Water Safety Plans Research Articles

Controlling Legionella and Pseudomonas aeruginosa re-growth in therapeutic spas: implementation of physical disinfection treatments, including UV/ultrafiltration, in a respiratory hydrotherapy system.

The study aimed to assess the efficacy of an integrated water safety plan (WSP) in controlling Legionella re-growth in a respiratory hydrotherapy system located in a spa centre, supplied with sulphurous water, which was initially colonized by Legionella pneumophila. Heterotrophic plate counts, Pseudomonas aeruginosa, Legionella spp. were detected in water samples taken 6-monthly from the hydrotherapy equipment (main circuit, entry to benches, final outlets). On the basis of the results obtained by the continuous monitoring and the changes in conditions, the original WSP, including physical treatments of water and waterlines, environmental surveillance and microbiological monitoring, was integrated introducing a UV/ultrafiltration system. The integrated treatment applied to the sulphurous water (microfiltration/UV irradiation/ultrafiltration), waterlines (superheated stream) and distal outlets (descaling/disinfection of nebulizers and nasal irrigators), ensured the removal of Legionella spp. and P. aeruginosa and a satisfactory microbiological quality over time. The environmental surveillance was successful in evaluating the hazard and identifying the most suitable preventive strategies to avoid Legionella re-growth. Ultrafiltration is a technology to take into account in the control of microbial contamination of therapeutic spas, since it does not modify the chemical composition of the water, thus allowing it to retain its therapeutic properties.

The human dimension of water safety plans: a critical review of literature and information gaps

A safe supply of drinking water is a cornerstone of public health and community well-being. Complacency among those responsible for the provision of safe drinking water (e.g., water suppliers, operators, and managers) has led to numerous and otherwise avoidable waterborne outbreaks. Water safety plans present a risk-based, proactive framework for water management, and when properly implemented, virtually eliminates the option for complacency. However, the uptake of water safety plans remain limited worldwide. This paper reports on the experiences of early water safety plan adopters and identifies a number of non-technical operational and human factors that have undermined previous efforts. Specifically, it identifies these factors as a gap in the water safety plan implementation literature and suggests incorporating the broader community in water safety planning through a community readiness approach. Assessing and building community readiness for water safety plans is suggested to be a critical pre-implementation step, and a potential tool for use by water suppliers and by policy makers.

Development of a risk-based approach for better protection of drinking water catchments in Flanders (Belgium)

Around 70% of the drinking water produced by De Watergroep (a Belgian public water company) is extracted from 83 groundwater pumping sites. To control the risks that endanger the drinking water supply and for the groundwater extracted to be as pure as possible, a risk-based approach for the protection of the catchment areas is developed, as part of the water safety plans. The approach consists of three steps: first, the compilation of a site-specific source file, second, the performance of a risk analysis for every catchment area, and third, the development of a monitoring strategy and action plans. The general goals are to lower the level of purification and to enhance the sustainability of groundwater extraction. The listed benefits make it worthwhile to implement this approach, despite the uncertainties.

Applying the water safety plan to water reuse: towards a conceptual risk management framework

The Water Safety Plan (WSP) is receiving increasing attention as a recommended risk management approach for water reuse through a range of research programmes, guidelines and standards.

A systems analysis of irrigation water quality in an environmental assessment of an E. coli O157:H7 outbreak in the United States linked to iceberg lettuce

A foodborne Escherichia coli O157:H7 outbreak in December 2006 included 77 illnesses reported in Iowa and Minnesota. Epidemiologic investigations by health departments in those states and the U.S. Centers for Disease Control and Prevention (CDC) identified shredded iceberg lettuce (Lactuca sativa L.) as the vehicle of transmission. The U.S. Food and Drug Administration (FDA) and Minnesota and California public health agencies traced the lettuce to several growing regions in California based on information from a lettuce processor in Minnesota.Samples from an environmental investigation initiated by the California Food Emergency Response Team (CalFERT) revealed a genetic match between the outbreak strain and environmental samples from a single farm, leading to an in-depth systems-based analysis of the irrigation water system on that farm. This paper presents findings from that systems-based analysis, which assessed conditions on the farm potentially contributing to contamination of the lettuce. The farm had three sources of irrigation water: groundwater from onsite wells, surface water delivered by a water management agency and effluent from wastewater lagoons on nearby dairy farms. Wastewater effluent was blended with the other sources and used only to irrigate animal feed crops. However, water management on the farm, including control of wastewater blending, appeared to create potential for cross-contamination. Pressure gradients and lack of backflow measures in the irrigation system might have created conditions for cross-contamination of water used to irrigate lettuce. The irrigation network on the farm had evolved over time to meet various needs, without an overall analysis of how that evolution potentially created vulnerabilities to contamination of irrigation water. The type of systems analysis described here is one method for helping to ensure that such vulnerabilities are identified and addressed. A preventive, risk-based management approach, such as the Water Safety Plan process for drinking water, may also be useful in managing irrigation water quality.

Current approaches to cyanotoxin risk assessment and risk management around the globe

Toxic cyanobacteria became more widely recognized as a potential health hazard in the 1990s, and in 1998 the World Health Organization (WHO) first published a provisional Guideline Value of 1μgL−1 for microcystin-LR in drinking-water. In this publication we compare risk assessment and risk management of toxic cyanobacteria in 17 countries across all five continents. We focus on the three main (oral) exposure vehicles to cyanotoxins: drinking-water, water related recreational and freshwater seafood. Most countries have implemented the provisional WHO Guideline Value, some as legally binding standard, to ensure the distribution of safe drinking-water with respect to microcystins. Regulation, however, also needs to address the possible presence of a wide range of other cyanotoxins and bioactive compounds, for which no guideline values can be derived due to insufficient toxicological data. The presence of microcystins (commonly expressed as microcystin-LR equivalents) may be used as proxy for overall guidance on risk management, but this simplification may miss certain risks, for instance from dissolved fractions of cylindrospermopsin and cyanobacterial neurotoxins. An alternative approach, often taken for risk assessment and management in recreational waters, is to regulate cyanobacterial presence – as cell numbers or biomass – rather than individual toxins. Here, many countries have implemented a two or three tier alert level system with incremental severity. These systems define the levels where responses are switched from Surveillance to Alert and finally to Action Mode and they specify the short-term actions that follow. Surface bloom formation is commonly judged to be a significant risk because of the elevated concentration of microcystins in a scum. Countries have based their derivations of legally binding standards, guideline values, maximally allowed concentrations (or limits named otherwise) on very similar scientific methodology, but underlying assumptions such as bloom duration, average body size and the amount of water consumed while swimming vary according to local circumstances. Furthermore, for toxins with incomplete toxicological data elements of expert judgment become more relevant and this also leads to a larger degree of variation between countries’ thresholds triggering certain actions. Cyanobacterial blooms and their cyanotoxin content are a highly variable phenomenon, largely depending on local conditions, and likely concentrations can be assessed and managed best if the specific conditions of the locality are known and their impact on bloom occurrence are understood. Risk Management Frameworks, such as for example the Water Safety Plan concept of the WHO and the ‘bathing water profile’ of the European Union are suggested to be effective approaches for preventing human exposure by managing toxic cyanobacteria from catchment to consumer for drinking water and at recreational sites.

Developing a national framework for safe drinking water--case study from Iceland.

Safe drinking water is one of the fundaments of society and experience has shown that a holistic national framework is needed for its effective provision. A national framework should include legal requirements on water protection, surveillance on drinking water quality and performance of the water supply system, and systematic preventive management. Iceland has implemented these requirements into legislation. This case study analyzes the success and challenges encountered in implementing the legislation and provide recommendations on the main shortcomings identified through the Icelandic experience. The results of the analysis show that the national framework for safe drinking water is mostly in place in Iceland. The shortcomings include the need for both improved guidance and control by the central government; and for improved surveillance of the water supply system and implementation of the water safety plan by the Local Competent Authorities. Communication to the public and between stakeholders is also insufficient. There is also a deficiency in the national framework regarding small water supply systems that needs to be addressed. Other elements are largely in place or on track. Most of the lessons learned are transferable to other European countries where the legal system around water safety is built on a common foundation from EU directives. The lessons can also provide valuable insights into how to develop a national framework elsewhere.

Microbial indicators, pathogens and methods for their monitoring in water environment.

Water is critical for life, but many people do not have access to clean and safe drinking water and die because of waterborne diseases. The analysis of drinking water for the presence of indicator microorganisms is key to determining microbiological quality and public health safety. However, drinking water-related illness outbreaks are still occurring worldwide. Moreover, different indicator microorganisms are being used in different countries as a tool for the microbiological examination of drinking water. Therefore, it becomes very important to understand the potentials and limitations of indicator microorganisms before implementing the guidelines and regulations designed by various regulatory agencies. This review provides updated information on traditional and alternative indicator microorganisms with merits and demerits in view of their role in managing the waterborne health risks as well as conventional and molecular methods proposed for monitoring of indicator and pathogenic microorganisms in the water environment. Further, the World Health Organization (WHO) water safety plan is emphasized in order to develop the better approaches designed to meet the requirements of safe drinking water supply for all mankind, which is one of the major challenges of the 21st century.

Exposure to WASH-borne hazards: A scoping study on peri-urban Ger areas in Ulaanbaatar, Mongolia

The present scoping study seeks to address the sources of water, sanitation, and hygiene (WASH) exposure of residents of peri-urban Ger areas of Ulaanbaatar, Mongolia. Field observations and semi-structured key informant interviews were carried out during 2012 and 2013 to assess the existing WASH situation in the peri-urban Ger areas of Ulaanbaatar, Mongolia. In addition, a knowledge, attitude, and practice (KAP) survey was conducted by Action Contre la Faim (ACF) Mongolia in 210 households to identify the sources of WASH-borne hazards in a statistically representative way. Moreover, the quality of drinking water was analyzed both at the household (n = 210) and water point (kiosk) (n = 40) levels to assess the risk of chemical and pathogenic contaminants. Both field observations and interviews revealed that the sanitary environment of the Ger residents is characterized by the lack of a drainage system, unimproved sanitation technology (e.g. unhygienic pit latrines and soak pits), unsafe water supply, and insufficient collection, transportation, and storage mechanisms. Poor infrastructure is associated with low standards of living. The transmission of WASH-borne disease (e.g. diarrhea, dysentery, hepatitis A) is the gravest consequence and source of hazards. The results from the water quality analysis demonstrate that Ger residents are more exposed to biological contamination of stored drinking water by Escherichia coli during the summer (May to August) than in the winter (November to February). During the winter, 36% of household storage containers were contaminated by E. coli at an average level of 12.5 E. coli per 100 ml, while, during the summer, 56% of household storage containers were contaminated at an average level of 50 E. coli per 100 ml. KAP surveys further reveal that the common practice of Ger residents to discharge greywater (with higher chemical oxygen demand) into pit latrines, soak-pits, yards, and streets likely causes environmental pollution and health hazards. Multifaceted WASH-borne exposure was addressed by the scoping study such that various WASH interventions could be planned for the study area and beyond. To tackle the above challenges and problems, a range of appropriate interventions and programs are recommended to reduce the exposure of WASH-borne hazards in the study area and other parts of the world – in both urban and peri-urban settings. The recommendations include: the development and implementation of a water safety plan (WSP), an effective monitoring system for collection, transportation and storage at both water kiosk and household levels, user training for correct use of water containers, effective coordination among stakeholders (including urban planners), development of a household greywater disposal system, and implementation of a functioning solid waste management system. Prior to taking these actions, a detailed study on the ‘pollution load from peri-urban to urban’ should be carried out to assess the WASH-borne vulnerability of both peri-urban and central urban population.

Water quality management for domestic rainwater harvesting systems in Fiji

Health risks from drinking rainwater are relatively small in the developing world context, but action is needed to ensure water safety. Water safety plans (WSPs) use an approach to manage water quality that has shown signs of success with public and communal water supplies, but relatively little research has been done to investigate the application of WSPs to self-supply systems. The aim of this paper is to investigate the primary issues surrounding appropriate water quality management of domestic rainwater harvesting (DRWH) systems in Fiji and consider how the principles of WSPs can be applied in this context. A qualitative research design was followed, utilising semi-structured interviews with 34 rural households and six key informants, sanitary inspections of DRWH systems and thematic data analysis. A number of challenges, including limited government resources and the limited knowledge and casual attitudes of rural rainwater consumers, constrain the practicality of adopting conventional WSPs at the household level, but steps for improvement can be taken.

Hospital water and opportunities for infection prevention.

Nosocomial waterborne pathogens may reach patients through several modes of transmission. Colonization of healthcare facility waterworks can occur in the proximal infrastructure, in the distal water outlets, or both. Infections with waterborne organisms such as Legionella, mycobacteria, Pseudomonas, and others cause significant morbidity and mortality, particularly in immunocompromised patients. Hospitals should have prospective water safety plans that include preventive measures, as prevention is preferable to remediation of contaminated hospital water distribution systems. Whole-genome sequencing may provide more informative epidemiologic data to link patient infections with hospital water isolates.

Risk assessment and water safety plan: case study in Beijing, China.

Two typical rural water utilities in Beijing, China were chosen to describe the principles and applications of water safety plans (WSP), to provide a methodological guide for the actual application and improve the quality of rural drinking water quality, and to establish an appropriate method for WSP applied in rural water supply. Hazards and hazardous events were identified and risk assessment was conducted for rural water supply systems. A total of 13 and 12 operational limits were defined for two utilities, respectively. The main risk factors that affect the water safety were identified in water sources, water processes, water disinfection systems and water utility management. The main control measures were strengthening the water source protection, monitoring the water treatment processes, establishing emergency mechanisms, improving chemical input and operating system management. WSP can be feasibly applied to the management of a rural water supply.

Co-occurrence profiles of trace elements in potable water systems: a case study.

Potable water samples (N = 74) from 19 zip code locations in a region of Greece were profiled for 13 trace elements composition using inductively coupled plasma mass spectrometry. The primary objective was to monitor the drinking water quality, while the primary focus was to find novel associations in trace elements occurrence that may further shed light on common links in their occurrence and fate in the pipe scales and corrosion products observed in urban drinking water distribution systems. Except for arsenic at two locations and in six samples, rest of the analyzed elements was below maximum contaminant levels, for which regulatory values are available. Further, we attempted to hierarchically cluster trace elements based on their covariances resulting in two groups; one with arsenic, antimony, zinc, cadmium, and copper and the second with the rest of the elements. The grouping trends were partially explained by elements' similar chemical activities in water, underscoring their potential for co-accumulation and co-mobilization phenomena from pipe scales into finished water. Profiling patterns of trace elements in finished water could be indicative of their load on pipe scales and corrosion products, with a corresponding risk of episodic contaminant release. Speculation was made on the role of disinfectants and disinfection byproducts in mobilizing chemically similar trace elements of human health interest from pipe scales to tap water. It is warranted that further studies may eventually prove useful to water regulators from incorporating the acquired knowledge in the drinking water safety plans.

Drinking water safety plans: barriers and bridges for small systems in Alberta, Canada

Water safety plans provide a relatively new management approach for identifying and addressing risks in a water supply. In 2011, the province of Alberta (Canada) became the first jurisdiction in North America to require that all water supplies develop drinking water safety plans (DWSPs). This research explored the implementation of DWSPs through the experiences of ‘early adopter’ operators who work in small communities. Specifically, in-person open-ended qualitative interviews with operators from 15 small communities from across Alberta were conducted to explore implementation challenges and opportunities. The findings highlight a number of barriers associated with the relationships between decision-making bodies, regulatory authorities and water operators, all of which have the potential to support or hinder the uptake of a DWSP. Findings also indicate that a DWSP can act as a bridge, providing a much-needed tool to facilitate communication about water supplies and help to support and manage relationships between stakeholders. This study revealed a number of important and useful insights to the small community early DWSP adopter experience in Canada that could be applied in other jurisdictions looking to adopt similar practices.

Risk assessment frameworks for MAR schemes in the UK

Managed aquifer recharge (MAR) provides a sustainable method to store large volumes of water. However, uncertainties around the associated risks, initial costs and regulatory regime are key influences on its development in the UK. This paper reports a critical review of available risk management frameworks as a first step towards the development of an assessment framework suitable for MAR schemes in the UK. Classification of risks across the MAR process involved deconstructing the process into functional elements; pre-treatment, recharge, storage, recovery, and post-treatment prior to final use, with each element presenting a range of risks to different receptors. An initial listing of seven potential frameworks were reduced to three (hazard and critical control point analysis, the world health organisation’s water safety plans and the Australian guidelines for water recycling using MAR) for detailed assessment. Although the hazard and critical control point analysis and the water safety plans may be adapted for use in MAR, they do not provide specific guidance for potential risks associated with aquifer recharge schemes. Furthermore, neither of them adequately addresses the risks associated with the recharge, storage and recovery elements of a scheme. The Australian guidelines provide guidance specific to MAR and are particularly effective in considering risk to these elements. The main conclusion is that although the Australian guidelines focus on potential hazards and might thereby not be suitable for identifying more process oriented considerations, they do constitute a robust basis for developing a framework for risk management for MAR schemes in the UK.

Development of an urban drainage safety plan concept based on spatial risk assessment

Hazard analysis and critical control points (HACCP) have proved their worth and contributed considerably to risk reduction of hazards being realised in the field of food industry as a stringent and preventive method. The risk management concept of the World Health Organization is based on HACCP, but the principles have been tailored to the context of water supply, which results in the development of the concept of a water safety plan. This concept is pro-active and provides operation and maintenance solutions to protect the critical infrastructure (CI). Urban drainage systems as well as water supply systems are categorised as CI, and thus, safety plans are crucial for protection, but in the field of urban drainage not established yet. Hence, the aims of this paper were to introduce urban drainage safety plans and to develop a concept for their implementation.

Application of risk-based assessment and management to riverbank filtration sites in India.

This is the first reported study of a riverbank filtration (RBF) scheme to be assessed following the Australian Guidelines for Managed Aquifer Recharge. A comprehensive staged approach to assess the risks from 12 hazards to human health and the environment has been undertaken. Highest risks from untreated ground and Ganga River water were identified with pathogens, turbidity, iron, manganese, total dissolved solids and total hardness. Recovered water meets the guideline values for inorganic chemicals and salinity but exceeds limits for thermotolerant coliforms frequently. A quantitative microbial risk assessment undertaken on the water recovered from the aquifer indicated that the residual risks of 0.00165 disability-adjusted life years (DALYs) posed by the reference bacteria Escherichia coli O157:H7 were below the national diarrhoeal incidence of 0.027 DALYs and meet the health target in this study of 0.005 DALYs per person per year, which corresponds to the World Health Organization (WHO) regional diarrhoeal incidence in South-East Asia. Monsoon season was a major contributor to the calculated burden of disease and final DALYs were strongly dependent on RBF and disinfection pathogen removal capabilities. Finally, a water safety plan was developed with potential risk management procedures to minimize residual risks related to pathogens.

Implementation of water safety plan for a large-piped water supply system.

A water safety plan for the city of Nagpur was developed by the National Environmental Engineering Research Institute (NEERI) and Nagpur Municipal Corporation (NMC). Possible hazards were identified through field visits. Based on this, an improvement plan was drawn up to suggest corrective actions and a time frame for implementation. The findings of this study are being used to modify or repair components of the water supply system and upgrade management procedures. This paper highlights the lessons learnt during implementation of the WSP and the key challenges faced.

Application of a basic monitoring strategy for <i>Cryptosporidium</i> and <i>Giardia</i> in drinking water

Despite the health risks associated with exposure to Cryptosporidium and Giardia, there is no uniform approach to monitoring these protozoan parasites across the world. In the present study, a strategy for monitoring Cryptosporidium and Giardia in drinking water was developed in an effort to ensure that the risk of exposure to these organisms and the risks of non-compliance to guidelines are reduced. The methodology developed will be applicable to all water supply systems irrespective of size and complexity of the purification works. It is based on monitoring procedures proposed by the US Environmental Protection Agency, the Drinking Water Inspectorate, Australia and New Zealand, as well as the risk-based procedure followed by Northern Ireland. The monitoring strategy developed represents a preventative approach for proactively monitoring Cryptosporidium and Giardia species in drinking water. The strategy consists of 10 steps: (i) assessment of the monitoring requirements, (ii) description and characterisation of the source water types, (iii) abstraction of source water, (iv) assessment of the water purification plant, (v) water quality monitoring, (vi) cryptosporidiosis and giardiasis outbreak, (vii) risk assessment, (viii) sample collection and laboratory processing, (ix) data evaluation, interpretation and storage, (x) process evaluation and review. Proper implementation of this protocol can contribute to the protection of drinking water consumers by identifying high-risk source water, identifying areas of improvement within the water treatment system, and also preventing further faecal pollution in the catchments. The protocol can also be integrated into the Water Safety Plans to optimise compliance. Furthermore, this methodology has a potential to contribute to Blue Drop certification as it should form part of the incident management protocols which are a requirement of Water Safety Plan implementation.Keywords: Cryptosporidium, Giardia, monitoring, risk score, drinking water

Long-Term Effects of Hospital Water Network Disinfection onLegionellaand Other Waterborne Bacteria in an Italian University Hospital

Legionella control still remains a critical issue in healthcare settings where the preferred approach to health risk assessment and management is to develop a water safety plan. We report the experience of a university hospital, where a water safety plan has been applied since 2002, and the results obtained with the application of different methods for disinfecting hot water distribution systems in order to provide guidance for the management of water risk. The disinfection procedures included continuous chlorination with chlorine dioxide (0.4-0.6 mg/L in recirculation loops) reinforced by endpoint filtration in critical areas and a water treatment based on monochloramine (2-3 mg/L). Real-time polymerase chain reaction and a new immunoseparation and adenosine triphosphate bioluminescence analysis were applied in environmental monitoring. After 9 years, the integrated disinfection-filtration strategy significantly reduced positive sites by 55% and the mean count by 78% (P < .05); however, the high costs and the occurrence of a chlorine-tolerant clone belonging to Legionella pneumophila ST269 prompted us to test a new disinfectant. The shift to monochloramine allowed us to eliminate planktonic Legionella and did not require additional endpoint filtration; however, nontuberculous mycobacteria were isolated more frequently as long as the monochloramine concentration was 2 mg/L; their cultivability was never regained by increasing the concentration up to 3 mg/L. Any disinfection method needs to be adjusted/fine-tuned in individual hospitals in order to maintain satisfactory results over time, and only a locally adapted evidence-based approach allows assessment of the efficacy and disadvantages of the control measures.