Leif Wolf

Sources and processes affecting the spatio-temporal distribution of pharmaceuticals and X-ray contrast media in the water resources of the Lower Jordan Valley, Jordan

The closed basin of the Lower Jordan Valley with the Dead Sea as final sink features high evapotranspiration rates and almost complete reuse of treated wastewater for irrigation farming. This study focuses on the water transfer schemes and the presence, spreading, and potential accumulation of pharmaceutical residues in the local water resources based on findings of a five-year monitoring program. Overall 16 pharmaceuticals and 9 iodinated X-ray contrast media were monitored in groundwater, surface water, and treated wastewater. A total of 95 samples were taken to cover all geographical settings and flow paths from origin (wastewater) to target (groundwater). Nine substances were detected in groundwater, with concentrations ranging between 11 ng/L and 33,000 ng/L. Sometimes, detection rates were higher than in comparable studies: Diatrizoic acid 75%, iopamidol 42%, iopromide 19%, iomeprol 11%, carbamazepine and iohexol 8%, ibuprofen 6%, and fenofibrate and iothalamic acid 3%. Concentrations in groundwater generally increase from north to south depending on the application of treated wastewater for irrigation. Almost all substances occurred most frequently and with highest concentrations in treated wastewater, followed by surface water and groundwater. As exception, diatrizoic acid was found more frequently in groundwater than in treated wastewater, with concentrations being similar. This indicates the persistence of diatrizoic acid with long residence times in local groundwater systems, but may also reflect changing prescription patterns, which would be in accordance with increasing iopamidol findings and surveys at local hospitals. Trend analyses confirm this finding and indicate a high probability of increasing iopamidol concentrations, while other substances did not reveal any trends. However, no proof of evaporative enrichment could be found. The high spatial and temporal variability of the concentrations measured calls for further systematic studies to assess the long-term evolution of organic trace substances in this reuse setting.

Urban Water Resources Toolbox - Integrating Groundwater into Urban Water Management

Holistic but applicable approaches are urgently needed to help plan long-term, cost-effective and sustainable urban water management systems. Groundwater is a central element in the urban water cycle of all cities located on aquifers, yet it remains inadequately integrated into urban water management practices. This book describes holistic approaches for quantification and balancing of urban water and solute fluxes that have been developed by the joint Euro-Australian research project AISUWRS. The new tools comprise a chain of interconnected models that link urban water supply, urban drainage and urban groundwater resources. These include a new sewer exfiltration, model that is based on pipe asset conditions which permits flows to the environment to be estimated. The book provides details on the further processing of this information through the unsaturated zone down to aquifer, where numerical groundwater flow and transport models are applied. Concise documentation is provided on each of the models. The practicability of applying the chain of models was tested by applying it in four case study cities in Australia, Germany, Slovenia and the United Kingdom that have diverse conditions in terms of hydrogeologic setup, climate and data availability. This permitted additional validation by field investigations, including problem-oriented monitoring campaigns aimed at assessing the impact of wastewater practice on groundwater. The book provides guidance and examples of the application of multilevel piezometers, on adapted monitoring strategies, and the use for interpretation purposes of microbiological parameters, pharmaceutical residues and related marker species. The socio-economic analysis in the case study cities sometimes uncovered distinctively different problem perceptions and priorities, both in the groups of experts responsible for the water management and with the remaining stakeholders. The AISUWRS project has developed tools to foster these urgently required deliberation processes. Methodologies for formal sustainability assessment with a triple bottom line background were also elaborated and tested during the case studies. The case studies have shown that the approach is valid and constitutes an important step towards integrated urban water management This title belongs to European Water Research Series ISBN: 9781843391388 (Print) ISBN: 9781780402437 (eBook)

Tracking changing X-ray contrast media application to an urban-influenced karst aquifer in the Wadi Shueib, Jordan

Sewage input into a karst aquifer via leaking sewers and cesspits was investigated over five years in an urbanized catchment. Of 66 samples, analyzed for 25 pharmaceuticals, 91% indicated detectable concentrations. The former standard iodinated X-ray contrast medium (ICM) diatrizoic acid was detected most frequently. Remarkably, it was found more frequently in groundwater (79%, median: 54 ng/l) than in wastewater (21%, 120 ng/l), which is supposed to be the only source in this area. In contrast, iopamidol, a possible substitute, spread over the aquifer during the investigation period whereas concentrations were two orders of magnitude higher in wastewater than in groundwater. Knowledge about changing application of pharmaceuticals thus is essential to assess urban impacts on aquifers, especially when applying mass balances. Since correlated concentrations provide conclusive evidence that, for this catchment, nitrate in groundwater rather comes from urban than from rural sources, ICM are considered useful tracers.

IMPACTS OF SEWER LEAKAGE ON URBAN GROUNDWATER

Leaky sewers have to be considered as potential sources for groundwater contamination in urban areas. The medium-sized city of Rastatt in SWGermany with 50,000 inhabitants was subject of a series of investigations on sewer leakage which are summarized and discussed in this paper. Amongst others factors, the degree of pollution depends on the chemical composition of the wastewater and the amount of exfiltration. The groundwater underneath the city area showed anthropogenic influence resulting in elevated concentrations especially of boron, potassium and sodium as well as a generally increased electrical conductivity. Groundwater in the close vicinity of broken sewers showed typical sewage indicators such as iodated X-ray contrast media and microbiological parameters. Contamination with pharmaceutical residues and gadolinium could not be found in groundwater, despite significant concentrations of pharmaceuticals in wastewater. In autumn, the contents of boron and microbiological pollution were higher than in spring, indicating a higher ratio of wastewater in groundwater during times of less natural recharge. Groundwater monitoring wells near prominent leaks showed short-time fluctuations of EC and groundwater levels which could be correlated to changes of the wastewater composition and the flow regime in

Accumulation of pharmaceuticals in groundwater under arid climate conditions - Results from unsaturated column experiments.

Intense reuse of treated wastewater in agriculture is practiced all over the world, especially in arid and water-scarce regions. In doing so, pharmaceutical residues in the water are irrigated to the soil and subsequently can percolate into the local aquifers. Since evaporation rates in these areas are typically high, persistent substances might enrich in the groundwater recharge of closed catchments like the Jordan Valley. Against this background, unsaturated column tests were conducted to investigate the potential for evaporative accumulation of the two pharmaceuticals bezafibrate and carbamazepine under simulated arid climate conditions. Parallel tests were conducted with inhibited microbiological activity where both substances showed an increase in the effluent concentrations proportional to the evaporation loss of the inflow solution. The mean accumulation factors of the pharmaceuticals correspond to the evaporated water loss. The experiments indicate the accumulation potential for pharmaceuticals with high persistence against biodegradation. For the first time, the overall potential for evaporative enrichment could be demonstrated for pharmaceuticals. Under the given experimental conditions, the two investigated pharmaceuticals did not enrich faster than chloride, which might result in soil salting prior to reaching harmful pharmaceutical concentrations in soil water. The findings are relevant to future assessments of environmental impacts of persistent trace substances, which need to take into account that concentrations in the aquatic cycle might increase further due to evaporative enrichment.

Estimation of Optimal Groundwater Substitution Volumes Using a Distributed Parameter Groundwater Model and Prediction Uncertainty Analysis

This paper describes the development of a methodology that can be used for determining the spatial and temporal distribution of additional water volumes required to meet a defined groundwater target, such as an historical peizometric surface. The methodology is demonstrated on a case study concerned with mitigating declining groundwater levels in an alluvial aquifer intensively used for agriculture in the Lockyer Valley, Queensland, Australia. The proposed mitigation measure is the importing of large volumes of purified recycled water (PRW) from a large scale indirect potable reuse scheme into the aquifer system. The developed methodology employs both a groundwater flow model together with linear uncertainty analysis. Therefore for the case study, a distributed parameter numerical groundwater flow model was developed for the Lockyer valley alluvial aquifer system using MODFLOW, calibrated to observed groundwater levels, and further constrained by estimates of diffuse and river recharge from water balance studies. The model was used to simulate groundwater levels in the aquifer over a 20-year period. Optimal spatial and temporal distribution of volumes of imported water required to mitigate declining groundwater levels over that period were then estimated, using a modified version of the MODFLOW General Head Boundary (GHB) package. Uncertainty in the predicted import volumes was estimated using linear bayesian analysis principles. The relative worth of data from each observation bore within the groundwater monitoring network was also assessed in terms of the extent to which predictions of import water volumes were made more reliable when furnished with that data. Application of the methodology to the Lockyer alluvial aquifer system illustrated the suitability of the developed methodology for estimating the additional water volumes required for managed aquifer recharge or groundwater substitution schemes in similarly over-exploited aquifers.