bluuebunny/crossref_metadata_2025 huggingface dataset:
A comparison of the survival of F+RNA and F+DNA coliphages in lake water microcosms
Authors: Long Sharon C. , Sobsey Mark D.
Published: May 2018

The survival of seven F+RNA phages (MS2 Group I ATCC type strain, two Group I environmental isolates, a Group II environmental isolate, a Group III environmental isolate, and two Group IV environmental isolates) and six F+DNA phages (M13, fd, f1, and ZJ/2 ATCC type strains, and two environmental isolates) were examined in microcosms using a surface drinking water source. Phages were spiked into replicate aliquots of a source water at about 20,000 pfu/ml. Replicate spikes were incubated at 4 and 20°C and monitored for 110 days. At 4°C, Groups I and II F+ RNA phages were detectable through 110 days, with reductions of about 1 and 3 log10, respectively. The Group III F+RNA phage demonstrated 5 log10 reduction after 3 weeks, and the Group IV F+RNA phages were reduced to detection limits (5 log10 reduction) within 10 days. Of the F+DNA phages, all four type strains were detectable with about 2.5 log10 reduction after 110 days at 4°C. The F+DNA environmental isolates were detectable with about a 4 log10 reduction after 110 days at 4°C. All phages demonstrated faster decay at 20°C. These results suggest that differences in F+ phage survival may influence their prevalence in environmental waters and the ability to attribute their prevalence to specific human and animal sources of faecal contamination.
Non-point source pollution: Determination of replication versus persistence of Escherichia coli in surface water and sediments with correlation of levels to readily measurable environmental parameters
Authors: Kinzelman Julie , McLellan Sandra L. , Daniels Annette D. , Cashin Susan , Singh Ajaib , Gradus Stephen , Bagley Robert
Published: May 2018

Racine, Wisconsin, located on Lake Michigan, experiences frequent recreational water quality advisories in the absence of any identifiable point source of pollution. This research examines the environmental distribution of Escherichia coli in conjunction with the assessment of additional parameters (rainfall, turbidity, wave height, wind direction, wind speed and algal presence) in order to determine the most probable factors that influence E. coli levels in surface waters. Densities of E. coli were highest in core samples taken from foreshore sands, often exceeding an order of magnitude greater than those collected from submerged sands and water. Simple regression and multivariate analyses conducted on supplementary environmental data indicate that the previous day's E. coli concentration in conjunction with wave height is significantly predictive for present-time E. coli concentration. Genetic fingerprinting using repetitive element anchored PCR and cellular fatty acid analysis were employed to assess the presence of clonal isolates which indicate replication from a common parent cell. There were relatively few occurrences of clonal patterns in isolates collected from water, foreshore and submerged sands, suggesting that accumulation of E. coli, rather than environmental replication, was occurring in this system. Non-point source pollution, namely transport of accumulated E. coli from foreshore sands to surface waters via wave action, was found to be a major contributor to poor recreational water quality at the Lake Michigan beaches involved in this study.
Optimal reconstruction of historical water supply to a distribution system: B. Applications
Authors: Aral M. M. , Guan J. , Maslia M. L. , Sautner J. B. , Gillig R. E. , Reyes J. J. , Williams R. C.
Published: May 2018

In a recently completed case-control epidemiological study, the New Jersey Department of Health and Senior Services (NJDHSS) with support from the Agency for Toxic Substances and Disease Registry (ATSDR) documented an association between prenatal exposure to a specific contaminated community water source and leukaemia in female children. An important and necessary step in the epidemiological study was the reconstruction of the historical water supply strategy of the water distribution system serving the Dover Township area, New Jersey. The sensitivity of solutions to: (1) pressure and pattern factor constraints, (2) allowable operational extremes of water levels in the storage tanks, and (3) the non-uniqueness of the water supply solution are analysed in detail. The computational results show that the proposed approach yields satisfactory results for the complete set of monthly simulations and sensitivity analyses, providing a consistent approach for identifying the historical water supply strategy of the water distribution system. Sensitivity analyses indicated that the alternative strategy obtained from the revised objective function and the variation of constraints did not yield significantly different water supply characteristics. The overall analysis demonstrates that the progressive optimality genetic algorithm (POGA) developed to solve the optimization problem is an effective and efficient algorithm for the reconstruction of water supply strategies in water distribution systems.
Cryptosporidium and Giardia in swimming pools in the Netherlands
Authors: Schets F. M. , Engels G. B. , Evers E. G.
Published: May 2018

The occurrence of Cryptosporidium and Giardia in indoor swimming pools in the Netherlands was studied at five locations. The backwash water from seven pool filters was analysed for the presence of Cryptosporidium oocysts and Giardia cysts for a period of 1 year. Of the 153 samples of filter backwash water analysed, 18 (11.8%) were found positive for either Cryptosporidium (4.6%), Giardia (5.9%) or both (1.3%). Oocysts and cysts were also detected in the water of one toddler pool and one learner pool. Although most of the (oo)cysts in the filter backwash water were dead, viable and potentially infectious oocysts were detected in the learner pool. On the basis of numbers of potentially infectious (oo)cysts detected in the learner pool, and assuming one visit to an infected pool per year, risk assessment indicated an estimated risk of infection with Cryptosporidium that exceeded the generally accepted risk of one infection per 10,000 persons per year. Guidelines for pool operators on how to manage faecal accidents and public information on the importance of hygiene in swimming pool complexes are recommended tools in controlling the risk of infection.
Tracking the origin of faecal pollution in surface water: an ongoing project within the European Union research programme
Authors: Blanch Anicet R. , Belanche-Muñoz Luis , Bonjoch Xavier , Ebdon James , Gantzer Christophe , Lucena Francisco , Ottoson Jakob , Kourtis Christos , Iversen Aina , Kühn Inger , Moce Laura , Muniesa Maite , Schwartzbrod Janine , Skraber Sylvain , Papageorgiou George , Taylor Huw D. , Wallis Jessica , Jofre Joan
Published: May 2018

The objectives of this study are to generate knowledge about methods to track the sources of faecal pollution in surface waters, with the aim of having one or a few easy procedures applicable to different geographic areas in Europe. For this, a first field study using already proposed methods (genotypes of F-specific RNA bacteriophages, bacteriophages infecting Bacteroides fragilis, phenotypes of faecal coliforms and enterococci, and sterols) has been done in five areas representing a wide array of conditions in Europe. The present faecal indicators (faecal coliforms, enterococci, sulfite reducing clostridia and somatic coliphages) have also been included in this first field study. At the same time some emerging methods have been settled or adapted to water samples and assayed in a limited number of samples. The results of this first field study indicate that no single parameter alone is able to discriminate the sources, human or non-human, of faecal pollution, but that a ‘basket’ of 4 or 5 parameters, which includes one of the present faecal indicators, will do so. In addition, numerical analysis of the data shows that this ‘basket’ will allow the successful building of predictive models. Both the statistical analyses and the studied predictive models indicate that genotype II of F-specific RNA bacteriophages, the coprostanol and the ratio coprostanol: coprostanol+epicoprostanol are, out of the studied parameters, those with a greater discriminating power. Either because unsuccessful adaptation of the methods to water samples or because the preliminary assays in water samples indicated low discriminating capability, only three (sorbitol-fermenting bifidobacteria, some species of bifidobacteria detected by PCR with specific primers and phages infecting Bacteroidestethaiotaomicron) of the newly assayed methods have been considered for a second field study, which is currently underway. Expectations are that these new tools will minimize the number of parameters in the ‘basket’, or at least minimize the difficulty in assaying them.
Effective water supply surveillance in urban areas of developing countries
Authors: Howard Guy , Bartram Jamie
Published: May 2018

Water supply surveillance generates data on the safety and adequacy of drinking water supply in order to contribute to the protection of human health. Most current models of water supply surveillance for urban areas come from developed countries and have significant shortcomings if directly applied elsewhere. There are differences not only in socio-economic conditions but also in the nature of water supply services, which often comprise a complex mixture of formal and informal services for both the ‘served’ and ‘unserved’. The development of approaches to water supply surveillance that allow targeting of activities on priority groups is assessed based on case studies from Peru and Uganda. The development of a zoning approach that incorporates indices for vulnerability is shown to be a useful tool to assist surveillance in targeting data collection. Zoning also assists in targeting subsequent interventions into communities and strategies where public health gains are likely to be greatest. Two approaches to urban zoning are presented from Peru and Uganda, both of which are effective.
Microbial quality of runoff following land application of cattle manure and swine slurry
Authors: Thurston-Enriquez Jeanette A. , Gilley John E. , Eghball Bahman
Published: May 2018

Concentrations of human health-related microorganisms in runoff from agricultural plots (0.75 m × 2 m) treated with fresh and aged cattle manure, swine slurry and no manure (control) were determined. Three consecutive simulated rainfall events, producing 35 mm rainfall and separated by 24 h, were carried out for each plot. Fecal indicator (Escherichia coli, enterococci, Clostridium perfringens and coliphage) loads released in rainfall runoff from plots treated with fresh cattle manure, aged cattle manure and swine slurry treatments ranged from 5.52 × 105 to 4.36 × 109, 3.92 × 104 to 4.86 × 108, and 9.63 × 105 to 3.05 × 108, respectively. Plot runoff concentrations of protozoa (Cryptosporidium oocysts and Giardia cysts) ranged from 1.65 × 105 to 1.04 × 106, 2.93 × 103 to 2.75 × 105, and 9.12 × 104 to 3.58 × 106 for fresh cattle manure, aged cattle manure and swine slurry plot treatments, respectively. These results suggest that large microbial loads could be released via heavy precipitation events that produce runoff from livestock manure-applied agricultural fields, of even modest size, and could have a significant impact on water bodies within the watershed. Because of the lack of multiplication in the environment, highly elevated concentrations in manured land runoff, and correlation to protozoan parasite presence, Clostridium may be an alternative indicator for livestock manure contamination.
Bushfires and tank rainwater quality: A cause for concern?
Authors: Spinks Jean , Phillips Suzanne , Robinson Priscilla , Van Buynder Paul
Published: May 2018

In early 2003, after a prolonged drought period, extensive bushfires occurred in the east of Victoria affecting 1.5 million hectares of land. At the time, smoke and ash from bushfires, settling on roofs, contained pollutants that could potentially contaminate rainwater collected and stored in tanks for domestic use. The major concerns include polycyclic aromatic hydrocarbons (PAHs) from incomplete combustion of organic matter and arsenic from burnt copper chrome arsenate (CCA) treated wood. An increase in microbial contamination through altered nutrient levels was also hypothesised. A pilot study of 49 rainwater tank owners was undertaken in north-east Victoria. A rainwater tank sample was taken and analysed for a variety of parameters including organic compounds, microbiological indicators, metals, nutrients and physico-chemical parameters. A survey was administered concurrently. A number of results were outside the Australian Drinking Water Guideline (ADWG) values for metals and microbiological indicator organisms, but not for any tested organic compounds. PAHs and arsenic are unlikely to be elevated in rainwater tanks as a result of bushfires, but cadmium may be of concern.
Identification of human fecal pollution sources in a coastal area: a case study at Oostende (Belgium)
Authors: Seurinck Sylvie , Verdievel Martin , Verstraete Willy , Siciliano Steven D.
Published: May 2018

From April to June 2001, a monitoring study at Oostende (Belgium) was conducted to obtain an insight into fecal pollution impairing water quality at this coastal area. Eight sampling sites were selected based on the historically low water quality at these sites compared to the remainder of the area. Indicator organisms such as fecal coliforms, Escherichia coli and fecal streptococci were monitored by plating. A real-time PCR assay for quantification of the human-specific HF183 Bacteroides 16S rRNA genetic marker was used to detect human fecal pollution at the sampling sites. Human fecal pollution was detected at all sampling sites. However, the frequency of detection ranged from 30–100% and the amount of human-specific Bacteroides markers recorded varied between the sampling sites. Concentrations of 107 human-specific Bacteroides markers per l to levels below the detection limit of the real-time PCR assay were recorded. Our results indicate that human fecal pollution is a re-occurring problem in certain areas. Of all the environmental parameters monitored during the study, only rainfall was strongly related to the detection of the indicator organisms and the human-specific Bacteroides marker.
Nutrient removal from septic effluents as affected by soil thickness and texture
Authors: Karathanasis A. D. , Mueller T. G. , Boone B. , Thompson Y. L.
Published: May 2018

This study evaluated the effectiveness of soils with different textures and thickness to treat BOD, N and P eluted from household septic effluent. The assessments were accomplished by leaching undisturbed soil monoliths of 30, 45 and 60 cm thickness and 25 cm in diameter, representing the four different textural groups and hydraulic loadings recommended by the Kentucky Health Department, with domestic wastewater effluent collected regularly from a household septic system. Effluent concentrations were monitored daily over a 15 d period for biochemical oxygen demand (BOD), total-N, NH4–N, NO3–N and total-P concentrations. The results of the study indicate an alarming frequency of failure to comply with EPA criteria for BOD, total-N and NH4–N concentrations when using a 30 cm vertical separation distance between the bottom of the drain field and a limiting soil interface. The treatment performance was particularly poor in coarse-textured soils, apparently due to insufficient reactive surface area. Although biomat development over time is expected to improve the treatment for some of these parameters, the high influent levels of BOD pose great concerns for surface and groundwater contamination during the early stages of operation. Fine-textured soils generally provided better treatment efficiency and more consistent compliance with EPA standards for BOD, total-N, NH4–N and total-P, as well as greater nitrification/denitrification potential. Treatment efficiency and compliance usually improved with increasing soil depth, with the 60 cm thickness providing the most consistent performance and compliance with MDL requirements. Considering that increasing soil thickness requirements may be impractical in many marginal soils, complementary or alternative treatment technologies should be adopted to improve treatment efficiency and prevent further deterioration of the quality of water resources.
Delineation of a chemical and biological signature for stormwater pollution in an urban river
Authors: Salmore Alissa K. , Hollis Erika J. , McLellan Sandra L.
Published: May 2018

Stormwater is a major source of Escherichia coli in urban waterways. This study assessed the chemical and bacterial contaminant load in stormwater entering an urban river using chemical analyses, E. coli enumeration and antibiotic resistance testing. Inline monitoring of five major stormwater outfalls revealed that E. coli concentrations can range from 100 to >240,000 CFU 100 ml−1 in stormwater; 15% of the samples contained >240,000 CFU 100 ml−1. E. coli levels increased from <200 CFU 100 ml−1 to between 1,500 and >20,000 CFU 100 ml−1 in the receiving waters following storm events. Metals and nutrients were significantly elevated (p < 0.05) in inline stormwater samples compared with baseflow river water. Chromium, zinc, lead and total phosphorus were co-ordinately elevated in stormwater, but E. coli levels did not correlate to this chemical signature. E. coli isolates from stormwater and river water samples (n = 2,478) were tested for resistance to 10 antibiotics and compared with over 1,800 isolates from human and non-human sources. The antibiotic resistance frequencies of isolates from human sources were considerably higher than those found in non-human sources. Isolates from human sources were resistant to multiple antibiotics; however, no specific multiple resistance pattern was found. One of five stormwater outfalls tested contained E. coli resistant to antibiotics at frequencies that were not significantly different from those of E. coli isolates from wastewater treatment plant influent (p < 0.05). The results from antibiotic resistance testing suggested that the elevated E. coli levels observed after storm events are a mixture of human and non-human sources. The results of this study demonstrate that there is a considerable E. coli load to receiving waters from stormwater and that sanitary sewage inputs may not be limited to recognized sewer overflows.
The treatment of hospital wastewater: an appraisal
Authors: Pauwels B. , Verstraete W.
Published: May 2018

Hospitals discharge considerable amounts of chemicals and microbial agents in their wastewaters. Problem chemicals present in hospital wastewater belong to different groups, such as antibiotics, X-ray contrast agents, disinfectants and pharmaceuticals. Many of these chemical compounds resist normal wastewater treatment. They end up in surface waters where they can influence the aquatic ecosystem and interfere with the food chain. Humans are particularly exposed by the drinking water, produced from surface water. Microbial agents of special concern are multiresistant microbial strains. The latter are suspected to contribute to the spread of antibiotic resistance. In this paper, we will discuss the different approaches towards hospital wastewater treatment. The principle of uncoupling hospitals from public sewers warrants in-depth evaluation by technologists and ecotoxicologists as well as public health specialists.
Water ingestion during swimming activities in a pool: A pilot study
Authors: Dufour Alfred P. , Evans Otis , Behymer Thomas D. , Cantú Ricardo
Published: May 2018

Chloroisocyanurates are commonly added to outdoor swimming pools to stabilize chlorine disinfectants. The chloroisocyanurates decompose slowly to release chlorine and cyanuric acid. Studies conducted to determine if the chloroisocyanurates might be toxic to swimmers showed that they were not and that ingested cyanuric acid passed through the body unmetabolized. This fact was used to determine the amount of water swallowed during swimming activity. Fifty-three recreational swimmers, using a community swimming pool disinfected with cyanuric acid stabilized chlorine, participated in the study. The participants did not swim on the day before or after the test swim. The swimmers were asked to actively swim for at least 45 minutes and to collect their urine for the next 24 hours. Cyanuric acid was measured in pool water using high performance liquid chromatography and porous graphitic carbon columns with UV detection. The urine sample assay required a clean-up procedure to remove urinary proteins and interfering substances. Results of the study indicate that non-adults ingest about twice as much water as adults during swimming activity. The average amount of water swallowed by non-adults and adults was 37 ml and 16 ml, respectively. The design for this study and the analytical methodology used to assay cyanuric acid in swimming pool water and human urine were effective for measuring the volume of water swallowed during swimming activity.
Studies on defluoridation of water by Tamarind seed, an unconventional biosorbent
Authors: Murugan M. , Subramanian E.
Published: May 2018

Tamarind seed, a household waste from the kitchen is used for the sorptive removal of fluoride from synthetic aqueous solution as well as from field water samples. Batch sorptive defluoridation was conducted under variable experimental conditions such as pH, agitation time, initial fluoride concentration, particle size and sorbent dose. Maximum defluoridation was achieved at pH 7.0. Defluoridation capacity decreases with increase in temperature and particle size. Further, defluoridation follows first order kinetics and Langmuir adsorption isotherm. Desorption was carried out with 0.1 N HCl and is 90 per cent. The surface and sorption characteristics were analysed using FTIR and SEM techniques. All these results indicate the involvement of energetic forces such as coulombic interaction in sorption. For domestic and industrial applications, defluoridation with 100% achievement and subsequent regeneration of adsorbent was performed with a household water filter and fixed bed column respectively.
Aesthetic issues for drinking water
Authors: Dietrich Andrea M.
Published: May 2018

Although many people expect their drinking water to be “flavorless”, natural and processed drinking waters have flavors due to minerals and organics in the natural water, inputs from any step of water processing or transport, and interaction of these chemicals with an individuals' nose and mouth. Since people can detect the flavor of water, the idea has been proposed that drinking water consumers be considered as sentinels who monitor water quality. This paper explores specific sensory components of drinking water, how humans perceive their drinking water, and future directions for aesthetic research that can better explain causes of and treatments for tastes and odors in drinking water and the human factors that make water a desirable beverage.
Drinking water and health research: a look to the future in the United States and globally
Authors: Sobsey Mark D.
Published: May 2018

Drinking water supplies continue to be a major source of human disease and death globally because many of them remain unsafe and vulnerable. Greater efforts are needed to address the key issues and questions which influence the provision of safe drinking water. Efforts are needed to re-evaluate and set new and better priorities for drinking water research and practice. More stakeholders need to be included in the processes of identifying key issues and setting priorities for safe drinking water. The overall approach to drinking water research and the provision of safe drinking water needs to become more rational and scientific, and become more visionary and anticipatory of the ever-present and emerging risks to drinking water safety. Collectively, we need to do a better job of making safe water available, accessible and affordable for all. One such approach to safe water for all is household water treatment and safe storage, which is being promoted globally by the World Health Organization and many other stakeholders and partners to reduce the global burden of waterborne disease.
Water taste: the importance of osmotic sensing in the oral cavity
Authors: Gilbertson Timothy A. , Baquero Arian F. , Spray-Watson Kristina J.
Published: May 2018

The sense of taste plays critical roles in nutrient identification and toxin avoidance. The ability to respond to hypoosmotic stimuli in mammalian taste receptor cells may reflect the importance of osmotic sensing by the gustatory system. Transduction for hypoosmotic stimuli involves water influx through aquaporins followed by activation of volume-regulated anion channels. The ability of these transduction elements to be regulated by natriferic hormones at the mRNA and protein level in other transporting epithelia suggest that the gustatory system may respond to extrinsic signals related to the restoration of salt and water balance. Plasticity in the peripheral gustatory system is consistent with the activity in the taste system being reflective of underlying nutritional status. Clearly, more research is needed to determine the link between nutrition, taste and the control of food and water intake.
Global challenges in water, sanitation and health
Authors: Moe Christine L. , Rheingans Richard D.
Published: May 2018

The year 2005 marks the beginning of the “International Decade for Action: Water for Life” and renewed effort to achieve the Millennium Development Goals (MDGs) to reduce by half the proportion of the world's population without sustainable access to safe drinking water and sanitation by 2015. Currently, UNICEF and WHO estimate that 1.1 billion people lack access to improved water supplies and 2.6 billion people lack adequate sanitation. Providing safe water and basic sanitation to meet the MDGs will require substantial economic resources, sustainable technological solutions and courageous political will. We review five major challenges to providing safe water and sanitation on a global basis: (1) contamination of water in distribution systems, (2) growing water scarcity and the potential for water reuse and conservation, (3) implementing innovative low-cost sanitation systems, (4) providing sustainable water supplies and sanitation for megacities, and (5) reducing global and regional disparities in access to water and sanitation and developing financially sustainable water and sanitation services.
China: The South–North Water Transfer Project—is it justified?
Authors: Berkoff Jeremy
Published: May 2018

The South-North Water Transfer Project (SNWTP), if fully developed, could divert 40-50 km3/yr from the Yangtse basin to the North China plain, alleviating water scarcity for 300-325M people living in what even then will be a highly water-stressed region. Construction of the next stage, diverting up to 20 km3 at a cost of about $17,000M (including $7000M in ancillary costs), is to start in 2002/3. A recent World Bank study suggests that the project is economically attractive. This conclusion has been disputed by the World Wildlife Fund (now the Worldwide Fund for Nature). This paper concludes that little confidence can be placed in either of these analyses. It therefore seeks to throw light on how the project fits within a broader regional and agricultural development setting. The project is hugely expensive, and would at the margin tend to preserve water in low value agriculture and require the resettlement of upwards of 300,000 people. On the other hand, the pace and scale of socio-economic change in China are without precedent, and adjustment problems on the North China plain are greatly exacerbated by water scarcity. Reallocation of water from irrigation to municipal and industrial uses or to the environment is socially divisive and in some instances physically impracticable. The transfer project would greatly alleviate these difficulties. It is these arguments (which are ultimately political and pragmatic), rather than those based strictly on economic or food security concerns, that make the Government's decision to proceed with the project fully understandable.
Institutional arrangements for integrated river basin management
Authors: Jaspers Frank G. W.
Published: May 2018

This paper considers the institutional arrangements that are needed and that being developed to enable communities to depart from sectoral and isolated water management in order to reach a higher level of integration. Key aspects are described that should be properly handled to manage river basins as a whole and in an integrated way.

The justification for various countries to opt for systems of integrated river basin management is explored. Triggers for change are identified: the need for integrated water management on hydrological boundaries; the added value of functional decentralisation enabling decision making at the lowest appropriate level; stakeholder participation in decision making and water resources planning; and cost recovery and water pricing.

Ongoing developments in processes of change are identified and described. A comparative assessment is carried out between the situation in Zimbabwe, South Africa, Tanzania, Turkey, Indonesia, France and The Netherlands. A common denominator of institutional arrangements is determined, from which developing countries in particular could benefit with regard to the introduction and establishment of systems of integrated river basin management. Sample competencies for effective functioning of river basin and sub-basin organisations are identified and described. Platforms of stakeholders with clear rules for representation and for participation in decision making in water resources planning are identified as crucial tools and described. In order to apply effective water pricing and to charge for pollution, a comprehensive system of water rights and discharge permits is considered necessary. The capacity to implement these necessary institutional arrangements is very variable, especially in developing countries, and hence the stage of implementation may differ substantially. Further, it is very important to have initial access to funds to kick-start the process of implementation. It has been found that systems of cost recovery can only be successfully introduced when acceptable service levels are established and when an enabling institutional environment is in place. Investments are needed and not all countries can afford that.

Above all, a major requirement for implementation of any institutional development is the presence of sufficient human and institutional capacity at the right time and at the right place.
Price specification issues under block tariffs: a Spanish case study
Authors: Martínez-Espiñeira Roberto
Published: May 2018

A panel of aggregate data from Spain is used to estimate domestic water demand functions under linear and non-linear tariffs. The use of intra-annual European data constitutes an innovative contribution. The average price per unit of water sold is compared with other price specifications that have been suggested to analyze aggregate data. Average-price elasticity estimates lie between -0.51 and -0.67 and are substantially larger than marginal-price elasticity estimates. Elasticities appear inversely correlated to the size of free allowances covered by minimum charges. Climatic variables seem to affect use, although less than in wealthier and drier areas.
Impact of irrigation on rural poverty in India: an aggregate panel-data analysis
Authors: Bhattarai Madhusudan , Narayanamoorthy A.
Published: May 2018

The main objective of this study is to quantify the marginal impacts of irrigation and selected input factors on spatial (across 14 states) and temporal (from 1970–1993) variation in the rural poverty level in India. The study uses the head count ratio measure (percent of population below the poverty line) of poverty to evaluate how the poverty level is affected by input factors: irrigation, adoption of HYVs, fertilizer application, rural literacy rate and rural road density. It was found that marginal (incremental) impacts of irrigation followed by the rural literacy rate were larger in explaining the variation of rural poverty level in India than those of other factor-inputs selected. The marginal impact of groundwater irrigation on poverty reduction was larger than that of canal irrigation, which is due to greater control in the application and widespread use of groundwater irrigation than of canal irrigation. Despite mixed findings about the impact of irrigation on poverty from past studies, we have found large-scale marginal impacts of irrigation on rural poverty in India. This quantitative information is expected to be useful for designing targeted poverty alleviation and rural development strategies that also enhance agricultural-productivity growth.
Women's participation in rural water supply projects in India: is it moving beyond tokenism and does it matter?
Authors: Stalker Prokopy Linda
Published: May 2018

Evidence supporting the claim that women's participation in large-scale rural water supply projects leads to improved project outcomes is largely limited to isolated case studies. This paper attempts to fill this gap by examining data from 45 villages in two World Bank-assisted projects in India. Using data from a variety of sources, including water committee members, household surveys and focus groups, women's participation is quantified - what percentage actually attend meetings or are involved at higher levels of participation such as decision-making? While it is determined that, in some cases, female committee members are nominal, or token, participants, there is evidence that being on a local water committee helps women develop skills and confidence. Overall community participation is found to have a positive and significant relationship with different measures of project success; however, women's participation at the levels observed in this study is found to have no relationship to project success.
Drip irrigation in India: can it solve water scarcity?
Authors: Narayanamoorthy A.
Published: May 2018

There is an urgent need to increase the existing water use efficiency in Indian agriculture, mainly due to the increasing demand for water from different sectors and the rapid decline of the available potential of water. Water use efficiency under the flood method of irrigation (FMI), predominantly practised in India, is very low owing to enormous losses in distribution and evaporation. The drip method of irrigation (DMI) introduced recently helps to increase water use efficiency significantly, besides increasing the productivity of crops. However, not many studies are available focusing on the effectiveness of the drip method of irrigation in the context of the sustainable use of irrigation water. An attempt is made in this paper to bring out the importance of the drip method of irrigation in the sustainable use of irrigation water using both primary and secondary level information. The results of experimental station data show that water saving from DMI varies from 12% to 84% per hectare for different crops besides increasing the productivity of crops. The farm level data do confirm that DMI helps to save water by 29% for bananas and 37% for grapes per hectare over FMI in addition to substantial increases in productivity. The core and net potential areas of DMI are estimated to be 51.42 million hectares (mha) and 21.27 mha, respectively, for the country as a whole. The achievable total saving of water, by utilising the net potential area of DMI, is estimated to be about 11.271 million ha m. From the saving of water, an additional irrigated area of 11.22 mha under FMI or 24.12 mha under DMI can be created.
Water institutional reforms: theory and practice
Authors: Saleth R. Maria , Dinar Ariel
Published: May 2018

This paper aims to set the stage with an outline of the conceptual, analytical and theoretical aspects of water institutional reforms and a synthesis of the main findings from the reform experiences of six countries: Australia, Chile, Morocco, Namibia, South Africa and Sri Lanka. Utilizing the latest developments in the literature on the subject, this paper presents the analytics of unbundling water institutions to show their endogenous and exogenous linkages, the transaction cost approach as a diagnostic framework for understanding the role of factors affecting water institutions, and a stage-based perspective to provide insights into the internal mechanics and dynamics evident in the process of water institutional change. Using this analytical framework and theoretical approach, this paper also identifies a few practically relevant principles for reform design and implementation. Based on a review of country reform experiences, the paper also synthesizes reform theories with actual practices by providing anecdotal evidence for various theoretical postulates and practical reform principles.
Evaluating changes in water institutions: methodological issues at the micro and meso levels
Authors: Livingston Marie
Published: May 2018

Institutions (formal rules) governing water allocation and use are often critical to a nation's development and prosperity. It is often necessary to change water institutions as economic, physical and political circumstance change. In this paper, a framework is presented to help understand the potential and need for change in water institutions. The pressure for institutional change can be analyzed at the micro level, in terms of the incentives for individuals to organize in order to influence the structure of rules governing water. Economic incentives and interest-group politics combine to produce changes that may or may not be efficient. Change in water institutions can also be evaluated at the meso level, where the structure and sequencing of actual change is at issue. The concepts of nesting, path dependency and institutional transaction costs are particularly useful in understanding this level of change. The concepts presented can help economists evaluate the pressure for, and obstacles to, institutional change in a particular country. These insights may be used by those interested in adapting and designing water institutions that yield improvements in the use of water resources.
Water institutional reforms in Australia
Authors: McKay Jennifer
Published: May 2018

With a brief description of the physical setting and institutional history of the Australian water sector, this paper reviews the water institutional reforms in Australia focusing especially on the nature and extent of reforms initiated since 1995 and provides a few case studies to highlight the issues and challenges in effecting changes in some key reform components. The reforms initiated in 1995 are notable for their comprehensiveness, fiscal incentives and clear and time-bound targets to be achieved. Although water institutions in Australia have undergone remarkable changes, thanks to the reforms, there are still issues and challenges inherent in reforming maturing water institutions. Regional diversity in legal systems and quality standards as well as conflicts between private interest and public welfare are still serious to constraining market-based water allocation and management. While Australia still needs further reforms, its recent reform experience provides considerable insights into the understanding of both the theory and the practice of water institutional reforms.
Future water institutions in Palestine
Authors: Haddad Marwan
Published: May 2018

The Palestinian water sector organizations operate under severe constraints: poor capacities, high political instability and uncertainty, and inadequate funds and sources of funding. A new centralized water systems management option is proposed, which can lead to optimized water resource development and a more reliable, safer and cost effective water supply and sanitation services and systems within a clear legal framework. The proposed approach provides four units of management, resources, administration and water supply and sanitation, which would be in charge of strategic and everyday decision making and integration of water sector management in Palestine. The proposed future institutional reforms are conditional on several legal-administrative, technical and financial considerations within the Palestinian National Authority but more importantly on the continuation of the Israeli military occupation of the Palestinian land and natural resources.
Who owns the water? A study of a water conflict in the Valley of Ixtlahuaca, Mexico
Authors: Dyrnes Gro Volckmar , Vatn Arild
Published: May 2018

This paper is about rights to water. It follows a conflict over use of groundwater in Mexico from the middle of the 1960s. It illustrates how previously defined rights concerning access to water resources can be eroded. Two main mechanisms seem to be involved. First, the character of the resource – groundwater – makes it difficult both to distribute rights and to define when they are violated. Second, unequal power to express ones interests and to influence the process of the de facto shifting of rights is of great importance. While the Valley of Ixtlahuaca prior to the 1960s was blessed with ample access to water, extraction to supply Mexico City, which has been taking place since 1966, lowered the water table rapidly. After a few years traditional access to groundwater by locals was made impossible and the functioning of the local ecosystems was disrupted. It is shown that the redistribution of access to water was not in accordance with the existing legal rules concerning water rights. Owing to continuing water shortage, a pricing system is proposed forcing previously right holders to pay for the water in the future.
Privatizing water and wastewater in developing countries: assessing the 1990s' experiments
Authors: Braadbaart Okke
Published: May 2018

In the 1990s, low and middle-income countries experimented extensively with public–private partnerships (PPPs) in water and wastewater. Concession-based contracts were the favored form of PPP. Although these experiments produced promising managerial innovations, they suffered from high rates of failure. These stemmed from the ambitious scope and hasty design of many concessions, which made them susceptible to macroeconomic shocks and political opportunism. A key lesson from the 1990s' experiments is that PPP contracts combining long-term financing and exploitation should be avoided in country settings combining weak governance with a volatile economy.
Remaining challenges for bi-national agreements on shared water: The Umbeluzi case
Authors: Juizo Dinis , Lidén Rikard , Vaz Álvaro Carmo
Published: May 2018

In Southern Africa, joint management of international waters is necessary for regional development and stability. The 1997 UN international convention on “watercourses for Non-navigational uses” and the 2000 revised SADC (South African Development Community) “Protocol on Shared Watercourses” form part of the platform towards minimising tension over utilisation of water resources in the region. Mozambique shares nine of 15 international rivers in SADC, hence its continued efforts towards reaching agreements with the riparian countries. However, effective implementation of these agreements remains a challenge.

This study focuses on the implementation of future agreements in Umbeluzi River which has only two co-riparian sovereign states – Mozambique and Swaziland. In this case, it was found that several factors affect the effective implementation of the desired equitable sharing principle. The most prominent are hydrological data uncertainty, lack of adequate modelling tools and insufficient institutional capacity. Factors like large climatic variability in the region further worsen the situation. The overall implementation of agreements is also dependent on stakeholders' willingness to cooperate, which in turn is linked to their sense of fairness on decisions imposed by officials. However, correct regulation and enforcement can narrow the gap between technical ingenuity and the actual system behaviour.
Drinking water treatment - understanding the processes and meeting the challenges
Authors: Bursill Don
Published: May 2018

On and follow Natural organic matter (NOM) derived from soil and vegetation in water catchments is the key factor influencing most, if not all water treatment processes. The structure of the NOM and its involvement in water treatment processes requires better understanding. It seems likely that a better understanding of NOM reactions could lead to far better predictive capacity for water treatment designers and operators. Certainly the removal of NOM as a first step to the production of drinking water has many attractions. This paper provides an overview of work done by the author and many of his colleagues to advance this issue.
Longterm experience in the use of polymeric coagulants at Umgeni Water
Authors: Nozaic D. J. , Freese S. D. , Thompson P.
Published: May 2018

Umgeni Water, the bulk treatment authority for the cities of Durban and Pietermaritzburg changed from inorganic coagulants to synthetic polymeric coagulants at its various works in the mid 1980s. The advantages and disadvantages experienced with the new chemicals are discussed in detail in the paper and the changes to test procedures necessary are highlighted. The polymeric coagulants were found to produce good quality water in line with international norms but their unsuitability for enhanced coagulation may preclude their use on some of the works where organic enrichment is becoming a problem.
Occurrence and removal of Giardia and Cryptosporidium at the Goreangab reclamation plant
Authors: Menge J.G. , Haarhoff J. , König E. , Mertens R. , van der Merwe B.
Published: May 2018

This paper deals with the occurrence of Giardia and Cryptosporidium in the water sources available for the Goreangab Reclamation Plant (GRP) and the subsequent removal during treatment at the reclamation plant. Giardia is detected more often than Cryptosporidium. 60% of the time it is detected in the samples from the dam and in 55% of the samples from the maturation pond effluent.

During the investigation, Giardia was detected in the final water 5% of the time and Cryptosporidium 2% of the time. The maximum Giardia cysts detected in a sample was 30, the 99% percentile was 20 and the 97% percentile 10 cysts. A maximum of 20 Cryptosporidium oocysts was detected in a sample. The 99% percentile counted 6.2 oocysts and the 97% percentile 0 oocysts.

From the data presented it is clear that the polluted dam water has the same risk level of Giardia and Cryptosporidium pollution as treated wastewater effluent. This emphasises the fact that the sources should be monitored continuously for these parasites. The sporadic high counts of Giardia and Cryptosporidium in the raw water sources indicate that a multiple-barrier approach must be followed to ensure the safe operation of even conventional treatment plants using polluted source water.

No correlation could be found between cyst and oocyst removal and other water quality parameters.

The advocating of a final water turbidity of 0.1 NTU and the use of particle counters can only be supported by these findings, as it is possible to achieve a turbidity of less than 0.1 NTU at the sand filter outlet, even in a developing country like Namibia. The challenge lies with the maintenance of equipment and vigilance of the operators.