How methanization preserves water resources in Evian, France

Summary

A methanization site on the evian impluvium on the Plateau de Gavot transforms farm waste into biogas and fertilizer: a way of creating a local circular energy economy, protecting evian’s natural mineral watershed and reinforcing sustainable farming practices.

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“Water and energy are closely interlinked and interdependent. Energy generation and transmission require the utilization of water resources, particularly for hydroelectric, nuclear, and thermal energy sources. Conversely, about 8% of the global energy generation is used for pumping, treating and transporting water to various consumers,” wrote the United Nations during the 2014 World Water Day, where the theme was the link between water and energy. Because of this codependency, it is crucial to think up “integrated approaches and solutions to water-energy issues” that “can achieve greater economic and social impacts.”

At Evian, in France, a project of this type was introduced in 2015 on the 35 km2 of the impluvium of Danone’s natural mineral water brand, evian: Terragr’Eau Méthanisation.

The concept is simple: Terragr’Eau is a treatment platform for organic waste produced by livestock (manure and liquid manure), which is then transformed into biomethane and natural fertilizer. The process produces renewable energy, thus furthering the fight against global warming, and guaranteeing safe drinking water for more than 12,000 people living in the area. This is because the methanization site goes hand-in-hand with a cooperative, which evenly distributes the fertilizer produced by the site over farmland. In March 2017, Terragr’Eau injected its biomethane into the local gas network for the first time.

Developing green energy and protecting the resource

As we described in our report on the evian impluvium, the sustainable management of water and preservation of its quality are central to evian’s work in this area. To make this mission even more effective, a whole phalanx of local players and stakeholders (the evian brand, the Evian Country Community and 41 local farmers working on the catchment area) decided to launch the Terragr’Eau project under the aegis of APIEME (the association for the protection of the Evian impluvium created in 1992), and with the support of the Danone Ecosystem Fund.

Illustration of the Terragr’eau project

Illustration of the Terragr’eau project

Local farmers provide the methanization site or anaerobic digester (a process that transforms organic waste into biomethane) with 36,000 metric tons of waste produced by 2,200 animals, and then make use of the resulting natural fertilizer, known as digestate.

Once the agricultural effluents have been transformed into fertilizer and biogas, they can begin their second life. The digestate is spread over farmland to limit the use of artificial inputs (the first phase of manure spreading began in late February 2017), while the biogas supplies the district with locally-produced renewable energy. On March 14, 2017, it was injected into the GRDF gas network for the first time.

To date, production covers the annual energy consumption of 1,000 households. The methanization site thus provides numerous benefits. Biomethane, as a natural gas, emits no particles during combustion, and this contributes to better-quality air. It is also neutral in terms of greenhouse gas emissions. The aim is to reduce these emissions by over 2,000 metric tons of CO2 each year, representing a drop of 10% in emissions generated by agricultural activity in the Evian area.

And then, there is the use of the natural fertilizers produced by the biogas plant to nourish the soil, which helps to protect the ecosystem as a whole and thus to preserve the quality of the water resource. This is because the digestate is spread on a territorial scale through a collective effort, enabling newer, more efficient fertilization practices. All human and material means (including agronomic expertise and GPS guidance systems for tractors) are brought into play to guarantee a high level of control and traceability in the use of fertilizers.

In short, the project creates a circular energy economy in the territory: the energy produced is 100% local and renewable, and what was previously considered waste is given a useful second life. A good example of how water-related problems can be closely linked… and thus solved together.

To learn more about this project, you can also watch the video!

Photo credit
The methanization site in Evian, France — Ixalp Drones ©