#01 | Reclaimed water in times of water stress

Author: Sara Espinosa (Cetaqua Andalucía)

Water stress has become one of the major and most concerning pressures nowadays in Europe having a direct impact on freshwater and natural resources in terms of quality and quantity. As a consequence, aquifer overexploitation, aquifer salinization, decrease in river flows and eutrophication are, among others, problems that the population and environment are facing.

Water stress means that there are not enough freshwater resources of sufficient quality to satisfy the demands of the environment, agriculture, public water supply and tourism activities.

According to the European Environment Agency, about 20% of the European territory is affected by water stress during an average year and the European Commission reports that over 50% of the population in the Mediterranean region is affected by water stress in summer. Moreover, the situation is expected to worsen within the climate crisis.

What if reclaimed water could contribute to relieving these pressures somehow?

Reclaimed water is an alternative resource, that could happen to be a great relief to these pressures being a reliable resource for increasing the available water resources and providing significant environmental, social, and economic benefits such as relieving the pressure of discharge from WWTP to sensitive areas, reducing investment costs, energy consumption and greenhouse gas emissions.

Furthermore, reclaimed water is an alternative resource that can provide stability of annual supply by not depending on seasonal weather events and being able to cover peaks of water demand.

Reclaimed water in numbers

According to the European Commission, the EU potential for water reuse is estimated in the order of 6 billion cubic meters, which means six times the current volume (1 billion cubic meters of treated urban wastewater is reused annually representing 2.4% of the treated urban wastewater effluents and less than 0.5% of annual EU freshwater withdrawals).

In Spain, as an example of huge potential for further uptake, between 5 and 12% of its effluents are currently reused.

Increasing this volume would mean bringing environmental, social, and economic benefits, contributing to improving the status of a circular economy.

What does it take and what needs to be done?

There are still some concerns about the risk of implementing its potential uses such as managed aquifer recharge, and the main reason is the uncertainty regarding risk transfer from reclaimed water to sensitive final uses (JRC Science for Policy Report JRC 09291).

Therefore, there are 3 main actions that must and need to be carried out in order to boost the use of reclaimed water:

– Awareness and social acceptance: from education by the scientific community and involving key stakeholders.

– Commitment of the public administrations to streamline the bureaucracy in providing necessary permits for the different uses of reclaimed water (until the date, sometimes it could take almost a year).

– Adapt the policies to the real and proven risks of its use, since both the quality control parameters and its thresholds for some of its uses (such as managed aquifer recharge) are more restrictive with respect to what has been demonstrated in different demo sites, meaning a stopper for its implementation(EU 2020/741 and RD 1620/2007 (in Spain); Donn et al (2020)).

Accordingly, the key element to boosting and promoting the use of reclaimed water to fight against water stress increasing water availability is making safety management of the environmental and sanitary risks associated with water reuse.

If you want to learn more about how the LIFE Matrix project provides a solution to boost reclaimed water use check the link!