The main goal of this project is to develop new sustainable sanitation concepts which have significant advantages in relation to ecological as well as to economical aspects compared to the conventional systems (end-of-pipe-system). After successful project completion, the new sanitation concept should be used in Berlin areas, where sewer systems are not installed, as well as other locations (national and international). The management of the project has been achieved as foreseen. No relevant modifications have been necessary. In relation to the technical development all eight tasks have been started. Some later than scheduled but this does not endanger the goal and end date of the project. The first results from the greywater treatment with the constructed wetland show that the effluent quality is comparable to the wastewater treatment plants of Berlin In contrary to the proposal the new sanitation concept using vacuum separation toilets will be realised in the office building instead of apartment building. Furthermore not fifteen but ten flats are taken into account for the project and all bathrooms will be completely retrofitted instead of installation of new toilet systems only. Due to the fact that external assistance for designing is necessary the costs for external assistance is higher than planned. The precise figure will be available earliest at the end of 2004. All modifications do not endanger the goal of the project. For the information and discussion with the national and international public and colleagues about this project many presentations, publications and visits of the demonstration project have been undertaken and organised, respectively. The envisioned progress up to the interim report in March 2005 will be the realisation and start up of operation of the sanitation concept in the apartment building, exchange of the gravity separation toilets against vacuum separation toilets in the office building, designing, installation and operation of the digester. Furthermore all work from subcontractors (Life-Cycle-Assessment, Urine treatment, Fertiliser usage) will continue. Different international presentations are also foreseen. In relation to the financial issues 325.906 € (21 %) of the total eligible costs of 1.552.116 € and 511.515 € (23 %) of the total real costs of 2.223.474 €, respectively, have been spent until now. The 30 % threshold of the total real costs will be achieved presumably at the end of 2004.

Bank filtration and artificial recharge provides an important drinking water source to the city of Berlin. Due to water recycling, the introduction of persistent trace pollutants (e.g. pharmaceuticals) in the drinking water may be a concern. The project “Organic Substances in Bank filtration and Groundwater Recharge - Process Studies” at the Technical University of Berlin is part of the “Natural and Artificial Systems for Recharge and Infiltration (NASRI)”-project of the Berlin Centre of Competence for Water. The research objectives of this part of the project are to study the removal of bulk and trace organics at different field sites with different characteristics in Berlin. In Berlin’s public drinking water supply nearly 70% of the 220 Mio m3 per year originate from bank filtration and groundwater recharge (~56% from bank filtration and ~14% from groundwater recharge (BWB 2003)). Since the 19th century Berlin has relied on bank filtration with retention times of several months to produce “new” ground water. A semi-closed urban water cycle has been created with the growth of the city. At some bank filtration sites the surface water is strongly influenced by highly treated domestic waste water effluent (e.g. 15-30% in Lake Tegel) (Ziegler et al. 2002). Despite this indirect potable reuse, the bank filtration system continues to provide high quality water which is distributed without chlorination. This unique situation in Berlin was an interesting field site for a research project of the Berlin Center of Competence for Water. Recently, the break through of organic trace pollutants in bank filtration systems has been studied in various research projects. Especially, since improved analytical methods can detect in ranges below 1µg/l. Since the processes during bank filtration are very complex, it is difficult to predict the fate of trace organics during bank filtration or to estimate important factors of influence for their degradation. In addition to redox state, factors such as retention time, initial degradable carbon concentration, soil properties and hydrogeological conditions may affect the final concentration. Many studies revealed positive findings of pharmaceuticals, pesticides or industrial chemicals (Hiemstra et al. 2003, Heberer et al. 2001, Verstraeten et al. 2002) in bank filtrate. Compounds like carbamazepine and clofibric acid were reported to be partly recalcitrant during underground transport (Stan and Linkerhäger 1994, Ternes et al. 2002). Furthermore, Ternes and Hirsch (2000) reported the occurrence of x-ray contrast media in surface waters and in surface water influenced groundwaters, where they constitute a major fraction of the adsorbable organic iodine (AOI). The contrast media were found to be very polar, persistent and difficult to remove in wastewater treatment (Jekel and Wischnack 2000). Hartig (2000) reported the break through of antibiotic sulfonamides from surface water to monitoring wells more than 50 m off the lake front (residence time~3 months). But in most of the reported cases the concentration in the bank filtrate is much lower than in the surface water. Since this concentration decline is not only due to dilution, long term bank filtration appears to have the capability to reduce trace organic pollutant concentrations. It would be of great practical value to classify the important trace organic pollutants by degradability during bank filtration and to evaluate the conditions that are favorable for the removal of certain compounds. This study begins to clarify these issues for a few trace organic pollutants. The factors of influence for degradation are studied for model compounds that represent groups of trace pollutants. Additionally, the infiltration process is characterized by several bulk-organic parameters. The goal of the study is to provide a tool that can be merged with hydrogeological models and soil properties to predict the removal efficiency of a given field site.

Bank filtration and artificial ground water recharge are important, effective, and cheap techniques for surface water treatment and removal of microbes, as well as inorganic, and some organic, contaminants. Nevertheless, physical, chemical, and biological processes of the removal of impurities are not understood sufficiently. A research project titled Natural and Artificial Systems for Recharge and Infiltration attempts to provide more clarity in the processes affecting the removal of these contaminants. The project focuses on the fate and transport of selected emerging contaminants during bank filtration at two transects in Berlin, Germany. Several detections of pharmaceutically active compounds (PhACs) in ground water samples from bank filtration sites in Germany led to furthering research on the removal of these compounds during bank filtration. In this study, six PhACs including the analgesic drugs diclofenac and propyphenazone, the antiepileptic drugs carbamazepine and primidone, and the drug metabolites clofibric acid and 1-acetyl–1-methyl–2-dimethyloxamoyl– 2-phenylhydrazide were found to leach from the contaminated streams and lakes into the ground water. These compounds were also detected at low concentrations in receiving public supply wells. Bank filtration either decreased the concentrations by dilution (e.g., for carbamazepine and primidone) and partial removal (e.g., for diclofenac), or totally removed PhACs (e.g., bezafibrate, indomethacine, antibiotics, and estrogens). Several PhACs, such as carbamazepine and especially primidone, were readily transported during bank filtration. They are thought to be good indicators for evaluating whether surface water is impacted by contamination from municipal sewage effluent or whether contamination associated with sewage effluent can be transported into ground water at ground water recharge sites.

In Berlin, 70 % of the drinkinq water is derived from bank filtrate or artificially recharged water. Because the surface water system contains elevated proportions of secondary treated municipal sewage, a number of sewage indicators from various sources can be detected in the bank filtrate. An artificial recharge site and a bank filtration site in Berlin Tegel are introduced and compared in terms of their hydrogeological and hydrochemical properties. Because of a permanent clogging layer and the geological properties, travel times are slower at the BF site and the hydrochemical conditions are more reducing. First estimates for the reaction rate constants of oxygen and nitrate are obtained with exponential data fitting. Some of the effects of the different redox conditions on minor substances such as drug residues are highlighted.

Simulation tools help develop an integrated approach for Berlin’s combined sewage system in which sewage overflows pose risk to groundwater and surface water quality

The effect of oscillating pumping regimes at the bank filtration site in Berlin Tegel is examined via a scenario based modelling study. There are several scenarios for the pumping regimes, some adopted from the operation of the plant by the Berlin Water Works (BWB), some hypothetical with a regular oscillating regime. A horizontal 2D model of the lower aquifer is set-up, in which the third type boundary condition is used to mimic the influence of an irregularly shaped till layer, overlying the main aquifer. Model results in form of flowpaths are presented for several pumping scenarios. They reveal that there is a substantial influence of the pumping regime on the flowpaths in the vicinity of the well gallery, while in the farfield, including the bank of the surface water body (here: Lake Tegel) the oscillating effect is rather small. It depends very much on the infiltration position on the bank, whether traveltime through the aquifer changes as effect of irregular pumping.

The effect of oscillating pumping regimes at the bank filtration site in Berlin Tegel is examined via a scenario based modelling study. Several scenarios for the pumping regimes are calculated, some adopted from the operation of the plant by the Berlin Water Works (BWB), some hypothetical with a regular oscillating regime. Two of these are presented here. A horizontal 2D model of the lower aquifer is set-up, in which the third type boundary condition is used to mimic the influence of an irregularly shaped till layer, overlying the main aquifer. Model results in form of flowpaths are presented for several pumping scenarios. They reveal that there is a substantial influence of the pumping regime on the flowpaths in the vicinity of the well gallery, while in the far field, including the bank of the surface water body (here: Lake Tegel) the oscillating effect is rather small. It depends very much on the infiltration position on the bank, whether traveltime through the aquifer changes as effect of oscillating pumping regime.

The spatial distribution of confining layers within a system of two aquifers strongly affects the hydraulics and sensitivity to pollution. The test site is located close to a well field. Wells are switched with short intervals and hydraulic heads are recorded in several observation wells. Because the absolute levels of simulated hydraulic heads do not always coincide with the measurements, the model is calibrated with short term head variations. The characteristic shape of the hydraulic heads at each observation wells contains sensitive information about the structure of the aquifer. A numerical technique is developed which enables to simulate the spatial distribution of the confining layer. The method comprises the use of pilot points and regularisation technique. Cross validation is carried out in order to show the results are physically based. The method is shown to provide significant results even under non optimal conditions.

Since the 1970s we know about the idea of real-time control of urban drainage systems. Anyway, global real-time control strategies still show a lack of implementation for large drainage systems of high complexity. In Berlin, Germany, a city of 3.5 million inhabitants covering an area of around 900 km², the demand for enhanced protection of the environment and the growing economic pressure have led to an increasing application of control assets and concepts within the sewage system. In the framework of the project “Integrated Sewage Management” the possibilities of a global and integrated control strategy for the Berlin system are examined. The paper is focused on the historical concept and design of the sewerage and the further improvement towards an environment-oriented system that builds the basis for today’s considerations. The operational method and functionality of local regulators that have already been implemented are described. Further more the model-based methodology for the analysis of the system and the development of global control concepts as well as results of system analysis are stated. On the basis of model simulations it is shown that a global coordination of pump stations can lead to a reduction of sewer overflows and consequently to an enhanced water protection.