City Water Supply Research Articles

Application of enhanced coagulation in drinking water treatment from the degraded catchment to reduce NOM: a major DBP precursor

ABSTRACT The occurrence of dissolved natural organic matter (NOM) in drinking water sources can potentially lead to the formation of disinfection byproducts (DBPs). In regions like the degraded soil of the Ethiopian highlands, which have low humic content, hydrophilic NOM tends to dominate. This study aimed to assess the effectiveness of enhanced coagulation in reducing precursors of DBPs in surface water used for drinking purposes. The Angereb reservoir, part of Gonder City's water supply in the Ethiopian highlands, was chosen as the study area. Jar testing was conducted to evaluate the NOM removal efficiency of enhanced coagulation methods using ferric chloride and aluminum sulfate coagulants. Water samples were collected during both dry and wet seasons in 2023. Various parameters, such as total organic carbon (TOC), ultraviolet absorbance at a wavelength of 254 nm (UVA@254), pH, and other water quality indicators, were analyzed. Results revealed that the NOM present was primarily hydrophilic, as anticipated, with specific ultraviolet absorbance values below 2 L/mg−1 m−1. The existing treatment process, which involved prechlorination and coagulation with aluminum sulfate, removed less than 28% of TOC and 14% of UVA@254. However, using ferric chloride-enhanced coagulation achieved a removal efficiency of 50% for both TOC and UVA@254.

Modeling dissolved organic carbon export from water supply catchments in the northeastern United States.

Natural organic matter (NOM) in rivers is an important energy source to sustain aquatic ecosystem health. However, in surface water supply systems where chlorination is often used for disinfection, NOM is also a precursor for the carcinogenic and mutagenic disinfection byproducts such as trihalomethanes and haloacetic acids. Effective management of NOM in rivers to maintain both aquatic ecosystem functions and high-quality water supply requires better understanding of the NOM transport patterns. NOM is often operationally measured by dissolved organic carbon (DOC). Challenges of using DOC data for analysis on a catchment scale largely relate to the spatial and temporal variations in DOC, and low sampling frequency which fails to capture the multi-scale transport patterns. To help improve the understanding of DOC sources and transport, we analyzed its long-term patterns in six water supply catchments in the New York City Water Supply System using monitoring data and models. We tested six empirical models for DOC prediction including linear, nonlinear and time-series based model formulations. We found that generalized additive models (GAMs) produced the most robust results across catchments. Then, we applied the calibrated GAM to predict daily DOC concentrations to estimate fluxes and analyze for trends. Finally, we compared the relationships between temporal patterns in DOC and catchment features to investigate the regional differences, focusing on the catchment mechanistic processes associated with DOC by parsing out the hydrological signals. The results showed that hydrology plays a larger role on DOC temporal patterns in three catchments where the top 5% streamflow corresponded to nearly 50% of the annual DOC export, whereas nutrient associated production processes were more important in others. The study presents a robust approach for DOC prediction in streams and can inform targeted monitoring strategies for DOC management in water supply source waters.

Мікроелементний склад питної води при централізованому водопостачанні промислових міст Дніпропетровської області

The purpose. Ecological and hygienic assessment of the quality of drinking water at the centralized water supply of industrial cities of the Dnipropetrovsk region by the content of trace elements from the group of heavy metals. Object and research methods. The analysis of the content of trace elements from the group of heavy metals in the drinking water of industrial cities of the Dnipropetrovsk region - Dnipro, Kryvyi Rih, Kamianske over a 5-year period was carried out. The evaluation of the obtained data was carried out in accordance with the requirements of the current legislation on the safety and quality of drinking water in accordance with SSRN 2.2.4-171-10, international recommendations and data from the scientific literature. Results. It has been established that in the Dnipropetrovs'k region over the 5-year study period, the percentage of non-standard drinking water samples for sanitary and chemical parameters ranged from 24.4-30.6% from centralized water supply systems, and 14.5-18.4% from water supply networks. The average long-term concentrations of metals in the drinking water of the studied cities ranged from 0.0001 mg/l for mercury to 0.19 mg/l for aluminum, which meets the MAC requirements, but the maximum values of the content of individual metals in all industrial cities exceeded the hygienic regulations, most pronounced for iron, which reached 60%. At the same time, the proportion of samples exceeding the hygienic standard in some years of the study was 5-12%. In the dynamics of the study, a gradual decrease of 14.2-54.5% in the concentration of lead in drinking water in all industrial and control cities was noted (p<0.05; R2= 0.51-0.78). A similar trend is also characteristic of the aluminum content in drinking water in Kryvyi Rih - a 2.5-fold decrease (p<0.001; R2=0.79) during the study period. At the same time, a significant increase in the content of a number of trace elements from the group of biotic and abiotic heavy metals was found in Kamianske, in particular copper and zinc - by 2.0-2.4 times (p<0.01; R2= 0.72-0.77), mercury and arsenic - by 1.3-1.9 times (p<0.01; R2= 0.87-0.92). The dynamics of concentrations of other heavy metals in the drinking water of the studied cities was unreliable. The sum of the ratio of the concentrations of trace elements from the group of heavy metals belonging to hazard classes I and II according to the sanitary and toxicological limiting sign of harmfulness ranges from 1.1 to 1.9, i.e. the simultaneous presence of these metals in the drinking water of industrial cities exceeds the safe level regulated by SSRN 2.2.4-171-10. Conclusions. The results of the conducted research indicate the urgency of the problem of ensuring the quality and safety of drinking water intended for human consumption and the need for further improvement of water treatment and control methods at all levels. Keywords. Trace elements, heavy metals, drinking water, content, pollution, impact, public health.

Modelling scenarios for water supply and sanitation technologies in Jordan

The influx of refugees, population growth and current agricultural practices have led to an increase in water demand in Jordan, placing pressure on existing water provision. Climate change further exacerbates declining water availability. Against this backdrop, the techno-economic feasibility of four water supply and sanitation alternatives for small and medium scale cities in Jordan were explored, using local unit costs and Al-Mafraq as a case study. City level piped network combined with household rooftop rainwater harvesting and surface runoff collection into local ponds and piped networks with treatment using the nature-based solution of root-zone for sanitation were demonstrated to provide the highest benefits in terms of cost, convenience and water conservation. Our work highlights the need to invest in long-term urban infrastructure networks to promote sustainable future growth of cities. This is vital to address severe water scarcity challenges that ultimately impact those at the urban fringes most.

Urban Groundwater in the cities of Europe: hidden challenges in a changing climate

In European cities, groundwater remains an issue of significant concern, largely because it is “out of sight and out of mind.” The general public, and even decision-makers, possess only a limited understanding of the state and characteristics of this vital resource. As a consequence, problems related to groundwater quality or changing water tables/piezometric surfaces may persist for years, or even decades, without being adequately addressed-or worse, without being noticed at all before resulting in land subsidence,saltwater intrusion, deep migration of persistent organic contaminants like PFAS (Le monde, 2023) or other irreversible consequences. The urban water cycle is central to ensuring the supply of clean, safe drinking water, effective sanitation, and wellfunctioning drainage systems for millions of residents. The impacts of human activities, such as land use change, excessive water abstraction and mismanagement, and the discharge of wastewater can exert a far greater influence on groundwater systems and hydrogeology than climate change. These activities alter the quantity and quality of both surface and groundwater, raising complex scientific, technical, socio-economic, cultural, and ethical challenges in urban water management. It is important to address the many challenges associated with ensuring water security and safety in cities (Quevauviller et al., 2024), as well as for development of effective climate change mitigation and adaptation strategies for urban areas (IPCC, 2024). Groundwater plays a critical role in the green transition and is an integral component of most climate change mitigation and adaptation strategies (Ingemarsson et al., 2022), and for meeting the increasing demand for freshwater in cities due to accelerating urbanization (United Nations, 2022). Many urbanized areas in Europe already face poor chemical and quantitative status (EEA, 2024; Sentek et al., 2024), and global change including increasing populations and sea level rise pose a tremendous challenge for safe and secure water supply especially in coastal European cities. Open access to digital subsurface data e.g. through the European Geological Data Infrastructure supports societal needs and UN sustainable development goals (Hinsby et al., 2024). This special issue demonstrates some of the important issues that the water supply of European cities are facing in times of increasing competing use of the subsurface (Volckko et al., 2020), projected climate change impacts on the hydrological cycle (Henriksen et al., 2023) and with freshwater now being among the transgressed planetary boundaries (Richardsson et al., 2023). [...]

Enumerating genotypic diversity and host specificity of Giardia in wild rodents around a New York watershed

Giardia is a genus of flagellated protozoans that parasitize the gastrointestinal tract of humans and wildlife worldwide. While G. duodenalis is well-studied due to its potential to cause outbreaks of diarrheal illness in humans, other Giardia species from wildlife have been largely understudied. This study examines the occurrence, host specificity, and genotypic diversity of Giardia in wild rodents living within the New York City water supply watershed. A novel nested PCR assay targeting the 18S ssu-rDNA gene is introduced, which captures nearly the entire gene for improved species-level determination versus existing molecular typing methods. Molecular characterization of 55 Giardia specimens reveals at least seven novel lineages. Phylogenetic analysis indicates a close relationship between the newly characterized Giardia lineages and rodent hosts, suggesting rodents as important reservoirs of Giardia and its close relatives. These findings provide insights into the diversity of Giardia species and their public health potential in localities with human-wildlife interaction and further emphasizes the need for continued efforts to improve the molecular tools used to study microbial eukaryotes, especially those with zoonotic potential.

Assessment of water quality from different water supply sources in the Kyiv district of the city of Kharkiv

Purpose To evaluate the quality of drinking water from various sources of water supply on the example of the Kyiv district of the city of Kharkiv. Methods. Field (selection of water samples from various sources), laboratory-analytical analysis of water quality, statistical (processing of received data and comparative analysis). Results. Water samples were taken from various sources of water supply: natural spring water, water from wells, from a well, from the city water supply and from drinking water dispensers. In the samples of artesian water of the "Roganska" trade mark (automatic water dispenser), no exceeding of the normative values ​​was determined for any indicator. Water samples from wells and centralized water supply have elevated levels of total hardness, chlorine, nitrate and iron content, which requires the restriction of their use as drinking water without additional treatment. Water samples from private wells have an increased level of general mineralization, salinity and electrical conductivity of water. Methods of purifying tap water from common salts at home were studied: water freezing, filtration, settling, boiling. Conclusions. On the basis of organoleptic, physico-chemical and toxicological parameters of water quality, according to DSTU 4808, water from the machine of TM "Roganska" corresponds to the 1st quality class, spring water - 2nd class, water from wells - 3rd class, and water from a well and centralized water supply - 4th class. In order to improve the quality of tap water from common salts at home, freezing and filtration are recommended.

Sediment analysis and water quality assessment in the Pixquiac basin: drinking water supply of Xalapa city (Veracruz, Mexico).

Fluvial sediment analysis and water quality assessment are useful to identify anthropic and natural sources of pollution in rivers. Currently, there is a lack of information about water quality in the Pixquiac basin (Veracruz state, Mexico), and this scarcity of data prevents authorities to take adequate measures to protect water resources. The basin is a crucial territory for Xalapa, the capital city of Veracruz state, as it gets 39% of its drinkable water from it. This research analyzed 10 physicochemical parameters and 12 metal concentrations in various rivers and sources during two seasons. Dissolved metals presented average concentrations (µg/L): Al (456.25) > Fe (199.4) > Mn (16.86) > Ba (13.8) > Zn (7.6) > Cu (1.03) > Pb (0.27) > As (0.12) > Ni (0.118) (Cd, Cr and Hg undetectable). Metals in sediment recorded average concentrations (ppm): Fe (38575) > Al (38425) > Mn (460) > Ba (206.2) > Zn (65.1) > Cr (29.8) > Ni (20.9) > Cu (16.4) > Pb (4.8) > As (2.1) (Cd and Hg undetectable). During the rainy season, Water Quality Index (WAWQI) classified stations P17 and P18's water as "unsuitable for drinking" with values of 110.4 and 117.6. Enrichment factor (EF) recorded a "moderate enrichment" of Pb in sediment in P24. Pollution was mainly explained by wastewater discharges in rivers but also because of erosion and rainfall events. Statistical analysis presented strong relationships between trace and major metals which could explain a common natural origin for metals in water and sediment: rock lixiviation.

Evaluating rooftop rainwater harvesting potential to satisfy urban water demand in Hosaena City, South Central Ethiopia

ABSTRACT The assessment of the rainwater harvesting (RWH) potential in Hosaena City from medium to large public buildings is the main objective of the study. ArcGIS with Google Earth Pro was used to calculate the rooftop area of the selected building, and RWH from each category of public buildings was evaluated by considering rooftop areas, monthly rainfall, and runoff coefficient. The result shows that the highest amount of rainwater was harvested from the City Administration building in August (197.1 m3), whereas the lowest was collected from the Health Center building in December (1.8 m3). Additionally, the contribution of RWH from individual public buildings for each month was evaluated, and its values ranged from 0.073 to 1.8%. The comparison shows that Wachemo University, Nigist Eleni Comprehensive Hospital, a technical and vocational institute, and teacher training center buildings, could have a significant potential for rainwater storage, ranging from 1.56 to 28.41%. This implies that, besides saving a noteworthy volume of potable water, the excess rainwater can be stored and utilized for the later dry months. As a result, it is recommended that rooftop RWH in Hosaena be the best source of the city's water supply system to reduce the current water supply shortage.

The longest multiannual drought in Northeastern Brazil

The Northeastern region of Brazil has long history of drought with impacts on water supply for cities and agriculture. However, the last drought that occurred in the region had unprecedented magnitude and periodicity, making it the longest multiannual drought in Northeastern Brazil. Thus, understanding and characterizing the behavior of this phenomenon is necessary, considering that another episodes may occur. Thus, the objective of this study was to characterize the drought trend in the Northeastern region of Brazil, with the application of the Palmer Drought Severity Index (PDSI). The application of PDSI was carried out with the monthly calculation of the water balance coefficients referring to the soil water balance between the years 2000 and 2019, depending on the relative soil moisture values. The results obtained were submitted to the Mann-Kendall test to identify monthly trends in the index. The annual drought variability in Northeastern Brazil showed moderate to extreme intensity, with the worst drought being observed between the years 2012 and 2019. The monthly drought average shows the Mid-Northern and “Sertão” regions as the most critical, with monthly trend of significant drought severity. The positive trend was observed in the Eastern, Southern and Western coast regions of NEB.

Watersheds and Infrastructure Providing Food, Energy, and Water to US Cities

AbstractCivil infrastructure underpins urban receipts of food, energy, and water (FEW) produced in distant watersheds. In this study, we map flows of FEW goods from watersheds of the contiguous United States to major population centers and highlight the critical infrastructure that supports FEW flows. To do this, we draw upon detailed records of agriculture, electricity, and public water supply production and couple them with commodity flow and infrastructure information. We also compare the flows of virtual water embedded in food and energy commodity flows with physical water flows in inter‐basin water transfer projects around the country. We found that the virtual blue water transfers through crops and electricity to major US cities was 53 billion and 8 billion m3 in 2017, respectively, while physical interbasin water transfers for crops, electricity, and public supply water averaged 20.8 billion m3. Highways are the primary infrastructure used to import virtual water associated with food and fuel into cities, although waterways and railways are most utilized for long‐distance transport. All of the 204 watersheds in the contiguous US support the food, energy, and/or water supplies of major US cities, with dependencies stretching far beyond each city's borders. Still, most cities source the majority of their FEW and embedded water resources from nearby watersheds. Infrastructure such as water supply dams and inland ports serve as important buffers for both local and supply‐chain sourced water stress. These findings can inform efforts to reduce water resources and infrastructure risks in domestic supply chains.

Analysis of influencing factors of seawater intrusion in the Yangtze River Estuary and control for water supply security

Seawater intrusion poses a significant threat to the water supply of coastal cities both presently and in the future. It is crucial to identify the controllable factors influencing seawater intrusion, both natural and anthropogenic, in order to ensure water supply security. This study examined seawater intrusion characteristics using monitoring data from 1994 to 2019. Factors such as daily flow rate, duration of intrusion, water quality, and tidal level were analyzed to establish correlations and identify the primary influencing factors in the Yangtze River Estuary. The findings reveal that seawater intrusion in this area is most prevalent from November to April, peaking in February and March. The key controllable factors affecting chloride levels at the intake are the daily flow rate at Datong Station and the tidal range at Xuliujing Station. Additionally, the study proposes control methods to safeguard water supply, including providing daily flow rate values for flushing seawater intrusion at Datong Station under different tidal ranges and intrusion durations. These research results provide valuable guidance for the emergency operation of the Three Gorges-centered reservoir group against seawater intrusion.

Occurrence and Health Risk Assessment of Phthalates in Municipal Drinking Water Supply of a Central Indian City.

In this study, the occurrence of phthalates in the municipal water supply of Nagpur City, India, was studied for the first time. The study aimed to provide insights into the extent of phthalate contamination and identify potential sources of contamination in thecity's tap water. We analyzed fifteen phthalates and the total concentration (∑15phthalates) ranged from 0.27 to 76.36µgL-1. Prominent phthalates identified were di-n-butyl phthalate (DBP), di-isobutyl phthalate (DIBP), benzyl butyl phthalate (BBP), di (2-ethylhexyl) phthalate (DEHP), di-n-octyl phthalate (DNOP), and di-nonyl phthalate (DNP). Out of the fifteen phthalates analyzed, DEHP showed the highest concentration in all the samples with the median concentration of 2.27µgL-1, 1.39µgL-1, 1.83µgL-1, 2.02µgL-1, respectively in Butibori, Gandhibaag, Civil Lines, and Kalmeshwar areas of the city. In 30% of the tap water samples, DEHP was found higher than the EPA maximum contaminant level of 6µgL-1. The average daily intake (ADI) of phthalates via consumption of tap water was higher for adults (median: 0.25µgkg-1day-1) compared to children (median: 0.07µgkg-1day-1). The hazard index (HI) calculated for both adults and children was below the threshold level, indicating no significant health risks from chronic toxic risk. However, the maximum carcinogenic risk (CR) for adults (8.44 × 10-3) and children (7.73 × 10-3) was higher than the threshold level. Knowledge of the sources and distribution of phthalate contamination in municipal drinking water is crucial for effective contamination control and management strategies.

Methods and techniques of architectural environment forming under the conditions of global climate change: the problems of flooding

This article highlights the methods and techniques of forming an architectural environment based on sustainable development, namely, how to adapt to the consequences of global climate change caused by the anthropogenic environment and its activities. One of the serious consequences of global climate change is an increase in the frequency and power of floods, especially they pose a danger to cities, where problems related to the comfort of human life are worsening. Floods destroy city infrastructure and endanger the city's water supply sources. Such natural disasters activate the scientific community to eliminate their consequences, on the one hand, on the other - to solve the shortage of water as an energy resource, raising the issue of developing technologies for accumulating its surplus and further use in many types of human life, as well as in the functioning systems of the city as a whole. The world scientific and practical experience of innovative methods of adaptation of the new and reconstruction of the existing architectural environment to climate changes in countries vulnerable to frequent flooding, which is a problem for Ukraine as well, is analyzed. The article analyzes methods from Denmark, Great Britain, the Netherlands and Pakistan, with which they create a flood-resistant architectural environment and turn the disadvantages of their flood-prone region of residence into advantages. The experience of these countries and their methods of combating natural disasters helps other regions of our planet to form a comfortable architectural environment that corresponds to today's rapidly changing weather conditions and the goals of sustainable development. The conducted analysis demonstrates a wide range of solutions to problems, from small elements of the architectural environment to the planning of individual districts and the city as a whole. These solutions are used individually, as well as in combination, which increases their effectiveness. Therefore, the use of a complex approach as the main method of forming the architectural environment under conditions of global climate change is revealed.

Experimental Analysis of the Effect of Limescale on the Wettability of Indirect Evaporative Cooling System Plates

Indirect evaporative cooling systems have attracted much interest in recent years as they guarantee good cooling effectiveness, with lower energy demand with respect to traditional systems, thus helping to address the issue of climate change. Many studies have shown that an increase in the wettability of recuperator plates results in an improvement in the system performance. However, if the water injected into the system comes from the city water supply, it will contain calcium carbonate residuals, which will form limescale layers on the plates, thus possibly changing their wetting behavior. Therefore, the wettability of three surfaces (an aluminum uncoated surface, AL, a standard epoxy coating, STD, and a hydrophilic lacquer, HPHI) was analyzed in the presence of limescale formations, and compared with that obtained in a previous study for corresponding clean surfaces. The results showed that the HPHI contact angle was reduced in the presence of limescale (median: 50°), that for STD was slightly increased (median: 81°), and that for AL was again reduced (median: 75°). Consequently, HPHI was confirmed to be the most wettable surface in both clean and limescale conditions. Finally, an analysis was undertaken evaluating the spreading factor and the reversible work of adhesion, which were in good agreement with the qualitative visual observations of the plates covered with limescale.

Updating the regulatory framework for the design and construction of water supply and sanitation systems

The paper discusses the aspects of updating and approaches to improving the regulatory and technical documents, i.e. Codes of Practice (CPs), State Standards (GOSTs) to enhance the efficiency of design, construction and operation of water supply and wastewater disposal systems in Russian cities and communities. The development of a methodology for switching over the system of regulatory and technical documents to the parametric standardization is analyzed. It is demonstrated that in recent years, the Russian construction sector has set a course for revising and updating the regulatory framework in the field of design and construction, thus reducing the statutory requirements in the Codes of Practice. The definitions of various methods for the development and application of regulations and standards in construction are given. It is demonstrated that the planned transition from the prescriptive regulation system to a parametric one with specified quality criteria for the finished product is aimed at the development of the quality criteria for the finished project or product using any alternative approaches and methods, transferring a significant part of building codes and regulations to the voluntary category. Evidently, such amendments to the regulatory framework require a very detailed scientific and practical justification.

Ensuring Clean and Safe Water Supply in The Context of Crisis: Case Study on The Adaptability of Ho Chi Minh City Water Supply Company During the Covid-19 Pandemic

The COVID-19 pandemic has posed unprecedented challenges to various sectors worldwide, including the water sector. This study delves into the strategies and adaptation measures applied by water utilities in Ho Chi Minh City to overcome the complex difficulties brought about by the pandemic. This study applies qualitative research method, data is collected by conducting in-depth interviews with participants. The target audience of the study is employees, managers, and directors at water supply companies. The research focuses on exploring innovative and creative approaches used in both operations and management practices to respond to crises. By analyzing the data collected, this study aims to provide a comprehensive understanding of the multifaceted responses to the pandemic in the water sector. These findings contribute to the knowledge base surrounding crisis management and organizational resilience, providing valuable insights for decision makers and stakeholders in similar industry. Ultimately, this research aims to facilitate informed decision-making and promote effective strategies to address future challenges arising from pandemics or other crises.

Trace Metal Accumulation in Rats Exposed to Mine Waters: A Case Study, Bor Area (Serbia).

Zinc (Zn), copper (Cu), iron (Fe), manganese (Mn), cadmium (Cd), and lead (Pb) levels were measured in the Bor City water supply system (control) and two watercourses exposed to mining wastewaters, i.e., the Lutarica River (one site) and the Kriveljska River (two sites). The same parameters were determined in the brain, heart, lungs, stomach, liver, spleen, kidneys, and testes of male Wistar rats given water from these sources for 2 months. Water Cu, Fe, Cd, and Pb were outside the safe range, excepting the reference site. Significant impacts on intra-organ metal homeostasis were detected, especially in the brain, stomach, kidneys, and testes. The dynamics and magnitude of these changes (versus controls) depended on the target organ, analyzed metal, and water origin. The greatest number of significant intra-organ associations between essential and non-essential metals were found for Cd-Zn, Cd-Cu, and Cd-Mn. A regression analysis suggested the kidneys as the most relevant organ for monitoring water manganese, and the stomach and brain for lead. These results highlight the environmental risks associated with mining wastewaters from the Bor area and could help scientists in mapping the spatial distribution and severity of trace metal contamination in water sources.

Changes in Blue/Green Water Partitioning Under Severe Drought

AbstractMuch attention has been given to the disproportionate streamflow deficits (relative to rainfall deficits) experienced by many catchments during the Millennium Drought (1998–2009) in southeastern Australia, along with lack of post‐drought streamflow recovery in some cases. However, mechanisms behind the coupled hydrologic and ecosystem dynamics are poorly understood. We applied a process‐based ecohydrologic model (RHESSys) in a Melbourne water supply catchment to examine changes in ecohydrologic behavior during and after the drought. Our simulations suggested that average transpiration (green water) was maintained under drought despite a substantial (12%) decrease in average rainfall, meaning that the entire rainfall deficit translated to reduced streamflow (blue water). Altered spatial patterns of vegetation behavior across the terrain helped the ecosystem maintain this unexpectedly high green water use. Decreased transpiration upland was compensated by increases in the riparian zone, which was less water limited and therefore able to meet higher water demand during drought. In the post‐drought period, we found greater transpiration and reduced subsurface water storage relative to pre‐drought, suggesting a longer‐term persistence in altered water partitioning. The post‐drought outcome was attributed to a combination of warmer climate and the persisting effects of the drought on nutrient availability. Given the importance of shifting ecohydrologic patterns across space, our results raise concerns for applying lumped conceptual hydrologic models under nonstationary or extreme conditions. Additionally, the processes we identified have important implications for water supply in Australia's second largest city under projected drying.

Drinking Water Supply System in Kathmandu Valley

This study designed to analyze physical, chemical and microbiological parameters of drinking water quality and its management by the city water supply system in the Kathmandu Valley. The study covers 18 core areas including 32 samples sites. Altogether 325 samples collected from intake, reservoirs, treatment plants and deep wells to their connectivity as well as alternative sources such as shallow wells, tube wells, processed water and stone spouts of Sundarijal water supply system. Primary information collected through In-depth interview with 155 households (hhs), 15 focus group discussions, interview with 20 water suppliers (government and private sector) and 30 school teachers and students of linking with water supply system within the study areas. The study analyzed 7 physical, 16 chemical and 2 microbiological parameters (Total coliform (TC) and Fecal coliform (FC) following the standard methods (APHA 2000). The findings have elaborated the water quality in the source is acceptable and it is deteriorate the quality linking with its supply chains and connectivity, which is severely affected by the scaled, rusted, leakage, old pipelines and intermittence of water supply. Most of the sampling sites were microbiologically, contaminated (TC 6->180MPN/100mL and FC 1-7MPN/100mL). The processed water contains lower level of essential minerals because of reverse osmosis treatments.
 The fluoride (0.8-2mg/L), manganese (0.1-0.5mg/L), ammonia (52-70mg/L), iron 5mg/L, color (20-25°Hazen), pH (6) and turbidity (32-40 NTU) in deep wells, its supplies, well, tube wells were found beyond the value of tolerance level recommended by NDWQS and WHO guidelines. About 98% hhs used traditional methods for water management; indicates poor handling practices. Hence water quality management is a big challenge in Kathmandu Valley in terms of adequate safe water and requires regular surveillances and monitoring system for improvement.