Technological Centre

At CETIM we obtain high quality reuse water in our R&D projects

We review the European and Spanish regulations that establish the minimum requirements for water quality and control for its reuse, and how this affects LIFE GREEN SEWER and LIFE DRAIN RAIN.

Laboratory water sampling.

Over the past few years, drought and water scarcity have emerged as significant concerns for global society. In response to these challenges, the European Union has implemented legal measures addressing the pressures on water resources. One notable example is Regulation (EU) 2020/741, which came into force in June 2020 and became applicable in June of this year. This regulation establishes minimum water quality and monitoring requirements for the reuse of treated water in agricultural irrigation.

These minimum requirements encompass the frequency of routine monitoring and the validation of monitoring characteristics, categorized according to the water quality class. Thus, following European legislation, the quality of reused water is classified as follows:

  • Class A: This classification entails the most stringent restrictions, indicating the purest water suitable for reuse in food crops consumed raw and in crops where the edible part is in direct contact with reclaimed water


  • Class B: Water in this class is suitable for reuse on food crops consumed raw when the edible part is produced above ground level and does not come into direct contact with reclaimed water. It is also applicable to processed food crops and non-food crops, encompassing all irrigation methods.


  • Class C: Similar to Class B, with the difference that the irrigation system specified here is drip irrigation.


  • Class D: This corresponds to the least restrictive classification, allowing water reuse for crops intended for industry, energy, and seed production.


In Spain, Royal Decree 1620/2007 regulates reuse for agricultural irrigation, urban uses, industrial uses, recreational and environmental uses. A comparison between both regulations reveals that Spanish law considers a broader spectrum of reuse areas and is less restrictive compared to European regulation. Additionally, the European regulation mandates validation control, leading to a more comprehensive evaluation of microbiological pollutants.

How do laws affect our water treatment R&D projects?

In the project we are leading, LIFE GREEN SEWER, we are researching the development and validation of a new secondary wastewater treatment system, allowing, at the same time, the recovery of energy and resources and reducing the presence of pollutants, costs and energy consumption. The project involves a consortium formed by CETIM, Emafesa, Magtel, Socamex  and the University of Barcelona.

After installation of a pilot plant at the EMAFESA wastewater treatment plant in Ferrol, we managed to eliminate 92% of the emerging pollutants present in the wastewater, with a removal rate of 90%. As a result, we obtained high quality treated water for agricultural irrigation class B, according to Regulation (EU) 2020/741.

LIFE GREEN SEWER pilot plant.

Another success story is our LIFE DRAIN RAIN project, in which we developed a new system for treating particularly polluted water (port esplanades, naval industry, machinery parks, etc.), which eliminated the pollution that rainwater carries with it, causing significant damage to the environment. In addition, the system made it possible to store this rainwater and treat the runoff water for subsequent reuse. The technologies developed were tested in two different places: on the esplanade of the port of Ferrol and on the shoulder of a road in Murcia.

This water obtained in the project reached the quality required by legislation for urban uses (irrigation of green areas, street washing, fire-fighting systems or industrial vehicle washing) according to Spanish law, but it could also be used as reuse water for growing food for raw consumption, non-food crops or crops for industry and energy production, thus applying class B and C of European regulations.

Implementation of LIFE DRAIN RAIN in Calasparra, Murcia.

The importance of legislating

The adoption of Regulation (EU) 2020/741 has established a legal framework for member states that promotes agricultural water reuse, ensuring the protection of the environment, human and animal health. It also contributes to the sustainable and responsible use of water resources, promoting the circular economy of water and mitigating the effects of climate change.