RBF_Cover (for eps) - National Water Research Institute

Session 4: Siting
Water-Quality Management for Existing Riverbank-
Filtration Sites along the Elbe River in Germany
Prof. Dr.-Ing. Thomas Grischek
University of Applied Sciences Dresden
Dresden, Germany
Introduction
In former times, the management of RBF sites in Germany focused on water quantity — how much
water could be abstracted and what groundwater levels would result. Control measures were based
on measurements of river and groundwater levels and pumping rates and on black-box models to
estimate the portion of riverbank filtrate abstracted (e.g., Luckner and Nestler, 1982). The
development of computer programs for groundwater flow and transport simulations resulted in
increasing management applications for RBF sites (e.g., Koster et al., 1994; Heinzmann, 1998;
Eckert et al., 2000).
The number of published papers dealing with the complex management of water quality at RBF
sites is very low. Besides work done by Sontheimer (1991) and Schubert (1999) at sites along the
Rhine River, a control and management concept for the Hengsen site on the Ruhr River
(Schöttler and Sommer, 1992) must be highlighted. At the end of the 1980s, water-quality
management also became a subject for RBF sites on the Elbe River due to problems with river and
raw-water quality. Initial work done by Müller, Schwan, and others between 1985 and 1989 was
continued by Nestler et al. (1998).
Water-quality management must be based on detailed knowledge of groundwater flow conditions
and monitoring measures to obtain sufficient data on water quality; however, this is not the case
for every site. Of course, for small waterworks, such investigations and investments may be higher
than the cost savings resulting from water-quality management. But, the optimization of water
abstraction can have long-term effects on raw-water quality and treatment cost savings. Waterquality
management systems are well established at sites where problems with contamination have
occurred (e.g., high concentrations of nitrate, organic halogens). In such cases, experiences may
not be published to give the impression of a “no problem waterworks” or because a clear
description is not easy due to the large amount of data needed to understand the complex system
and site-specific boundary conditions.
General Water-Quality Management Measures
The first step in water-quality management is to clarify which advantage of RBF is the most
important and to identify the main aims or problems. At one site, the nitrate concentration in the
raw water should be decreased; at another site, the concentration of DOC, dissolved iron, or an
organic contaminant should decrease.
Correspondence should be addressed to:
Prof. Dr.-Ing. Thomas Grischek
Professor
Institute for Geotechnics & Water Sciences
University of Applied Sciences Dresden • Friedrich-List-Platz 1 • 01069 Dresden, Germany
Phone: +49 351 4623350 • Fax: +49 351 4623567 • Email: grischek@htw-dresden.de
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