57 quality incidents in the Ebro River Basin. Achieving environmental sustainability step by step

Every year, the Hydrographic Confederation of the Ebro (CHE) implements an action plan to prevent and reduce pollution of surface and groundwater in the Ebro River Basin and to protect the right of users (drinking water treatment plants, irrigation communities, industry, fish farms, hydroelectric power stations, wastewater treatment plants…and citizens themselves) to a water environment of appropriate quality. In line with a strategy geared towards innovation, the CHE took the decision to implement a network of automatic water quality alert and control stations. In 2014, over one million events and alarms were registered resulting in the detection of 57 cases of pollution. This detection and monitoring enabled the definition of a more effective contingency plan, thereby minimising the impact of pollution on the environment and guaranteeing both social and economic benefits for the population. The network ensures protection at the inlet to drinking water treatment plants and water of optimal quality for irrigation, industry, bathing, etc.

The Hydrographic Confederation of the Ebro (CHE), which operates under the aegis of the Ministry of Agriculture, Food and Environmental Affairs, is responsible for the management of the waters of the Ebro River Basin. With respect to water quality, the responsibilities of the CHE encompass both surface water and groundwater and its main function is to ensure that these waters are in good chemical and environmental condition.

Each year, the CHE implements an action plan in accordance with analysis of potential environmental impacts and the final use of the water (supply, irrigation and agricultural uses, industrial uses, aquiculture, recreational uses, hydroelectric power stations, wastewater treatment plants…).

This action plan centres around the environmental control networks of rivers, which are designed for periodic sampling of surface water masses using monitoring, operational or benchmark controls. In addition to the basic physicochemical indicators, biological (macroinvertebrates, diatoms and macrophytes), hydromorphological (indexes of river habitats and the quality of riverside wooded areas) and hydrogeomorphological indicators are determined.

The periodic sampling networks provide information on quality trends and highlight deviations in parameters. They enable the characterisation of the waterways sampled thanks to extensive historic data, sometimes going back more than 15 years. The Ebro River Basin has a number of “conflictive” points, where there is greater risk of adverse water quality incidents.

Some of these episodes may not be identified by periodic sampling and, at best, there is detection of the negative effect on biological communities. However, this effect does not facilitate identification of the origin of the problem. On other occasions, incidents are only discovered when, due to their great significance, they have a considerable effect on the aquatic environment (fish kills, problems at drinking water treatment plants, etc.)

This is why these points require special controls that enable rapid action and serve to help locate the possible cause of the incident and protect the rights of users to appropriate water quality.

Such exhaustive, decisive control is possible thanks to the quality alert network, comprising facilities that provide continuous information to a control centre on physicochemical water quality parameters (e.g., temperature, pH, ammonium or nitrate content, etc.). This makes it possible to monitor water quality trends and detect possible incidents.

These monitoring networks must comply with the different national regulations and European directives, including the Water Framework Directive (WFD) and the European Nitrates Directive, which establish a framework for the protection of different water masses and set out the necessary ecological and physicochemical criteria for preventing and reducing pollution, fostering sustainable use and improving the situation of aquatic ecosystems.

With this clear objective, in 1993 the CHE, committed to an innovative, pioneering strategy, undertook the implementation of a network of automatic alert and control stations to provide continuous monitoring of the quality of surface water, which is the basis for the current SAICA project. These stations are located at strategic points, mainly selected for the purpose of protecting water supply and controlling water quality at points of significant discharges. The SAICA network currently consists of a total of 28 stations, of which nine have already been adapted to incorporate new technologies and operational modes in order to achieve enhanced operation and lower maintenance costs.

In 2009, control systems began to be installed in reservoirs and in 2012, within the framework of the RIADE (Network of Environmental Indicators in the Ebro Delta), a control system was installed in the lower Ebro basin and the Ebro Delta region. This system enables the monitoring of flows and water quality in rivers, canals, lagoons, bays and wetlands.

Data monitoring and management is carried out from the control centre of the SAICA project. By way of illustration, in 2014, more than 12.5 million measurements were taken and over one million events and alarms were registered. This data resulted in 159 daily reports, 53 weekly reports, and 8 monthly reports on quality and operation. Thanks to these reports, a total of 57 quality incidents were identified, mostly related to increases in ammonium or conductivity caused by unauthorised discharges, wastewater treatment plant issues, stormwater or increases in flow rates.

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Salvador Romera, Maintenance Coordinator of the SAICA Ebro project – ADASA.
Mª Carmen Martínez. Chief Laboratory Officer of the SAICA Ebro project– ADASA.

Article published in: FuturENVIRO September 2015