Nitrate contamination leaves Spanish towns without drinking water

Given the complexity of remediation, the solutions involve prevention and supply-side action.

In the last few weeks, and as usual in the summer season, there has been an increase in the number of news items reporting drinking water supply problems in many municipalities in Spain. The cause, in addition to the typical population increase in these places in summer, is the nitrate contamination of aquifers, coming from the slurry used in agricultural and livestock production.

According to the Ministry of Health, 67,050 analyses carried out in 2019 on a national scale showed that the water was not drinkable and sources from the Ministry of Ecological Transition reveal that a quarter of the country’s groundwater stations measure a concentration of nitrates above or close to the potability threshold. In fact, Spain is one of the countries in Europe with the highest contamination of aquifers associated with nitrates, which has led to sanctions.

The problem with this contamination is the difficulty in remediating it, as Carlos Herrarte, head of Litoclean’s Madrid office, explains: “This is diffuse contamination, which means that there is no primary source that can be addressed, but rather that the contaminants are filtering into the groundwater from many different locations.

The autonomous communities and hydrographic confederations have tried to tackle the problem with programs that attempt to reduce the use of fertilizers, but they have not provided a real solution. Many municipalities end up opting for supplying drinking water to their population by tanker trucks or bottled water, which has a more negative impact on the environment due to CO2 emissions and waste generation. Litoclean appeals to the development of technology that allows citizens to have access to drinking water, as Herrarte explains: “Administrations have to look for effective solutions. One corrective measure that could work is to install a portable treatment plant in the same well that supplies the water, so that the groundwater resource can be used without resorting to external supply”.

Diffuse nitrate pollution is a problem of great magnitude that requires a serious commitment on the part of the administration so that dozens of towns in Spain can enjoy such a basic good as drinking water.