The final report of the project COSMA describes the modeling results of four different scenarios regarding the pressure build-up in shallow aquifers due to the injection of CO2 into the sandstone aquifers of the Detfurth Formation. It is based on the “Technical Report on hydrogeological and static structural geological model implementation” (D 2.1) which focuses on the compilation of geological and hydrogeological background data (average values) and the development of a simplified conceptual hydrogeological model for a setting typical for the Northern German Sedimentary Basin as well as the model selection, model parameterization, definition of boundary conditions and implementation in hydrogeological flow model software packages. The hydrogeological model of the Cenozoic includes Quaternary and Tertiary aquifers down to the layer beneath the Rupelian clay. Moreover, a concept for modeling the interaction between deep, consolidated, saline aquifers with unconsolidated freshwater aquifers was developed. This report describes scenario analyses by using the numerical hydraulic model of the Detfurth Formation (Middle Bunter) and the simplified numerical groundwater model of the Cenozoic. The numerical models can be used to assess the key parameters, having an impact on the upconing of deeper saline groundwater beneath the well fields of water works (in shallow aquifer) due to imposed pressure signals.

Emerging subsurface activities (ESA) describe a set of methodologies and technologies using the earths subsurface for energy production or capture and storage of carbon dioxide. The earth’s heat is used as a clean source of energy (deep geothermal systems, DGS), process-related CO2 emissions can be stored in suitable geological formations (geological CO2 storage, GCS) and since the technique of horizontal drilling was developed, the exploitation of unconventional reserves of natural gas via hydraulic fracturing (shale gas extraction, SGE) expanded. At the same time, 97% of global freshwater resources are stored in the earth's subsurface, too, so that exploitation interests may come into conflict with the issue of groundwater and environmental protection. Main objective of deliverable D 3.1 of the COSMA-1 project therefore was to identify best practices of monitoring for geological carbon storage, deep geothermal systems and shale gas extraction projects with special focus on groundwater protection. Chapter 2 summarizes current groundwater monitoring standards, including monitoring network designs for emission-based (operators) and immission-based (water suppliers) monitoring. It further presents an identification of hazards related to ESA and a brief overview about the state of regulation. Finally, knowledge gaps concerning groundwater protection are identified. Chapters 3 to 5 describe for each of the above-named types of ESA the project stages and according monitoring needs and methods. Main target was to identify the key parameters and monitoring network designs ensuring reliable groundwater monitoring. As the most relevant hazards were drilling fluids, fracking fluids and brine migration as well as the mobilisation of methane, and the most likely pathways are leakages due to insufficient well integrity, for all three ESA types, pressure, temperature and TDS were recommended as key monitoring parameters. For shale gas extraction, in addition methane emission should be monitored. Key to any monitoring is i) the baseline sampling prior to the start of subsurface activities and ii) the adequate delineation of the area of review. All further monitoring to be implemented base on site-specific considerations and the authorities’ priorities. In any case, monitoring network should include the up-gradient, down-gradient and depth component. Monitoring wells and equipment should cover the full extension of horizontal bores and additional wells should be placed above potential pathways for fluid (or brine) migration as e.g. fault systems. The use of abandoned wells for monitoring is also recommended. The conception of appropriate monitoring strategies has further to be coordinated with the competent authorities, which have to control the compliance with all requirements. Therefore, site operator and water producer should report their monitoring plans and data at regular intervals to the competent authorities. The findings were summarized by transferring them to a risk management matrix following the Water Safety Plan (WSP) approach (WHO 2009). For shale gas extraction, deliverable D 3.2 will add specific mitigation measures to reduce the previously identified risk of negative impacts on shallow groundwater. Geological carbon storage was further investigated by means of the development of a coupled model for a theoretical case study site in the North-Eastern German Basin in the scope of work package 2 of the COSMA-project (D 2.3).

Different types of managed aquifer recharge (MAR) schemes are widely distributed and applied on various scales in the European countries, but no systematic categorization and compilation existed up to now. The European MAR catalogue presented herein includes a wide range of parameters, e.g. operational information, hydrogeological properties and water quality monitoring for different types of MAR. The database includes currently 270 MAR sites, but is neither a representative nor an exhaustive data compilation. Nevertheless, based on the available data it is shown that MAR plays an important role in the European water supply producing large water quantities for the domestic water supply.

Hydrogeochemical and hydrodynamic surface/groundwater interactions were investigated at the urban floodplain aquifer in Delhi, India. The heavily polluted Yamuna River is in hydraulic contact to the groundwater and river seepage results in a contamination plume. A conceptual redox zonation was developed based on the occurrence or absence of terminal electron acceptors. The redox zonation shows an inverted zonation from sulphate-reducing conditions close to the river over manganese- and iron-reducing conditions to a mixed oxic/suboxic zone. This study shows that the occurrence of problematic substances such as ammonium and arsenic in the groundwater is a consequence of the high load of untreated sewage in the river in combination with losing river conditions. Sequential extraction of aquifer material was performed to obtain information on geochemical availability of arsenic associated with different mineral phases and binding forms. Geogenic and anthropogenic arsenic sources contribute to overall arsenic concentration, and arsenic is found to be attributed mainly to amorphous iron oxide and sulphidic phases in the sediment. The contamination plume at the urban floodplain aquifer makes the groundwater unfit for drinking water purposes.

Emerging countries frequently afflicted by waterborne diseases require safe and cost-efficient production of drinking water, a task that is becoming more challenging as many rivers carry a high degree of pollution. A study was conducted on the banks of the Yamuna River, Delhi, India, to ascertain if riverbank filtration (RBF) can significantly improve the quality of the highly polluted surface water in terms of virus removal (coliphages, enteric viruses). Human adenoviruses and noroviruses, both present in the Yamuna River in the range of 10(5) genomes/100 mL, were undetectable after 50 m infiltration and approximately 119 days of underground passage. Indigenous somatic coliphages, used as surrogates of human pathogenic viruses, underwent approximately 5 log10 removal after only 3.8 m of RBF. The initial removal after 1 m was 3.3 log10, and the removal between 1 and 2.4 m and between 2.4 and 3.8 m was 0.7 log10 each. RBF is therefore an excellent candidate to improve the water situation in emerging countries with respect to virus removal.

In Chennai (India) public water supply and agriculture depend on groundwater to various extents, but the valuable resource shows increasing salinity over the past decades due to seawater intrusion. This study aims at identifying major hydrogeological processes which lead to salinity ingress in the main aquifer and investigates the effect of MAR structures such as check dams. Regional hydrochemistry is discussed by a combination of stiff diagrams, Cl/Br ratios, ion exchange diagram and stable isotopes (d18O, dD). The identified hydrogeochemical processes were high saline evolution due to intensive seawater evaporation for commercial salt production and typical ion displacement under refreshening and salinization conditions. Stable isotopes give new insights on (1) mixing processes of different end members (2) occurrence and degree of evaporation in ground- and surface water and (3) isotopical characterisation of groundwater recharge of the region. The identified processes were summarized in a conceptual model of the region. © 2014 Springer-Verlag Berlin Heidelberg.

Integrated planning of stormwater management requires a quantitative description of positive and negative effects of possible measures. We suggest quantifying these effects with generic performance indicators within eight categories: building physics and services, landscape quality, urban climate, biodiversity, groundwater, surface water, direct costs and indirect environmental costs. First results indicate that the defined performance indicators allow an objective pre-selection of measures based on their ability to reach local stormwater management goals. The final selection of measures should be based on an evaluation for a specific city quarter (to reduce indicator uncertainty) and reviewed by local stake holders.

Urban water infrastructures are increasingly facing challenges resulting from climate change and demographic developments. Using Berlin as an example, the project KURAS, which is supported by the Federal German Ministry for Education and Research, aims at demonstrating how the future waste water disposal, water quality, urban climate and quality of life in the city can be improved through intelligently coupled storm water and waste water management. The project consists of a network of partners from research and industry as well as Berlin decision makers (eight research institutions, four industrial partners, two public authorities and one public utility, responsible for drinking water supply and wastewater disposal).

Im Fokus des Projektes "Mikrobielle Verockerung in technischen Systemen" standen neutrophile und acidophile Eisenbakterien, die in Leitungen, Brunnen und an und in Pumpen vorkommen und dort Ablagerungen unlöslicher Eisenverbindungen verursachen. In Brunnen, werden diese Ablagerungsprozesse, die den Zustrom behindern und damit die Brunnenleistung mindern, auch als Brunnenalterung bezeichnet. Nach derzeitigem Stand des Wissens weisen in Deutschland dabei rund 80% der gealterten Brunnen biochemisch induzierte Eisenablagerungen auf (Houben & Treskatis 2002). Die Wiederherstellung der Brunnenleistung im Rahmen von Regenerierungen und präventiven Instandhaltungsmaßnahmen ist ressourcen- und energieintensiv, so dass ein besseres Verständnis der Schlüsselparameter und Lebensbedingungen der Eisenbakterien hilft, den Brunnenbetrieb und die Instandhaltungsmaßnahmen zu optimieren und die Brunnenalterung zu reduzieren. Das Kompetenzzentrum Wasser Berlin (KWB) war einer von insgesamt 14 Verbundprojektpartnern in dem interdisziplinären Team aus Wissenschaftlern, Ingenieuren und Technikern. In Teilprojekt 5 standen Probenahmen von Berliner Betriebsbrunnen und das Datenmanagement des Gesamtprojektes im Mittelpunkt der Arbeiten. Inhaltlich knüpften die Felduntersuchungen an das von den Berliner Wasserbetrieben (BWB) initiierte und am KWB koordinierte Forschungsprojekt WELLMA (für 'well management') an. Wesentliche Aufgabe des KWB war der frühzeitige Transfer der bei den Forschungspartnern erarbeiteten Ergebnisse in die Betriebspraxis bei den Berliner Wasserbetrieben (Teilprojekt 6). Dazu wurden Brunnen und Unterwassermotorpumpen aus der Trinkwassergewinnung der BWB durch die Projektpartner der TU Berlin (Teilprojekte 1a und 1b) hinsichtlich des Vorhandenseins und der Zusammensetzung biochemisch induzierter Eisenablagerungen untersucht. Neben Belagsproben von Pumpen bei Instandhaltungsarbeiten wurden dabei auch tiefenorientierte, zielgerichtete Proben aus dem Innenrohr (Vollrohr und Filterrohr) von Brunnen sowie Ablagerungsproben aus Steig- und Rohwassersammelleitungen entnommen und mikrobiologisch und chemisch untersucht. Eigene Feldarbeiten des KWB umfassten daneben in-situ-Messungen des Redoxpotentials im nahen Umfeld eines Brunnens sowie in-situ-Messungen der Feststofffracht (Trübung) in Abhängigkeit betrieblicher Randbedingungen. Wesentliche Ziele waren die Identifizierung von Schlüsselparametern zum Verständnis der Prozesse der Eisenverockerung und -rücklösung und die Quantifizierung des sich daraus ergebenden Verbesserungspotentials im Betrieb und der Instandhaltung aus dem Bezug der Untersuchungen auf die wasserchemischen, baulichen und betrieblichen Eigenschaften der untersuchten Brunnen. Im Ergebnis wurden von März 2012 bis September 2013 Pumpen aus 26 von geplanten 30 Brunnen beprobt. Zu deren Auswertung wurden drei Cluster unterschieden: (i) Brunnen, bei denen die Pumpen stark eisenverockert waren (ii) Brunnen ohne sichtbare Eisenverockerung, aber mit Biofilmen und (iii) Brunnen mit sauberen Pumpen. Der Abgleich mit im Rahmen von Instandhaltungsarbeiten erfolgten Kamerabefahrungen bestätigte einen Zusammenhang zwischen der Stärke der Verockerung der Pumpe und dem Vorhandensein und der Stärke von Ablagerungen im Filterrohrbereich.Schlüsselparameter aus statistisch belastbaren Zusammenhängen zwischen den Eisenbakterien-Gemeinschaften, den chemisch-mineralogischen Ockereigenschaften und den wasserchemischen, baulichen und betrieblichen Parametern konnten jedoch nicht herausgearbeitet werden, da die Diversität der beteiligten Eisenbakterien höher als vermutet war und sich selbst direkt benachbarte Brunnen mit ähnlichen Eigenschaften hinsichtlich der Ocker stark unterschieden. Auch stellten die Probenahmen immer nur Momentaufnahmen der zeitlich hochvariablen Anströmbedingungen dar.