scholarly journals Potential Transformative Changes in Water Provision Systems: Impact of Decentralised Water Systems on Centralised Water Supply Regime

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1709
Author(s):  
van Duuren ◽  
van Alphen ◽  
Koop ◽  
de Bruin
Keyword(s):  
Large Scale ◽  
Potable Water ◽  
Climate Adaptation ◽  
Water System ◽  
Future Generation ◽  
Water Systems ◽  
System Failures ◽  
Sustainable Urban Water Management ◽  
Water Provision ◽  
Systems Thinking Approach

Sustainable Urban Water Management (SUWM) is a paradigm in which decentralisation is key. There has been little work directed towards the large-scale possibilities of decentralised water systems and their implications on the functioning of the centralised (potable) water system. This study includes both a historical and future (scenario) analysis of decentralised developments. Integrated morphological socio-technical scenarios are combined with quantitative water flows for a case study (the Province of Limburg, the Netherlands) and examined by a transdisciplinary group of experts. The study shows how SUWM measures which focus on climate adaptation and circularity can have a significant impact on existing centralised potable water systems. In turn, influencing the total water and peak demands and thus resulting in different utilisation rates. This can result in more system failures (e.g., longer residence time, bacterial growth, reduced self-cleaning capacity), significant changes in the centralised infrastructure (e.g., more wells), increasing water bills (e.g., inequalities), and the preservation of aquifers for future generation. Different scenarios either have regime-reproducing or regime-diversifying impacts. SUWM measures are studied in isolation and thus externalities are not fully considered. Therefore, when planning for decentralised SUWM solutions, a systems thinking approach is recommended, which takes into account externalities.

scholarly journals Introduction of Monochloramine into a Municipal Water System: Impact on Colonization of Buildings by Legionella spp

2006 ◽  
Vol 72 (1) ◽  
pp. 378-383 ◽  
Author(s):  
Matthew R. Moore ◽  
Marsha Pryor ◽  
Barry Fields ◽  
Claressa Lucas ◽  
Maureen Phelan ◽  
...  
Keyword(s):  
Potable Water ◽  
Sampling Site ◽  
Water System ◽  
Water Source ◽  
Water Systems ◽  
Hot Water ◽  
County Government ◽  
Single Family ◽  
Pinellas County ◽  
Municipal Water

ABSTRACT Legionnaires' disease (LD) outbreaks are often traced to colonized potable water systems. We collected water samples from potable water systems of 96 buildings in Pinellas County, Florida, between January and April 2002, during a time when chlorine was the primary residual disinfectant, and from the same buildings between June and September 2002, immediately after monochloramine was introduced into the municipal water system. Samples were cultured for legionellae and amoebae using standard methods. We determined predictors of Legionella colonization of individual buildings and of individual sampling sites. During the chlorine phase, 19 (19.8%) buildings were colonized with legionellae in at least one sampling site. During the monochloramine phase, six (6.2%) buildings were colonized. In the chlorine phase, predictors of Legionella colonization included water source (source B compared to all others, adjusted odds ratio [aOR], 6.7; 95% confidence interval [CI], 2.0 to 23) and the presence of a system with continuously circulating hot water (aOR, 9.8; 95% CI, 1.9 to 51). In the monochloramine phase, there were no predictors of individual building colonization, although we observed a trend toward greater effectiveness of monochloramine in hotels and single-family homes than in county government buildings. The presence of amoebae predicted Legionella colonization at individual sampling sites in both phases (OR ranged from 15 to 46, depending on the phase and sampling site). The routine introduction of monochloramine into a municipal drinking water system appears to have reduced colonization by Legionella spp. in buildings served by the system. Monochloramine may hold promise as community-wide intervention for the prevention of LD.

scholarly journals Water Stagnation and Flow Obstruction Reduces the Quality of Potable Water and Increases the Risk of Legionelloses

2020 ◽  
Vol 8 ◽  
Author(s):  
Muhammad Atif Nisar ◽  
Kirstin E. Ross ◽  
Melissa H. Brown ◽  
Richard Bentham ◽  
Harriet Whiley
Keyword(s):  
Potable Water ◽  
Public Awareness ◽  
Water System ◽  
Positive Association ◽  
Water Systems ◽  
Water Safety ◽  
Stagnation Points ◽  
Plumbing Systems ◽  
The Impact

Legionella is an opportunistic waterborne pathogen associated with Legionnaires' disease and Pontiac fever. Despite improved public awareness, the incidence of Legionella associated infections has been increasing. Aerosols generated from engineered potable water systems are a demonstrated cause of both nosocomial and community-acquired legionellosis. The ecology of Legionella in these systems is complex with multiple factors impacting their colonization and persistence. Flow dynamics has been identified as an important factor and stagnation in cooling towers is an accepted risk for increased Legionella growth; however, less is known about the impact of flow dynamic on Legionella in potable water systems. This is especially complex due to the inherent intermittent and variable usage observed within outlets of a potable water system. This systematic literature review examines the role of fluid dynamics and stagnation on the colonization and growth of Legionella in potable water systems. Twenty two of 24 identified studies show a positive association between stagnation zones and increased colonization of Legionella. These zones included dead legs, dead ends, storage tanks, and obstructed water flow (such as intermittent usage or flow restriction). Prolonged stagnation in building plumbing systems also deteriorates the quality of thermally or chemically treated potable water. This stimulates the colonization of Legionella established biofilms. Such biofilms are intrinsically resistant to disinfection procedures and accelerate the rate of decay of chemical disinfectants. Sub-lethal doses of disinfectants and the presence of protozoan hosts in stationary water promote generation of viable but non-culturable Legionella cells. This results in false negatives in surveillance methods that use culture methodology. In conclusion, elimination of temporal and permanent stagnation points can improve the quality of potable water, efficacy of disinfectants, and reduce the risk of legionellosis. Current guidelines and water safety plans recognize the risks associated with permanent stagnation point (dead ends and dead legs); however, there is a need for greater emphasis on controlling temporal stagnation arising from intermittent usage.

scholarly journals The limits to large scale supply augmentation: Exploring the crossroads of conflicting urban water system development pathways

2021 ◽  
Author(s):  
Jonatan Godinez Madrigal ◽  
Nora Van Cauwenbergh ◽  
Jaime Hoogesteger ◽  
Pamela Claure Gutierrez ◽  
Pieter van der Zaag
Keyword(s):  
Large Scale ◽  
Water System ◽  
Distribution Networks ◽  
Water Systems ◽  
Urban Water ◽  
Infrastructure Development ◽  
Development Pathway ◽  
Urban Water System ◽  
Trade Offs ◽  
Urban Water Systems

Abstract. Managers of urban water systems constantly make decisions to guarantee water services by overcoming problems related to supply-demand imbalances. A preferred strategy has been supply augmentation through hydraulic infrastructure development. However, despite considerable investments, many systems seem to be trapped in lackluster development pathways making some problems seem like an enduring, almost stubborn, characteristic of the systems: over-exploitation and pollution of water sources, distribution networks overwhelmed by leakages and non-revenue water, and unequal water insecurity. Because of these strategies and persistent problems, water conflicts have emerged, whereby social actors oppose these strategies and propose alternative technologies and strategies. This can create development pathways crossroads of the urban water system. To study this development pathway crossroads, we selected the Zapotillo conflict in Mexico where a large supply augmentation project for two cities experiencing water shortages is at stake. The paper concludes that urban water systems that are engaged in a trajectory characterized by supply-side strategies may experience a temporal relief but neglect equally pressing issues that stymie the human right to water in the medium and long run. However, there is not a straightforward, self-evident development pathway to choose from, only a range of multiple alternatives with multiple trade-offs that need to be thoroughly discussed and negotiated between the stakeholders. We argue that this development pathway crossroads can cross-fertilize technical disciplines such as socio-hydrology, and social disciplines based on hydrosocial studies, which both ambition to make their knowledge actionable and relevant.

The History and Visual Culture of Mexico City’s Xochimilco Potable Water System during the Porfiriato

2016 ◽  
Author(s):  
Jeffrey M. Banister ◽  
Stacie G. Widdifield
Keyword(s):  
Visual Culture ◽  
Large Scale ◽  
Potable Water ◽  
Water System ◽  
Water Control ◽  
Water Shortages ◽  
Porfirio Diaz ◽  
The Public ◽  
History Of ◽  
Traditional Sense

Historians have extensively explored the topic of water control in Mexico City. From the relationship between political power and hydraulics to detailed studies of drainage and other large-scale infrastructure projects, the epic story of water in this megalopolis, constructed over a series of ancient lakes, continues to captivate people’s imaginations. Securing potable water for the fast-growing city is also a constant struggle, yet it has received comparatively less attention than drainage in historical research. Moreover, until quite recently scholars have not been especially concerned with water control as a process of representation—that is, a process shaped by, and shaping, visual culture. Yet, potable water brings together many stories about people and places both within and outside of the Basin of Mexico. As such, the history of potable water is communicated through a diverse array of objects and modern infrastructures not limited to the idea of waterworks in the traditional sense of the term. A more expansive view of “infrastructure” incorporates more than the commonplace objects of hydraulic management such as aqueducts, pumps, wells, and pipes: it also involves architecture, photography, and narrative history, official and unofficial. Built in the first decade of the 20th century as a response to acute water shortages, the impressively modern Xochimilco Potable Water Works exemplifies a system that delivered far more than fresh drinking water through its series of modern electric pumps and aqueduct. The system was a result of a larger modernization initiative launched by the administration of Porfirio Díaz (1876–1911). It wove together an official history of water, which included the annexation of Xochimilco’s springs, through its diverse infrastructures, including the engineering of the potable water system as well as the significance of the structures themselves in terms of locations and architectural elaboration in neo-styles (also known as historical styles) typical of the period. Demonstrably clear from the sheer investment in making the Xochimilco waterworks appealing to the public is that infrastructure can possess a rich visual culture of its own.

Sporadic Legionnaires' disease: the role of domestic electric hot-water tanks

2011 ◽  
Vol 140 (1) ◽  
pp. 172-181 ◽  
Author(s):  
S. F. DUFRESNE ◽  
M. C. LOCAS ◽  
A. DUCHESNE ◽  
C. RESTIERI ◽  
J. ISMAÏL ◽  
...  
Keyword(s):  
Potable Water ◽  
Water System ◽  
Water Systems ◽  
Pulsed Field Gel Electrophoresis ◽  
Hot Water ◽  
Clinical Isolates ◽  
Domestic Hot Water ◽  
Legionnaires Disease ◽  
Water Tanks

SUMMARYSporadic community-acquired legionellosis (SCAL) can be acquired through contaminated aerosols from residential potable water. Electricity-dependent hot-water tanks are widely used in the province of Quebec (Canada) and have been shown to be frequently contaminated withLegionellaspp. We prospectively investigated the homes of culture-proven SCAL patients from Quebec in order to establish the proportion of patients whose domestic potable hot-water system was contaminated with the sameLegionellaisolate that caused their pneumonia. Water samples were collected in each patient's home. Environmental and clinical isolates were compared using pulsed-field gel electrophoresis. Thirty-six patients were enrolled into the study.Legionellawas recovered in 12/36 (33%) homes. The residential and clinical isolates were found to be microbiologically related in 5/36 (14%) patients. Contaminated electricity-heated domestic hot-water systems contribute to the acquisition of SCAL. The proportion is similar to previous reports, but may be underestimated.

scholarly journals Evaluating adenosine triphosphate bioluminescence for biomonitoring in potable water systems

2020 ◽  
Vol 69 (7) ◽  
pp. 668-677
Author(s):  
Angela B. Rodriguez ◽  
Steven J. Duranceau
Keyword(s):  
Adenosine Triphosphate ◽  
Distribution System ◽  
Potable Water ◽  
Water System ◽  
Water Systems ◽  
Source Water ◽  
Microbiological Activity ◽  
Suitable Candidate ◽  
Atp Bioluminescence ◽  
Technological Limitations

Abstract The application of adenosine triphosphate (ATP) bioluminescence technology as a rapid microbiological activity monitor within a potable water system has been demonstrated. ATP measurements were taken pre- and post-infrastructure improvements within a watershed and throughout two potable water systems from source to tap. A reduction in ATP, as measured by relative light units, was identified post-infrastructure improvements. Peak ATP values for the watershed were found within the reservoirs. The treated source water remained biologically stable throughout the distribution system, with peaks attributed to nitrification. A mathematical model for predicting microbial ATP using pH, temperature, and alkalinity, was developed for the watershed studied, with an adjusted R2 of 0.84 at a 95% confidence level. Overall, ATP bioluminescence technology was found to be a suitable candidate for rapid microbiological activity testing in drinking water systems; however, technological limitations remain with respect to reproducibility that should be addressed prior to full-scale implementation.

Iodine sensitivity of bacteria isolated from iodinated water systems

1989 ◽  
Vol 35 (4) ◽  
pp. 520-523 ◽  
Author(s):  
Barry H. Pyle ◽  
Gordon A. McFeters
Keyword(s):  
Phosphate Buffer ◽  
Potable Water ◽  
Povidone Iodine ◽  
Water System ◽  
Brain Heart Infusion ◽  
Water Systems ◽  
Pseudomonas Cepacia ◽  
Anion Exchange Resins ◽  
Exchange Resins ◽  
Povidone Iodine Solution

Fourteen bacterial isolates, predominantly Pseudomonas sp., from two water systems disinfected by iodinated anion-exchange resins were studied and compared with an isolate of Pseudomonas aeruginosa from a povidone-iodine solution and four other isolates. Pseudomonas cepacia and P. aeruginosa grown in brain heart infusion were 3 to 5 logs less sensitive to 1 mg/L I2 (pH 7.2, 1 min) when compared with cultures grown in phosphate buffer. Another P. cepacia isolate was the least sensitive culture when grown in brain heart infusion (1 log decrease) but was more sensitive after cultivation in phosphate buffer (5 logs). Isolates from an iodinated potable water system, including P. cepacia, Staphyloccus warneri, and a Bacillus sp., were all less sensitive to iodine than a "resistant" P. aeruginosa and three other isolates when grown in brain heart infusion. A clinical isolate of P. aeruginosa exhibited intermediate sensitivity. The sensitivity of bacteria to iodine is thus highly variable, depending on the organism as well as the growth conditions.Key words: iodine, disinfection, water.

A simple method for the eradication ofLegionella pneumophilafrom potable water systems

1997 ◽  
Vol 43 (12) ◽  
pp. 1189-1196 ◽  
Author(s):  
Carmen Moreno ◽  
Isabel de Blas ◽  
Francisca Miralles ◽  
David Apraiz ◽  
Vicente Catalan
Keyword(s):  
Legionella Pneumophila ◽  
Potable Water ◽  
Cold Water ◽  
Tap Water ◽  
Water System ◽  
Water Systems ◽  
Hot Water ◽  
Residual Chlorine ◽  
Water Heater ◽  
Simple Method

In this paper we describe a simple method, noncorrosive to pipes, for the eradication of Legionella pneumophila from potable water systems. This method is based on the systematic purging of the pipe networks with cold water containing 1 – 1.5 mg residual chlorine/L. In the hot water system, a new pipe bypassing the water heater was installed, whereas in the air conditioning system, the circuit is purged with water from the tap water system. The feasibility of this method was studied in two hotels in which the presence of Legionella was detected despite treatment of the water by the hyperchlorination method. The evolution of the presence of Legionella was studied by culture and polymerase chain reaction. Eighty samples from hotel A and sixty-seven samples from hotel B were analyzed during the time that the eradication method was applied. Our results showed that this method permitted the effective elimination of L. pneumophila after 5 months in hotel A and 7 months in hotel B.Key words: Legionella pneumophila, eradication.

Sewers and the Quality of Canals and Ditches in Amsterdam

1993 ◽  
Vol 27 (5-6) ◽  
pp. 61-67 ◽  
Author(s):  
E. Jacobs ◽  
J. W. van Sluis
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Sediment Quality ◽  
Water System ◽  
Water Systems ◽  
Sewer System ◽  
Water And Sediment ◽  
Combined Sewer ◽  
Water And Sediment Quality

The surface water system of Amsterdam is very complicated. Of two characteristic types of water systems the influences on water and sediment quality are investigated. The importance of the sewer output to the total loads is different for both water systems. In a polder the load from the sewers is much more important than in the canal basin. Measures to reduce the emission from the sewers are much more effective in a polder. The effect of these measures on sediment quality is more than the effect on water quality. Some differences between a combined sewer system and a separate sewer system can be found in sediment quality.

Design of rural water systems using dynamic models

1999 ◽  
Vol 39 (4) ◽  
pp. 221-231
Author(s):  
A. H. Lobbrecht
Keyword(s):  
Dynamic Models ◽  
Water System ◽  
Design Procedure ◽  
Real Data ◽  
Water Systems ◽  
Design Methods ◽  
Water Quality Criteria ◽  
Rural Water ◽  
Rural Water Systems ◽  
The Way

The properties of main water ways and infrastructure of rural water systems are often determined by very general design methods. These methods are based on standards that use only little information of the actual water system. Most design methods applied in the Netherlands are based on land use and soil texture. Standards have been developed on the basis of generalized properties of water systems. Details of the actual layout of the water system and the way in which that system is controlled, are usually not incorporated. Present-day dynamic simulation programs and the computer power currently available enable more detailed modeling and incorporation of location-specific data into models. Such models can be used to design the water system and can include real data. A model-based design method is introduced, in which the actual situation of the water system is taken into consideration as well as the way in which the water system is controlled. Stochastics concerning the operation and availability of controlling infrastructure are included in the method. Models can be evaluated by including real data. In this way the actual safety of the water system, for example during floods, can be determined. Water-quantity design criteria can be incorporated as well as water-quality criteria. Application of the method makes it possible to design safe water systems in which excess capacities are avoided and in which all requirements of interest are met. The method, called the ‘dynamic design procedure’, can result in considerable savings for water authorities when new systems have to be designed or existing designs have to be reconsidered.

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