Improving the quality of Europe’s groundwater sources
A better understanding of groundwater pollution to protect and enhance water quality is urgent. Organic and inorganic chemicals, as well as pathogenic contamination of groundwater due to human activities, is a growing concern. A report from the European Environment Agency(opens in new window) found that 26 % of the European Union’s groundwater supplies have been impacted by chemical pollution. Fertilisers and pesticides in farming are among the most common source of contaminants, but industrial and urban activities also have a footprint. Analysis shows sources are polluted by a noxious cocktail of plasticisers, halogenated compounds, pharmaceuticals, personal care products and industrial compounds, toxic heavy metals, and pathogens. Research fellow at the Institute of Environmental Assessment and Water Research(opens in new window) (IDAEA), and an UPWATER(opens in new window) project manager, Eike Thaysen(opens in new window) explains: “These contaminants can harm the environment for a long time, and fixing the damage is difficult and expensive. So, we need cost-effective and affordable measures to prevent and mitigate pollution and to get these measures in place as soon as possible.” But to do so requires evidence-based policymaking which draws on robust field data, which is where the project comes in.
Complex issues of groundwater contamination require a combination of approaches
UPWATER set out to develop a four-pronged approach(opens in new window): developing monitoring and modelling methods, mitigation solutions, and prevention methods. “We wanted to build on and further develop existing tools and technologies, and bring together a variety of methods to get a clearer picture of the contamination of European groundwater bodies, enabling the design of adequate improvement strategies,” says Thaysen. The UPWATER team compared grab sampling with different passive sampling methods. “Grab sampling in groundwater monitoring involves collecting individual water samples at a specific location and time, which then provides a snapshot of the water quality at a given moment,” she adds. The project used passive sampling, in which the contaminants bind onto sorbent material(opens in new window). Thaysen explains: “As passive samplers are deployed for several days to weeks, this process allows the accumulation of contaminants over time, providing a time-integrated and hence more representative sample of the environmental concentration in a given water body.” Another activity undertaken by IDAEA concerned the use of biochar wetlands in Barcelona, Spain, to treat secondary treated wastewater treatment plant effluent which acts as a contributor to local river and groundwater contamination. Biochar acts as a porous, low-cost substrate that traps and facilitates biodegradation of nutrients, organic pollutants, viruses and heavy metals. “Remarkably,” notes Thaysen, “the biochar wetland pilot managed to remove over 80 % of the studied contaminants during the warm period, at 400 mm daily hydraulic loading.”
Giving decision makers the tools they need to protect the EU’s groundwater network
The project brought together specialists from different domains across Europe. “It was a comprehensive project that looked at keeping our water supplies safe, from multiple angles,” remarks Thaysen. The tools tested provided accurate and timely data on groundwater quality, along with suggesting cost-effective ways of mitigating and preventing the impact of pollution, into the hands of decision makers. “The high impact of UPWATER is the outcome of the work of dedicated researchers innovating and collaborating closely with local stakeholders to improve the quality of our groundwater systems. Of course, the work goes on, we will not stop here!”
