Geophysical Investigation at the COMPORTA WWTP SAT-MAR Facility, Portugal, Demo Site Subtitle
As part of the ongoing investigations at the Comporta Demo site in Portugal, the LNEC team performed geophysical surveys on May 5th, 7th, 12th, and 19th 2025, focusing on the infiltration basin and surrounding upstream and downstream zones within the SAT-MAR system.
The primary aim of this study was to investigate the infiltration pathway of secondary TWW through the vadose zone into the underlying aquifer, and to delineate a possible contamination plume in the saturated zone. To achieve this, geophysical surveys were deployed across the infiltration basin as well as in the upstream and downstream areas.
The upstream zone was considered as a reference area representing the natural background conditions of the aquifer system, unaffected by the infiltration process. In contrast, the downstream area was investigated to track the subsurface distribution and potential migration pathway of the infiltrated TWW, allowing for a comparative assessment with the upstream (reference) conditions.
Additionally, hourly geophysical readings on three parallel profiles crossing one of the infiltration basins were conducted to provide temporal data on infiltration dynamics. These frequent measurements were designed not only to monitor the infiltration process in detail but also to estimate the infiltration rate over time. A further objective of the study was to visualise the potential migration of contaminants during infiltration and to assess the recharge plume, particularly its influence on the depth of the water table.
Moreover, the 4th sampling campaign of April 2025 was completed, started on April 3rd and continued on the 17th and 24th. In this campaign, LNEC and AgdA teams have collected samples from the treated wastewater effluent, groundwater at four piezometers and soil water samples from the -25 cm and -50 cm depths of the unsaturated zone at six different points.
To know more about the Comporta Demo Site, watch the full interview with our partners.
