Berlin Water Research Articles

Cyanotoxins associated with macrophytes in Berlin (Germany) water bodies – Occurrence and risk assessment

Fatal dog poisoning after uptake of neurotoxic cyanobacteria associated with aquatic macrophytes in Tegeler See (Berlin, Germany) raised concerns about critical exposure of humans, especially children, to cyanotoxins produced by macrophyte associated cyanobacteria during recreational activity. From 2017 to 2021 a total of 398 samples of macrophytes washed ashore at bathing sites located at 19 Berlin lakes were analysed for anatoxins, microcystins, and cylindrospermopsins, as were 463 water samples taken in direct proximity to macrophyte accumulations. Cyanotoxins were detected in 66 % of macrophyte samples and 50 % of water samples, with anatoxins being the most frequently detected toxin group in macrophyte samples (58 %) and cylindrospermopsins in water samples (41 %). Microcoleus sp. associated with the water moss Fontinalis antipyretica was identified as anatoxin producing cyanobacterium in isolated strains as well as in field samples from Tegeler See. Anatoxin contents in macrophyte samples rarely exceeded 1 μg/g macrophyte fresh weight and peaked at 9. 2 μg/g f.w. Based on established toxicological points of departure, a critical anatoxin content of macrophyte samples of 3 μg/g f.w. is proposed. Five samples, all taken in Tegeler See and all associated with the water moss Fontinalis antipyretica, exceeded this value. Contents and concentrations of microcystins and cylindrospermopsins did not reach critical levels. The potential exposure risks to anatoxins for children and dogs are assessed and recommendations are given.

Cyanotoxins Associated with Macrophytes in Berlin (Germany) Water Bodies – Occurrence and Risk Assessment

Cyanotoxins Associated with Macrophytes in Berlin (Germany) Water Bodies – Occurrence and Risk Assessment

Comparison of Online Sensors for Liquid Phase Hydrogen Sulphide Monitoring in Sewer Systems

Hydrogen sulfide (H2S) related to wastewater in sewer systems is known for causing significant problems of corrosion and odor nuisance. Sewer systems severely affected by H2S typically rely on online H2S gas sensors for monitoring and control. However, these H2S gas sensors only provide information about the H2S emission potential at the point being monitored, which is sometimes inadequate to design control measures. In this study, a comparison of three market-ready online sensors capable of liquid-phase H2S detection in sewer systems was assessed and compared. Two of the three sensors are based on UV/Vis spectrophotometry, while the other adapted the design and principles of a Clark-type electrochemical microsensor. The H2S measurements of the sensors were statistically compared to a standard laboratory method at first. Following that, the performance of the online sensors was evaluated under realistic sewer conditions using the Berlin Water Company (BWB) research sewer pilot plant. Test applications representing scenarios of typical H2S concentrations found in sulfide-affected sewers and during control measures were simulated. The UV/Vis spectrometers showed that the performance of the sensors was highly dependent on the calibration type and measurements used for deriving the calibration function. The electrochemical sensor showed high sensitivity by responding to alternating anaerobic/anoxic conditions simulated during nitrate dosing. All sensors were prone to measurement disturbances due to high amounts of sanitary solids in wastewater at the study site and required continuous maintenance for reliable measurements. Finally, a summary of the key attributes and limitations of the sensors compared for liquid phase H2S detection is outlined.

Dosing Free Nitrous Acid as an Alternative Sulphide Control Technology for Pressure Sewers in Germany

Sulphide build-up in pressure sewers has been identified as the main cause for the occurrence of odour and corrosion in sewer systems. Despite the efforts to optimize commonly used control technologies such as nitrate and iron salts to reduce sulphide emission, continuous addition of these chemicals is still required. A biocidal agent such as free nitrous acid can be added intermittently, less frequently, and in smaller quantities whilst achieving total sulphide control. So far, laboratory and field studies in Australia and the USA have successfully proven and applied the use of this control technology, exhibiting its strong biocidal effects during intermittent addition. In this study, nine trials were made to assess the application of the free nitrous acid (FNA) as an alternative sulphide control technology in Germany. The sewer pilot plant of the Berlin Water Utility Company was used to perform the trials at a technical scale using a supply of raw sewage. FNA exposure times ranging from 5 to 24 h in varying concentrations were investigated. The effectiveness of the FNA treatment was monitored using the online hydrogen sulphide (H2S) gas and dissolved-sulphide sensors installed in the sewer pilot plant. Effective sulphide control was only possible during dosing periods, with rapid resumption of sulphide production for the trials with exposure times of <12 h and concentrations ranging from 0.08 to 0.56 mg HNO2-N L−1 suggesting a slight inhibitory effect. A more pronounced biocidal effect was observed for the trials exposed to FNA treatment for 24 h at concentrations >0.29 mg HNO2-N L−1. Overall, the trials of this study demonstrated that the biofilms were FNA resistant and that the concentrations and exposure times used were inadequate to develop an effective intermittent dosing strategy.

Dosing Free Nitrous Acid as an Alternative Sulphide Control Technology for Pressure Sewers in Germany

Sulphide build-up in pressure sewers has been identified as the main cause for the occurrence of odour and corrosion in sewer systems. Despite the efforts to optimize commonly used control technologies such as nitrate and iron salts to reduce sulphide emission, continuous addition of these chemicals is still required. A biocidal agent such as free nitrous acid can be added intermittently, less frequently, and in smaller quantities whilst achieving total sulphide control. So far, laboratory and field studies in Australia and the USA have successfully proven and applied the use of this control technology, exhibiting its strong biocidal effects during intermittent addition. In this study, nine trials were made to assess the application of the free nitrous acid (FNA) as an alternative sulphide control technology in Germany. The sewer pilot plant of the Berlin Water Utility Company was used to perform the trials at a technical scale using a supply of raw sewage. FNA exposure times ranging from 5 to 24 h in varying concentrations were investigated. The effectiveness of the FNA treatment was monitored using the online hydrogen sulphide (H2S) gas and dissolved-sulphide sensors installed in the sewer pilot plant. Effective sulphide control was only possible during dosing periods, with rapid resumption of sulphide production for the trials with exposure times of 0.29 mg HNO2-N L−1. Overall, the trials of this study demonstrated that the biofilms were FNA resistant and that the concentrations and exposure times used were inadequate to develop an effective intermittent dosing strategy.

The partial-privatisation of the Berlin Water Company in 1999 and urban development in 1990s Berlin

The partial-privatisation of the Berlin Water Company in 1999 and urban development in 1990s Berlin

Community participation and sustainable investment in city projects: The Berlin Water Consumer Stock Ownership Plan

Water supply issues and sustainable urban development are inextricably linked in cities across the world and are becoming even more urgent given the everincreasing scale and nature of demand. As with many large cities across the world, Berlin is situated along a river, the Spree. What regularly causes massive fish death is not emission-intensive industries or citizens illegally disposing of waste. During heavy rainfall as the sewers threaten to become overburdened, the combined sewage system discharges its contents directly into the river to prevent an overflow into the streets. This problem is common to countless metropolitan regions. The measures implemented by the city of Berlin to date — underground concrete basins as buffers and an intelligent canal control system — remain insufficient to capture the 3–4 million cubic metres of untreated wastewater still discharged into the river each year. LURITEC, a new system of pre-manufactured, modular synthetic glass fibre tubes that are placed in the river instead of underground, can make a cost-efficient contribution towards closing this gap. The system is complementary to traditional concrete tanks. Two major obstacles have so far hindered implementation of the €60m LURITEC pilot project: first, a lack of financing; and secondly, a lack of political support. Here, citizens’ financial participation can lower public costs while providing a grassroots democratic backbone. A Consumer Stock Ownership Plan (CSOP) offers low-risk loan financing of a significant share of the project while requiring only a small financial contribution from the CSOP participants. Combining different revenue sources, the redemption period for repaying the €12.4m debt is 8.5 years. Community participation, in particular citizen capital participation as proposed in this article, anchors the citywide project in the citizenry, thus strengthening its democratic legitimacy and facilitating sustainable urban development.

Pilot-Scale Investigation of Micropollutant Removal with Granular and Powdered Activated Carbon

Activated carbon is investigated as adsorptive barrier for organic micropollutants (OMP) within the Berlin water cycle. In a pilot plant using granular activated carbon (GAC) as upper layer in dual-media filtration, OMP concentrations in treated wastewater could be reduced without any negative impact on filtration efficiency. OMP breakthroughs occurred after shorter runtimes than estimated according to isotherm experiments with powdered activated carbon (PAC). Batch adsorption tests comparing the used GAC to new GAC showed that the capacity of the used GAC was not exhausted, indicating that besides direct site competition, pore blocking is also responsible for the poor GAC performance. A pilot plant application of PAC of the same type as GAC showed significantly higher OMP removals at lower dosages, taking advantage of immobilization of PAC particles in the filters. Both PAC and GAC applications can be integrated into tertiary wastewater treatment without significant constructional changes.

Fluid populations, immobile assets: Synchronizing infrastructure investments with shifting demography

In this article we reconstruct and test conventional economic theory’s deductive claims about the nature of infrastructure assets and the demography of end-users who demand infrastructure outputs. We find that the conventional theory puts forward three mutually reinforcing propositions: that infrastructure assets have a natural tendency towards monopoly owing to technical economies of scale; that infrastructure outputs (such as cubic metres of water or kilowatt–hours of electricity) and end-users of these outputs are essentially homogenous; and that future demand of infrastructure is predictable with a reasonable degree of certainty. These conventional propositions in practice have promulgated a ‘bigger is better’ paradigm in the planning of infrastructure assets and networks that has entrenched the practice of building large immobile infrastructure assets. In contrast, building on evidence from multiple cases – Berlin water authority (Berliner Wasserbetriebe) and World Bank-financed water supply projects in six developing countries – we show that conventional economics theory has led to the development of poor planning practices that are yielding unfavourable outcomes in infrastructure investments. We find that the heterogeneous populations of end-users (individuals, households and organizations) are fluid across space and time. This fluidity makes immobile assets subject to frequent and costly obsolescence. Instead of being theorized as large immobile (and monopoly tending) assets, infrastructure assets should be viewed as modular, plug-and-play, increments. These modules can be flexibly assembled over time to expand or contract capacity in specific places for specific users.

From post-politics to a politics of possibility? Unravelling the privatization of the Berlin Water Company

This article explores the constraints and contingencies of contemporary urban governance, with reference to the partial privatization (1999) and partial remunicipalization (2012) of the Berlin Water Company (BWB). It outlines the processes through which this major shift in Berlin politics occurred, showing how the mainstream consensus on privatization was disrupted and alternatives to apparent neoliberal conformity emerged. Dynamics apparent in the BWB case – commercialization, privatization, re-regulation, public contestation and remunicipalization – are indicative of the challenges and opportunities of making policy in and beyond the global norms of neoliberalism. It is argued that this case is important because it reveals something about what we might call the “politics of possibility” within the paradigm of neoliberal urban governance: the continuing potential for change within the constraints of an urban governance configured to the logics and needs of markets. Given this, the paper concludes that local contingencies in urban governance problematize sweeping notions of a post-political condition. However observable post-political strategies and outcomes in Berlin and elsewhere are, researchers should not assume that they are inevitably dominant or universal.

Anthropogenic organic micro-pollutants and pathogens in the urban water cycle: assessment, barriers and risk communication (ASKURIS)

Abstract In urban areas, water often flows along a partially closed water cycle in which treated municipal wastewater is discharged into surface waters which are one source of raw waters used for drinking water supply. A number of organic micro-pollutants (OMP) can be found in different water compartments. In the near future, climatic and demographic changes will probably contribute to an increase of OMP and antibiotic-resistant pathogens in aquatic ecosystems. The occurrence of OMP, possible adverse effects on aquatic organisms and human health and the public perception must be carefully assessed to properly manage and communicate potentially associated risks and to implement appropriate advanced treatment options at the optimum location within the water cycle. Therefore, the interdisciplinary research project ASKURIS focuses on identification and quantification, toxicological assessment and removal of organic micro-pollutants and antibiotic-resistant pathogens in the Berlin water cycle, life cycle-based economic and environmental assessment, public perception and management of potential risks.

Occurrence and distribution of psychoactive compounds and their metabolites in the urban water cycle of Berlin (Germany)

The occurrence and distribution of six psychoactive compounds (primidone, phenobarbital, oxazepam, diazepam, meprobamate, and pyrithyldione) and a metabolite of primidone (phenylethylmalonamide) were investigated in wastewater treatment plant (WWTP) effluents, surface water, groundwater of a bank filtration site, raw and final drinking water, and in groundwater affected by former sewage irrigation.Primidone and its metabolite phenylethylmalonamide were found to be ubiquitous in environmental water samples in Berlin. Maximum concentrations of 0.87 and 0.42 μg/L, respectively, were encountered in WWTP effluents. Both compounds are apparently not removed when passaging through the different compartments of the water cycle and concentrations are only reduced by dilution. Phenobarbital was present at nearly every stage of the Berlin water cycle with the exception of raw and final drinking water. The highest concentrations of phenobarbital (up to 0.96 μg/L) were measured in groundwater influenced by former sewage irrigation. Oxazepam was only present in WWTP effluents and surface waters (up to 0.18 μg/L), while diazepam was not detected in any matrix. Due to their withdrawal from the German market years ago, the pharmaceuticals meprobamate and pyrithyldione were only found in sewage farm groundwater (up to 0.50 and 0.04 μg/L, respectively) and, in case of meprobamate, also in decade old bank filtrate (0.03 μg/L).Our results indicate a high persistence of some of the investigated compounds in the aquatic system. As a consequence, these pollutants may potentially reach drinking water resources via bank filtration if present in WWTP effluents and/or surface waters in partly closed water cycles such as Berlin's.

Consultants, depoliticization and arena-shifting in the policy process: privatizing water in Berlin

This paper examines the effects of the growing presence of management consultants in policy processes. In particular, it addresses the key concern that consultants employed by governments often operate in new institutional arrangements not subject to the formal rules of political systems. Their activities, often secretive, are seen to undermine the democratic legitimacy of political decision-making. Despite the significance of these concerns there is still a lack of conceptual and empirical research on these topics. Addressing this gap, the paper first seeks to begin a more conceptual discussion about the role of consultants and “governance”. Turning to the literature on depoliticization in public policy, and following Flinders and Buller (Br Polit 1(3):293–318, 2006), it is argued that the hiring of consultants should be seen not as a move from political to apparently neutral, expert forms of policy-making, but as a shift in the arena of political decision-making. Such shifts can contribute to the emergence of what Hajer (Policy Sci 36(2):175–195, 2003a) calls the “institutional voids” of governance: the emergence of ad hoc political spaces in which the rules and outcomes of policy-making are unclear. It is argued that these ad hoc spaces may work to undermine the traditional institutions of political systems without providing an alternative form of democratic legitimacy. The paper examines these issues with reference to a case study of consultants working for the Berlin government on the privatization of the Berlin Water Company in 1999. It concludes by reflecting on the usefulness of the arena-shifting notion and outlining areas for future research.

A coupled transport and reaction model for long column experiments simulating bank filtration

AbstractWithin the scope of the interdisciplinary Natural and Artificial Systems for Recharge and Infiltration research project dealing with riverbank filtration processes at the Berlin water works, a semi‐technical column experiment has been ongoing since January 2003. Here, a 30 m long soil column is infiltrated with surface water sampled from Lake Tegel (Berlin, Germany) under saturated flow conditions. Changes in pore water hydrochemistry sampled on 21 non‐equidistant distributed points are verified by coupled transport and reaction modelling. The objective of reactive transport modelling was to identify the main biogeochemical processes within the soil column during the flushing experiment as a conceptual model for riverbank filtration. Modelling was done with a combination of MATLAB and PHREEQC. The main processes identified are: (1) biogeochemical degradation due to interaction of natural surface water with the soil matrix; (2) continuous dissolution of refractory air bubbles from the soil column matrix. Copyright © 2006 John Wiley & Sons, Ltd.

From municipal sewage to drinking water: fate and removal of pharmaceutical residues in the aquatic environment in urban areas

Recently, the occurrence and fate of pharmaceutically active compounds (PhACs) in the aquatic environment was recognized as one of the emerging issues in environmental chemistry and as a matter of public concern. Residues of PhACs have been found as contaminants in sewage, surface, and ground- and drinking water samples. Since June 2000, a new long-term monitoring program of sewage, surface, ground- and drinking water has been carried out in Berlin, Germany. Samples, collected periodically from selected sites in the Berlin area, are investigated for residues of PhACs and related contaminants. The purpose of this monitoring is to investigate these compounds over a long time period to get more reliable data on their occurrence and fate in the different aquatic compartments. Moreover, the surface water investigations allow the calculation of season-dependent contaminant loads in the Berlin waters. In the course of the monitoring program, PhACs and some other polar compounds were detected at concentrations up to the microg/L-level in all compartments of the Berlin water cycle. The monitoring is accompanied and supported by several other investigations such as laboratory column experiments and studies on bank filtration and drinking water treatment using conventional or membrane filtration techniques.

Long‐term effects of human influence on fish community structure and fisheries in Berlin waters: an urban water system

Commercial catch and fisheries monitoring data were compared with hydrological and water course characteristics conditions to identify the cause of changes in fisheries production in Berlin water courses since the 1950s. The urban parts of Berlin are densely populated, and the waters are under pressure from shipping, hydraulic engineering, pollution and recreation use. Most Berlin waters are polytrophic or hypertrophic, with an annual nutrient input of 595 t of total phosphorous and 8640 t of total nitrogen. A total of 34 fish species were recorded, eight of which were introduced. According to historical records, seven native fish species are extinct or missing. At present, the fish community is dominated by a few eurytopic species, i.e. roach, Rutilus rutilus (L.), common bream, Abramis brama (L.), silver bream, Blicca bjoerkna (L.), and perch, Perca fluviatilis L., which contribute 85% of all individuals caught. Two ‘faunal breaks’ were identified. The first was the changing of river character from a barbel to bream zone caused by damming and river regulation. This started in the thirteenth century and ended at the beginning of the twentieth century with the extinction of anadromous fishes. The second break was during the 1960s and 1970s, with the eutrophication of Berlin waters and the near total loss of submerged macrophytes. All phytophilic fish species declined greatly and a mass development of eurytopic species started. The catch of pike, Esox lucius L., common carp, Cyprinus carpio L., and tench, Tinca tinca (L.), became negligible, and at present, eel, Anguilla anguilla (L.), and pikeperch, Stizostedion lucioperca (L.), are the main commercial fish species. Concomitantly, the profitability of the fisheries declined and was linked to a decrease in the number of people employed in fisheries by more than 75% compared with 1950.

Occurrence of cyanobacterial toxins—microcystins and anatoxin-a—in Berlin water bodies with implications to human health and regulations

Occurrence of cyanobacterial toxins—microcystins and anatoxin-a—in Berlin water bodies with implications to human health and regulations

Occurrence of cyanobacterial toxins?microcystins and anatoxin-a?in Berlin water bodies with implications to human health and regulations

Main Berlin waterways are lowland rivers Spree, Dahme, and Havel, which are connected to some shallow lakes. High nutrient concentrations support heavy blooms of cyanobacteria which produce toxic substances (“cyanotoxins”). Concentrations of microcystins (MC), anatoxin-a, chlorophyll-a, and cyanobacterial biomass were analyzed in surface water. Two methods [enzyme linked immunosorbert assay (ELISA) and high-pressure liquid chromatography (HPLC)] were used for MC analysis. Different preparation techniques were carried out determining dissolved and cell-bound microcystins. Furthermore, the health implication for people using lakes for swimming and recreation was assessed as a basis of a proposal to health and water authorities for further regulations. Concentrations of total (cell-bound and dissolved) microcystin (with ELISA) varied between 0.14 and 119 μg/L; 95 of 128 samples showed values above 1 μg/L (nearly 74%), 49 above 10 μg/L (nearly 38%), and 2 above 100 μg/L (nearly 2%). With wide variability, concentrations of microcystins measured with HPLC were 65% (median) of values obtained using the immunologic method. Compared to total microcystin concentrations (dissolved and cell-bound toxin) proportion of dissolved toxin varied from 0.3 to 12% (n=46; mean: 4%). Using animal toxicity data for risk assessment we assume that for children a single intake of 25 μg MC-LR has no adverse effects. Under conservative uptake assumption for contaminated water a concentration of 100 μg MC/L in surface water is safe. On this basis, regulations (as provisional orientation) are proposed to health and water authorities. Levels of anatoxin-a measured in 14 surface samples of two Berlin lakes (Unterhavel and Muggelsee) were under detection limit of 0.01 μg/L. © 2000 John Wiley & Sons, Inc. Environ Toxicol 15: 120–130, 2000

Soil and Groundwater Contamination by Low Boiling Chlorinated Hydrocarbons in Berlin. Formation of Metabolites and their Analytical Determination

Abstract Some years ago, drinking water analysis in Berlin showed a remarkable but not critical concentration of low-boiling chlorinated hydrocarbons in the pg-range which led to investigations of the wells of one of the Berlin water works and of the respective catchment area.