HR: 0800h
AN: H51B-0457    [Abstracts]
TI: Effects Of Leaky Sewers On Groundwater Quality
AU: * Leschik, S
EM: sebastian.leschik@ufz.de
AF: UFZ - Helmholtz Centre for Environmental Research, Department of Hydrogeology, Permoserstrasse 15, Leipzig, 04318, Germany
AU: Musolff, A
AF: UFZ - Helmholtz Centre for Environmental Research, Department of Hydrogeology, Permoserstrasse 15, Leipzig, 04318, Germany
AU: Reinstorf, F
AF: UFZ - Helmholtz Centre for Environmental Research, Department of Hydrogeology, Permoserstrasse 15, Leipzig, 04318, Germany
AU: Strauch, G
AF: UFZ - Helmholtz Centre for Environmental Research, Department of Hydrogeology, Permoserstrasse 15, Leipzig, 04318, Germany
AU: Oswald, S E
AF: UFZ - Helmholtz Centre for Environmental Research, Department of Hydrogeology, Permoserstrasse 15, Leipzig, 04318, Germany
AU: Schirmer, M
AF: UFZ - Helmholtz Centre for Environmental Research, Department of Hydrogeology, Permoserstrasse 15, Leipzig, 04318, Germany
AB: The impact of urban areas on groundwater quality has become an emerging research field in hydrogeology. Urban subsurface infrastructures like sewer networks are often leaky, so untreated wastewater may enter the urban aquifer. The transport of wastewater into the groundwater is still not well understood under field conditions. In the research platform WASSER Leipzig (Water And Sewershed Study of Environmental Risk in Leipzig- Germany) the effects of leaky sewers on the groundwater quality are investigated. The research is focused on the occurrence and transport of so-called "xenobiotics" such as pharmaceuticals and personal care product additives. Xenobiotics may pose a threat on human health, but can also be considered a marker for an urban impact on water resources. A new test site was established in Leipzig to quantify mass fluxes of xenobiotics into the groundwater from a leaky sewer. Corresponding to the leaks which were detected by closed circuit television inspections, monitoring wells were installed up- and downstream of the sewer. Concentrations of eight xenobiotics (technical-nonylphenol, bisphenol-a, caffeine, galaxolide, tonalide, carbamazepine, phenazone, ethinylestradiol) obtained from first sampling programmes were found to be highly heterogeneous, but a relation between the position of the sampling points and the sewer could not be clearly identified. However, concentrations of sodium, chloride, potassium and nitrate increased significantly downstream of the sewer which may be due to wastewater exfiltration, since no other source is known on the water flowpath from the upstream to the downstream wells. Because of the highly heterogeneous spatial distribution of xenobiotics at the test site, a monitoring concept was developed comprising both high-resolution sampling and an integral approach to obtain representative average concentrations. Direct-push techniques were used to gain insight into the fine-scale spatial distribution of the target compounds. An integral pumping test was performed to determine the total xenobiotic mass fluxes along control planes down- and upstream of the leaky sewer. The new monitoring concept helped to obtain robust estimates of xenobiotic mass fluxes into the groundwater.
DE: 1803 Anthropogenic effects (4802, 4902)
DE: 1828 Groundwater hydraulics
DE: 1831 Groundwater quality
DE: 1834 Human impacts
SC: Hydrology [H]
MN: 2007 Fall Meeting