Dynamic Numerical Assessments of Risk Control Strategies: Case Study in a Pb-Zn Tailing-Pond-Impacted Aquifer

Assessment of sustainable groundwater management under climate change scenarios using an integrated MODFLOW-NSGA-II framework: a case study of Sidi Okba Region, Algeria

From sources to solutions: An integrated framework for industrial risk assessment, subsurface contaminant dynamics, and Nature-Based remediation from RemTech Europe 2024.

Effective territorial preservation and contaminated site management require an integrated, multi-scale framework that bridges macroeconomic tracking with site-specific physics, chemical forensics, and biotechnology. Within this framework, this Brief Communication synthesizes seven key advancements discussed at RemTech Europe 2024. Environmental assessments presented during the meeting span from the macro-regional level with soil pollution inventories in the Western Balkans to localized atmospheric Natural-Hazard Triggered Technological Accidents (NaTech) risk modeling for industrial facilities. At the subsurface scale, the dynamic interplay of groundwater table fluctuations controls light non-aqueous phase liquid (LNAPL) migration, while hydrogeological fingerprinting isolates distinct anthropogenic PFAS sources. Addressing these complex matrices, biotechnological assessments elucidate how emerging graphene-related nanomaterials interact with biodegradative enzymes to evaluate targeted biodegradation pathways. Finally, the scale transitions to nature-based engineering solutions, utilizing urban green gutters for stormwater retention and quantifying the long-term recovery of ecosystem services through spontaneous quarry revegetation. The integration of modeling, forensic analysis, biotechnologies, and nature-based solutions provides actionable insights for environmental risk management and sustainable land-use planning. Ultimately, this collective evidence offers regulators and stakeholders an operational roadmap to accelerate the transition from hazard identification to scale-appropriate, climate-resilient remediation strategies.

Risk assessment and techno-economic feasibility of managed aquifer recharge under high clogging conditions for pasture irrigation: a case study of the Koksu River Basin

This study evaluates the operational efficiency of Managed Aquifer Recharge (MAR) systems utilizing open-type infiltration structures in the Koksu District of Southeastern Kazakhstan. Field investigations conducted between 2022 and 2024 characterized the filtration hydrodynamics and mechanical clogging kinetics within the vadose zone and the underlying gravel–pebble aquifer. Our methodology integrated the use of local surface water and groundwater to provide a high-resolution assessment of recharge performance under authentic hydrogeological conditions. The results demonstrate a significant, multi-stage degradation of infiltration capacity, primarily driven by mechanical clogging. Initial infiltration rates (12.0–6.0 m/day) underwent a sharp decline to 4.1–2.0 m/day within 92 days of operation, eventually plateauing at a critical minimum of 0.8 m/day. This reduction correlates with the accumulation of an 11 mm fine-grained sediment layer, induced by surface water turbidity (18–38 mg/dm 3 ), resulting in a six-fold reduction of the infiltration coefficient. Concurrently, MAR operations facilitated a maximum groundwater rise of 3.1 m, while total dissolved solids (TDS) of groundwater were effectively halved through freshwater dilution, significantly improving water quality. Economically, the implementation of the MAR system increased regional water availability by 20–25%. These findings establish that while the unconfined aquifers of the Koksu Basin possess high potential for seasonal storage, their long-term viability is contingent upon systematic mechanical regeneration. This research provides a robust technical framework for MAR deployment to support livestock watering and sustainable pasture irrigation in arid Central Asia.

Technical design and hydrogeochemical evaluation of a stormwater-based managed aquifer recharge pilot site in an intensively cultivated region (Hallertau, Germany)

Managed aquifer recharge (MAR) with stormwater remains underexplored in rural settings due to uncertainties related to source-water variability, treatment performance, and groundwater-quality impacts. This study presents the design and hydrogeochemical evaluation of a stormwater-based MAR pilot site implemented in 2024 in Hüll (Bavaria, Germany), a flood-prone agricultural region underlain by a heterogeneous Tertiary aquifer. The system integrates a stormwater retention basin, treatment units, an infiltration well, and a comprehensive monitoring framework combining multi-parameter online sensors, detailed laboratory analyses, and contextual information on catchment activities. Hydraulic testing confirmed strong aquifer heterogeneity but also demonstrated high injectivity of the target formation. Hydrochemical monitoring evaluated raw water characteristics, treatment efficiency, and groundwater responses. The treatment unit effectively removed pesticides and substantially reduced suspended solids, while stormwater nitrate concentrations were consistently lower than those in groundwater, indicating dilution potential during recharge. The pilot demonstrates that rural stormwater can serve as a reliable MAR source under variable hydrological conditions. The integrated design and monitoring concept provides a transferable framework for similar agricultural regions and supports future calibration of site-scale hydrogeological and reactive transport models.

Full-Cycle Ecological Damage Assessment Framework for Sudden Water Pollution Accidents: Multi-Model Coupled Prediction and Three-Dimensional Quantitative Evaluation with a Case Study of Tailings Dam Breach

Sudden tailings dam breaches trigger large-scale heavy metal compound pollution in coupled surface water–groundwater systems, requiring systematic full-cycle ecological damage quantification tools applicable to diverse contamination types. This study constructs an integrated full-cycle ecological damage assessment framework for sudden water pollution accidents, integrating three core modules: multi-model pollutant migration prediction, multi-scale aquatic biological damage diagnosis, and three-dimensional ecological-economic loss accounting. The framework adopts a modular design that can potentially accommodate heavy metals (Cd, Cr, As, Pb) and organic pollutants such as polycyclic aromatic hydrocarbons (PAHs), with standardized molecular, individual, and population-level biological endpoints and corresponding pollutant dose–response templates reserved as reference calculation modules. However, applicability beyond this case has not been validated and requires case-specific calibration. To verify the operability and accuracy of the proposed integrated system, a typical tailings dam leakage incident dominated by hexavalent chromium (Cr(VI)) and arsenic (As) pollution was selected as the practical validation case; all field monitoring, pollutant simulation, and final economic loss quantification in this case exclusively rely on on-site measured Cr(VI) and As data, while Cd and PAH-related biological response curves and remediation cost formulas retained in the manuscript only serve as illustrative universal template components of the framework rather than case-measured results. For the Cr(VI)/As pollution case, the advection–diffusion model simulation revealed that the Cr(VI) contamination plume horizontally spread 250 m within 48 h and extended to 560 m after seven days, and anaerobic groundwater environments drove the transformation of toxic mobile trivalent arsenic (As(III)) from primary pentavalent arsenic. The calibrated SWAT model achieved Nash–Sutcliffe efficiency (NSE) coefficients of 0.75 for dissolved Cr(VI) and 0.68 for particulate As. The graph theory-based rapid prediction model cut computation duration down to minutes; when validated against independent field monitoring data, it yielded an average relative error of 14.2%, and its consistency with the SWAT model reached 10.5% relative deviation, satisfying the accuracy requirement for emergency early warning. Field biological monitoring demonstrated substantial ecological impairment: metallothionein (MT) expression in fish tissues was markedly elevated (the reported 6.2-fold induction value derives from standard Cd exposure template tests within the framework, with analogous MT upregulation also observed for field Cr(VI)/As co-stress), and benthic community Shannon diversity declined by over 50% in polluted river reaches. The standardized Ecological Damage Index (EDI) of the case was calculated as 480.2, indicating severe aquatic ecosystem damage, with total comprehensive ecological and economic losses reaching 17.25 million CNY. This study innovatively couples high-precision physical transport models with fast emergency prediction algorithms and establishes a complete multi-tier biological indicator chain linking molecular biomarkers to community integrity metrics; the three-dimensional loss accounting system integrating ecosystem service impairment, restoration expenditure, and post-pollution recovery loss realizes closed-loop full-cycle damage evaluation. The proposed framework, demonstrated for Cr(VI) and As pollution, has a modular design that may potentially be extended to other pollutants such as Cd and PAHs by adjusting model parameters, providing a quantitative reference for emergency disposal, pollution remediation, and ecological compensation of water contamination accidents, although further validation across different pollutants and hydrological settings is required.

Groundwater Quality Assessment, Trace Element Pollution, and Health Risk Assessment of Hand-Dug Wells within Ladoke Akintola University of Technology Campus and Environs, Ogbomoso, Southwestern Nigeria

Groundwater is the primary source of potable water within Ladoke Akintola University of Technology (LAUTECH). Natural geochemical processes and increasing anthropogenic activities may compromise its quality and pose potential health risks. This study evaluated the physicochemical characteristics, trace-element concentrations, groundwater pollution status, and associated health risks of groundwater from thirty-nine (39) hand-dug wells. Sixteen (16) wells were selected for detailed pollution-index and health-risk assessments based on their spatial distribution and contamination characteristics. Physicochemical parameters and trace-element concentrations were determined using standard analytical procedures. Groundwater pollution was evaluated using the Heavy Metal Pollution Index (HPI), Heavy Metal Evaluation Index (HEI), and Contamination Index (Cd). Health risks were assessed using United States Environmental Protection Agency (USEPA, 2011) models based on the Hazard Quotient (HQ), Hazard Index (HI), and Cancer Risk (CR). The groundwater was moderately acidic to neutral (pH 4.92–6.94), and most physicochemical parameters complied with the World Health Organization (WHO, 2022) and Nigerian Standard for Drinking Water Quality issued by the Standards Organisation of Nigeria (SON, 2015) guideline values. Elevated concentrations of cadmium (Cd), lead (Pb), and nickel (Ni) were detected in representative wells, resulting in varying degrees of groundwater contamination. The HI ranged from 0.216 to 0.639 for adults and from 0.504 to 1.491 for children. All adult HI values were below the acceptable threshold, whereas selected wells recorded values greater than one for children, indicating potential non-carcinogenic health risks. Total Cancer Risk (TCR) values ranged from 1.23 × 10⁻³ to 3.72 × 10⁻³ for adults and from 2.87 × 10⁻³ to 8.68 × 10⁻³ for children, exceeding the USEPA acceptable cancer-risk range (10⁻⁶–10⁻⁴) in all assessed wells. Cadmium and nickel were the principal contributors to carcinogenic risk. The results emphasise the need for continuous groundwater-quality monitoring, effective waste management, source protection, and appropriate groundwater treatment to safeguard public health.