Hydrochemical and Isotopic Monitoring Dataset of Groundwater, Surface Waters and Wastewater of a Wastewater treatment Plant (2013–2024)

The dataset contains hydrochemical and isotopic data collected between 2013 and 2024 during a long-term environmental monitoring program associated with a wastewater treatment plant (WWTP) located in the Pisa alluvial plain (central Italy). The monitoring activities aimed to evaluate groundwater quality and to assess potential interactions between the wastewater treatment processes and the surrounding aquifer system. The dataset includes: groundwater samples from monitoring wells and piezometers, surface runoff waters, wastewater samples collected along the treatment process. For each sample, the dataset reports field parameters, chemical analyses and isotopic tracers. The Site The monitoring site is located in the eastern sector of the Pisa coastal plain (central Italy) within an industrial area where a wastewater treatment plant processes both municipal and industrial effluents. Hydrogeological setting The hydrostratigraphic structure includes: - a shallow silty-clay sequence that acts as a regional confining unit; - an underlying artesian sandy aquifer; - a deeper multilayer confined aquifers composed mainly of coarse alluvial deposits. These permeable horizons allow groundwater circulation, while the fine-grained layers locally control vertical hydraulic connectivity. Monitoring network and sampling points The monitoring network includes groundwater, surface water and wastewater sampling locations. Code Description B1 Shallow monitoring piezometer B2 Shallow monitoring piezometer B3 Shallow monitoring piezometer GR2 Monitoring piezometer located in the chemical treatment section PA Deep monitoring well screened in two confined aquifer levels SM Surface runoff water SV Surface runoff water SRC Civil wastewater SRI Industrial wastewater EQU Equalization basin SRD Wastewater from a nearby slaughterhouse COOP Wastewater from a nearby frozen food storage facility S Final discharge of the wastewater treatment plant