KWR peer reviewed: Quantifying the vulnerability of well fields towards anthropogenic pollution; The Netherlands as an example

Recentelijk publiceerden  Mendizabal, I. and Stuyfzand, P.J. in: Journal of Hydrology (2011) DOI 10.1016/j.jhydrol.2010.12.026 (in Press)

 

 Abstract

A new method is presented to asses the vulnerability of public supply well fields (PSWFs), other well fields or individual wells. The Intrinsic Vulnerability Index towards Pollution (VIP) is based on the age, redox level, alkalinity (or acidity), and surface water fraction of the pumped water, resulting in a score ranging from 0 for old, deeply anoxic, high alkalinity ground water to 30 for young, (sub)oxic, acid ground water.

The Specific Vulnerability Index towards Pollutant X (VIPX) combines VIP with four aspects: the current concentration of X in the pumped water; the mobility or mobilization potential of X in the hydrogeochemical environment as derived from the redox state and alkalinity of the raw water; the land use within the ground water catchment area; and the pollution risk for X, derived from its concentration in shallow groundwater and/or in the infiltrating surface water.

A national survey of all active PSWFs in the Netherlands revealed a low VIP in 50% and high VIP in 9% of them. Most PSWFs with a low VIP pump from very deep aquifers, and those with high VIP from either acidified, phreatic sandy aquifers, (sub)oxic, artificially recharged coastal dunes, (sub)oxic river banks or oxic limestone.

Research highlights: â–º We quantify the vulnerability of public supply well fields (PSWFs) and wells. â–º Both intrinsic vulnerability (VIP) and specific vulnerability (VIPX) are addressed. â–º VIP uses the age, redox level, alkalinity (or acidity), and surface water fraction. â–º VIPX also requires land use, capture zone, pollution risk and mobilization potential. â–º Our national survey of 241 PSWFs in the Netherlands revealed a good quality status.

Link: http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V6C-51TYF9N-1&...

 

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KWR peer reviewed: Preliminary study on the occurrence and risk arising from bacteria internalized in zooplankton in drinking water

Recentelijk publiceerden Bichai, F., Hijnen, W., Baars, E., Rosielle, M., Dullemont, Y. and Barbeau, B. in: Water Science and Technology 63(2011)1, p. 108-114.

 

Abstract 
In this study, an environmental sampling campaign was conducted to detect internalized E. coli and C. jejuni bacteria in zooplankton and amoebae samples collected at various stages of three water treatment plants in Amsterdam, the Netherlands. Eight sampling locations were selected and sampling was performed twice, at a two-week interval, at each location. Chlorination was used to inactivate free (external) bacteria in the concentrated zooplankton samples and sonication was used to disrupt zooplankton organisms in order to release and recover internalized bacteria. Zooplankton enumeration was performed by microscopy. No internalized E. coli or C. jejuni bacteria were recovered from all of the samples analyzed. The occurrence of internalized E. coli or C. jejuni bacteria in drinking water was estimated to be lower than one internalized bacteria in 10(5) zooplankton organisms, as derived from the detection limit of the sampling campaign. By using the QMRA approach and the Beta-Poisson model, a risk of infection of less than 9.2E-6 and 5.9E-5 was estimated for internalized E. coli and C. jejuni in drinking water, respectively. This study remains preliminary due to the limited number of samples taken at each location.

 

Link: http://www.ncbi.nlm.nih.gov/pubmed/21245561

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KWR peer reviewed: Radial transport processes as a precursor to particle deposition in drinking water distribution systems

Recentelijk publiceerden van Thienen, P., Vreeburg, J.H.G. and Blokker, E.J.M. in: Water Resaerch 45(2011),4, p.1807-1817.


Abstract

Various particle transport mechanisms play a role in the build-up of discoloration potential in drinking water distribution networks. In order to enhance our understanding of and ability to predict this build-up, it is essential to recognize and understand their role. Gravitational settling with drag has primarily been considered in this context. However, since flow in water distribution pipes is nearly always in the turbulent regime, turbulent processes should be considered also. In addition to these, single particle effects and forces may affect radial particle transport. In this work, we present an application of a previously published turbulent particle deposition theory to conditions relevant for drinking water distribution systems. We predict quantitatively under which conditions turbophoresis, including the virtual mass effect, the Saffman lift force, and the Magnus force may contribute significantly to sediment transport in radial direction and compare these results to experimental observations. The contribution of turbophoresis is mostly limited to large particles (>50 μm) in transport mains, and not expected to play a major role in distribution mains. The Saffman lift force may enhance this process to some degree. The Magnus force is not expected to play any significant role in drinking water distribution systems.


Link: http://www.ncbi.nlm.nih.gov/pubmed/21186040

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KWR peer reviewed: Hydrochemical system analysis of public supply well fields, to reveal water-quality patterns and define groundwater bodies: The Netherlands

Recentelijk publiceerden Mendizabal, I., Stuyfzand, P.J. and Wiersma, A.P. in: Hydrogeology Journal 19(2011), p. 83-100.

 

 Abstract
Hydrochemical system analysis (HCSA) is used to better understand the individual state of and spatial patterns in groundwater quality, by addressing the spatial distribution of groundwater bodies with specific origins (hydrosomes) and characteristic hydrochemical zones within each hydrosome (facies). The origin is determined by environmental tracers or geomorphological and potentiometric maps, the facies by combining age, redox and alkalinity indices. The HCSA method is applied to all 206 active public supply well fields (PSWFs) in The Netherlands, resulting in the distinction of nine hydrosomes and eleven facies parameters—age (young, intermediate, old), redox ((sub)oxic, anoxic, deep anoxic, mixed) and alkalinity (very low, low, intermediate and high). The resulting classification of PSWFs provides a means to (1) predict their vulnerability; (2) optimize groundwater-quality monitoring programs; and (3) better delineate groundwater bodies, by considering groundwater origin and flow. The HCSA translates complex hydrochemical patterns into easily interpretable maps by showing PSWFs, groundwater bodies and hydrochemical facies. Such maps facilitate communication between researchers, water resources managers and policy makers and can help to solve complex groundwater resources management problems at different scales, ranging from a single well(field) or region to the national or European scale.  

 
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KWR peer reviewed: Concentration and Diversity of Uncultured Legionella spp. in Two Unchlorinated Drinking Water Supplies

Recentelijk publiceerden Wullings, B.A., Bakker, G. and van der Kooij, D. "Concentration and Diversity of Uncultured Legionella spp. in Two Unchlorinated Drinking Water Supplies with Different Concentrations of Natural Organic Matter" in: Applied and Environmental Microbiology 77(2011)2, p.634-641.


 

Abstract
Two unchlorinated drinking water supplies were investigated to assess the potential of water treatment and distribution systems to support the growth of Legionella spp. The treatment plant for supply A distributed treated groundwater with a low concentration (<0.5 ppm of C) of natural organic matter (NOM), and the treatment plant for supply B distributed treated groundwater with a high NOM concentration (8 ppm of C). In both supplies, the water temperature ranged from about 10°C after treatment to 18°C during distribution. The concentrations of Legionella spp. in distributed water, analyzed with quantitative PCR (Q-PCR), averaged 2.9 (± 1.9) × 10(2) cells liter(-1) in supply A and 2.5 (± 1.6) × 10(3) cells liter(-1) in supply B. No Legionella was observed with the culture method. A total of 346 clones (96 operational taxonomical units [OTUs] with ≥97% sequence similarity) were retrieved from water and biofilms of supply A and 251 (43 OTUs) from supply B. The estimation of the average value of total species richness (Chao1) in supply A (153) was clearly higher than that for supply B (58). In each supply, about 77% of the sequences showed <97% similarity to described species. Sequences related to L. pneumophila were only incidentally observed. The Legionella populations of the two supplies are divided into two distinct clusters based on distances in the phylogenetic tree as fractions of the branch length. Thus, a large variety of mostly yet-undescribed Legionella spp. proliferates in unchlorinated water supplies at temperatures below 18°C. The lowest concentration and greatest diversity were observed in the supply with the low NOM concentration.


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KWR peer reviewed: Governance without governance: how nature policy was democratized in the Netherlands

Recentelijk publiceerden Turnhout E, van der Zouwen M. in: Critical Policy Studies 4 (2010), p.344-361.

 

Abstract

Trends in governance, including a changing role for the state and increasing civil society participation, are often seen as promising ways to achieve democratic legitimacy. The prominent presence of these claims and intentions in the new Dutch nature policy plan, 'Nature for People, People for Nature', stimulated us to look more closely into how this plan came about. Our analysis shows that the process started with the organization of several informal participatory processes, which involved not only traditional but also new actors. However, it ended in a fairly traditional way, with limited participation, which involved mostly traditional actors, and which was strictly orchestrated by central government. Based on these findings, we argue that although the plan itself was clearly intended to achieve participatory governance, the participatory characteristics of the process can be questioned. For this reason, the case may be seen as one of 'governance without governance'. The article ends by discussing the implications of these findings for democratic legitimacy.

 

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KWR peer reviewed: Transdisciplinary EU science institute needs funds urgently

Recentelijk publiceerden Vasbinder, J.W., Andersson, B., Arthur, W.B., Boasson, M., De Boer, R., Changeux, J.P., Domingo, E., Eigen, M., Fersht, A., Frenkel, D., Rees, M., Groen, T., Huber, R., Hunt, T., Holland, J., May, R., Norrby, E., Nijkamp, P., Lehn, J.M., Rabbinge, R., Scheffer, M., Schuster, P., Serageldin, I., Stuip, J., De Vries, J., Van Vierssen, W. and Willems, R. in: Nature 463 (2010) 7283, p. 876.

 

Abstract

Europe's future hinges on funding transdisciplinary scientific collaboration. But career paths, peer recognition, publication channels and the public funding of science are still mostly geared to maintain and reinforce disciplinarity. http://www.nature.com/nature/journal/v463/n7283/full/463876a.html

 

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KWR peer reviewed: Detection of Protozoan Hosts for Legionella pneumophila in Engineered Water Systems by Using a Biofilm Batch Test

Recentelijk publiceerden Rinske M. Valster, Bart A. Wullings, and Dick van der Kooij in: APPLIED AND ENVIRONMENTAL MICROBIOLOGY, Nov. 2010, p. 7144–7153.

Abstract
Outlook

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KWR peer reviewed: Concentration and Diversity of Uncultured Legionella spp. in Two Unchlorinated Drinking Water Supplies with Different Concentrations of Natural Organic Matter

Recentelijk publiceerden Bart A. Wullings,Geo Bakker, and Dick van der Kooij in: APPLIED AND ENVIRONMENTAL MICROBIOLOGY, Jan. 2011, p. 634–641.

Abstract

Outlook

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KWR peer reviewed: Consumer-inclusive innovation strategies for the Dutch water supply Sector: opportunities for more sustainable products and services

Recentelijk publiceerden Hegger D.L.T., Spaargaren G., Vliet B.J.M. van, Frijns J. in: NJAS - Wageningen Journal of Life Sciences (2010) doi:10.1016/j.njas.2010.10.001

Abstract
This article reflects on the consequences of contemporary shifts in the relationships between water utilities, their competitors and domestic end users. Such changing relations come along with the development of new more sustainable products and services. By distinguishing between ‘upstream’ vs. ‘downstream’ and ‘core’ vs. ‘non-core’ innovations in water supply, a conceptual tool was developed and applied to analyse innovations in the Dutch water supply sector both from a provider and a consumer perspective. To assess the role of (eco)innovations in the Dutch water supply sector, the paper reviews current trends in water consumption; consumers’ perception of water services and contemporary innovation strategies of water supply companies. Based on focus group discussions with both water professionals and water consumers, new roles and products for Dutch water supply companies were identified. It was shown that there are fits as well as misfits in the ways in which providers and consumers tend to look at the future of sustainable water supply. Knowing about and relating to consumer preference and practices can be instrumental for water providers when developing new products, services, images and roles.

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