This project report summarizes work conducted in work package 11. Along with the deliverable 11.1 and milestone report 11 it covers the tasks from work package 11 as formulated in the Description of Work (DoW). The content of the different sections is interrelated, but each section is organized as an independent part. Title of this report differs from DoW because recommendations for optimum design and operation will be handled in the deliverable 12.2. The sections in this report cover various topics and each section can be found as a stand-alone report in the DEMEAU tool box (http://demeaufp7.eu/toolbox/) for download. Detailed summaries can be found for each section separately.

The La Vall d’Uixó (Spain) pilot site has been selected by DEMEAU because it is a new Aquifer Storage Transfer and Recovery (ASTR) site consisting of two injection wells surrounded by farmer wells for irrigation in a water scarce area. Potential water source for this MAR site is the effluent of the local WWTP, which is a quite constant water source in terms of availability, but gives concerns in terms of water quality. The investigations carried out within DEMEAU supports the work previously done by the Water Recovery Project (2011 – 2014), coordinated by IGME (Instituto Geológico y Minero de España) and UJI (Universitat Jaume I). The Water Recovery Project consists of different implementation phases and aimed to establish an appropriate MAR scheme with reclaimed wastewater to counteract salinity ingress in the coastal aquifer. In the third phase of the project two injection wells have recharged 310,000 m3 with water from the Belcaire River. To foster the implementation of the fourth and final phase of the Water Recovery Project, DEMEAU focused on the evaluation of the effluent of the local WWTP as source water for the ASTR system. This has been done by three sampling campaigns to analyse bulk chemistry, emerging pollutants and bioassays in native groundwater (six agricultural wells), Belcaire River (the current source water of the MAR scheme) and WWTP effluent (potential future source water). Risk assessment based on Australian MAR guidelines have been applied to evaluate risks related to the usage of WWTP effluent as source water. The Australian guidelines have been applied in two steps: entry level assessment and maximal risk assessment. Entry level assessment concluded that La Vall d’Uixó is suitable for a MAR scheme using reclaimed water, while maximal risk assessment identified hazards associated to reclaimed water as source water. As La Vall d’Uixó is an agricultural area of citrus crops, the use of reclaimed water for the injection in the MAR system must be compatible with the use of recovered water for irrigation. The risk assessment done in this report considered this end use of water, as there are no drinking water wells in the area. High risks have been identified for inorganic chemicals (conductivity, chloride and bicarbonate) and nutrients (nitrate). Risks associated to inorganics can be minimized by mixing effluent and Belcaire River water 1:1. Bulk chemistry coincided mainly with the description carried out in Water Recovery project, identifying two main quality problems in native groundwater: (1) salinity ingress (2) high nitrate concentration due to the intensive agricultural practices in the area. Ion displacement pattern in groundwater samples clearly indicates on-going salinization and documents minor effects of the injected water on few wells only. Cl/Br ratios indicate additional sources of chloride apart from seawater. It seems plausible that the underlying Keuper formations (Triassic) contribute to salinity ingress and SO4 excess in groundwater to some extent. Chlorides and nitrate are regulated by the implementation in Spain of the EU Water Framework Directive for the Castellón aquifer. The threshold value for nitrate is 200 mg/L, while the threshold value for chloride is 650 mg/L. WWTP effluent has nitrate and chlorides below the threshold concentrations (60 mg/L and 140 mg/L respectively) and, therefore, the MAR with reclaimed water would suppose a reduction of groundwater pollution and a step towards a qualitative good status in the aquifer. In total 63 organic micro pollutants have been analysed in groundwater, surface water and WWTP effluent. WWTP effluent shows elevated concentrations in almost all groups of organic micro pollutants compared to river- or groundwater. Only pesticides are found in higher concentrations in groundwater compared to the effluent. The Belcaire River shows the lowest concentrations for all groups of micro pollutants. It was shown that the Vall d’Uixó aquifer is contaminated by various organic micro pollutants and does not reflect a near natural aquifer condition. The aquifer chemistry in terms of organic micro pollutants reflects the usage of (untreated) effluent for direct irrigation over years. Elevated concentration of artificial sweeteners, analgesics, stimulants, caffeine metabolites and cocaine metabolites were found in WWTP samples taken during weekends compared to workday samples. In contrast, iopromide has been quantified in higher concentrations in the effluent of WWTP in work days than in the weekend, as this contrast media is used in hospitals for diagnostic tests normally carried out from Monday to Friday. These patterns of the effluent of WWTP during the week of weekend could be determinant for the selection of the working days as most suitable days to store treated waste water. In order to link analysed chemical concentrations to the observed toxicity in the samples a procedure based on bioassay-specific relative potency (REP) factors was applied. REP factors are determined by the effect concentrations of the reference compound and of the test compound. Despite the lack of toxicological data for a number of the selected target compounds and the lower relevance of the selected compounds for (eco)toxicological risk assessment, this study greatly demonstrate the usefulness of combined analyses of environmental samples. Effect-based methods could complement conventional chemical analysis in water quality monitoring as pre-screening techniques by (1) identifying toxic “hotspots” for further investigation, (2) assessing the effect of the entire mixture of compounds present in waters and therefore and (3) reduce uncertainty in safety evaluation.

The Australian Guidelines for Water Recycling – Managed Aquifer Recharge provide a ready-to -use and user-friendly compendium of knowledge. Practical instructions and checklists provide a step wise approach with a strong focus on implementation. The proposed models for water flow and substance transport allow a first tier estimation of present concentrations in ambient groundwater and the impacted zone in the aquifer. The use of stochastic models is not mandatory within the guidelines. A criticism which can be identified related to the use of models simply based on point estimates, is that especially in early stage risk assessments, where uncertainties are usually high, these models tend to pretend a level of certainty which often does not represent reality. Risks associated to inorganic chemicals are required to be treated with more detail. Rigorous quantification of biodegradation kinetics (e.g. first-order rate constants) and adsorption parameters (e.g. linear distribution coefficients) for EOCs during subsurface passage determined on field scale are still scarce. It is clear that first-order rate constants and linear distribution coefficients provide only a simplified description of the removal mechanisms during subsurface passage, because they neglect spatial and temporal dynamics of physical and chemical conditions. Nevertheless, this approach often provides a good approximation and allows also for site independent comparison of removal processes. Regarding the demonstration site in Berlin-Tegel the analysis showed that if the model of the Australian Guidelines is applied to the MAR system the travel time of 50d during subsurface passage cannot be guaranteed. In Germany, a residence time of 50d is usually considered to sufficiently reduce the risk of microbial hazards. Although risk calculations did not reveal immediate concern, it is recommended to develop and apply suitable verification monitoring techniques to quantify travel times and reduce present uncertainties. Moreover, this risk assessment and the study about the influence of the groundwater replenishment site on ambient groundwater (Sprenger and Grützmacher, 2015) clearly showed the need for protective measures against the input of undesired substances from shallow ambient groundwater.

Within Work Area 5 of the DEMEAU project, selected innovative technologies and tools for emerging contaminants removal and monitoring are assessed in their environmental and economic benefits and impacts by using life-cycle based tools such as environmental Life Cycle Assessment (LCA) and economic Life Cycle Costing (LCC). Six case studies were assessed to quantify their environmental and economic profiles and formulate unique selling propositions to promote market uptake and implementation. These case studies include managed aquifer recharge for groundwater replenishment or for drinking water production in combination with advanced oxidation process, hybrid ceramic membrane filtration with powdered activated carbon for tertiary wastewater treatment, automatic neural net control systems to optimize membrane operation, ozonation of wastewater treatment plant effluent, and bioassays as screening tool for water quality monitoring. This report summarizes the study layout, input data, and results of LCA and LCC for all case studies and indicates unique selling propositions based on the outcomes of the assessment.

The recovery of phosphorus (P) from sewage sludge, sludge liquor, or ash from monoincineration can be realized with different processes which have been developed, tested or already realized in full-scale in recent years. However, these pathways and processes differ in their amount of P that can be recovered in relation to the total P content in sludge, in the quality of the recovered P product, and in their efforts in energy, chemicals, fuels, and infrastructure required for P recovery. This study analyses selected processes for P recovery from sludge, liquor, or ash in their potential environmental impacts, following the method of Life Cycle Assessment (LCA, ISO 14040/44). Based on available process data from technology providers and end users, these processes are implemented in a hypothetical reference system for sludge digestion, dewatering and disposal in mono-incineration, including potential side-effects on mainstream wastewater treatment with the return load from sludge dewatering. Recovered products (e.g. P or N fertilizer, electricity, district heating) are accounted as credits for substituting equivalent industrial products. Depending on the maturity of the investigated process, collected process data of process efficiency, product quality, and energy and material demand originates from full-scale plants, pilot trials, or prospective modeling (status in 2014). This data is validated with the technology providers, transferred to the reference system and evaluated with a set of environmental indicators for energy demand, global warming, acidification, abiotic resource depletion, eutrophication, and human and ecotoxicity. Results show that pathways and processes for P recovery differ heavily in their amount of recovered P, but also in energy and related environmental impacts (e.g. greenhouse gas emissions). As direct struvite precipitation in sludge or liquor relies on the dissolved amount of P in digested sludge, these processes are only applicable in wastewater treatment plants with biological P removal. Here, they can recover 4-18% of total P in sludge with a relatively low effort in energy and chemicals, reducing return load to the mainstream process and eventually improving sludge dewaterability in case of direct precipitation in sludge. Acidic leaching of P from digested sludge can yield up to 48% of P for recovery, but requires a significant amount of chemicals for control of pH (leaching and precipitation) and for minimizing heavy metal transfer into the product. The quality of products from sludge and liquor is good with low content on heavy metals, leading to a low potential toxicity for humans and ecosystems. Leaching of monoincineration ash with sulphuric acid yields 70% P with moderate chemical demand, but the leached ash and co-precipitated materials have to be disposed, and the product contains some heavy metals. Complete digestion of ash in phosphoric acid and multi-stage cleaning with ion exchangers yields high recovery of 97% P in a high-quality product (H3PO4) and several coproducts, having an overall low environmental impact. Thermo-chemical treatment of ash can recover up to 98% P with moderate energy input in case of integration into an existing monoincineration facility, but the product still contains high amounts of selected heavy metals (Cu, Zn). Metallurgic treatment of dried sludge or ash can also recover up to 81% of P, but the process has still to be tested in continuous pilot trials to validate product quality, energy demand, and energy recovery options. Sensitivity analysis shows that other pathways of sludge disposal (e.g. co-incineration combined with upstream P extraction, direct application in agriculture) may also be reasonable from an environmental point of view depending on local boundary conditions and political targets. In general, the use of life-cycle based tools is strongly recommended to evaluate and select suitable strategies for regional or national concepts of P recovery from sewage sludge.

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.

Das Projekt Nitrolimit hatte das Ziel, sich mit der Stickstofflimitation in Binnengewässern zu beschäftigen. Die Frage „Ist Stickstoffreduktion ökologisch sinnvoll und wirtschaftlich vertretbar?“ war zu beantworten. Das KWB arbeitete als einer der Projektpartner in Nitrolimit an der Modellierung der Gewässergüte von Flusssystemen am Beispiel der Berliner Stadtspree mittels QSim. Es wurde gezeigt, dass das Phytoplanktonwachstum dort derzeit nicht durch Nährstoffe, sondern vorwiegend durch Licht limitiert ist. Dennoch kann Phosphor bei einem entsprechend niedrigen Nährstoff- und Phytoplankton-Grundniveau zur steuernden Größe werden. Damit bestätigt das Modell die Hypothese, dass auch in urbanen, stark nährstoffbelasteten Gewässern eine Nährstofflimitation erreicht werden kann. Obwohl aus der Arbeit keine konkrete Grenzkonzentration abgeleitet werden kann, bedeutet das Ergebnis für die Praxis, dass bei entsprechenden Gewässern eine bedeutende Nährstoffreduktion notwendig ist, um einen positiven Effekt auf die Gewässergüte zu erreichen. Bei der Suche nach einer geeigneten Strategie für die Verbesserung des ökologischen Zustandes eines Gewässers wurde in Nitrolimit am Beispiel der unteren Havel die Strategie verfolgt, sowohl ökologische wie auch sozioökonomische Aspekte zu berücksichtigen. Wichtige Grundlage dafür waren Informationen zu Kosten und Wirksamkeit von einzelnen Maßnahmen zur Reduktion der Stickstoffeinträge aus den Bereichen Landwirtschaft und urbane Systeme. Diese Informationen wurden in Form eines Maßnahmenkatalogs in einer Datenbank zusammengefasst. Das KWB war hier verantwortlich für die Maßnahmen aus dem urbanen Bereich und veröffentlichte diese Ergebnisse separat als Nitrolimit Diskussionspapier Band 2. Über eine Ökobilanz wurden zudem nicht-monetäre ökologische Auswirkungen von weitergehenden Stickstoffeliminierungsverfahren für Großkläranlagen beschrieben. Dabei wurden alle direkten und indirekten ökologischen Auswirkungen von fünf Verfahren auf Großkläranlagen in einer ganzheitlichen Betrachtungsweise untersucht und verglichen. So konnten die direkten Effekte der verbesserten Ablaufqualität hinsichtlich der N-Fracht den zusätzlichen Aufwendungen durch die vorgelagerten Prozesse (resultierend aus dem veränderten Strom- und Chemikalienverbrauch und der benötigten Infrastruktur) gegenübergestellt werden. Es zeigte sich, dass die einzelnen Maßnahmen bei vergleichbaren Wirkungen auf die N-Fracht sehr unterschiedliche zusätzliche Aufwendungen in Energieverbrauch und Treibhausgasemissionen erfordern. Letztendlich war es möglich, Szenarien für die Verbesserung des Zustandes der Unteren Havel vorzuschlagen und zu analysieren. Es haben dafür mehrfach Gespräche mit den Stakeholder aus Berlin und Brandenburg (SenStadtUm, BWB, LUGV) stattgefunden, um die Entwicklung der Szenarien abzustimmen. Das KWB prüfte und validierte in enger Zusammenarbeit mit dem IGB und der TUB die Ergebnisse des Nährstoffmodells MONERIS für die verschiedenen Szenarien.

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).