Why do we need to care about transboundary aquifers and how do we solve their issues?

As the reliance on transboundary groundwater is increasing globally, it is important to understand and address the specifc issues raised by the assessment and management of transboundary aquifers (TBAs). Building on 20 years of TBA experience and through a three-pillar framework (assessment, cooperation-collaboration, shared management), the key elements to addressing TBA issues are described, including a multidisciplinary approach, identifcation of hotspot zones, local vs border-wide approaches, appropriate funding models, and an increased recognition of the role and value of each TBA

Why do we need to care about transboundary aquifers and how do we solve their issues?

As the reliance on transboundary groundwater is increasing globally, it is important to understand and address the specific issues raised by the assessment and management of transboundary aquifers (TBAs). Building on 20 years of TBA experience and through a three-pillar framework (assessment, cooperation-collaboration, shared management), the key elements to addressing TBA issues are described, including a multidisciplinary approach, identification of hotspot zones, local vs border-wide approaches, appropriate funding models, and an increased recognition of the role and value of each TBA

Hydraulic and geochemical impact of occasional saltwater intrusions through a submarine spring in a karst and thermal aquifer (Balaruc peninsula near Montpellier, France)

International audienceSubmarine springs are a common discharge feature of the karst aquifers along the Mediterranean coast. In some instances, occasional and localized saltwater intrusions can occur through the submarine spring and negatively impact the quality of the groundwater resource. The hydraulic and geochemical behavior of a submarine spring discharging into the Thau lagoon just offshore of the Balaruc peninsula near Montpellier, France has been characterized to determine the impacts of such phenomena to better understand the dynamics of a regional karst aquifer and improve its groundwater management. This work is based on both historical and new hydrogeological and geochemical data, illustrating 6 occasional saltwater intrusion events (from 1967 to 2014) in the Thau lagoon area (southern France). Hydraulic perturbation of the aquifer is propagated instantly within the Balaruc-les-Bains peninsula and reaches a distance of about 5 km upgradient within 9 days. Comparison of hydraulic heads during seawater intrusion events in 2010 and 2014 indicates an aggravation of the phenomenon with an increase in hydraulic head variations. In contrast, isotopic tracers (87 Sr/ 86 Sr, D/H, 18 O/ 16 O,) and Rare Earth Elements (REE) demonstrate that the geochemical impact of these inversac events is only observed at the local scale, but is still perceptible several years after the event. For example, some of the thermal wells had not recovered their initial geochemical state 20 and 40 months after the last two inversac events (2010 and 2014, respectively), suggesting a geochemical legacy of this phenomenon within the complex karst system. By contrast, an adjacent deep karst compartment 2located south of the study area is not affected by the saltwater intrusion and is characterized by distinctly different hydrodynamic behavior.Overall, this work onoccasionaland localized saltwater intrusions constitutes a key step in understanding the dynamics of this complex karstic and thermal aquifer and will support the management of the groundwater resource

PER- AND POLYFLUOROALKYL SUBSTANCE (PFAS) TRANSPORT FROM GROUNDWATER TO STREAMS NEAR A PFAS MANUFACTURING FACILITY IN NORTH CAROLINA, USA

We quantified per- and polyfluoroalkyl substance (PFAS) transport from groundwater to five tributaries of the Cape Fear River near a PFAS manufacturing facility in North Carolina (USA). Hydrologic and PFAS data were coupled to quantify PFAS fluxes from groundwater to the tributaries. Up to 29 PFAS were analyzed, including perfluoroalkyl acids and recently identified fluoroethers. Total quantified PFAS (ΣPFAS) in groundwater was 20−4773 ng/L (mean = 1863 ng/L); the range for stream water was 426−3617 ng/L (mean = 1717 ng/L). Eight PFAS constituted 98% of ΣPFAS; perfluoro-2-(perfluoromethoxy)propanoic acid (PMPA) and hexafluoropropylene oxide dimer acid (GenX) accounted for 61%. For PFAS discharge from groundwater to one tributary, values estimated from stream water measurements (18 ± 4 kg/yr) were similar to those from groundwater measurements in streambeds (22−25 ± 5 kg/yr). At baseflow, 32 ± 7 kg/yr of PFAS discharged from groundwater to the five tributaries, eventually reaching the Cape Fear River. Given the PFAS emission timeline at the site, groundwater data suggest the abundant fluoroethers moved through the subsurface to streams in ≪50 yr. Discharge of contaminated groundwater may lead to long-term contamination of surface water and impacts on downstream drinking water supplies. This work addresses a gap in the PFAS literature: quantifying PFAS mass transfer between groundwater and surface water using field data

Province-Paris. Topographie littéraire du xixe siècle

Entre province et capitale, la littérature du xixe siècle se plaît à multiplier les trajets. Chacun de ces deux espaces prend forme et sens par différence avec l'autre, dans un rapport tant de complémentarité que d'opposition. Depuis les "scènes" de La Comédie Humaine, l'imaginaire littéraire se construit sur cette ambivalence des lieux et des discours, par un renvoi en miroir des clichés positifs et négatifs : le paradis provincial où l'on meurt d'ennui ; l'enfer parisien indispensable aux grandes destinées. Ce volume rassemble vingt-cinq communications, pour la plupart présentées lors du colloque qui s'est tenu à Rouen les 19 et 20 mars 1999