The objective of the report is to identify enabling and hindering factors for the uptake of ICT solutions to water governance, through the analysis of the process of development and the introduction of three digital applications in three different contexts of water management.
This final deliverable builds on a preliminary (deliverable 3.4) for WP3 which was submitted in November 2020. The report applies the structure proposed in the Guiding Protocol (Deliverable 3.1).

This report describes the main functionalities the SMART-Control web-based tool T1B Quantitative microbial risk assessment. The tool helps to quantify the pathogen occurrence in source water and their removal by various treatment steps at MAR facilities by using a probabilistic approach. The interactive web-based QMRA tool supports the evidence-based risk assessment to minimize water-related infectious diseases.

Subsurface travel time from the area of recharge to the point of abstraction during MAR is a critical parameter to ensure sufficient attenuation for hygienic parameters and other undesired substances. A new simulation tool has been developed by the SMART-Control project partners KWB and TUD for determination of groundwater hydraulic residence time (HRT) using seasonal temperature fluctuations observed in recharge water and MAR recovery wells. This tool represents a proxy for quick, costs-effective and reliable control of travel time during aquifer passage. Time series of seasonal temperature measurements observed in surface water and abstraction wells can be fitted to sinusoidal functions. Peak values represented as local maxima and local minima and turning points from the fitted sinusoidal curves are used for the approximation of travel times between surface water and abstraction well. The calculated values are adjusted by a thermal retardation factor. The developed tool is userfriendly and offers the possibility to use existing hystorical temperature measurements as well as online sensor data. Data acquisition is resolved through the internal connectivity with other web-tools developed within the SMART-Control project, providing thus an integrated simulation environment.

This report summarizes the work for monitoring of hydraulic residence time (HRT) carried out at the Managed Aquifer Recharge (MAR) site Berlin-Spandau waterworks. The newly installed monitoring system consists of realtime online sensor data and evaluation algorithms implemented as a web-based software tool. The combination of online data with processing tools allows time-efficient HRT evaluation. Apart from HRT estimations, the monitoring also included measurements by flow-through cytometry (FCM), meta-genomic DNA sequencing and classical microbial cultivation-based analysis. FCM cell counting allows to quantitatively detect microbial cells after staining with a DNA-binding fluorescent dye. The aim of FCM measurements was to gain insights on microbial dynamics along the flow path from the infiltration basin to the abstraction well. The FCM device was installed to measure in the infiltration basin, groundwater observation well and abstraction well in a continuously flowing sampling line that allowed for automatic and continuous monitoring in water. Microbial indicators of viruses, bacteria and protozoa were sampled and analysed by classical cultivation-based methods in parallel to the FCM measurements. The combination of FCM with cultivation-based methods aimed to establish an indicative reference cell count representing a hygienically safe water. The high-frequency flow cytometry data revealed decreasing order of total cell counts from surface water in the infiltration basin water to groundwater in the abstraction well. The fairly constant measurements in the abstraction well may allow to use FCM fingerprinting as a fast monitoring tool in combination with cultivation based methods. However, long-term measurements of FCM for at least 6 months are recommended to assess seasonal fluctuation in both source water and groundwater. Water samples were in addition characterised by DNA sequencing enabling a complete "meta genomic" analysis and taxonomic profiling including bacterial, archaea, viral, eukaryotic DNA. The DNA sequencing in combination with FCM measurements showed that total cell counts decreased along the flow path while the biodiversity increased.

In 2015, the town of El Port de la Selva in Spain implemented soil-aquifer treatment (SAT) using tertiary treated wastewater effluents to replenish the local potable aquifer. This study evaluated the initial phase of this indirect potable water reuse system including a characterization of hydraulic conditions in the aquifer and monitoring of microbial contaminants and 151 chemicals of emerging concern (CECs). The combined treatment resulted in very low abundances of indicator bacteria, enteric viruses and phages in the monitoring wells after three days of infiltration and a reduction of antibiotic microbial resistance to background levels of local groundwater. After tertiary treatment, 94 CECs were detected in the infiltration basin of which 15 chemicals exceeded drinking water thresholds or health-based monitoring trigger levels. Although SAT provided an effective barrier for many chemicals, 5 CECs were detected above health-based threshold levels in monitoring wells after short hydraulic retention times. However, additional attenuation is expected due to dilution prior to abstraction via downstream drinking water wells and during granular activated carbon (GAC) filtration, which was recently installed to mitigate residual CECs. Overall, the results demonstrate that indirect potable water reuse can be a reliable option for smaller communities, if related risks from microbial and chemical contaminants are adequately addressed by tertiary treatment and subsequent SAT, providing sufficient hydraulic retention times for pathogen decay and CEC removal.

In Berlin wird Trinkwasser ohne aufwändige technische Aufbereitung über naturnahe Verfahren gewonnen. Ca. 80% des geförderten Rohwassers stammen aus Uferfiltration oder künstlich angereichertem Grundwasser (Möller & Burgschweiger 2008). Nach der Entfernung von Eisen und Mangan über Belüftung und Filtration wird im Routinebetrieb grundsätzlich auf eine chemische Desinfektion verzichtet. Zur Gewährleistung der hygienischen Sicherheit haben die Wasserschutzgebiete und hier insbesondere die engere Schutzzone (Zone II) daher eine wichtige Bedeutung. Deren Ausdehnung reicht von der Fassungsanlage bis zu der Linie, von der aus das genutzte Grundwasser 50 Tage im Grundwasserleiter fließt, bevor es über Brunnen zum Wasserwerk gefördert wird (DVGW 2006). Durch die Einhaltung dieser 50-Tage-Richtlinie wird v.a. der Schutz vor mikrobiellen Verunreinigungen angestrebt. Die Aufenthaltszeit des Wassers in der Untergrundpassage kann direkt durch Markierungsversuche ermittelt werden. Da solche Tracer-Untersuchungen zeitlich und technisch aufwändig sind, wurde im Rahmen verschiedener gemeinsamer Forschungsprojekte der Berliner Wasserbetriebe und des Kompetenzzentrums Wasser Berlin geprüft, mit welchen einfachen, kostengünstigen Methoden die Fließzeiten und die Auswirkungen sich ändernder klimatischer Randbedingungen im Betrieb der Grundwasseranreicherung und der Trinkwasserbrunnen überwacht werden können (Sprenger et al. 2016). Dabei wurden unter anderem kontinuierlich messende Temperatur-Druck-Sonden eingesetzt, sowie Geräte zur Quasi-Echtzeitmessung mikrobiologischer Parameter. Parallel wurde für einen Wasserwerksstandort in Berlin ein vereinfachtes numerisches Modell erstellt, mit dem Anreicherungsszenarien in Abhängigkeit der Temperatur des angereicherten Wassers gerechnet und bewertet werden können. Außerdem wurde der Einfluss der Wassertemperatur auf betriebliche Parameter der Oberflächenwasseraufbereitung untersucht. Die Untersuchungen sind ebenfalls Grundlage für risikobasierte Bewertungsansätze für hydraulische und mikrobiologische Parameter und die Ableitung betrieblicher Maßnahmen gegen eine Unterschreitung der 50-Tage-Verweilzeit.

The types and objectives to apply managed aquifer recharge (MAR) are manifold and so are the risks that can arise during the planning, implementation and operation of a MAR facility. In general, operational, regulatory, business, human health, and environmental risks can occur and should be identified already during the planning and implementation stage to apply preventive measures and secure the safe and realibale operation of a MAR facility. This report represents risk assessment based on recommendations of international guidelines (AlcaldeSanz and Gawlik, 2017; NRMMC-EPHC-NHMRC, 2008; WHO, 2009, 2011) at six MAR sites which are at different stages of development. Three case studies are at the feasibility or pilot stage: two ASR systems in João Pessoa and Recife, Brazil and one induced bank filtration site at the Beberibe River in Brazil, and three case studies at the operational stage: one SAT system in the Ezousa catchment in Cyprus, and two infiltration basin systems in Hyères, France (Aquarenova site) and Berlin-Spandau, Germany. The entrylevel assessment according to the Australian guidelines (NRMMC-EPHC-NHMRC, 2009) has been conducted for the feasibility or pilot scale schemes For fully operational MAR schemes, in addition to the entry-level assessment, the degree of difficulty assessment and the maximal risk assessment were carried out. At all stages of site development, risk assessment helps to identify and characterize potential hazards that may cause risks to human health and the environment. This report may be used to assist in clarifying which actions or further investigations are required to identify and reduce the uncertainty of risks and to implement remediation measures if necessary. In addition, this report intends to show how sitespecific hazards have been assessed to varying degrees depending upon the level of risk assessed at each project development stage.

The last 60 years has seen unprecedented groundwater extraction and overdraft as well as development ofnew technologies for water treatment that together drive the advance in intentional groundwater replenishment known as managed aquifer recharge (MAR). This paper is the first known attempt to quantify the volume ofMAR at global scale, and to illustrate the advancement of all the major types ofMAR and relate these to research and regulatory advancements. Faced with changing climate and rising intensity ofclimate extremes, MAR is an increasingly important water management strategy, alongside demand management, to maintain, enhance and secure stressed groundwater systems and to protect and improve water quality. During this time, scientific research—on hydraulic design offacilities, tracer studies, managing clogging, recovery efficiency and water quality changes in aquifers—has underpinned practical improvements in MAR and has had broader benefits in hydrogeology. Recharge wells have greatly accelerated recharge, particularly in urban areas and for mine water management. In recent years, research into governance, operating practices, reliability, economics, risk assessment and public acceptance ofMAR has been undertaken. Since the 1960s, implementation of MAR has accelerated at a rate of 5%/year, but is not keeping pace with increasing groundwater extraction. Currently, MAR has reached an estimated 10 km3/year, ~2.4% of groundwater extraction in countries reporting MAR (or ~1.0% of global groundwater extraction). MAR is likely to exceed 10% of global extraction, based on experience where MAR is more advanced, to sustain quantity, reliability and quality ofwater supplies.