ALBERT

Description: Water Expert : a conceptualized framework for development of a rule-based decision support system for distribution system decontamination Drinking Water Engineering and Science, 8, 9-24, 2015 Author(s): J. L. Gutenson, A. N. S. Ernest, J. R. Fattic, L. E. Ormsbee, A. A. Oubeidillah, and X. Zhang Significant drinking water contamination events pose a serious threat to public and environmental health. Water utilities often must make timely, critical decisions without evaluating all facets of the incident. The data needed to enact informed decisions are inevitably dispersant and disparate, originating from policy, science, and heuristic contributors. Water Expert is a functioning hybrid decision support system (DSS) and expert system framework that emphasizes the meshing of parallel data structures in order to expedite and optimize the decision pathway. Delivered as a thin-client application through the user's web browser, Water Expert 's extensive knowledgebase is a product of inter-university collaboration that methodically pieced together system decontamination procedures. Decontamination procedures are investigated through consultation with subject matter experts, literature review, and prototyping with stakeholders. This paper discusses the development of Water Expert , analyzing the development process underlying the DSS and the system's existing architecture specifications. Water Expert constitutes the first system to employ a combination of deterministic and heuristic models which provide decontamination solutions for water distribution systems. Results indicate that the decision making process following a contamination event is a multi-disciplinary effort. This contortion of multiple inputs and objectives limit the ability of the decision maker to find optimum solutions without technological intervention.

Description: Geochemical study on hot-spring water in West New Britain Province, Papua New Guinea Geothermal Energy Science, 3, 61-67, 2015 Author(s): M. M. Lahan, R. T. Verave, and P. Y. Irarue West New Britain Province, which occupies the western part of New Britain Island in Papua New Guinea, is ideally located within an active tectonic region that influences volcanism creating an environment favourable for geothermal activity. Geothermal mapping of surface manifestations reveals high temperature geothermal prospects along the northern coastline of West New Britain Province that are further confirmed by geochemical analysis. The occurrence of geothermal features is confined to the Quaternary Kimbe Volcanics and alluvium in the lowland areas. The features in Talasea appear to be controlled by deep-seated northerly trending faults while structures in Hoskins also appear to be deep seated but have not been identified. The geothermal systems in West New Britain Province have not been drilled, but preliminary reconnaissance geothermal mapping and geochemical analysis reveals four high temperature geothermal prospects suitable for further investigation and development of geothermal energy. These are the Pangalu (Rabili) and Talasea Station geothermal prospects in Talasea and Kasiloli (Magouru) and Silanga (Bakama and Sakalu) geothermal prospects in Hoskins. The calculated reservoir temperatures for these fields are in the range of 245–310 °C. Recommendations are made for further follow-up exploratory investigations.

Description: Estimating fast and slow reacting component in surface and groundwater using 2R model Drinking Water Engineering and Science Discussions, 8, 197-217, 2015 Author(s): P. Jamwal, M. N. Naveen, and Y. Javeed Maintaining residual chlorine levels in a water distribution networks is a challenging task; especially in the context of developing countries where water is usually supplied intermittently. To model chlorine decay in water distribution networks, it is very important to understand chlorine kinetics in bulk water. Recent studies suggested that chlorine decay rate depends on initial chlorine levels and type of organic and inorganic matter present in water, indicating that first order decay model is unable to accurately predict chlorine decay in bulk water. In this study, we employed two reactant model (2R) to estimate the fast and slow reacting components in surface water and groundwater. We carried out bench scale test for surface and groundwater at initial chlorine level of 1, 2 and 5 mg L −1 . We used decay datasets to estimate optimal parameter values for both surface water and groundwater. After calibration, the 2R model was validated with two decay dataset with varying initial chlorine concentration (ICC). This study came up with three important findings (a) the ratio of slow to fast reacting components in groundwater was thirty times greater than that of the surface water, (b) 2R model can accurately predict chlorine decay in surface water, 98 % of the variance in the chlorine decay test was explained by the model and (c) in case groundwater, 2R model prediction accuracy reduced with the decrease in ICC levels, only 87 % variance in data was explained by the model. This could be attributed to high slow to fast reactant ratio in groundwater.

Description: Overcoming challenges in the classification of deep geothermal potential Geothermal Energy Science, 3, 19-39, 2015 Author(s): K. Breede, K. Dzebisashvili, and G. Falcone The geothermal community lacks a universal definition of deep geothermal systems. A minimum depth of 400 m is often assumed, with a further sub-classification into middle-deep geothermal systems for reservoirs found between 400 and 1000 m. Yet, the simplistic use of a depth cut-off is insufficient to uniquely determine the type of resource and its associated potential. Different definitions and criteria have been proposed in the past to frame deep geothermal systems. However, although they have valid assumptions, these frameworks lack systematic integration of correlated factors. To further complicate matters, new definitions such as hot dry rock (HDR), enhanced or engineered geothermal systems (EGSs) or deep heat mining have been introduced over the years. A clear and transparent approach is needed to estimate the potential of deep geothermal systems and be capable of distinguishing between resources of a different nature. In order to overcome the ambiguity associated with some past definitions such as EGS, this paper proposes the return to a more rigorous petrothermal versus hydrothermal classification. This would be superimposed with numerical criteria for the following: depth and temperature; predominance of conduction, convection or advection; formation type; rock properties; heat source type; requirement for formation stimulation and corresponding efficiency; requirement to provide the carrier fluid; well productivity (or injectivity); production (or circulation) flow rate; and heat recharge mode. Using the results from data mining of past and present deep geothermal projects worldwide, a classification of the same, according to the aforementioned criteria is proposed.

Description: Natural manganese deposits as catalyst for decomposing hydrogen peroxide Drinking Water Engineering and Science, 8, 3-8, 2015 Author(s): A. H. Knol, K. Lekkerkerker-Teunissen, and J. C. van Dijk Drinking water companies (are intending to) implement advanced oxidation processes (AOP) in their treatment schemes to increase the barrier against organic micropollutants (OMPs). It is necessary to decompose the excessive hydrogen peroxide after applying AOP to avoid negative effects in the following, often biological, treatment steps. A drinking water company in the western part of the Netherlands investigated decomposition of about 5.75 mg L −1 hydrogen peroxide in pre-treated Meuse river water with different catalysts on pilot scale. In down flow operation, the necessary reactor empty bed contact time (EBCT) with the commonly used granulated activated carbon (GAC) and waste ground water filter gravel (MCFgw) were found equal with 149 s, corresponding with a conversion rate constant r of 0.021 s −1 . The EBCT of the fine coating of ground water filter gravel (MC) was significantly shorter with a little more than 10 s ( r = 0.30 s −1 ). In up flow operation, with a flow rate of 20 m h −1 , the EBCT of coating MC increased till about 100 s ( r = 0.031 s −1 ), from which can be concluded, that the performance of this waste material is better compared with GAC, in both up and down flow operation. The necessary EBCT at average filtration rate of full scale dual layer filter material (MCFsw) amounted to 209 s ( r = 0.015 s −1 ). Regarding the average residence time in the full scale filters of 700 s, applying AOP in front of the filters could be an interesting alternative which makes a separate decomposition installation superfluous, on the condition that the primary functions of the filters are not affected.

Description: Reservoir characterization of the Upper Jurassic geothermal target formations (Molasse Basin, Germany): role of thermofacies as exploration tool Geothermal Energy Science, 3, 41-49, 2015 Author(s): S. Homuth, A. E. Götz, and I. Sass The Upper Jurassic carbonates of the southern German Molasse Basin are the target of numerous geothermal combined heat and power production projects since the year 2000. A production-orientated reservoir characterization is therefore of high economic interest. Outcrop analogue studies enable reservoir property prediction by determination and correlation of lithofacies-related thermo- and petrophysical parameters. A thermofacies classification of the carbonate formations serves to identify heterogeneities and production zones. The hydraulic conductivity is mainly controlled by tectonic structures and karstification, whilst the type and grade of karstification is facies related. The rock permeability has only a minor effect on the reservoir's sustainability. Physical parameters determined on oven-dried samples have to be corrected, applying reservoir transfer models to water-saturated reservoir conditions. To validate these calculated parameters, a Thermo-Triaxial-Cell simulating the temperature and pressure conditions of the reservoir is used and calorimetric and thermal conductivity measurements under elevated temperature conditions are performed. Additionally, core and cutting material from a 1600 m deep research drilling and a 4850 m (total vertical depth, measured depth: 6020 m) deep well is used to validate the reservoir property predictions. Under reservoir conditions a decrease in permeability of 2–3 magnitudes is observed due to the thermal expansion of the rock matrix. For tight carbonates the matrix permeability is temperature-controlled; the thermophysical matrix parameters are density-controlled. Density increases typically with depth and especially with higher dolomite content. Therefore, thermal conductivity increases; however the dominant factor temperature also decreases the thermal conductivity. Specific heat capacity typically increases with increasing depth and temperature. The lithofacies-related characterization and prediction of reservoir properties based on outcrop and drilling data demonstrates that this approach is a powerful tool for exploration and operation of geothermal reservoirs.

Description: Confirming anthropogenic influences on the major organic and inorganic constituents of rainwater in an urban area Drinking Water Engineering and Science Discussions, 8, 77-117, 2015 Author(s): K. Chon, Y. Kim, D. H. Bae, and J. Cho The chemical composition and organic compounds of rainwater were investigated from June to December 2012 at Gwangju in Korea. The volume weighted mean of pH ranged from 3.83 to 8.90 with an average of 5.78. 50 % of rainwater samples had pH values below 5.6. The volume-weighted mean concentration (VWMC) of major ions followed the order: Cl − 〉 SO 4 2− 〉 NH 4 + 〉 Na + 〉 NO 3 − 〉 Ca 2+ 〉 Mg 2+ 〉 K + . The VWMC of trace metals decreased in the order as follows Zn 〉 Al 〉 Fe 〉 Mn 〉 Pb 〉 Cu 〉 Ni 〉 Cd 〉 Cr. The VWMCs of major ions and trace metals were higher in winter than in summer. The high enrichment factors indicate that Zn, Pb, Cu, and Cd originated predominantly from anthropogenic sources. Factor analysis (principal component analysis) indicates the influence of anthropogenic pollutants, sea salt, and crustal materials on the chemical compositions of rainwater. Benzoic acids, 1H-Isoindole-1,3(2H)-dione, phthalic anhydride, benzene, acetic acids, 1,2-benzenedicarboxylic acids, benzonitrile, acetaldehyde, and acetamide were the most prominent pyrolysis fragments for rainwater organic compounds identified by pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). The results indicate that anthropogenic sources are the most important factors affecting the organic composition of rainwater in urban area.

Description: Geothermal resources and reserves in Indonesia: an updated revision Geothermal Energy Science, 3, 1-6, 2015 Author(s): A. Fauzi More than 300 high- to low-enthalpy geothermal sources have been identified throughout Indonesia. From the early 1980s until the late 1990s, the geothermal potential for power production in Indonesia was estimated to be about 20 000 MWe. The most recent estimate exceeds 29 000 MWe derived from the 300 sites (Geological Agency, December 2013). This resource estimate has been obtained by adding all of the estimated geothermal potential resources and reserves classified as "speculative", "hypothetical", "possible", "probable", and "proven" from all sites where such information is available. However, this approach to estimating the geothermal potential is flawed because it includes double counting of some reserve estimates as resource estimates, thus giving an inflated figure for the total national geothermal potential. This paper describes an updated revision of the geothermal resource estimate in Indonesia using a more realistic methodology. The methodology proposes that the preliminary "Speculative Resource" category should cover the full potential of a geothermal area and form the base reference figure for the resource of the area. Further investigation of this resource may improve the level of confidence of the category of reserves but will not necessarily increase the figure of the "preliminary resource estimate" as a whole, unless the result of the investigation is higher. A previous paper (Fauzi, 2013a, b) redefined and revised the geothermal resource estimate for Indonesia. The methodology, adopted from Fauzi (2013a, b), will be fully described in this paper. As a result of using the revised methodology, the potential geothermal resources and reserves for Indonesia are estimated to be about 24 000 MWe, some 5000 MWe less than the 2013 national estimate.

Description: Natural manganese deposits as catalyst for decomposing hydrogen peroxide Drinking Water Engineering and Science Discussions, 8, 1-20, 2015 Author(s): A. H. Knol, K. Lekkerkerker-Teunissen, and J. C. van Dijk Drinking water companies more and more implement Advanced Oxidation Processes (AOP) in their treatment schemes to increase the barrier against organic micropollutants (OMPs). It is necessary to decompose the excessive hydrogen peroxide after applying AOP to avoid negative effects in the following, often biological, treatment steps. A drinking water company in the western part of the Netherlands investigated decomposition of about 5.75 mg L −1 hydrogen peroxide in pre-treated Meuse river water with different catalysts on pilot scale. In down flow operation, the necessary reactor Empty Bed Contact Time (EBCT) with the commonly used Granulated Activated Carbon (GAC) and waste ground water filter gravel (MCFgw) were the same with 149 s, corresponding with a conversion rate constant r of 0.021 s −1 . The EBCT of the fine coating of ground water filter gravel (MC) was significantly shorter with a little more than 10 s ( r = 0.30 s −1 ). In up flow operation, with a flow rate of 20 m h −1 , the EBCT of coating MC increased till about 100 s ( r = 0.031 s −1 ), from which can be concluded, that the performance of this waste material is better compared with GAC, in both up and down flow operation. The necessary EBCT at average filtration rate of full scale dual layer filter material (MCFsw) amounted to 209 s ( r = 0.015 s −1 ). Regarding the average residence time in the full scale filters of 700 s, applying AOP in front of the filters could be an interesting alternative which makes a separate decomposition installation superfluous, on the condition that the primary functions of the filters are not affected.

Description: Shower heat exchanger: reuse of energy from heated drinking water for CO 2 reduction Drinking Water Engineering and Science Discussions, 8, 119-141, 2015 Author(s): Z. Deng, S. Mol, and J. P. van der Hoek The heating of drinking water in households contributes for a significant amount to the emission of greenhouse gases. As a water utility aiming to operate climate neutral by 2020, Waternet needs to reduce its CO 2 emission by 53 kton yr −1 . To contribute to this ambition, a pilot project was carried out in Uilenstede, Amstelveen, the Netherlands, to recover the shower heat energy with a shower heat exchanger from Dutch Solar Systems. An experimental set up was built in the Waternet laboratory to compare field conditions and lab conditions. The energy recovery efficiency observed in the lab was 61–64 % under winter conditions and 58–62 % under summer conditions, while the energy recovery efficiency observed in Uilenstede was 57 % in December 2014. Based on the observations, 4 % of the total energy consumption of households in Amsterdam (electricity and gas) can be recovered with a shower heat exchanger installed in all households in Amsterdam, which also means a 54 kton yr −1 CO 2 emission reduction.

Description: Assessing variable speed pump efficiency in water distribution systems Drinking Water Engineering and Science Discussions, 5, 47-65, 2012 Author(s): A. Marchi, A. R. Simpson, and N. Ertugrul Energy savings and greenhouse gas emission reductions are increasingly becoming important design targets in many industrial systems where fossil fuel based electrical energy is heavily utilised. In water distribution systems (WDSs) a significant portion of operational cost is related to pumping. Recent studies have considered variable speed pumps (VSPs) which aim to vary the operating point of the pump to match demand to pumping rate. Depending on the system characteristics, this approach can lead to considerable savings in operational costs. In particular, cost reductions can take advantage of the demand variability and can decrease energy consumption significantly. One of the issues in using variable speed pumping systems, however, is the total efficiency of the electric motor/pump arrangement under a given operating condition. This paper aims to provide a comprehensive discussion about the components of WDS that incorporate variable speed pumps (including electric motors, inverters and the pumps themselves) to provide an insight of ways of increasing the system efficiency and hence to reduce energy consumption. In addition, specific attention is given to selection of motor types, sizing, duty cycle of pump (ratio of on-time and time period), losses due to installation and motor faults. All these factors affect the efficiency of motor drive/pump system.

Description: Accumulation and modeling of particles in drinking water pipe fittings Drinking Water Engineering and Science Discussions, 5, 139-171, 2012 Author(s): K. Neilands, M. Bernats, and J. Rubulis The effect of pipe fittings – mainly T-pieces – on particle accumulation in drinking water distribution networks is shown in this work. The online measurements of flow and turbidity for cast iron, polyethylene and polyvinylchloride pipe sections have been linked with the analysis of pipe geometry. Up to 0.29 kg of the total mass of particles was found to be accumulated in T-pieces ranging from DN 100/100–DN 250/250. The accumulated amount of particles in the fittings was defined as J and introduced into the existing turbidity model PODDS (Prediction of Discolouration in Distribution Systems) proposed by Boxall et al. (2001), which describes the erosion of particles leading to discoloration events in drinking water networks, viz. sections, of straight pipes. It does not interpret the mobilization of particles in pipe fittings, however, which have been considered in this article. T-pieces were the object of this study and depending on the diameter or daily flow velocity, the coefficient J varied from 1.16 to 8.02.

Description: Dynamic hydraulic models to study sedimentation in drinking water networks in detail Drinking Water Engineering and Science Discussions, 5, 121-137, 2012 Author(s): I. W. M. Pothof and E. J. M. Blokker Sedimentation in drinking water networks can lead to discolouration complaints. A sufficient criterion to prevent sedimentation in drinking water networks is a daily maximum velocity of 0.25 m s −1 . Flushing experiments have shown that this criterion is a sufficient condition for a clean network, but not a necessary condition. Drinking water networks include many locations with a maximum velocity well below 0.25 m s −1 without sediment. Other criteria need to be developed to predict which locations are susceptible to sedimentation and to prevent sedimentation in future networks. More distinctive criteria are helpful to prioritise flushing operations and to prevent water quality complaints. The authors use three different numerical modelling approaches – quasi-steady, rigid column and water hammer – with a temporal discretisation of 1 s in order to assess the influence of unsteady flows on the wall shear stress, causing resuspension of sediment particles. The model predictions are combined with results from flushing experiments in the drinking water distribution system of Purmerend, the Netherlands. The waterhammer model does not result in essentially different flow distribution patterns, compared to the rigid column and quasi-steady modelling approach. The extra information from the waterhammer model is a velocity oscillation of approximately 0.02 m s −1 around the quasi-steady solution. The presence of stagnation zones and multiple flow direction reversals seem to be interesting new parameters to predict sediment accumulation, which are consistent with the observed turbidity data and theoretical considerations on critical shear stresses.

Description: Convective, intrusive geothermal plays: what about tectonics? Geothermal Energy Science, 3, 51-59, 2015 Author(s): A. Santilano, A. Manzella, G. Gianelli, A. Donato, G. Gola, I. Nardini, E. Trumpy, and S. Botteghi We revised the concept of convective, intrusive geothermal plays, considering that the tectonic setting is not, in our opinion, a discriminant parameter suitable for a classification. We analysed and compared four case studies: (i) Larderello (Italy), (ii) Mt Amiata (Italy), (iii) The Geysers (USA) and (iv) Kizildere (Turkey). The tectonic settings of these geothermal systems are different and a matter of debate, so it is hard to use this parameter, and the results of classification are ambiguous. We suggest a classification based on the age and nature of the heat source and the related hydrothermal circulation. Finally we propose to distinguish the convective geothermal plays as volcanic, young intrusive and amagmatic.

Description: Conversion of organic micropollutants with limited bromate formation during the Peroxone process in drinking water treatment Drinking Water Engineering and Science, 8, 25-34, 2015 Author(s): A. H. Knol, K. Lekkerkerker-Teunissen, C. J. Houtman, J. Scheideler, A. Ried, and J. C. van Dijk Advanced oxidation with O 3 / H 2 O 2 (peroxone) was conducted on pilot plant scale on pre-treated Meuse river water to investigate the conversion of organic micropollutants (OMPs) and the formation of bromate. Fourteen selected model compounds were dosed to the pre-treated river water on a regular basis to assess the efficiency of the peroxone process and to establish the influence of the water matrix. The ozone dose was the main factor in the conversion of the model compounds, however, the ozone dose was limited because of bromate formation. The hydrogen peroxide dosage had only a minor effect on the conversion, but it limited the bromate formation effectively. In terms of limited chemical consumption, maximal conversion and to comply the strict Dutch drinking water act for bromate of 1 μg L −1 , a practical peroxone setting was 6 mg L −1 hydrogen peroxide and 1.5 mg L −1 ozone. During the investigation period, the average conversion of the model compounds was 78.9 %. The conversion of OMPs was higher at higher water temperatures and lower concentrations of DOC and bicarbonate. The bromate formation also was higher at higher water temperature and lower bicarbonate concentration and proportional with the bromide concentration, above a threshold of about 32 μg L −1 bromide. The peroxone process can be controlled on basis of the (derived) parameters water temperature, bicarbonate and DOC.

Description: Clay-biodegradable polymer combination for pollutant removal from water Drinking Water Engineering and Science Discussions, 8, 177-196, 2015 Author(s): M. F. Mohd Amin, S. G. J. Heijman, and L. C. Rietveld In this study, a new treatment alternative is investigated to remove micropollutants from wastewater effectively and in a more cost-effective way. A potential solution is the use of clay in combination with biodegradable polymeric flocculants. Flocculation is viewed as the best method to get the optimum outcome from the combination of clay with starch. Clay is naturally abundantly available and relatively inexpensive compared to the conventional adsorbents used. Experimental studies were carried out with four different clays to select the best clay for further optimisation. The atrazine removal achieved is in the range of 10–99 % based on the clay concentration of 10–50 g L −1 . Optimisation of the best clay performer leads towards atrazine reduction of 〉 99 % with a dosage of 100 mg L −1 . The best and underperforming clays were then tested in other experiments with the addition of cationic starch flocculants. In this experiment, the addition of a polymer increased the atrazine removal for the underperforming clay to 46 % with only 10 mg L −1 clay dosages. The clay flocculation test was also performed to test the flocculation efficiency of clays by the polymer. Approximately 80–84 % of the clay is flocculated, which shows exceptional flocculation efficiency in removing both clays and atrazine from the water matrices.

Description: Confirming anthropogenic influences on the major organic and inorganic constituents of rainwater in an urban area Drinking Water Engineering and Science, 8, 35-48, 2015 Author(s): K. Chon, Y. Kim, D. H. Bae, and J. Cho Recently, rainwater composition affected by atmospheric pollutants has been the topic of intense study in East Asia because of its adverse environmental and human health effects. In the present study, the chemical composition and organic compounds of rainwater were investigated from June to December 2012 at Gwangju in Korea. The aim of this study is to determine the seasonal variation of rainwater chemical composition and to identify possible sources of inorganic and organic compounds. The volume-weighted mean of pH ranged from 3.83 to 8.90 with an average of 5.78. Of rainwater samples, 50 % had pH values below 5.6. The volume-weighted mean concentration (VWMC) of major ions followed the order Cl − 〉 SO 4 2− 〉 NH 4 + 〉 Na + 〉 NO 3 − 〉 Ca 2+ 〉 Mg 2+ 〉 K + . The VWMC of trace metals decreased in the order Zn 〉 Al 〉 Fe 〉 Mn 〉 Pb 〉 Cu 〉 Ni 〉 Cd 〉 Cr. The VWMCs of major ions and trace metals were higher in winter than in summer. The high enrichment factors indicate that Zn, Pb, Cu, and Cd originated predominantly from anthropogenic sources. Factor analysis (principal component analysis) indicates the influence of anthropogenic pollutants, sea salt, and crustal materials on the chemical compositions of rainwater. Benzoic acids, 1H-isoindole-1,3(2H)-dione, phthalic anhydride, benzene, acetic acids, 1,2-benzenedicarboxylic acids, benzonitrile, acetaldehyde, and acetamide were the most prominent pyrolysis fragments for rainwater organic compounds identified by pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). The results indicate that anthropogenic sources are the most important factors affecting the organic composition of rainwater in an urban area.

Description: Thermodynamic and thermoeconomic analysis of combined geothermal space heating and thermal storage using phase change materials Geothermal Energy Science, 3, 69-80, 2015 Author(s): V. Chauhan and Á. Ragnarsson The present work discusses the utilization of phase change materials for energy storage in geothermal space heating systems. Thermodynamics and thermoeconomics of the combined heating and thermal storing system were studied to show the scope of energy storage and cost savings. A computational model of the combined space heating and thermal storage system was developed and used to perform thermodynamic studies of the heat storage process and heating system efficiency at different times and ambient temperatures. The basis for these studies is daily variations in heating demand that is higher during the night than during the day. The results show the scope of the utilization of phase change material for low ambient temperature conditions. Under proper conditions a sufficient amount of exergy is stored during the charging period at a low ambient temperature to fulfill the daytime heat load requirement. Under these conditions the cost flow rate of exergy storage is found to be lower than the radiator heating cost flow rate. Thus, the use of exergy storage at low ambient temperatures for heating at higher ambient temperatures makes a significant contribution to cost savings.

Description: Non-residential water demand model validated with extensive measurements Drinking Water Engineering and Science Discussions, 5, 455-471, 2012 Author(s): E. J. Pieterse-Quirijns, E. J. M. Blokker, E. van der Blom, and J. H. G. Vreeburg Existing guidelines related to the water demand of non-residential buildings are outdated and do not cover hot water demand for the appropriate selection of hot water devices. Moreover, they generally overestimate peak demand values required for the design of an efficient and reliable water system. Recently, a procedure was developed based on the end-use model SIMDEUM ® to derive design rules for peak demand values of both cold and hot water during various time steps for several types and sizes of non-residential buildings, i.e. offices, hotels and nursing homes. In this paper, the design rules are validated with measurements of cold and hot water patterns on a per second base. The good correlation between the simulated patterns and the measured patterns indicates that the basis of the design rules, the SIMDEUM simulated standardised buildings, is solid. Moreover, the SIMDEUM based rules give a better prediction of the measured peak values for cold water flow than the existing guidelines. Furthermore, the new design rules can predict hot water use well. In this paper it is illustrated that the new design rules lead to reliable and improved designs of building installations and water heater capacity, resulting in more hygienic and economical installations.

Description: Numerical and experimental investigation of leaks in viscoelastic pressurized pipes Drinking Water Engineering and Science Discussions, 5, 473-494, 2012 Author(s): S. Meniconi, B. Brunone, M. Ferrante, and C. Massari This paper extends the analysis concerning the importance in numerical models of unsteady friction and viscoelasticity to transients in plastic pipes with an external flow due to a leak. In fact recently such a benchmarking analysis has been executed for the cases of a constant diameter pipe (Duan et al., 2010), a pipe with a partially closed in-line valve (Meniconi et al., 2012a), and a pipe with cross-section changes in series (Meniconi et al., 2012b). The analysis is based on laboratory tests carried out at the Water Engineering Laboratory (WEL) of the University of Perugia, Italy, and numerical experiments by means of different 1-D numerical models. The results show that it is crucial to take into account the viscoelasticity to simulate the main characteristics of the transients, also in the case of a damaged pipes.

Description: Accumulation and modeling of particles in drinking water pipe fittings Drinking Water Engineering and Science, 5, 47-57, 2012 Author(s): K. Neilands, M. Bernats, and J. Rubulis The effect of pipe fittings (mainly T-pieces) on particle accumulation in drinking water distribution networks were shown in this work. The online measurements of flow and turbidity for cast iron, polyethylene and polyvinyl chloride pipe sections were linked with analysis of pipe geometry. Up to 0.29 kg of the total amount mobilized in T-pieces ranging from DN 100/100–DN 250/250. The accumulated amount of particles in fittings was defined as J and introduced into the existing turbidity model PODDS (prediction of discoloration in distribution systems) proposed by Boxall et al. (2001) which describes the erosion of particles leading to discoloration events in drinking water network viz sections of straight pipes. However, this work does not interpret mobilization of particles in pipe fittings which have been considered in this article. T-pieces were the object of this study and depending of the diameter or daily flow velocity, the coefficient J varied from 1.16 to 8.02. The study showed that pipe fittings act as catchment areas for particle accumulation in drinking water networks.

Description: Leakages and pressure relations: an experimental research Drinking Water Engineering and Science Discussions, 5, 403-419, 2012 Author(s): F. De Paola and M. Giugni Leaks in water systems are presently a frequent and increasing event that involves cost increase and poor service, not compliant to quality standards and modern management criteria. The most recent data available in Italy, resumed into the report issued by Control Committee for Water Resources Use (CONVIRI), shows leakages with an average value of 37%. It is important, for maintenance perspective, to investigate occurrence and evolution of water leaks and the analytical links between leaks Q p and network pressure P , for a reliable calibration of water networks quali-quantitative simulation models. The present work reports the results of an experimental campaign started at Laboratory of Hydraulic of Department of Hydraulic, Geotechnical and Environmental Engineering of University of Naples Federico II in order to analyze the features of Q p ( P ) relation, which are compared with principal results issued in literature.

Description: Fluoride in the drinking water of Pakistan and the possible risk of crippling fluorosis Drinking Water Engineering and Science Discussions, 5, 495-514, 2012 Author(s): M. A. Tahir and H. Rasheed To explore the possibility of fluoride toxicity, seven hundred and forty seven (747) water samples were collected from surface and ground water sources of sixteen major cities of Pakistan, adopting a uniform sampling design with distribution of samples as: Lahore (79), Kasur (46), Faisalabad (30), Khushab (50), Chakwal (51), Mianwali (30), Jhelum (53), Bahawalpur (60), Karachi (60), Mirpur Khas (55), Peshawar (38), Risalpur (35), Quetta (81), Ziarat (21), Loralai (21), Mastung (37). The comparison of analytical findings with WHO Guidelines of Drinking Water for Fluoride (i.e. 1.5 ppm) has concluded that 16% of the monitored water sources have fluoride concentration beyond the permissible, safe limit of 1.5 mg l −1 , falling in the concentration range of 1.6–25 mg l −1 . The highest fluoride contamination (22%) has been detected in the Balochistan province followed by 19% in Punjab province. Comparatively higher fluoride levels of 〉20% in groundwater sources such as hand pumps has supported the possibility of increased ground water contamination, as excessive fluoride concentrations are expected to come from calcium-poor aquifers and from areas where fluoride-bearing minerals are common or where cation exchange of sodium for calcium occurs. Field observations have also indicated the prevalence of fluoride-associated health implications in the study areas with excessive fluoride in water sources. The findings in this study have provided a bidirectional vision for epidemiological investigations as well as for mitigating the issues in the affected vicinities of fluoride-rich areas.

Description: Modelling water quality in drinking water distribution networks from real-time direction data Drinking Water Engineering and Science, 5, 39-45, 2012 Author(s): S. Nazarovs, S. Dejus, and T. Juhna Modelling of contamination spread and location of a contamination source in a water distribution network is an important task. There are several simulation tools developed, however the significant part of them is based on hydraulic models that need node demands as input data that sometimes may result in false negative results and put users at risk. The paper considers applicability of a real-time flow direction data based model for contaminant transport in a distribution network of a city and evaluates the optimal number of flow direction sensors. Simulation data suggest that the model is applicable for the distribution network of the city of Riga and that the optimal number of sensors in this case is around 200.

Description: The large-scale impact of climate change to Mississippi flood hazard in New Orleans Drinking Water Engineering and Science Discussions, 5, 333-349, 2012 Author(s): T. L. A. Driessen and M. van Ledden The objective of this paper is to describe the impact of climate change on the Mississippi River flood hazard in the New Orleans area. This city has a unique flood risk management challenge, heavily influenced by climate change, since it faces flood hazards from multiple geographical locations (e.g. Lake Pontchartrain and Mississippi River) and multiple sources (hurricane, river, rainfall). Also the low elevation and significant subsidence rate of the Greater New Orleans area poses a high risk and challenges the water management of this urban area. Its vulnerability to flooding became dramatically apparent during Hurricane Katrina in 2005 with huge economic losses and a large number of casualties. A SOBEK Rural 1DFLOW model was set up to simulate the general hydrodynamics. This improved model includes two important spillways that are operated during high flow conditions. Subsequently, a weighted multi-criteria calibration procedure was performed to calibrate the model for high flows. Validation for floods in 2011 indicates a very reasonable performance for high flows and clearly demonstrates the necessity of the spillways. 32 different scenarios are defined which includes the relatively large sea level rise and the changing discharge regime that is expected due to climate change. The impact of these scenarios is analysed by the hydrodynamic model. Results show that during high flows New Orleans will not be affected by varying discharge regimes, since the presence of the spillways ensures a constant discharge through the city. In contrary, sea level rise is expected to push water levels upwards. The effect of sea level rise will be noticeable even more than 470 km upstream. Climate change impacts necessitate a more frequent use of the spillways and opening strategies that are based on stages. Potential alternatives on how to cope with the flood hazard of this river in the long term, such as river widening and large-scale redistribution of the flow through diversions, are proposed.

Description: Effect of biostimulation on biodegradation of dissolved organic carbon in biological filters Drinking Water Engineering and Science, 5, 23-29, 2012 Author(s): K. Tihomirova, A. Briedis, J. Rubulis, and T. Juhna The addition of labile organic carbon (LOC) to enhance the biodegradation rate of dissolved organic carbon (DOC) in biological columns was studied. Acetate standard solution (NaAc) and Luria Bertrani (LB) medium were used as LOC as biostimulants in glass column system used for measurements of biodegradable dissolved organic carbon (BDOC). The addition of LOC related with the increase of total DOC in sample. The concentration of BDOC increased up to 7 and 5 times and was utilized after 24 min. contact time. The biodegradation rate constant was increased at least 26 times during adaptation-biostimulation period. There was a strong positive correlation between the biodegradation rate constant and the concentration of BDOC. Biostimulation period ranged from 24 to 53 h for NaAc biostimulant and from 20 to 168 h for LB. The study has shown that LOC could be used as stimulator to enhance the biodegradation rate of DOC during biofiltration.

Description: Natural organic matter removal by ion exchange at different positions in the drinking water treatment lane Drinking Water Engineering and Science Discussions, 5, 375-401, 2012 Author(s): A. Grefte, M. Dignum, E. R. Cornelissen, and L. C. Rietveld To guarantee a good water quality at the customers tap, natural organic matter (NOM) should be (partly) removed during drinking water treatment. The objective of this research was to improve the drinking water quality, including biological stability, by incorporating anion exchange (IEX) for NOM removal. Different placement positions of IEX in the treatment lane (IEX positioned before coagulation, before ozonation or after slow sand filtration) are compared on water quality as well as costs. For this purpose the pre-treatment plant at Loenderveen and production plant Weesperkarspel of Waternet were used as a case study. NOM removal can be done efficiently before ozonation and after slow sand filtration; it was found that the position in the treatment lane did not influence the NOM removal capacity. The operational costs were assumed to be directly dependent of the NOM removal rate and determined the difference between the IEX positions. The operational costs for IEX positioned before coagulation were higher than for IEX positioned after slow sand filtration, however the savings on following treatment processes caused a cost reduction compared to IEX positioned after slow sand filtration. IEX positioned before coagulation or ozonation were most cost effective and produced the highest water quality.

Description: Assessing variable speed pump efficiency in water distribution systems Drinking Water Engineering and Science, 5, 15-21, 2012 Author(s): A. Marchi, A. R. Simpson, and N. Ertugrul Energy savings and greenhouse gas emission reductions are increasingly becoming important design targets in many industrial systems where fossil fuel based electrical energy is heavily utilised. In water distribution systems (WDSs) a significant portion of operational cost is related to pumping. Recent studies have considered variable speed pumps (VSPs) which aim to vary the operating point of the pump to match demand to pumping rate. Depending on the system characteristics, this approach can lead to considerable savings in operational costs. In particular, cost reductions can take advantage of the demand variability and can decrease energy consumption significantly. One of the issues in using variable speed pumping systems, however, is the total efficiency of the electric motor/pump arrangement under a given operating condition. This paper aims to provide a comprehensive discussion about the components of WDS that incorporate variable speed pumps (including electric motors, variable frequency drives and the pumps themselves) to provide an insight of ways of increasing the system efficiency and hence to reduce energy consumption. In addition, specific attention is given to selection of motor types, sizing, duty cycle of pump (ratio of on-time and time period), losses due to installation and motor faults. All these factors affect the efficiency of motor drive/pump system.

Description: Reliability of water distribution networks due to pumps failure: comparison of VSP and SSP application Drinking Water Engineering and Science Discussions, 5, 351-373, 2012 Author(s): N. Mehzad, M. Tabesh, S. S. Hashemi, and B. Ataee Kia Reliability is an important indicator to ensure the operation of Water Distribution Networks (WDNs). To optimize the operation of WDN, it is necessary to incorporate the reliability of active components (such as pumps and tanks) besides the reliability of pipes. In this research, a concept is suggested to calculate the reliability of WDNs' pumping stations. A computer code is provided in Visual Basic and is linked to EPANET2.0. To evaluate the proposed methodology a real WDN near the city of Tehran is considered. According to the obtained results, it is concluded that by increasing the demand of the WDN during a day, the reliability of pumps decrease. Therefore, it seems that decision-making is necessary if high demand hours are considered, in order to increase the reliability of the system. On the other hand, it is observed in this research that using variable speed pumps not only reduces the energy cost of the network, but also the reliability of the pumping stations with variable speed pumps is higher than single speed pumps. Therefore, using VSP is highly recommended in WDNs.

Description: Predicting the residual aluminum level in water treatment process Drinking Water Engineering and Science Discussions, 5, 243-264, 2012 Author(s): J. Tomperi, M. Pelo, and K. Leiviskä In water treatment processes, aluminum salts are widely used as coagulation chemical. High dose of aluminum has been proved to be at least a minor health risk and some evidence points out that aluminum could increase the risk of Alzheimer's disease thus it is important to minimize the amount of residual aluminum in drinking water and water used at food industry. In this study, the data of a water treatment plant (WTP) was analyzed and the residual aluminum in drinking water was predicted using Multiple Linear Regression (MLR) and Artificial Neural Network (ANN) models. The purpose was to find out which variables affect the amount of residual aluminum and create simple and reliable prediction models which can be used in an early warning system (EWS). Accuracy of ANN and MLR models were compared. The new nonlinear scaling method based on generalized norms and skewness was used to scale all measurement variables to range [−2...+2] before data-analysis and modeling. The effect of data pre-processing was studied by comparing prediction results to ones achieved in an earlier study. Results showed that it is possible to predict the baseline level of residual aluminum in drinking water with a simple model. Variables that affected the most the amount of residual aluminum were among others: raw water temperature, raw water KMnO 4 and PAC / KMnO 4 -ratio. The accuracies of MLR and ANN models were found to be almost equal. Study also showed that data pre-processing affects to the final prediction result.

Description: How much are households willing to contribute to the cost recovery of drinking water supply? Results from a household survey Drinking Water Engineering and Science Discussions, 5, 225-241, 2012 Author(s): S. Tarfasa Improving existing drinking water supply services in developing countries depends crucially on available financial resources. Cost recovery rates of these services are typically low, while demand for more reliable services is high and rapidly growing. Most stated preference based demand studies in the developing world apply the contingent valuation method and focus on rural areas. This study examines the willingness of households to pay for improved water supply services employing a choice model (CM) in an urban area in Ethiopia, a country with the lowest water supply coverage in Sub-Saharan Africa. The design of the choice model allows the estimation of the values of both drinking water reliability and safety. The estimated economic values can be used in policy appraisals of investment decisions. Despite significant income constraints, households are willing to pay up to 60% extra for improved levels of water supply over and above their current water bill, especially households living in the poorest part of the city with the lowest service levels. Women value the improvement of water quality most, while a significant effect is found for averting behavior and expenditures.

Description: Subsurface arsenic removal column tests: from the laboratory to the field Drinking Water Engineering and Science Discussions, 5, 193-207, 2012 Author(s): D. H. Moed, D. van Halem, J. Q. J. C. Verberk, J. A. M. van Paassen, and L. C. Rietveld Previous laboratory column experiments have given evidence of competitive effects between different groundwater constituents in the process of subsurface arsenic removal, a process in which arsenic is removed from groundwater by injecting water with oxygen into the subsurface. The presence of phosphate and other anions significantly limited arsenic removal. To investigate the influence of phosphate in natural groundwater, pumping stations in Loosdrecht (the Netherlands) and Subotica (Serbia) both with low phosphate concentrations (

Description: A new model for the simplification of particle counting data Drinking Water Engineering and Science, 5, 9-14, 2012 Author(s): M. F. Fadal, J. Haarhoff, and S. Marais This paper proposes a three-parameter mathematical model to describe the particle size distribution in a water sample. The proposed model offers some conceptual advantages over two other models reported on previously, and also provides a better fit to the particle counting data obtained from 321 water samples taken over three years at a large South African drinking water supplier. Using the data from raw water samples taken from a moderately turbid, large surface impoundment, as well as samples from the same water after treatment, typical ranges of the model parameters are presented for both raw and treated water. Once calibrated, the model allows the calculation and comparison of total particle number and volumes over any randomly selected size interval of interest.

Description: Water investment in Mexico City: contradictory elements preventing investment efficiency Drinking Water Engineering and Science Discussions, 5, 209-223, 2012 Author(s): M. J. Marquez-Dorantes The complex connections between environmental and socio-economic variables in the water sector system involve not only ecological changes such as climate change but also a need for changes in socio-economic arenas to reduce the impacts of climate change. It is necessary not only to acknowledge the elements of change but also to understand the constraints preventing change in specific cases. The challenges faced by the water sector in Mexico City, as the world's second largest urban agglomeration with its fast growing population, limited external water sources, depleted aquifers and increased disaster risks, call for urgent measures to resolve the inefficiencies found in the traditional approach to water investment. This paper explores how far the multiple objectives of different actors involved in water projects are balanced to attain integrated water management. The Santa Catarina Water Supply Project, which is in a highly contentious area because of the limited availability of drinking water, is presented as a case study. The analysis shows that the multiple objectives of the different actors involved, together with an institutional structure that perpetuates a traditional engineering approach, constrain the effective and efficient delivery of water projects. The institutional analysis development framework (Ostrom, 2006) is used to analyse the arena of investment decision-making in water for Mexico City. Following the notion of institutional arrangements as " incentives and deterrents " (Ostrom, 1976), eight contradictory elements are proposed to illustrate the process by which institutional arrangements, implemented by specific actors with the intention of producing specific outcomes, are inefficient in delivering the expected outcomes, and can even produce negative ones when interacting with other existing formal and informal arrangements determined by other actors. These elements explain both the resilience of the system, which has so far prevented its collapse, and the magnitude of a growing problem that demands change.

Description: Robust optimization methodologies for water supply systems design Drinking Water Engineering and Science Discussions, 5, 173-192, 2012 Author(s): J. Marques, M. C. Cunha, J. Sousa, and D. Savić Water supply systems (WSSs) are vital infrastructures for the well-being of people today. To achieve good customer satisfaction the water supply service must always be able to meet people's needs, in terms of both quantity and quality. But unpredictable extreme conditions can cause severe damage to WSSs and lead to poorer levels of service or even to their failure. Operators dealing with a system's day-to-day operation know that events like burst water mains can compromise the functioning of all or part of a system. To increase a system's reliability, therefore, designs should take into account operating conditions other than normal ones. Recent methods based on robust optimization can be used to solve optimization problems which involve uncertainty and can find designs which are able to cope with a range of operating conditions. This paper presents a robust optimization model for the optimal design of water supply systems operating under different circumstances. The method presented here uses a hydraulic simulator linked to an optimizer based on a simulated annealing heuristic. The results show that robustness can be included in several ways for varying levels reliability and that it leads to more reliable designs for only small cost increases.

Description: Modelling water quality in drinking water distribution networks from real-time direction data Drinking Water Engineering and Science Discussions, 5, 31-46, 2012 Author(s): S. Nazarovs, S. Dejus, and T. Juhna Modelling of contamination spread and location of contamination source in a water distribution network is an important task. The paper considers applicability of real-time flow direction data based model for contaminant transport for a distribution network of a city. Simulations of several contamination scenarios are made to evaluate necessary number of flow direction sensors. It is found that for a model, containing major pipes of Riga distribution system, sensor number decrease from 927 to 207 results in average 20% increase of simulated contaminated length of pipes. Simulation data suggest that optimal number of sensors for Riga model is around 200.

Description: Effect of biostimulation on biodegradation of dissolved organic carbon in biological granular activated carbon filters Drinking Water Engineering and Science Discussions, 5, 67-83, 2012 Author(s): K. Tihomirova, A. Briedis, J. Rubulis, and T. Juhna The addition of labile organic carbon (LOC) to enhance the biodegradation rate of dissolved organic carbon (DOC) in biological columns was studied. Acetate standard solution (NaAc) and LB (Luria Bertrani) medium were used as LOC as biostimulants in glass column system used for measurements of biodegradable dissolved organic carbon (BDOC). The addition of LOC related with the increase of total DOC in sample. The concentration of BDOC increased up to 7 and 5 times and was utilized after 24 min. contact time. The biodegradation rate constant was increased at least 8 times during adaptation-biostimulation period. There was a strong positive correlation between the biodegradation rate constant and the concentration of BDOC. Biostimulation period ranged from 24 to 53 h for NaAc biostimulant and from 20 to 168 h for LB. The study has shown that LOC could be used as stimulator to enhance the biodegradation rate of DOC during biofiltration.

Description: Development of a iron pipe corrosion simulation model for a water supply network Drinking Water Engineering and Science Discussions, 5, 85-120, 2012 Author(s): M. Bernats, S. W. Osterhus, K. Dzelzitis, and T. Juhna Corrosion in water supply networks is unwanted process that causes pipe material loss and subsequent pipe failures. Nowadays pipe replacing strategy most often is based on pipe age, which is not always the most important factor in pipe burst rate. In this study a methodology for developing a mathematical model to predict the decrease of pipe thickness in a large cast iron networks is presented. The quality of water, the temperature and the water flow regime were the main factors taken into account in the corrosion model. The water quality and flow rate effect were determined by measuring corrosion rate of metals coupons over the period of one year at different flow regimes. The obtained constants were then introduced in a calibrated hydraulic model (Epanet) and the corrosion model was validated by measuring the decrease of wall thickness in the samples that were removed during the regular pipe replacing event. The validated model was run for 30 yr to simulate the water distribution system of Riga (Latvia). Corrosion rate in the first year was 8.0–9.5 times greater than in all the forthcoming years, an average decrease of pipe wall depth being 0.013/0.016 mm per year in long term. The optimal iron pipe exploitation period was concluded to be 30–35 yr (for pipe wall depth 5.50 mm and metal density 7.5 m 3 t −1 ). The initial corrosion model and measurement error was 33%. After the validation of the model the error was reduced to below 15%.

Description: Status of organochlorine pesticides in Ganga river basin: anthropogenic or glacial? Drinking Water Engineering and Science Discussions, 5, 1-30, 2012 Author(s): P. K. Mutiyar and A. K. Mittal This study reports the occurrences of organochlorine pesticides (OCPs) in Ganga river basin covering 3 states, i.e. Uttarakhand, Uttar Pradesh and Bihar covering 72% of total river stretch consisting of 82 sampling points covered through 3 sampling campaigns. Samples were monitored for 16 major OCPs, including HCHs, Endosulfan group, Aldrin group, DDTs and Heptachlor group pesticides. The results showed the ng l −1 levels contamination of OCPs in all the stretches sampled during these campaigns. The results also revealed that different type of OCPs were dominating in different stretches in accordance to the land use practices and agricultural runoff generated from those stretches. HCHs were most frequently detected (detection rate = 75%) in mountainous stretch; Endosulfans were prominent in UP (detection rate = 75%) stretch while BR stretch Aldrin group pesticides were paramount (detection rate = 34%). Source apportionment of the OCP's revealed that in the upper reaches of the Ganges i.e. in the state of Uttarakhand, the glacial melt may be responsible for the presence of OCP's. In the lower reaches, intensive agriculture and industrial activities may be significantly contributing these pesticides. The sample from tributaries of Ganga river were found to contain higher number of pesticides as well as higher concentrations. The maximum total pesticide in an individual sample from these sampling campaigns was found in Son river sample (0.17 μg l −1 , Location: Koilwar, Bhojpur, Bihar).

Description: Proposal of a consistent framework to integrate geothermal potential classification with energy extraction Geothermal Energy Science, 3, 7-11, 2015 Author(s): G. Falcone The classification of geothermal resources is dependent on the estimate of their corresponding geothermal potential, so adopting a common assessment methodology would greatly benefit operators, investors, government regulators and consumers. Several geothermal classification schemes have been proposed, but, to date, no universally recognised standard exists. This is due to the difficulty in standardising fundamentally different geothermal source and product types. The situation is not helped by the accepted use of inconsistent jargon among the geothermal community. In fact, the term "geothermal potential" is often interpreted differently by different geothermal practitioners. This paper highlights the importance of integrating the classification of geothermal potential with that of geothermal energy extraction from well-defined development projects. A structured progression, from estimates of in situ quantities for a given prospect to actual production, is needed. Employing a unique, unambiguous framework would ensure that the same resource cannot exist simultaneously under different levels of maturity of the estimate (as in double bookings of resources), which would let stakeholders better assess the level of risk involved and the steps needed for a geothermal potential to achieve commercial extraction.

Description: Corrosion control using hydroxide and bicarbonate alkalising agents in water drinking processes Drinking Water Engineering and Science Discussions, 8, 53-76, 2015 Author(s): P. Torres-Lozada, K. A. Bueno-Zabala, L. G. Delgado-Cabrera, L. E. Barba-Ho, and C. H. Cruz-Vélez The water supply industry is faced with three phenomena of great importance: the aggressiveness, corrosion, and incrustation of water distribution systems (WDS), which are primarily due to the low alkalinity of water sources and the addition of chemicals used in water treatment processes, which require pH adjustments during the last stage of the treatment process before going into the WDS. This article presents the results of using Ca(OH) 2 and NaOH with doses between 2 and 20 mg L −1 and NaHCO 3 and Na 2 CO 3 between 10 and 250 mg L −1 to adjust the pH of water treated from the Cauca River, which is located in Cali, Colombia, using stabilisation indices normally used in water treatment plants for pH monitoring processes and to better predict the behaviour of water in the WDS. The results indicate that for the case of the surface water source studied, which exhibits low alkalinity levels, the evaluated alkalising agents, with the exception of NaHCO 3 , can create conditions that lead to the precipitation of a~protective calcium carbonate film. Because the pH values that guarantee an adequate pH adjustment are higher (8.7–9.0) than those specified by the Colombian water code and because other international rules indicate that these values do not compromise the health of consumers, it is advisable to review and adjust the code in this respect.

Description: Classification of geothermal resources by potential Geothermal Energy Science, 3, 13-17, 2015 Author(s): L. Rybach When considering and reporting resources, the term "geothermal potential" is often used without clearly stating what kind of potential is meant. For renewable energy resources it is nowadays common to use different potentials: theoretical, technical, economic, sustainable, developable – decreasing successively in size. In such a sequence, the potentials are progressively realizable and more and more rewarding financially. The theoretical potential describes the physically present energy, the technical potential the fraction of this energy that can be used by currently available technology and the economic potential the time- and location-dependent fraction of the previous category; the sustainable potential constrains the fraction of the economic potential that can be utilized in the long term; the developable potential is the fraction of the economic resource which can be developed under realistic conditions. In converting theoretical to technical potential, the recovery factor (the ratio extractable heat/heat present at depth) is of key importance. An example (global geothermal resources) is given, with numerical values of the various potentials. The proposed classification could and should be used as a kind of general template for future geothermal energy resources reporting.

Description: Conversion of organic micropollutants with limited bromate formation during the Peroxone process in drinking water treatment Drinking Water Engineering and Science Discussions, 8, 21-51, 2015 Author(s): A. H. Knol, K. Lekkerkerker-Teunissen, C. J. Houtman, J. Scheideler, A. Ried, and J. C. van Dijk Advanced oxidation with O 3 /H 2 O 2 (peroxone) is conducted on pilot plant scale on pre-treated Meuse river water to investigate the conversion of organic micropollutants (OMPs) and the formation of bromate. Fourteen selected model compounds are dosed to the pre-treated river water on a regular basis to assess the efficiency of the peroxone process and to establish the influence of the water matrix. The height of the ozone dose is the main factor in the conversion of the model compounds. The conversion of OMPs can be increased by further increasing the ozone dose, however, the ozone dose is limited concerning the bromate formation. The hydrogen peroxide dosage has only a~minor effect on the conversion, but it limits the bromate formation effectively. In terms of limited chemical consumption, maximal conversion and adherence to the strict Dutch guideline for bromate in drinking water, a practical full-scale setting is 6 mg L −1 hydrogen peroxide and 1.5 mg L −1 ozone. During the investigation period, the average conversion of the model compounds was 78.9%. The conversion of OMPs is higher at higher water temperatures and lower concentrations of DOC and bicarbonate. The bromate formation also is higher at higher water temperature and lower bicarbonate concentration and proportional with the bromide concentration, above a threshold of about 32 μg L −1 bromide, below which no bromate is formed. The peroxone process can be controlled on basis of the (derived) parameters water temperature, bicarbonate and DOC.

Description: Method development for arsenic analysis by modification in spectrophotometric technique Drinking Water Engineering and Science, 5, 1-8, 2012 Author(s): M. A. Tahir, H. Rasheed, and A. Malana Arsenic is a non-metallic constituent, present naturally in groundwater due to some minerals and rocks. Arsenic is not geologically uncommon and occurs in natural water as arsenate and arsenite. Additionally, arsenic may occur from industrial discharges or insecticide application. World Health Organization (WHO) and Pakistan Standard Quality Control Authority have recommended a permissible limit of 10 ppb for arsenic in drinking water. Arsenic at lower concentrations can be determined in water by using high tech instruments like the Atomic Absorption Spectrometer (hydride generation). Because arsenic concentration at low limits of 1 ppb can not be determined easily with simple spectrophotometric technique, the spectrophotometric technique using silver diethyldithiocarbamate was modified to achieve better results, up to the extent of 1 ppb arsenic concentration.

Description: 〈b〉Thermodynamic and thermoeconomic analysis of combined geothermal space heating and thermal storage using phase change materials〈/b〉〈br〉 V. Chauhan and Á. Ragnarsson〈br〉 Geoth. Energ. Sci., 3, 69-80, https://doi.org/10.5194/gtes-3-69-2015, 2015〈br〉 The present work discusses the utilization of phase change materials for energy storage in geothermal space heating systems. The thermodynamics and thermoeconomics of the combined heating and thermal storing system were studied to show the scope of energy storage and cost savings. A computational model of the combined space heating and thermal storage system was developed and used to perform thermodynamic studies of the heat storage process and heating system efficiency.

Description: 〈b〉Geochemical study on hot-spring water in West New Britain Province, Papua New Guinea〈/b〉〈br〉 M. M. Lahan, R. T. Verave, and P. Y. Irarue〈br〉 Geoth. Energ. Sci., 3, 61-67, https://doi.org/10.5194/gtes-3-61-2015, 2015〈br〉 West New Britain Province, which occupies the western part of New Britain Island in Papua New Guinea, is ideally located within an active tectonic region that influences volcanism creating an environment favourable for geothermal activity. Geothermal mapping of surface manifestations reveals high temperature geothermal prospects along the northern coastline of West New Britain Province that are further confirmed by geochemical analysis. The occurrence of geothermal features is confined to the Quaternary Kimbe Volcanics and alluvium in the lowland areas. The features in Talasea appear to be controlled by deep-seated northerly trending faults while structures in Hoskins also appear to be deep seated but have not been identified. The geothermal systems in West New Britain Province have not been drilled, but preliminary reconnaissance geothermal mapping and geochemical analysis reveals four high temperature geothermal prospects suitable for further investigation and development of geothermal energy. These are the Pangalu (Rabili) and Talasea Station geothermal prospects in Talasea and Kasiloli (Magouru) and Silanga (Bakama and Sakalu) geothermal prospects in Hoskins. The calculated reservoir temperatures for these fields are in the range of 245–310 °C. Recommendations are made for further follow-up exploratory investigations.

Description: 〈b〉Convective, intrusive geothermal plays: what about tectonics?〈/b〉〈br〉 A. Santilano, A. Manzella, G. Gianelli, A. Donato, G. Gola, I. Nardini, E. Trumpy, and S. Botteghi〈br〉 Geoth. Energ. Sci., 3, 51-59, https://doi.org/10.5194/gtes-3-51-2015, 2015〈br〉 We revised the concept of convective geothermal plays by analysing four case studies: Larderello and Mt. Amiata (Italy), The Geysers (USA), and Kizildere (Turkey). We suggest a classification based on the age and nature of the heat source and the related hydrothermal circulation, considering that the tectonic setting is not a discriminant parameter suitable for a classification. Finally we propose to distinguish the convective geothermal plays as volcanic, young intrusive and amagmatic.

Description: 〈b〉Overcoming challenges in the classification of deep geothermal potential〈/b〉〈br〉 K. Breede, K. Dzebisashvili, and G. Falcone〈br〉 Geoth. Energ. Sci., 3, 19-39, https://doi.org/10.5194/gtes-3-19-2015, 2015〈br〉 The geothermal community lacks a universal definition of deep geothermal systems. A minimum depth of 400 m is often assumed, with a further sub-classification into middle-deep geothermal systems for reservoirs found between 400 and 1000 m. Yet, the simplistic use of a depth cut-off is insufficient to uniquely determine the type of resource and its associated potential. Different definitions and criteria have been proposed in the past to frame deep geothermal systems. However, although they have valid assumptions, these frameworks lack systematic integration of correlated factors. To further complicate matters, new definitions such as hot dry rock (HDR), enhanced or engineered geothermal systems (EGSs) or deep heat mining have been introduced over the years. A clear and transparent approach is needed to estimate the potential of deep geothermal systems and be capable of distinguishing between resources of a different nature. In order to overcome the ambiguity associated with some past definitions such as EGS, this paper proposes the return to a more rigorous petrothermal versus hydrothermal classification. This would be superimposed with numerical criteria for the following: depth and temperature; predominance of conduction, convection or advection; formation type; rock properties; heat source type; requirement for formation stimulation and corresponding efficiency; requirement to provide the carrier fluid; well productivity (or injectivity); production (or circulation) flow rate; and heat recharge mode. Using the results from data mining of past and present deep geothermal projects worldwide, a classification of the same, according to the aforementioned criteria is proposed.

Description: 〈b〉Classification of geothermal resources by potential〈/b〉〈br〉 L. Rybach〈br〉 Geoth. Energ. Sci., 3, 13-17, https://doi.org/10.5194/gtes-3-13-2015, 2015〈br〉 A new resource classification scheme is described, based on different geothermal potentials: theoretical, technical, economic, sustainable, developable – decreasing successively in size. In converting theoretical to technical potential, the recovery factor (the ratio extractable heat/heat present at depth) is of key importance. The proposed classification of potentials provides a useful template for standardizing the future reporting of geothermal energy resources worldwide.

Description: 〈b〉Proposal of a consistent framework to integrate geothermal potential classification with energy extraction〈/b〉〈br〉 G. Falcone〈br〉 Geoth. Energ. Sci., 3, 7-11, https://doi.org/10.5194/gtes-3-7-2015, 2015〈br〉 The classification of geothermal resources is dependent on the estimate of their corresponding geothermal potential, so adopting a common assessment methodology would greatly benefit operators, investors, government regulators and consumers. 〈br〉〈br〉 Several geothermal classification schemes have been proposed, but, to date, no universally recognised standard exists. This is due to the difficulty in standardising fundamentally different geothermal source and product types. The situation is not helped by the accepted use of inconsistent jargon among the geothermal community. In fact, the term "geothermal potential" is often interpreted differently by different geothermal practitioners. 〈br〉〈br〉 This paper highlights the importance of integrating the classification of geothermal potential with that of geothermal energy extraction from well-defined development projects. A structured progression, from estimates of in situ quantities for a given prospect to actual production, is needed. Employing a unique, unambiguous framework would ensure that the same resource cannot exist simultaneously under different levels of maturity of the estimate (as in double bookings of resources), which would let stakeholders better assess the level of risk involved and the steps needed for a geothermal potential to achieve commercial extraction.

Description: Dynamic hydraulic models to study sedimentation in drinking water networks in detail Drinking Water Engineering and Science, 5, 87-92, 2012 Author(s): I. W. M. Pothof and E. J. M. Blokker Sedimentation in drinking water networks can lead to discolouration complaints. A sufficient criterion to prevent sedimentation in the Dutch drinking water networks is a daily maximum velocity of 0.25 m s −1 . Flushing experiments have shown that this criterion is a sufficient condition for a clean network, but not a necessary condition. Drinking water networks include many locations with a maximum velocity well below 0.25 m s −1 without accumulated sediments. Other criteria need to be developed to predict which locations are susceptible to sedimentation and to prevent sedimentation in future networks. More distinctive criteria are helpful to prioritise flushing operations and to prevent water quality complaints. The authors use three different numerical modelling approaches – quasi-steady, rigid column and water hammer – with a temporal discretisation of 1 s in order to assess the influence of unsteady flows on the wall shear stress, causing resuspension of sediment particles. The model predictions are combined with results from flushing experiments in the drinking water distribution system of Purmerend, the Netherlands. The waterhammer model does not result in essentially different flow distribution patterns, compared to the rigid column and quasi-steady modelling approach. The extra information from the waterhammer model is a velocity oscillation of approximately 0.02 m s −1 around the quasi-steady solution. The presence of stagnation zones and multiple flow direction reversals seem to be interesting new parameters to predict sediment accumulation, which are consistent with the observed turbidity data and theoretical considerations on critical shear stresses.

Description: Water use scenarios as a tool for adaptation to climate change of a water supply company Drinking Water Engineering and Science Discussions, 5, 265-289, 2012 Author(s): R. Jacinto, M. J. Cruz, and F. D. Santos The project ADAPTACLIMA, promoted by EPAL, the largest Portuguese Water Supply Utility, aims to provide the company with an adaptation strategy in the medium and long term to reduce the vulnerabilities of its activities to climate change. We used the special report emissions scenarios (SRES) of the IPCC (Intergovernmental Panel on Climate Change) to produce local scenarios of water use. Available population SRES for Portugal were downscaled to the study area using a linear approach. Local land use scenarios were produced using the following steps: (1) characterization of the present land use for each municipality of the study area using Corine Land Cover and adapt the CLC classes to those used in the SRES; (2) identification of recent tendencies in land use change for the study area; (3) identification of SRES tendencies for land use change in Europe; and (4) production of local scenarios of land use. Water use scenarios were derived considering both population and land use scenarios as well as scenarios of change in other parameters (technological developments, increases in efficiency, climate changes, or political and behavioural changes). The A2 scenario forecasts an increase in population (+16%) in the study area while the other scenarios show a reduction of resident population (−6 to 8%). All scenarios, but especially A1, show a significant reduction in agricultural area and an increase in urban area. Regardless of the scenario, water use will progressively be reduced until 2100. These reductions are mainly due to increased water use efficiency and reduction of irrigated land. The results concord with several projects modelling water use at regional and global level.

Description: Low-cost multi-stage filtration enhanced by coagulation-flocculation in upflow gravel filtration Drinking Water Engineering and Science Discussions, 5, 291-332, 2012 Author(s): L. D. Sánchez, L. M. Marin, J. T. Visscher, and L. C. Rietveld This paper assesses the operational and design aspects of coagulation and flocculation in upflow gravel filters (CF-UGF) in a multi-stage filtration (MSF) plant. This study shows that CF-UGF units improve the performance of MSF considerably, when the system operates with turbidity above 30 NTU. It strongly reduces the load of particulate material before the water enters in the slow sand filters (SSF) and therewith avoids short filter runs and prevents early interruption in SSF operations. The removal efficiency of turbidity in the CF-UGF with coagulant was between 85 and 96%, whereas the average efficiency without coagulant dosing was 46% (range: 21–76%). Operating with coagulant also improves the removal efficiency for total coliforms, E-coli and HPC. No reduction was observed in the microbial activity of the SSF, no obstruction of the SSF bed was demonstrated and SSF runs were maintained between 50 and 70 days for a maximum head loss of 0.70 m. The most important advantage is the flexibility of the system to operate with and without coagulant according to the influent turbidity. It was only necessary for 20% of the time to operate with the coagulant. The CF-UGF unit represented 7% of total construction costs and the O&M cost for the use of coagulant represented only 0.3%.

Description: Preventive strategy in response to climate change and infrastructural failures for Jakarta slum dwellers Drinking Water Engineering and Science Discussions, 5, 421-434, 2012 Author(s): V. Pooroe and I. Prabaharyaka Jakarta is a city with unpredictable yet annual water shortages, both during the dry and wet season, which disproportionately affect the urban poor. One possible solution is to redevelop the existing water supply system which is now working in one of the largest slum area in Penjaringan, North Jakarta. This system is equipped with a large meter, the Master Meter, to record the communal water consumption and individual meters to record household consumptions. The Community Based Organization uses, operates, and maintains the system based on agreement with water users. Improvement of the Master Meter is achieved by harvesting uncollected rain water during the wet season with its high rainfall intensity, modifying the water storage system and improving the influent water quality. This paper aims to provide a preventive strategy in response to climate change and infrastructural failures based on a case study of community-based water supply project in Penjaringan, Jakarta.

Description: Abnormal quality detection and isolation in water distribution networks using simulation models Drinking Water Engineering and Science Discussions, 5, 435-453, 2012 Author(s): F. Nejjari, R. Pérez, V. Puig, J. Quevedo, R. Sarrate, M. A. Cugueró, G. Sanz, and J. M. Mirats This paper proposes a model based detection and localisation method to deal with abnormal quality levels based on the chlorine measurements and chlorine sensitivity analysis in a water distribution network. A fault isolation algorithm which correlates on line the residuals (generated by comparing the available chlorine measurements with their estimations using a model) with the fault sensitivity matrix is used. The proposed methodology has been applied to a District Metered Area (DMA) in the Barcelona network.

Description: Robust optimization methodologies for water supply systems design Drinking Water Engineering and Science, 5, 31-37, 2012 Author(s): J. Marques, M. C. Cunha, J. Sousa, and D. Savić Water supply systems (WSSs) are vital infrastructures for the well-being of people today. To achieve good customer satisfaction the water supply service must always be able to meet people's needs, in terms of both quantity and quality. But unpredictable extreme conditions can cause severe damage to WSSs and lead to poorer levels of service or even to their failure. Operators dealing with a system's day-to-day operation know that events like burst water mains can compromise the functioning of all or part of a system. To increase a system's reliability, therefore, designs should take into account operating conditions other than normal ones. Recent approaches based on robust optimization can be used to solve optimization problems which involve uncertainty and can find designs which are able to cope with a range of operating conditions. This paper presents a robust optimization model for the optimal design of water supply systems operating under different circumstances. The model presented here uses a hydraulic simulator linked to an optimizer based on a simulated annealing heuristic. The results show that robustness can be included in several ways for varying levels reliability and that it leads to more reliable designs for only small cost increases.

Description: Application of DVC-FISH method in tracking Escherichia coli in drinking water distribution networks Drinking Water Engineering and Science Discussions, 5, 515-532, 2012 Author(s): L. Mezule, S. Larsson, and T. Juhna Sporadic detection of live (viable) Escherichia coli in drinking water with molecular methods but not with standard plate counts has raised concerns about the reliability of this indicator in the surveillance of drinking water safety. Previous studies have shown that in low numbers metabolically active E. coli can be found in the biofilm of drinking water. The aim of this study was to analyse the distribution of non-cultivable E. coli in the drinking water distribution system meeting microbiological quality standards and evaluate the importance of the biofilm as its harbour. In total 24 biofilm samplings and 40 at least 100 times pre-concentrated water samples were taken over a period of two years from two water treatment plants (surface water and groundwater) and four locations in water distribution network of a large city. Cultivable, total and able to divide (viable) E. coli concentration was measured in all samples. The results showed that none of the network biofilm samples contained cultivable E. coli and less than two cells per 10 l were detected in the pre-concentrated water samples. However, almost all of the samples contained viable E. coli in the range of 1–50 cells per litre or cm 2 which represented approximately 53% of all E. coli detected. The amount of viable E. coli was higher in the biofilm after surface water treatment when compared to the outlet from the groundwater plant and the number tended to increase from both treatment plants further into the network irrespective of the season. In conclusion, E. coli in the water supply is not necessarily directly linked to recent faecal contamination and tends to accumulate in the networks where it is less exposed to disinfectants. Thus it can be accepted that biofilm formation in the drinking water distribution networks increases the risk of accumulation of viable but not cultivable E. coli in the system.

Description: Leakages and pressure relation: an experimental research Drinking Water Engineering and Science, 5, 59-65, 2012 Author(s): F. De Paola and M. Giugni Leaks in water systems are presently a frequent and increasing event that involves cost increase and poor service, not compliant to quality standards and modern management criteria. The most recent data available in Italy, resumed into the report issued by Control Committee for Water Resources Use (CONVIRI), shows leakages with an average value of 37%. It is therefore important, for maintenance perspective, to investigate occurrence and evolution of water leaks and the analytical link between leaks Q p and network pressure P , for a reliable calibration of water networks quali-quantitative simulation models. The present work reports the first results of an experimental campaign started at Laboratory of Hydraulics of Department of Hydraulics, Geotechnical and Environmental Engineering of University of Naples Federico II in order to analyze the features of Q p (P) relation, which are compared with other results issued in literature.

Description: Method of evaluation of efficiency improvement potential for water supply systems with focus on variable speed centrifugal pumps Drinking Water Engineering and Science Discussions, 5, 533-553, 2012 Author(s): D. Pilscikovs and E. Dzelzitis The goal of this research is the derivation of the method for evaluation of efficiency improvement potential for public water supply systems with a focus on centrifugal network pumps. The efficiency of proportional pressure control usage has been analyzed for variable speed pumps. It has been done if proportional pressure control is used in comparison with constant pressure control mode. For this reason, energy calculation analyses have been realized for variable speed centrifugal pumps, and the theoretical tool of estimation of the efficiency improvement potential for public water supply systems has been derived. The conclusions are as follows: (1) it has been found that 1110 MWh of annually consumed electrical energy can be saved up, if the control mode of variable speed network pumps will be changed from constant pressure to proportional pressure control mode with the deviation of 20% from head value of duty point at zero flow; (2) about 13 MWh of annually consumed electrical energy can be saved up, if the proportional pressure control mode with the deviation of 15% will be changed to the deviation of 20%; (3) totally about 1123 MWh or 1.12 GWh (14% of the annually consumed electrical energy by variable speed network pumps) can be saved up in small public water supply systems in Latvia.

Description: Low-cost multi-stage filtration enhanced by coagulation-flocculation in upflow gravel filtration Drinking Water Engineering and Science, 5, 73-85, 2012 Author(s): L. D. Sánchez, L. M. Marin, J. T. Visscher, and L. C. Rietveld This paper assesses the operational and design aspects of coagulation and flocculation in upflow gravel filters (CF-UGF) in a multi-stage filtration (MSF) plant. This study shows that CF-UGF units improve the performance of MSF considerably, when the system operates with turbidity above 30 NTU. It strongly reduces the load of particulate material before the water enters in the slow sand filters (SSF) and therewith avoids short filter runs and prevents early interruption in SSF operations. The removal efficiency of turbidity in the CF-UGF with coagulant was between 85 and 96%, whereas the average efficiency without coagulant dosing was 46% (range: 21–76%). Operating with coagulant also improves the removal efficiency for total coliforms, E-coli and HPC. No reduction was observed in the microbial activity of the SSF, no obstruction of the SSF bed was demonstrated and SSF runs were maintained between 50 and 70 days for a maximum head loss of 0.70 m. The most important advantage is the flexibility of the system to operate with and without coagulant according to the influent turbidity. It was only necessary for 20% of the time to operate with the coagulant. The CF-UGF unit represented 7% of total construction costs and the O&M cost for the use of coagulant represented only 0.3%.

Description: Abnormal quality detection and isolation in water distribution networks using simulation models Drinking Water Engineering and Science, 5, 67-72, 2012 Author(s): F. Nejjari, R. Pérez, V. Puig, J. Quevedo, R. Sarrate, M. A. Cugueró, G. Sanz, and J. M. Mirats This paper proposes a model based detection and localisation method to deal with abnormal quality levels based on the chlorine measurements and chlorine sensitivity analysis in a water distribution network. A fault isolation algorithm which correlates on line the residuals (generated by comparing the available chlorine measurements with their estimations using a model) with the fault sensitivity matrix is used. The proposed methodology has been applied to a District Metered Area (DMA) in the Barcelona network.

Description: Household water treatment and safe storage – effectiveness and economics Drinking Water Engineering and Science Discussions, 8, 143-176, 2015 Author(s): S. M. L. Stubbé, A. Pelgrim-Adams, G. L. Szanto, and D. van Halem Household Water Treatment and safe Storage (HWTS) systems aim to provide safe drinking water in an affordable manner to users where safe piped water supply is either not feasible or not reliable. In this study the effectiveness, costs and cost drivers of three selected HWTS systems were identified. The selected systems are SODIS, ceramic filter and biosand filter. These options were selected based on their current usage rate, available scientific data, and future potential. Data was obtained through peer-reviewed literature, reports, web-pages and informal sources. The findings show a wide dispersion for log removal of effectiveness of the HWTS systems. For bacteria, log removals of 1–9 (SODIS), 0.5–7.2 (ceramic) and 0–3 (biosand) were reported. In the case of viruses, log removals of 0–4.3 (SODIS), 0.09–2.4 (ceramic) and 0–7 (biosand) were found. The dispersions of log removal for both bacteria and viruses range from non-protective to highly protective according to WHO performance targets. The reported costs of HWTS systems show a wide range as well. The price per cubic meter water is found to be EUR 0–8 (SODIS), EUR 0.37–6.4 (ceramic) and EUR 0.08–12.3 (biosand). The retail prices found are: negligible (SODIS), USD 1.9–30 (ceramic) and USD 7–100 (biosand). No relationship was observed between removal efficiency and economics of the three systems.

Description: 〈b〉Geothermal resources and reserves in Indonesia: an updated revision〈/b〉〈br〉 A. Fauzi〈br〉 Geoth. Energ. Sci., 3, 1-6, https://doi.org/10.5194/gtes-3-1-2015, 2015〈br〉 More than 300 high- to low-enthalpy geothermal sources have been identified throughout Indonesia. From the early 1980s until the late 1990s, the geothermal potential for power production in Indonesia was estimated to be about 20 000 MWe. The most recent estimate exceeds 29 000 MWe derived from the 300 sites (Geological Agency, December 2013). 〈br〉〈br〉 This resource estimate has been obtained by adding all of the estimated geothermal potential resources and reserves classified as "speculative", "hypothetical", "possible", "probable", and "proven" from all sites where such information is available. However, this approach to estimating the geothermal potential is flawed because it includes double counting of some reserve estimates as resource estimates, thus giving an inflated figure for the total national geothermal potential. 〈br〉〈br〉 This paper describes an updated revision of the geothermal resource estimate in Indonesia using a more realistic methodology. The methodology proposes that the preliminary "Speculative Resource" category should cover the full potential of a geothermal area and form the base reference figure for the resource of the area. Further investigation of this resource may improve the level of confidence of the category of reserves but will not necessarily increase the figure of the "preliminary resource estimate" as a whole, unless the result of the investigation is higher. A previous paper (Fauzi, 2013a, b) redefined and revised the geothermal resource estimate for Indonesia. The methodology, adopted from Fauzi (2013a, b), will be fully described in this paper. As a result of using the revised methodology, the potential geothermal resources and reserves for Indonesia are estimated to be about 24 000 MWe, some 5000 MWe less than the 2013 national estimate.

Description: 〈b〉Reservoir characterization of the Upper Jurassic geothermal target formations (Molasse Basin, Germany): role of thermofacies as exploration tool〈/b〉〈br〉 S. Homuth, A. E. Götz, and I. Sass〈br〉 Geoth. Energ. Sci., 3, 41-49, https://doi.org/10.5194/gtes-3-41-2015, 2015〈br〉 The Upper Jurassic carbonates of the southern German Molasse Basin are the target of numerous geothermal combined heat and power production projects since the year 2000. A production-orientated reservoir characterization is therefore of high economic interest. Outcrop analogue studies enable reservoir property prediction by determination and correlation of lithofacies-related thermo- and petrophysical parameters. A thermofacies classification of the carbonate formations serves to identify heterogeneities and production zones. The hydraulic conductivity is mainly controlled by tectonic structures and karstification, whilst the type and grade of karstification is facies related. The rock permeability has only a minor effect on the reservoir's sustainability. Physical parameters determined on oven-dried samples have to be corrected, applying reservoir transfer models to water-saturated reservoir conditions. To validate these calculated parameters, a Thermo-Triaxial-Cell simulating the temperature and pressure conditions of the reservoir is used and calorimetric and thermal conductivity measurements under elevated temperature conditions are performed. Additionally, core and cutting material from a 1600 m deep research drilling and a 4850 m (total vertical depth, measured depth: 6020 m) deep well is used to validate the reservoir property predictions. Under reservoir conditions a decrease in permeability of 2–3 magnitudes is observed due to the thermal expansion of the rock matrix. For tight carbonates the matrix permeability is temperature-controlled; the thermophysical matrix parameters are density-controlled. Density increases typically with depth and especially with higher dolomite content. Therefore, thermal conductivity increases; however the dominant factor temperature also decreases the thermal conductivity. Specific heat capacity typically increases with increasing depth and temperature. The lithofacies-related characterization and prediction of reservoir properties based on outcrop and drilling data demonstrates that this approach is a powerful tool for exploration and operation of geothermal reservoirs.

Description: Corrigendum to "Preface: CCWI 2013" published in Drink. Water Eng. Sci., 7, 99–100, 2014 Drinking Water Engineering and Science, 8, 1-1, 2015 Author(s): B. Brunone, M. Ferrante, S. Meniconi, and L. Berardi

Description: Specific activities of radiocarbon in annual tree rings corresponding to 1980-2009 are reported for a pine tree located 2 km from the Qinshan Nuclear Power Plant (Qinshan NPP), China. While a negligible enhanced 14C activity due to operation of the Qinshan NPP Plant I is evident, a relative increase (1.8–62.6 Bq/kg C) was observed in the specific activity after operation of the Qinshan NPP Plant II in 2002 and Plant III in 2003. The enhanced values were primarily affected by the 14C discharged from Plant III (CANDU-type reactor), and a good correlation was found between the 14C discharged from Plant III in the growing season and the 14C excess value. The excess 14C activities peaked in 2005 (at 302.0 Bq/kg C, which is 62.6 Bq/kg C above the “clean air” 14C level), and then declined due to the improvement in 14C discharge management of Plant III. In 2009, the 14C-specific activity was near the background level.

Description: During the Last Glacial Maximum (LGM) about 25,000 yr ago, the area of what is now New York State (USA) was almost entirely covered by the Laurentide Ice Sheet (LIS; Dyke et al. 2002). Subsequent habitation of this area after the melting of the LIS necessitates dispersal of fauna, and the timing of the dispersal of particular species may aid in the understanding of how the modern ecosystems of New York were assembled. Mastodons and mammoths represent the most abundant post-LGM Pleistocene megafauna recovered in New York. However, many of the specimens have not been dated. This paper presents a set of dates from bone and tooth dentine collagen of late Pleistocene mastodon (n = 7) and mammoth (n = 3) specimens housed in the Vertebrate Paleontology Collections at the New York State Museum, Albany, New York, USA.

Description: The Radiocarbon Dating Laboratory was established at the Middle East Technical University in the Physics Department with the equipment provided by the British Government through former CENTO auspices and financial support by the Ford Foundation. This list reports on 14C dates measured up to July 1987.

Description: This project was initiated by Alan Mix working in cooperation with Jack Dymond. It involves measurements of one size fractions and hand-picked foraminifera shells from material caught in sediment traps deployed in the equatorial Pacific Ocean (see Tables 14, 15).

Description: Small sample 14C dating is tested using conventional as well as high-resolution low-level liquid scintillation (LS) spectrometers. Contrasted are the results obtained dating ∼25, 125 and 250mg of elemental carbon in standard size counting vials (3mL) and 0.3mL teflon and quartz vials. It is demonstrated that the improved performance of the 0.3mL counting vials enables just adequate resolution of 25mg and very good resolution of 100mg carbon samples both at Modern and Old age limits when the determination is made in a high-resolution low-level LS spectrometer.

Description: GEOTOP is the geochemistry and geochronology research center of the Université du Quebec à Montréal (UQAM). The Radiocarbon Laboratory was established to meet the growing demand for radiocarbon dating in Québec. The laboratory was founded by Claude Hillaire-Marcel. The first measurements were completed in October 1978. The laboratory was managed by Pierre Pagé until May 1985. Serge Occhietti and Pierre Pichet are presently in charge. Technical maintenance is under the direction of Claude Jacob.

Description: This study was undertaken in cooperation with David Clark of the University of Wisconsin in order to confirm the previous estimates of low sedimentation rates in the Arctic Basin (see Table 7).

Description: This study was carried out in cooperation with Steve Emerson of the University of Washington. The purpose was to obtain benthic-planktonic and planktonic-planktonic age differences on hand-picked foraminifera shells. Material was taken from two separate subcores from the primary 50cm2 box core (see Tables 8, 9).

Description: The study of this core was undertaken in cooperation with James Kennett. The purpose was to establish the chronology of the Mississippi River melt water record (see Figs 7,8; Table 6).

Description: Since 1984, a large multi-disciplinary archaeological team, under the direction of the author, has collected artifactual, ecofactual, and radiocarbon samples from a series of Native American sites spanning the past 9600 14C years. Occupied historically by the Chumash Indians, the Santa Barbara coast (Fig 1) has seen dramatic cultural and environmental change during the course of the Holocene. One of the goals of the research is to reconstruct patterns in the evolution of the local coastline, while examining the effects of environmental change on human adaptation along the Santa Barbara coast.

Description: To aid in the development of a biological profile for human remains found in Collyhurst (Manchester, England), we undertook radiocarbon analysis of tooth enamel, tooth collagen, and bone collagen on behalf of the Greater Manchester Police. On the basis of the analyses of the teeth, we concluded that the person was born between 1950 and 1954, while on the basis of our analyses of cortical and trabecular bone we estimated the year of death to be between 1969 and 1974. This would make the maximum age range around 15 to 24 yr. Analyses of the dentition and other skeletal parameters can eliminate the younger part of the range, so an age of around 18 to 24 yr at death would seem most likely. The δ13C and δ15N values for the bone collagen were higher than would be expected for someone subsisting on a purely terrestrial diet, implying some consumption of marine resources, which could lead to reduced 14C activities. Taking any potential marine effect into account could reduce this age range to around 18 to 21 yr.

Description: In the original proposal entitled Reconstructing Ancient Israel – The Exact and Life Sciences Perspective, two of us (Israel Finkelstein and Steve Weiner) wrote, “If the microscopic data are well integrated into the macroscopic (archaeological) record, they will undoubtedly provide new insights into the study of Ancient Israel.” And this was what this 5-year (2009–2014) European Research Council (ERC) sponsored program (details below) was all about. New ground was broken on three fronts: conceptual, methodological, and in the generation of new data that indeed provide novel insights into the history and material culture of Ancient Israel in particular and the Iron Age Levant in general. The reviews presented in this special volume synthesize some of these new insights. The findings have been published in about 70 papers (see Appendix).

Description: Radiocarbon investigation of atmospheric PM2.5 aerosol synchronized with 14CO2 observations began in Debrecen in the winter of 2010. The aim of the study was to determine the contemporary and fossil carbon fractions in the aerosol and to set them against the fossil CO2 excess data referring to the same period. The mass of the collected PM2.5 mode on prebaked quartz filters was determined gravimetrically, while its total carbon mass was calculated from the pressure of CO2 gas produced after the combustion of the filters. As a result of the applied sampling and preparation method, the stable, nonvolatile carbon forms were principally studied. 14C measurements of the tiny aerosol bulk samples were performed using the EnvironMICADAS accelerator mass spectrometer at ATOMKI. The sample preparation method was tested using several blanks, standards, and real samples. Test results showed good reproducibility for the applied aerosol sample preparation and accelerator mass spectrometry (AMS) 14C analyses. Atmospheric fossil CO2 excess data were calculated according Levin et al. (2003), using the 14C results of collected CO2 samples measured by the gas proportional counting system at ATOMKI. Mass concentration of PM10 involving the PM2.5 mode in the city air exceeded the daily average of 50 μg/m3 (24-hr limit value in the EU) several times in 2011, mainly during the winter. The results showed that recently derived carbon most likely from domestic wood burning was causing the elevated carbon mass concentration of PM2.5 in Debrecen at the time. In the course of the 1-yr-long continuous and systematic comparison of fossil carbon mass concentration of PM2.5 mode and mole fraction of fossil excess of atmospheric CO2, similar and synchronous trends were observed during the studied period in Debrecen.

Description: The oasis of Samarkand in the Middle Zeravshan Valley (modern Uzbekistan) was a major political and economic center in ancient western Central Asia. The chronology of its irrigation system was, until now, only constrained by the quality and quantity of archaeological findings and several different hypotheses have been proposed for it. We use a new approach combining archaeological surveying, radiocarbon dating, sedimentary analysis, and the numerical modeling of a flood event to offer new evidence for, and quantitative dating of, the development of irrigation system on the southern flank of the Middle Zeravshan Valley. We analyzed 13 bones and charcoals from 3 archaeological sites and obtained new 14C ages from Afrasiab (ancient Samarkand), a dwelling damaged by flooding in the 2nd century AD (site code: SAM-174) and the fortress of Kafir Kala. We established the origin of sedimentary deposits at the sites to infer the presence of the 2 most important canals of the southern flank: the Dargom and the Yanghiaryk. Finally, we show with a numerical model of overland flow that a natural flood was unlikely to have produced the damage observed at SAM-174. The combined results of the study indicate that the canals south of Samarkand existed, and were mainly developed, in the 2nd century AD and were not connected to the main feeding canal of Afrasiab at that time.

Description: We present the results of accelerator mass spectrometry (AMS) radiocarbon dating of 11 samples collected from 4 locations in southern Iraq. As a result of the hiatus in fieldwork in that region since 1990, and the antiquity of the majority of archaeological excavations conducted there, the record of 14C dates for southern Mesopotamia is patchy for all periods. This is especially true for the mid-Holocene, when the world's oldest and longest-sustained urban system first emerged there. The dates here reported not only make a significant contribution to available dates for this important region and period; they fill specific gaps in crucial geographic coverage, and shed light on the extent of marshland boundaries and the antiquity of settlement at key urban centers.

Description: Two soil profiles from northeast India, one from Bakrihawar, an agricultural land, and the other from Chandipur, a virgin hilly area from Assam, are investigated to understand the organic carbon dynamics of the area. Due to frequent flooding, the Bakrihawar soil has accumulated a higher clay content than that of Chandipur. The carbon content is less than 1% by weight in both the sites. The higher clay content is responsible for relatively more soil organic carbon at Bakrihawar. The mean δ13C values at both sites reflect the values of the overlying vegetation. At Bakrihawar, both rice cultivation (C3) and natural C4 grasses contribute to higher mean enriched values of 13C relative to Chandipur, where the surface vegetation is mostly of C3 type. The turnover time of organic carbon, estimated using the residual radiocarbon content, depends strongly on the soil particle size distribution, especially the clay content (i.e. it increases with clay content). To the best of our knowledge, this is the first soil carbon dynamics study of its kind from northeast India.

Description: Anomalous dates prior to 1000 yr BP have been reported for near-surface site deposits at Puapua'a in the dry and rocky zone of leeward (west) Hawai'i Island, compared to archipelago-wide earliest cultural layers generally in buried contexts 1000–800 yr BP. Redating and closer examination cannot validate these early dates in cultural association. In the thin sedimentary deposits, preserved cultural materials mostly postdate 600–400 yr BP, but some older materials were incorporated into the layer matrix. The results suggest a much shorter extant chronology of human settlement of this particular zone, whereas earliest sites most likely are preserved in different settings of the Hawaiian Islands.

Description: Paleoenvironmental and paleogeomagnetic tracing studies from Chinese loess 10Be have progressed in recent years (Zhou et al. 2007a,b, 2010). In this approach, 10Be flux determined from sediment concentration and accumulation rate may be used to recover information about paleomonsoon rainfall rates as well as past variations in the geomagnetic field strength. However, these methods require that a correction be made for residual undecayed 10Be in remobilized dust. To better understand the feature of the 10Be signals related to the remobilized dust, we report the first observational study on 10Be concentration of modern falling dust using the 3MV multi-element accelerator mass spectrometer (AMS) in the Xi'an AMS Center. Ten samples collected at Ansai observation station (109°19′E, 36°51′N) in northern China from May 2008 to June 2009 are measured along with 3 chemical blanks. The results clearly show that the 10Be content of modern falling dust is relatively uniform, with a mean value of 1.21 x 108 atoms/g, a measurement similar to that of Chinese loess (Zhou et al. 2007a) and to the value found in the study by Shen et al. (2009) on dust 10Be falling near Dingbian, China (1.25 ± 0.06 x 108 atoms/g). Despite the fact that modern dust flux is much higher in spring relative to summer in northern China, 10Be concentration in falling dust remains fairly constant. In addition, we find that dust 10Be concentration is roughly independent of the local precipitation changes. This feature might be considered as an analogue to improve our understanding on the fundamental information of the source component contained in loess 10Be records and its spatial/temporal distribution features.

Description: The recent progress in radiocarbon dating of the prehistoric cultural complexes in the Russian Far East is discussed against the background of ancient chronologies for greater East Asia. Since 1997, the wide use of accelerator mass spectrometry (AMS) radiocarbon dating along with the continuation of conventional dating has allowed us to establish the age of several key Paleolithic, Neolithic, and Paleometal sites. It has also contributed to advancing a deeper understanding of the timing for the beginning of pottery production, maritime adaptation, and agriculture, and several other important issues in prehistoric chronology for the studied region. Reservoir age correction values for the Japan and Okhotsk seas are now used to adjust the age for samples of marine origin. Some of the cultural-chronological models for prehistoric far eastern Russian complexes put forward in the last 10 yr lack a solid basis, and are critically evaluated herein.

Description: This article discusses 18 accelerator mass spectrometry (AMS) radiocarbon dates from the peat bog sites Sakhtysh 2a, Ozerki 5, and Ozerki 17 in the Upper Volga region. The aim is to contribute to a better understanding of the emergence and dispersal of early ceramic traditions in northern Eurasia and their connection to the Baltic. With 1 exception, all dates were obtained from charred residue adhering to the sherd. A possible reservoir effect was tested on 1 piece of pottery from Sakhtysh 2a by taking 1 sample from charred residue, and another sample from plant fiber remains. Although a reservoir effect was able to be ruled out in this particular case, 4 other dates from Sakhtysh 2a and Ozerki 5 seem too old on typological grounds and might have been affected by freshwater reservoir effects. Considering all other reliable dates, the Early Neolithic Upper Volga culture, and with it the adoption of ceramics, in the forest zone of European Russia started around 6000 cal BC.

Description: Radiocarbon dating of closely associated marine mollusk shells and terrestrial material (charred wood or bone) collected from archaeological contexts on Tenerife and Fuerteventura islands allowed us to quantify the marine 14C reservoir effect (ΔR) around the Canary Archipelago. Coastal Fuerteventura has a positive weighted mean ΔR value of +185 ± 30 14C yr, while for Tenerife a range of negative and positive values was obtained, resulting in a ΔR weighted mean value of 0 ± 35 14C yr. These values are in accordance with the hydrodynamic system present off the Canary Islands characterized by a coastal upwelling regime that affects the eastern islands (Fuerteventura and Lanzarote) but not the other islands of the archipelago, namely Tenerife. Because of this oceanographic pattern, we recommend the extrapolation of these results to the remaining islands of the archipelago, i.e. the first value must be used for the eastern islands, while for the central and western islands the acceptable ΔR value is 0 ± 35 14C yr.

Description: Excavation of the Schurovo archaeological site, located on a ∼12-m river terrace, has revealed 3 occupation periods: 1) as a dwelling site of the Migration period (4th–5th centuries AD); 2) as local burial mounds (termed “houses of the dead” in Russian); 3) and as a ground burial period, which left a cremation layer directly on the ground and is now covered by the Little Ice Age overbank alluvium. The latter 2 periods contain few artifacts, which makes radiocarbon dating more appropriate for establishing their chronology. The burial mounds were dated to the mid-6th to mid-7th centuries AD. The accumulation of colluvium in mound ditches points to a rather long (at least a century) pause between the construction of burial mounds and the appearance of ground burials. Dates from the cremation layer (ground burials) span a wide range from the 8th to 13th centuries AD. As the younger dates do not correspond to regional historical and archaeological contexts, we believe them to be “rejuvenated” due to their long exposure before burial to the young alluvium. The ground burials are dated to the mid-8th to mid-10th centuries AD, the so-called “dark ages” in the Moscow region characterized by very few archaeological data. An isolated ancient branch of the Oka River near the archaeological site was radiocarbon dated and found to be active until the mid-10th to later-12th centuries AD, meaning that it was likely used as a local harbor on the transit river route throughout the site's occupation.

Description: Progressive stages in the development of the Old Town region of the city of Klaipėda (in German, Memel) were ascertained by analyzing archaeological and historical data combined with an analysis of pollen, diatom, plant macrofossil, and osteological findings as cross-referenced with radiocarbon measurements. The port city of Klaipėda, located on the eastern part of the Baltic Sea, was an important political, economic, and religious center during the last millennium. In addition to its environmental history, the character of human activity and urbanization of the area during the 16th–17th centuries AD were examined. The chronology of these records is based on archaeological, historical, and 14C data. The results obtained indicate the predominance of a wet boggy environment and the presence of a pond in the investigated territory of Klaipėda during the late 15th and early 16th centuries AD. The formation of a new Danė River channel created an island town, resulting in a defensible residual area for the town inhabitants. An ongoing deposition of a cultural layer began in the mid-16th century AD. Rich zooarchaeological data found in this layer provided new details on human diet and exposed a predominance of domestic animals, especially cattle. Due to intensive amelioration of this area, layers of sandy and clayey deposits were formed during the second half of the 16th century AD. A significant presence of cultivars, ruderals, and weeds were recorded, indicating substantial human activity and increasing urbanization of the landscape. According to the paleobotanical, archaeological, and historical data, the culmination of this process took place at the end of the 16th and beginning of the 17th centuries AD, when residential areas were established.

Description: We submit that anomalies in radiocarbon data in archaeological studies should be viewed positively as a stimulus to undertake further targeted research. Additional analyses to resolve anomalies have the potential to provide important insights into heretofore unstudied or incompletely understood depositional or geochemical processes affecting 14C values, particularly in certain types of samples and samples from certain types of environments. We consider 2 major categories or sources of 14C dating anomalies that we posit are mostly responsible for the vast majority of problematic 14C results: anomalous sample contexts and anomalous sample composition. Two additional sources of 14C anomalies are much more rarely encountered. Six case studies taken from New World archaeological studies are briefly presented to provide examples of where questions concerning the validity of 14C measurements generated additional and ultimately more accurate understandings of temporal relationships. AMS-based 14C measurement technology has rendered detailed investigations of 14C anomalies routinely feasible.

Description: Bronze Age human and animal bone collagen from several steppe Bronze Age cultures (i.e. Early Catacomb, East and West Manych Catacomb, and Lola cultures) shows large variations in δ13C and δ15N values. In general, we observed that the older the sample, the lower the δ13C and δ15N values. We hypothesize that more positive values of δ13C and δ15N are caused by change in diet and a more arid climate. For ancient sheep during drier periods of the Early Catacomb, East and West Manych Catacomb, and Lola cultures, we observed 2 groups with different C and N isotopic compositions, reflecting consumption of different types of fodder. During periods of aridization, C4 and C3 plants with high δ15N values appeared in the vegetation, also influencing bone collagen values. Human bones show reservoir effects, caused by aquatic diet components. These effects can be quantified by paired dating of human bone and associated terrestrial samples. Reservoir corrections have revised chronologies for the region. Some paired dates do not reveal reservoir effects. This can be explained in 2 alternative ways. One is that the human diet did not include aquatic components; rather, the diet was based on C3 vegetation with high δ15N values (13–15‰), and flesh/milk of domesticated animals. An alternative explanation is that humans consumed food from freshwater resources without reservoir effects.

Description: Analytical methods based on particle accelerators are widely used in cultural heritage diagnostics and archaeological sciences from the absolute dating of organic materials by means of radiocarbon accelerator mass spectrometry (AMS) to the analysis of the elemental composition of a wide range of materials (metals, obsidians, pottery) via ion beam analysis (IBA) techniques. At CEDAD (Centre for Dating and Diagnostics), the accelerator facility of the University of Salento, AMS 14C dating and PIXE (particle-induced X-ray emission)-PIGE (particle-induced gamma-ray emission) compositional analysis in external beam mode are combined to study certain archaeological materials. We present a review of the combined application of these analytical methods in the study of casting cores of the Riace bronzes, 2 classical Greek statues of extraordinary importance for the history of art.

Description: Local reservoir ages are often estimated from the difference between the radiocarbon ages of aquatic material and associated terrestrial samples for which no reservoir effect is expected. Frequently, the selected aquatic material consists of bivalve shells that are typically well preserved in the archaeological record. For instance, large shell middens attest to the importance of mussel consumption at both coastal and inland sites. However, different physiological mechanisms associated with tissue and shell growth may result in differences in reservoir effects between the surviving component (shell) and the component relevant to dietary reservoir effects in consumers (tissue). The current study examines bivalve tissue-shell age differences both from freshwater and marine contexts close to archaeological sites where human consumption of mollusks has been attested. Results exhibited significant 14C age differences between bivalve tissue and shell in a freshwater context. In a marine context, no significant bivalve tissue-shell age differences were observed. The results also showed that riverine and lacustrine shells show large and variable freshwater reservoir effects. The results have important implications for establishing local reservoir effects especially in a freshwater environment. For good a priori knowledge of expected 14C differences in organic and inorganic water, carbon is thus necessary. Furthermore, the high variability in freshwater shell 14C ages implies the need for representative sampling from the archaeological record.

Description: The unique archaeological monument of Okhta 1 (Neolithic-Early Metal Age) was excavated in 2008 in central Saint Petersburg (Russia). Radiocarbon and wiggle-match dating of organic materials and artifacts (charcoal wood samples and ceramic food crusts) from lithological and cultural layers helped to determine the main stages of cultural-historical processes and paleogeographical events in the coastal zone of the Baltic Sea bay during the Holocene. Humans occupied the Okhta Cape from 4200–3600 cal BC, after the Littorina Sea regression. Prehistoric people of the Middle-Late Neolithic, identified by their characteristic Pit Combed Ware ceramics, used this territory for fishing and hunting. The wood pile constructions used for fishing in 3500 cal BC were built on the coast and in river channels. From 3200–3000 cal BC, settlements and burials appeared of the Late Neolithic-Early Metal Age. The strategic geographical position of this territory was favorable for trade activity, fishing, and hunting, and shaped important interactions for different cultural groups.

Description: The Fifth International Radiocarbon Comparison (VIRI) provided a suite of 5 bone samples with consensus ages ranging from 969 to 39,305 14C yr BP (Scott et al. 2010). These bones were used herein in a comparison of decalcification methods using either HCl or EDTA to produce collagen, and the results demonstrate age concordance between both preparation methods and the VIRI consensus values. Additional isotopic analyses of the collagen (δ13C, δ15N, and δ18O) illustrate the increasing sensitivity of carbon, nitrogen, and oxygen isotopes in assessing gelatin degradation.

Description: In this contribution, we establish a radiocarbon-based chronology of early ceramic sequences in eastern Fennoscandia utilizing a Bayesian approach. The data consist of 56 individual 14C dates from charred or fermented food remains (charred crust, food residue) and birch bark tar used to seal cracks in vessels. We present the results of the models, discuss the chronological boundaries obtained, and compare the outcome with contemporary archaeological knowledge of the Subneolithic in eastern Fennoscandia. We also look at the role of charred crust δ13C values as indicators of reservoir effect present in the dates, perform some preliminary correction procedures for the dates, and discuss their effect on the chronologies.