriptions. The management of the composting site becomes an integral part of their job.

replicability and future perspectives

The difficulties of the project lie upstream: the steps are long, tedious and prohibitive for the installation of the composter in residences. As it is a collective request from the residences, it is necessary that all the inhabitants agree, have the project voted on by the trade union council and have the agreement of the municipality.

However, once this stage is over, the project can be set up and, thanks to the high level of support from the association, is always a great success. Indeed, the site referents have to follow several trainings, which guarantees a good composting process. Thus, since 2012, all the composting sites installed have been a success. No site has been transformed into a landfill or garbage dump, as some might fear when such a project is set up. 

For collective catering, there are unfortunately few associations that provide support such as Humus & Associés. The only actors that could be described as “competitors” are bio-waste collection companies, their work is complementary to that of the association. Indeed, local composting is justified below a certain volume of waste produced. For example, when a canteen serves more than 1,000 meals a day, the amount of bio-waste produced becomes too large. Composting then becomes a constraint and no longer a relevant solution for the employees who take care of it. Thus, the solution proposed by the association is ideal for small structures. For larger structures, a short circuit collection and composting system proposed by Les Alchimistes (see article) for example is an ideal solution to recycle their bio-waste. 

The association aims to continue to set up composters in the residences of Toulouse Métropole. In particular, it wishes to find suitable solutions for ultra-urbanised areas without green spaces, by setting up composting sites in public spaces for example. It also wishes to develop its activity more with collective catering and producers of green waste, in order to forge a solid link between kitchen bio-waste and green bio-waste, which allows for quality composting. Indeed, in order to have a quality compost, it is necessary to combine green waste rich in carbon with food leftovers, rich in nitrogen. 

The anti-waste law for a circular economy has brought forward the date of generalization of the sorting at source of bio-waste to December 31, 2023. [6] All producers of bio-waste will be obliged to sort it at the source (even private individuals). Local authorities must propose solutions to citizens and businesses to be able to sort bio-waste. A relevant outlet is therefore local composting. Thus, the association Humus & Associés could have a key role in the implementation of such approaches, thanks to its experience of over 8 years. In this context, the setting up of a composting site within a residence would no longer be a voluntary step on the part of its inhabitants but rather a necessary service offered by the municipality. Therefore, the success of such a project will depend on the motivation of the residence to get involved or not in the composting of its bio-waste. 

Our meeting with the Humus & Associés association was very enriching. We discovered the advantages of local composting. 

Its work is complementary to companies such as Les Alchimistes since it offers composting solutions on a smaller scale. This makes it possible to reduce as much as possible the economic and environmental costs of the logistics and transports required for the collection and composting of bio-waste. Finally, the green spaces present in the residences allow an easy valorization of the compost.

Copyright CirculAgronomie 2020