Municipal Drinking Water Systems Research Articles

The Municipal Drinking Water Database

Drinking water services in the U.S. are critical for public health and economic development but face technical, political, and administrative challenges. Understanding the root cause of these challenges and how to overcome them is hindered by the lack of integrative, comprehensive data about drinking water systems and the communities they serve. The Municipal Drinking Water Database (MDWD) combines financial, institutional, demographic, and environmental conditions of U.S. municipalities and their community water systems (CWS). Municipally owned and operated CWS are ubiquitous and play a critical role in ensuring safe, affordable drinking water services for most Americans; they also offer important opportunities for understanding municipal government behavior and decision making. The MDWD is publicly available and will enable researchers and practitioners interested in viewing or tracking drinking water spending, the financial condition of municipal governments, or myriad demographic, political, institutional, and physical characteristics of municipal drinking water systems to access the data quickly and easily. This paper describes the database and its creation, details examples of how the data can be used and discusses illustrative analyses of trends and insights that can be gleaned from the database. Building and sharing more integrated datasets provides new opportunities for asking novel questions about the drivers and consequences of local decision making about drinking water.

Modification of Disinfection Process at a Local Water Treatment Plant—Skawina (Poland)

This paper summarizes studies undertaken at a water treatment plant in Skawina (WTP Skawina) where the disinfection process was modified by introducing a mobile ozonation system. The application of a small-size, fully-automated ozonation installation only slightly complicates the water treatment process, without the need to redesign the water treatment line, and with relatively low investment costs. The aim of this study was to analyze whether the change of the disinfection method affects the final water quality. The investigated water samples were treated in the mobile ozonation system using a disinfection process with only sodium hypochlorite. Treated water was of excellent quality, and seasonal variations in raw water parameters (variable organic matter contents) did not result in elevated trihalomethanes (THM) and bromate concentrations. Despite the trace amounts of bromides in the water prior to treatment, the water in the municipal drinking water system did not contain determinable amounts of bromates. The bromine concentrations in the treated water supplied to the water distribution system were higher than in raw water, which could be attributable to the presence of bromine as a contaminant in sodium hypochlorite (the disinfection agent). Water quality tests carried out by the water treatment plant (WTP) and by the State Sanitary Inspectorate after the modification of the process line confirmed the high quality of water in the distribution network after the change of disinfection method.

Operator‐informed risk assessment tool: Opportunities and barriers to support risk management practices

AbstractSuccessfully implementing water safety plans (WSPs) in small, municipal drinking water systems is understudied in affluent jurisdictions where WSPs are not required by regulations. We piloted a computer‐based risk assessment survey in eight municipal water systems in Nova Scotia, Canada to evaluate the benefits and challenges of implementing risk assessment strategies in non‐WSP jurisdictions. Semi‐structured interviews were conducted with water operators and managers to gather feedback on the risk assessment survey and process. Results indicated difficulties quantifying risk despite streamlining the risk identification process, resulting in key informants viewing the risk assessment as strictly diagnostic and unlikely to be integrated into operational practice if not required. We identified a need to shift water system culture from a regulatory‐based to a knowledge‐based mindset for successful risk assessment implementation. Clear lines of communication, increased understanding of risk, and commitment to improvement are critical to shifting water system culture toward a risk‐based water quality management approach.

Overlooked legacies: Climate vulnerability and risk as incrementally constructed in the municipal drinking water system of Lima, Peru (1578–2017)

This article analyzes “not knowing” and overlooked or invisibilized information related to the drinking water system in Lima, Peru, a rapidly expanding megacity of the Global South in a region considered to be at high risk to climate related hazards. Within this system, unavailable, or disregarded information exists for a range of topics, from quantitative information about reservoir levels to more qualitative concerns about decision-making and administration. Currently, information made publicly available focuses on end users, specifically: census data on percent of homes connected to the municipal network and statistics comparing consumption patterns across neighborhoods. This deflects attention from topics related to water supply (expansion of urban hydraulic reach, infrastructure investment), and decision-making and control. However, this article considers a type of “not knowing” underlying all of the above, which is the forgotten or overlooked development of Lima’s drinking water system over time. It presents results of a study of the history of this system from its origins in the 16th century through modernization in the early- and mid-20th century, concluding with infrastructure investment in the era of climate change. It focuses on continuities in the spatial orientation of water infrastructure as well as long-term conflicts over its administration, to demonstrate how the current system is the result of a centuries-long process of accretion, rather than a system designed to serve the current urban population. Finally, it concludes with a discussion of the significance of this infrastructural and conceptual inertia for understandings of Lima’s water risk and vulnerability.

A UVC based advanced photooxidation reactor design for remote households and communities not connected to a municipal drinking water system

A household scale UVC/TiO2 based advanced oxidation process (AOP) reactor was developed for drinking water treatment. A 3D UVC absorption model to predict light energy absorbed by the photocatalyst coatings was developed and agreed with direct light irradiance measurements. The tubular reactor was used with and without titanium dioxide (TiO2) coated plates lining inside and was found to simultaneously inactivate a high initial concentration of Escherichia coli and degrade uracil, which was used as a synthetic water pollutant. The reactor, lined with replaceable TiO2 coated plates, degraded uracil by 34.2% and natural organic matter in raw lake water by 33.2% within 24 minutes. An additional low dose of hydrogen peroxide also demonstrated an advantage to a reactor without TiO2 coated plates. The electrical energy per order value was evaluated for this UVC/TiO2 reactor to be 8.13 kWh/m3, which is in the competitive range for a photocatalytic reactor. The UV/photocatalyst based AOP water treatment reactor design shows practical application potential for remote households and communities that do not have access to municipal water treatment.

Pre-emptively Averting the Advent of Water Crisis using AI/ML

With a diverse population that is three times the size of the United States but one-third the physical size, India has the second largest population in the world. Despite harbouring 18 percentage of the global population, India only accounts for 4 percentage of the world’s water resources. Although India has made improvements over the past decades to both the availability and quality of municipal drinking water systems, its large population has stressed planned water resources and rural areas are left out. India is also a major grain producer with a great need for water to support the commodity. As with all countries with large agricultural output, excess water consumption for food production depletes the overall water table. Also, regardless of improvements to drinking water, many other water sources are contaminated with both bio and chemical pollutants, and over 21 percentage of the country’s diseases are water-related. Other concern is that India may lack overall long term availability of replenishable water resources. India’s water crisis is often the result of a lack of government planning, limited business closure, industrial and human pollution, and government corruption. In addition, India’s water shortage is expected to increase as population growth is expected to rise to 1.6 billion by 2050. Niti Aayog estimates that around 100 Million Indians are expected to run out of water by 2030. To that end, global water scarcity is expected to become a leading cause of national political conflict in the future, and the prognosis for India is no different. In such scenario rain-water harvesting and desalination becomes inevitable. On a positive note, some areas of India are fortunate to have a relatively wet climate, even in the most arid regions. However, with no rain catchment programs in place, most of the water is displaced or dried up instead of used. In these areas, rain harvesting could be one solution for water collection. Collected water can be immediately used for agriculture, and with improved filtration practices to reduce water-borne pathogens, also quickly available for human consumption. Whatever the means, India needs solution. Children in 100 million homes in the country lack water, and one out of every two children are malnourished. Environmental justice needs to be restored to India so that families can raise their children with dignity, and providing water to communities is one such way to best ensure that chance. Hence the solution is “USWAD: Unified system for Sustainable Water management solutions using AI/ML (Deep Learning) and Data Analytics.” The details of this system are explained ahead in the report.

Capacity for source water protection in Ontario’s privately-serviced rural areas

This research examined the capacity for source water protection (SWP) of privately-serviced rural areas in Ontario. Privately-serviced areas refer to communities where households and public buildings either fully or partially derive their drinking water from private water systems (i.e. private wells), which are not serviced by a municipal drinking water system. Capacity for SWP in these areas was explored through a framework consisting of the following elements of capacity: technical/human, financial, social, and institutional. A case study approach was employed using the Cataraqui Source Protection Area and the North Bay-Mattawa Source Protection Area. Thirty key informant interviews were conducted and analyzed, together with a literature review and member checking. It was found that privately-serviced rural communities often do not see the protection of drinking water as one of their mandated responsibilities and that there are institutional, technical/human, social, and financial capacity gaps for undertaking SWP in privately-serviced areas. Further investigation is needed regarding options for a new, integrated, implementable and context appropriate SWP framework for privately-serviced areas in rural Ontario. The findings of this research provide transferable lessons for the creation of rural policy in general, and the need for a rural (rather than an urban focused) approach to policies and programs to protect rural drinking water.

The impact of UV treatment on microbial control and DBPs formation in full-scale drinking water systems in northern China

To manage potential microbial risks and meet increasingly strict drinking water health standards, UV treatment has attracted increasing attention for use in drinking water systems in China. However, the effects of UV treatment on microbial control and disinfection by-products (DBPs) formation in real municipal drinking water systems are poorly understood. Here, we collected water samples from three real drinking water systems in Beijing and Tianjin to investigate the impacts of UV treatment on microbial control and DBP formation. We employed heterotrophic plate count (HPC), flow cytometry (FCM), quantitative PCR analysis, and high-throughput sequencing to measure microorganisms in the samples. Different trends were observed between HPC and total cell count (measured by FCM), indicating that a single indicator could not reflect the real degree of biological re-growth in drinking water distribution systems (DWDSs). A significant increase in the 16S rRNA gene concentration was observed when the UV system was stopped. Besides, the bacterial community composition was similar at the phylum level but differed markedly at the genera level among the three DWDSs. Some chlorine-resistant bacteria, including potential pathogens (e.g., Acinetobacter) showed a high relative abundance when the UV system was turned off. It can be concluded that UV treatment can mitigate microbial re-growth to some extent. Finally, UV treatment had a limited influence on the formation of DBPs, including trihalomethanes, haloacetic acids, and nitrogenated DBPs. The findings of this study may help to understand the performance of UV treatment in real drinking water systems.

Breaking bad: When does polycentricity lead to maladaptation rather than adaptation?

AbstractPolycentric governance structures are often touted as part of the solution to overuse and degradation of natural resources. In theory, when multiple, overlapping decision centers work independently and in coordination, they contribute more than either monocentric or atomized governance arrangements to ensuring robust, adaptive social‐ecological systems (SESs). However, the degraded state of many municipal drinking water systems demonstrate Vincent Ostrom's observation that multilevel governance structure alone does not guarantee increased functionality. Two U.S. case studies drawn from opposite ends of the SES performance continuum provide insights into the differences between structural and functional features of polycentricity and the cross‐cutting conditions under which these features lead to adaptation or maladaptation. New York City's water system has served as an international model of sustainable, collaborative governance for several decades, whereas Flint, Michigan's water system achieved notoriety for a tragic string of errors and a pattern of neglectful governance in the mid‐2010s. Through process tracing, this article analyzes the pathways that began from a shared governance structure of polycentric federalism to starkly different decisions and outcomes in the two cities. The results highlight the dynamic and interactive nature of polycentricity, including how it can be functionally disabled when key factors converge across levels and scales: these include norms of quiescent rule enforcement, incentives that favor blame avoidance over problem solving, persistent power imbalances, large wealth inequalities, and deficits of social capital and leadership.

Assessment of bacterial diversity in western Accra, Ghana, drinking water samples

Abstract The design and performance characteristics of municipal drinking water systems can profoundly influence public health. To assess the operational attributes of an Accra, Ghana drinking water distribution system, high-throughput 454 pyrosequencing was employed to characterize its bacterial community composition. Samples from the waterworks and four household sources (one household tap and three polytank storage units) were analyzed within one of the Accra's distribution networks over a 4-month period. Samples provided between 9,059 and 20,076 reads (average = 13,056) that represented a broad range of bacterial diversity, including rare genera. Minimum Entropy Decomposition (MED) analysis showed that the sequences described four major assemblages. Assemblages 1 and 2 dominated the waterworks and household tap samples while polytank storage unit samples, with one exception, contained assemblages 3 or 4. The considerable bacterial taxonomic difference between different sources suggests that contamination and/or selective growth shapes bacterial community structures after treatment at the waterworks. Of particular interest are the major differences between the polytank samples following storage and the tap/waterworks samples, suggesting that water storage (stagnation) can select for unique microbial populations.

Influences of water quality and climate on the water-energy nexus: A spatial comparison of two water systems

As drinking water supply systems plan for sustainable management practices, impacts from future water quality and climate changes are a major concern. This study aims to understand the intraannual changes of energy consumption for water treatment, investigate the relative importance of water quality and climate indicators on energy consumption for water treatment, and predict the effects of climate change on the embodied energy of treated, potable water at two municipal drinking water systems located in the northeast and southeast US. To achieve this goal, a life cycle assessment was first performed to quantify the monthly energy consumption in the two drinking water systems. Regression and relative importance analyses were then performed between climate indicators, raw water quality indicators, and chemical and energy usages in the treatment processes to determine their correlations. These relationships were then used to project changes in embodied energy associated with the plants' processes, and the results were compared between the two regions. The projections of the southeastern US water plant were for an increase in energy demand resulted from an increase of treatment chemical usages. The northeastern US plant was projected to decrease its energy demand due to a reduced demand for heating the plant's infrastructure. The findings indicate that geographic location and treatment process may determine the way climate change affects drinking water systems.

Confronting fluoroethers

Larry Cahoon found out two weeks before most of his neighbors that their tap water held a cocktail of never-before-seen industrial chemicals. Last May, Cahoon invited a handful of scientists to talk with a local group working to restore striped bass and other migratory fish in North Carolina’s Cape Fear River. At that event, one of the panelists discussed a recently published study that found perfluorinated ethers in a municipal drinking water system that draws from the river (Environ. Sci. Technol. Lett. 2016, DOI:10.1021/acs.estlett.6b00398). Cahoon, a University of North Carolina, Wilmington, biology professor who studies aquatic ecology, had read the paper and surmised that the chemicals came from a Chemours plant on the outskirts of Fayetteville, N.C. But the study did not name the town with the contaminated tap water. The panelist, however, did name the locale: The affected city was Wilmington, N.C., said Detlef Knappe, a North Carolina State

CONTAMINATION OF GROUNDWATER WITH PHENOL DERIVATIVES AROUND A DECOMMISSIONED CHEMICAL FACTORY

In this study, the concentrations of 15 phenol derivatives were analyzed from the phreatic and groundwater wells surrounding a decommissioned chemical factory in a village from the western part of Romania. An UPLC-MS method was used to assess the concentrations of the chemical target compounds in the water samples. The most frequent compounds were 4-chlorophenol, 4-tertoctylphenol and 4-nonylphenol, being detected in 17 of the 19 sampling sites, while the least frequent compound was 2,4,6trichlorophenol, that was found in only 7 samples. The highest mean concentration was obtained for bisphenol A (47.54 ng.mL 1), while 2,4-dinitrophenol was found with the lowest mean concentration (9.38 ng.mL 1). The most contaminated water samples were found in the monitoring wells placed downstream of the factory. With the exception of the samples taken from the municipal drinking water system, the samples from phreatic water wells contained the target phenol derivatives, at various concentrations. Although the platform has ceased completely, the hazard caused by decades of continuous phenolic pollutant leakage is still significant to the present day.

Longitudinal and Source-to-Tap New Orleans, LA, U.S.A. Drinking Water Microbiology.

The two municipal drinking water systems of New Orleans, LA, U.S.A. were sampled to compare the microbiology of independent systems that treat the same surface water from the Mississippi River. To better understand temporal trends and sources of microbiology delivered to taps, these treatment plants and distribution systems were subjected to source-to-tap sampling over four years. Both plants employ traditional treatment by chloramination, applied during or after settling, followed by filtration before distribution in a warm, low water age system. Longitudinal samples indicated microbiology to have stability both spatially and temporally, and between treatment plants and distribution systems. Disinfection had the greatest impact on microbial composition, which was further refined by filtration and influenced by distribution and premise plumbing. Actinobacteria spp. exhibited trends with treatment. In particular, Mycobacterium spp., very low in finished waters, occurred idiosyncratically at high levels in some tap waters, indicating distribution and/or premise plumbing as main contributors of mycobacteria. Legionella spp., another genus containing potential opportunistic pathogens, also occurred ubiquitously. Source water microbiology was most divergent from tap water, and each step of treatment brought samples more closely similar to tap waters.

Behavior of non-regulated disinfection by-products in water following multiple chlorination points during treatment

In this study, the behavior of regulated (trihalomethanes–THMs, haloacetic acids–HAAs) and non-regulated (haloacetonitriles–HANs, haloketones–HKs, chloropicrin–CPK) disinfection by-products (DBPs) was investigated during treatment and distribution in a municipal drinking water system that adds chlorine at multiple points within the water treatment plant (WTP). Three to eight locations in the WTP and four locations in the distribution network were sampled weekly for DBP measurements during the warmest period of the year. The results show that most DBPs found in the study area are formed during treatment, not distribution. However, the DBP species studied behave differently during treatment and distribution. Moreover, the location where DBP concentration is the highest in the distribution network differs among species of the same family, especially HAAs and HKs, and between the sampling campaigns. As a result, the relevance of using the sum of the concentrations of the species of the same DBP family to select sampling sites for DBP monitoring is questionable. This study illustrates the difficulties that drinking water supply managers must face to control and monitor the presence of DBPs.

Asset condition assessment of municipal drinking water, wastewater and stormwater systems – Challenges and directions forward

The technical bases for the development of asset management plans (AMPs) for municipal water infrastructure are rapidly evolving, with regard to both available software and strategies for data assembly. The challenges and assistance available from an array of AMPs in the technical literature are reviewed, including the capabilities and suitability of some data acquisition technologies. Specific strategies which are important for municipalities while developing effective AMPs are also described. The review concludes there is extensive literature on ‘how’ successful AMPs can be implemented for drinking water and wastewater systems in Canada, but guidance for stormwater is lacking. Guidance on assessing the condition of existing assets, how to define and maintain acceptable levels of service, and the availability of software tools to assist in asset management exist for the former, but not the latter. Moving forward, opportunities to better link both grey (traditional) and green (non-traditional) stormwater, wastewater and drinking water infrastructure are described.

Assessing regulatory violations of disinfection by-products in water distribution networks using a non-compliance potential index.

Inactivating pathogens is essential to eradicate waterborne diseases. However, disinfection forms undesirable disinfection by-products (DBPs) in the presence of natural organic matter. Many regulations and guidelines exist to limit DBP exposure for eliminating possible health impacts such as bladder cancer, reproductive effects, and child development effects. In this paper, an index named non-compliance potential (NCP) index is proposed to evaluate regulatory violations by DBPs. The index can serve to evaluate water quality in distribution networks using the Bayesian Belief Network (BBN). BBN is a graphical model to represent contributing variables and their probabilistic relationships. Total trihalomethanes (TTHM), haloacetic acids (HAA5), and free residual chlorine (FRC) are selected as the variables to predict the NCP index. A methodology has been proposed to implement the index using either monitored data, empirical model results (e.g., multiple linear regression), and disinfectant kinetics through EPANET simulations. The index's usefulness is demonstrated through two case studies on municipal distribution systems using both full-scale monitoring and modeled data. The proposed approach can be implemented for data-sparse conditions, making it especially useful for smaller municipal drinking water systems.

Estimating the burden of acute gastrointestinal illness due to Giardia, Cryptosporidium, Campylobacter, E. coli O157 and norovirus associated with private wells and small water systems in Canada.

Waterborne illness related to the consumption of contaminated or inadequately treated water is a global public health concern. Although the magnitude of drinking water-related illnesses in developed countries is lower than that observed in developing regions of the world, drinking water is still responsible for a proportion of all cases of acute gastrointestinal illness (AGI) in Canada. The estimated burden of endemic AGI in Canada is 20·5 million cases annually - this estimate accounts for under-reporting and under-diagnosis. About 4 million of these cases are domestically acquired and foodborne, yet the proportion of waterborne cases is unknown. There is evidence that individuals served by private systems and small community systems may be more at risk of waterborne illness than those served by municipal drinking water systems in Canada. However, little is known regarding the contribution of these systems to the overall drinking water-related AGI burden in Canada. Private water supplies serve an estimated 12% of the Canadian population, or ~4·1 million people. An estimated 1·4 million (4·1%) people in Canada are served by small groundwater (2·6%) and surface water (1·5%) supplies. The objective of this research is to estimate the number of AGI cases attributable to water consumption from these supplies in Canada using a quantitative microbial risk assessment (QMRA) approach. This provides a framework for others to develop burden of waterborne illness estimates for small water supplies. A multi-pathogen QMRA of Giardia, Cryptosporidium, Campylobacter, E. coli O157 and norovirus, chosen as index waterborne pathogens, for various source water and treatment combinations was performed. It is estimated that 103 230 AGI cases per year are due to the presence of these five pathogens in drinking water from private and small community water systems in Canada. In addition to providing a mechanism to assess the potential burden of AGI attributed to small systems and private well water in Canada, this research supports the use of QMRA as an effective source attribution tool when there is a lack of randomized controlled trial data to evaluate the public health risk of an exposure source. QMRA is also a powerful tool for identifying existing knowledge gaps on the national scale to inform future surveillance and research efforts.

Estimating the number of cases of acute gastrointestinal illness (AGI) associated with Canadian municipal drinking water systems.

The estimated burden of endemic acute gastrointestinal illness (AGI) annually in Canada is 20·5 million cases. Approximately 4 million of these cases are domestically acquired and foodborne, yet the proportion of waterborne cases is unknown. A number of randomized controlled trials have been completed to estimate the influence of tap water from municipal drinking water plants on the burden of AGI. In Canada, 83% of the population (28 521 761 people) consumes tap water from municipal drinking water plants serving >1000 people. The drinking water-related AGI burden associated with the consumption of water from these systems in Canada is unknown. The objective of this research was to estimate the number of AGI cases attributable to consumption of drinking water from large municipal water supplies in Canada, using data from four household drinking water intervention trials. Canadian municipal water treatment systems were ranked into four categories based on source water type and quality, population size served, and treatment capability and barriers. The water treatment plants studied in the four household drinking water intervention trials were also ranked according to the aforementioned criteria, and the Canadian treatment plants were then scored against these criteria to develop four AGI risk groups. The proportion of illnesses attributed to distribution system events vs. source water quality/treatment failures was also estimated, to inform the focus of future intervention efforts. It is estimated that 334 966 cases (90% probability interval 183 006-501 026) of AGI per year are associated with the consumption of tap water from municipal systems that serve >1000 people in Canada. This study provides a framework for estimating the burden of waterborne illness at a national level and identifying existing knowledge gaps for future research and surveillance efforts, in Canada and abroad.

Detection of Pathogenic and Non-pathogenic Bacteria in Drinking Water and Associated Biofilms on the Crow Reservation, Montana, USA.

Private residences in rural areas with water systems that are not adequately regulated, monitored, and updated could have drinking water that poses a health risk. To investigate water quality on the Crow Reservation in Montana, water and biofilm samples were collected from 57 public buildings and private residences served by either treated municipal or individual groundwater well systems. Bacteriological quality was assessed including detection of fecal coliform bacteria and heterotrophic plate count (HPC) as well as three potentially pathogenic bacterial genera, Mycobacterium, Legionella, and Helicobacter. All three target genera were detected in drinking water systems on the Crow Reservation. Species detected included the opportunistic and frank pathogens Mycobacterium avium, Mycobacterium gordonae, Mycobacterium flavescens, Legionella pneumophila, and Helicobacter pylori. Additionally, there was an association between HPC bacteria and the presence of Mycobacterium and Legionella but not the presence of Helicobacter. This research has shown that groundwater and municipal drinking water systems on the Crow Reservation can harbor potential bacterial pathogens.