First Field Sampling Campaign Successfully Completed in Barcelona

The CSIC team has successfully completed its first field sampling campaign, carried out over the last three weeks as part of the project activities. The campaign took place under particularly challenging conditions, as several extreme rainfall events occurred during the sampling period, causing the river to overflow its banks.

Despite these difficulties, the samples collected during this campaign will provide valuable insights into the impact of wet-weather conditions on both river water quality and groundwater quality. During heavy rainfall events, water from urban drainage systems is discharged into the river and can subsequently infiltrate into the aquifer. Understanding these processes is essential for assessing the interactions between surface water and groundwater and for quantifying the contribution of drainage discharges, sewer leakage, and river water to aquifer recharge.

A total of 28 water samples were collected from groundwater, drainage outlets during wet-weather conditions, sewers during dry-weather conditions, and river water under both conditions. Sampling within the sewer system was made possible thanks to the support of the Sant Adrià de Besòs City Council, whose collaboration was instrumental to the successful completion of the campaign.

In addition, 15 passive samplers were deployed within the aquifer to measure fluxes of PFAS, PMOCs, major ions, and metals. The comparison between the samples collected during this campaign and those that will be obtained when the passive samplers are retrieved, together with the information provided by the passive samplers themselves, will allow researchers to assess their efficiency and representativeness.

Furthermore, four groundwater samples were collected along the groundwater flow path for bacterial counts, providing additional information on the microbiological characteristics of the aquifer system.

The data generated during this first campaign will play a key role in the development and calibration of the project’s models and will contribute to a better understanding of contaminant transport and groundwater-surface water interactions in the study area.

One of the water-level sensors installed by the CSIC. The recorded data were downloaded during the sampling campaign.

Samples were collected from the sewer system under dry-weather conditions to determine whether sewer leakages affect groundwater quality in the aquifer.

Left: The river during an extreme rainfall event, when water levels rose significantly.
Right: One of the drainage system discharge points where samples were collected for water-quality analysis