Spatial Modelling of Micro-pollutants in a Strongly Regulated Cross-border Lowland Catchment

Abstract

Anthropogenically influenced transboundary catchment areas require an appropriately adapted exposure modelling. In such catchments, water management decisions strongly influence and override natural river hydrology. We adapted the existing exposure assessment model GREAT-ER to better represent artificially overprinted hydrological conditions in the simulations. Changes in flow directions and emission routes depending on boundary conditions can be taken into account by the adopted approach. The approach was applied in a case study for the drug metformin in the cross-border catchment of Vecht (Germany/Netherlands). In the Dutch part, pumps to maintain necessary water levels and minimum flow rates during dry periods lead to a reversal of the (natural) flow directions and as a consequence to additional pollutant input from the Lower Rhine/Ijssel along with a spatial redistribution of emissions in the catchment area. The model results for the pharmaceutical product metformin show plausible concentration patterns that are consistent with both monitoring results and literature findings at mean discharges and the effects of the changed hydrology in times of low natural discharges, namely an increase in polluted river sections under dry conditions due to the pumping activities. The adapted methodology allows for realistic application of the GREAT-ER model in anthropogenically modified catchments. The approach can be used in similar catchments worldwide for more realistic aquatic exposure assessment.

(Antibiotic-Resistant) E. coli in the Dutch–German Vecht Catchment─Monitoring and Modeling

“…Instead, two different scenarios describing season-specific typical hydrologic conditions were created for the Vecht catchment. A detailed description of the setup and the hydrological representation is provided by Lämmchen et al Its general applicability was recently confirmed by a case study with pharmaceuticals. , The first scenario represents the situation of dry weather in summer (dry summer scenario), and the second one describes humid periods throughout the whole year (average flow scenario), where the flow rate is affected by interflow and surface runoff due to precipitation (see Table S9 for more details).…”

“…The GREAT-ER ( Geography-Referenced Regional Exposure Assessment Tool for European Rivers ) model is well established for simulating chemical exposure in whole river catchments. It has been successfully applied to predict environmental concentrations of different chemicals like detergents, pharmaceuticals, − and even dissolved zinc in various catchments. Recently, it has been applied for risk assessment of selected pharmaceuticals in the Dutch–German transboundary catchment of the Vecht River .…”

Impact of wastewater reuse on contaminants of emerging concern in an effluent-dominated river

“…Due to the complexity, there is no standard for modeling CECs in river systems (Keller, 2015). Various process-based and empirical water quality models such as EPA SWMM (Park et al, 2007;Jackson et al, 2011;Dittmer et al, 2020), SWAT (Wang et al, 2019), QUAL2K (Zhi et al, 2022), GREAT-ER, (Koormann et al, 2006;Sumpter et al, 2006;Lämmchen et al, 2021a;Lämmchen et al, 2021b), and WASP (Agustin et al, 2023), have been modified or developed to simulate the fate and transport of CECs (Sharma and Kansal, 2013). Others, more recently, have applied various machine learning approaches to simulate concentrations and loads of CECs in rivers (Yun et al, 2021).…”

High Spatiotemporal Model-Based Tracking and Environmental Risk-Exposure of Wastewater-Derived Pharmaceuticals across River Networks in Saxony, Germany

“…At this point, substance-routing models can be employed for river networks to understand the behavior of waterborne substances and track their spatiotemporal dynamics, especially when MEC data is scarce [27]. The predicted environmental concentrations (PEC) derived from modeling approaches can serve to fill the spatiotemporal gaps of monitoring programs and support to conduct ERA by screening of exposure risks with the comparison of PEC with the ecotoxicological thresholds PNEC|EQS [28][29][30].…”