Superlative levels of arsenic (As) in groundwater and sediment often result from industrial pollution, as is the case for a coastal aquifer in Southern Italy, with a fertilizer plant atop. Understanding conditions under which As is mobilized from the sediments, the source of that As, is necessary for developing effective remediation plans. Here, we examine hydrogeological and geochemical factors that affect groundwater As concentrations in a contaminated coastal aquifer. Groundwater has been subject to pump-and-treat at a massive scale for more than 15 years and is still ongoing. Nevertheless, As concentrations (0.01 to 100 mg/L) that are four orders of magnitude more than Italian drinking water standard of 10 μg/L are still present in groundwater collected from about 50 monitoring wells over three years (2011, 2016, and 2018). As was quantified in three different locations by sequential extractions of 29 sediment cores in 2018 (depth 2.5 m to −16.5 m b.g.l.), combined with groundwater As composition, the aqueous and solid partitioning of As were evaluated by partition coefficient (Kd) in order to infer the evolution of the contaminant plumes. Most sediment As is found in easily extractable and/or adsorbed on amorphous iron oxides/hydroxides fractions based on sequential extractions. The study shows that As contamination persists, even after many years of active remediation due to the partitioning to sediment solids. This implies that the choice of remediation techniques requires an improved understanding of the biogeochemical As-cycling and high spatial resolution characterization of both aqueous and solid phases for sites of interest.

No abstract

No abstract

This study is focused on the analysis of seasonal and annual variability in groundwater levels of the coastal aquifer of Castelporziano Presidential Estate, a protected area of 59 Km2 located in the periphery of Rome. A comparison with the local trends of rainfall at “Castello” gauging station at different time scales (monthly, seasonal and annual) has been carried out. The results highlight differences between the coastal area and eastern and northern sector of the Estate. Indeed, the seasonal effect due to local meteoric recharge is direct and regular during the year in the coastal area in respect to the eastern and northern sectors of the Estate. Moreover, annual steady regime and multi-year trend of groundwater levels suggest the contribution from the adjacent volcanic aquifer of Albani Hills. In the latter case, the regional circulation of groundwater is affected by the effects of intense withdrawals. The maintenance of the monitoring network will allow to define the flow paths of the groundwater that characterize the coastal aquifer of Castelporziano.

<p>Water resources management is becoming increasingly challenging under current climate change. Water utilities need to assess planning adaptation strategies aimed at sustainable water resource exploitation. In this study, we estimate the potential impacts of climate change on hydrological variables and future spring discharge availability. Specifically, we exploit an empirical regressive model based on the statistical relationship between Standardized Precipitation-Evapotranspiration Index (SPEI) and minimum annual spring discharge, in combination with Regional Climate Models (RCMs) provided by the EURO-CORDEX initiative. In this regard, two Representative Concentration Pathways (RCPs) are considered, RCP4.5 (intermediate emissions scenario) and RCP8.5 (high emissions scenario), as well as two future time horizons, namely the near future 2021-2050 and the far future 2041-2070. Then, after bias correction of the so estimated minimum spring discharge values, the curves relating spring discharge and reliability in satisfying water demand are assessed. We carried out our investigation for karst aquifers located in the Italian Apennines, which are used for the water supply system of the city of Rome (Italy) and the surrounding areas, managed by ACEA Ato2, serving over 4 million users. Overall, the results indicate a general decrease in the demand that can be satisfied with high reliability, pointing out significant potential impacts of climate change on water availability on both near and far future. The proposed methodology could be a useful tool for water managers, since it provides a support for planning adaptation measures aimed at minimizing future socio-economic impacts of climate change.</p>