Selected Aspects of the Water Supply System Safety

2019

IJERPH

Informing users of waterworks systems about the quality of tap water is an obligatory trend. It should be accompanied by studies on the influence of the risk of threats on public health. Waterworks systems, being included in a critical infrastructure of the city, should be subject to special protection in this respect. In the paper, the authors’ method of assessing threats to people and property from waterworks systems functioning in self-government units (SGUs), is proposed. Four categories of factors affecting the risk of threat to tap water consumers were assumed: the frequency or the probability of exposure—P, financial losses—C, damages to peoples’ health—HL, the degree of the security—S. Based on this, a four-parametric risk matrix was developed. It was assumed that risk is a function of the parameters mentioned above: r = f(P, C, HL, S). For every parameter the five-parametric weight scale was assumed. An example of applying the method is presented. The proposed method should be an important element of water safety plans. It can also be adopted for other municipal systems subject to SGU.

Section: Methodsmentioning

confidence: 99%

“…Risk assessment requires determining the value of both factors. The joint consideration of human damages and material losses raises ethical concerns [34,35]. For this reason, we should categorize the risk associated with material losses and with human damage separately.…”

Section: Methodsmentioning

confidence: 99%

A Hazard Assessment Method for Waterworks Systems Operating in Self-Government Units

Rak

Tchórzewska-Cieślak

2019

IJERPH

“…The second half of the twentieth century brought many major accidents and disasters relating to the functioning of public water supply systems (WSS) in urban and industrial agglomerations. In this regard, there can be no doubt that WSS operations are subject to risk [1][2][3][4][5][6], hence the key importance of risk analysis that determines the location and size of such risk, as well as the actions to be taken with a view to its reduction or elimination [7]. Activities allowing these relations to be studied fall under the heading of risk management, which should be organized and comprehensive, in relation to both the entire WSS and elements associated with it [8].…”

Section: Introductionmentioning

confidence: 99%

Approaches to Failure Risk Analysis of the Water Distribution Network with Regard to the Safety of Consumers

Tchórzewska-Cieślak

2018

Water

Contemporary risk assessment makes reference to current world trends, whereby there is increased emphasis on safety. This paper has thus sought mainly to present new approaches to failure risk assessment where the functioning of a water distribution network (WDN) is concerned. The framework for the research involved here has comprised of: (a) an analysis of WDN failure in regard to an urban agglomeration in south-east Poland; (b) failure rate analysis, taking account of the type of a water pipe (mains, distribution, service connections (SC)) and months of the year, with an assessment of results in terms of criterion values for failure rate; (c) a determination—by reference to analyses performed previously—of the compatibility of experts’ assessments in terms of standards of failure and obtained results, through rank analysis; and (d) the proposing of a modified Multi-Criteria Decision Analysis with implementation of an Analytical Hierarchy Process, to allow failure risk assessment for the WDN to be performed, on the basis of the calculated additive value of obtained risk. The analysis in question was based on real operating data, as collected from the water distribution company. It deals with failures in the WDN over a period of 13 years in operation, from 2005 to 2017.

“…Now, however, work is underway on a new Directive obliging water-supply companies to implement WSPs-on the basis of analyses and risk assessments.The threshold values for permissible concentrations of pollutants of water that are set out in various norms allow suitability for drinking and for economic purposes to be determined [36,37]. However, in a majority of cases, technological processes relating to water treatment do not take account extreme situations, in which there are times during which the designed or existing water-treatment process does not guarantee compliance with quality standards [38][39][40][41].Some examples of extreme situations influencing many recipients in recent years were as follows:…”

mentioning

confidence: 99%

“…And the solution here thus requires that frequencies and durations of periods of non-compliance be determined [8,39]. This is possible on the basis of reliability theory, which provides for study of the random phenomena that cause periodic reductions in the amount or quality of water [40]. This is done using the so-called risk indices that allow for numerical characterisation of damage resulting from various failures, and contaminations occurring periodically in a random manner.…”

mentioning

confidence: 99%

An Approach to Determine Risk Indices for Drinking Water–Study Investigation

Rak

2019

Sustainability

In accordance with the water quality standard, the safe functioning of the water treatment system operation is considered. This paper alludes to extreme situations, which arise where there is periodic deterioration of the quality of raw water, for which the technological process of water treatment is not prepared. A conception method is presented by which to assess indices of risk vis-à-vis drinking water, on the basis of a probability estimation methodology. The categorisation of water pipes in line with quality-reliability as regards the physical and chemical composition of drinking water or water intended for business purposes is proposed. An example of the method being put to use is also offered, and it is recognised how the approach being proposed could be the basis for further analysis that takes different conditions of functioning of water-supply systems into account.Sustainability 2019, 11, 3189 2 of 12 unprecedented terrorist threat [9]. According to these requirements, the assessment of diversification degree of water supply for human consumption from independent sources should be performed. Such possibility provides the Shannon Wiener index, which allows for objective comparison between water supply systems with different final water production [10]. Other methods for estimating the risk of failure are based on the assumptions of classical matrix methods while information from the system operation is inaccurate, as proposed in [11,12]. Also, an important issue constitutes an analysis of failure scenarios framework in order to determine the probability of the threat occurrence by implementation of the Fault Tree Analysis or the Preliminary Hazard Analysis Method, which are helpful for failure analysis in a decision-making process and preventive strategies [13,14]. Conclusions arising out of the history of particular failures entailing the large-scale contamination of tap water in urban agglomerations offer a perfect guide as to how risk management of an active nature needs to be engaged in [9].This leaves it vital that risk-reduction procedures be pursued, and decision-support tools devised, on the basis of analyses and risk assessments that accompany the functioning of a WSS, also in compliance with guidelines vis-à-vis risk and crisis management where the security of the supply of drinking water is concerned [15,16], with account also taken of the principles of sustainable development. The paradigm becomes the argument, as we wish to live-and to drink safe water-in conditions of peace and certainty, in the belief that there is no risk or effective protection against it [17]. Meanwhile, the specialist scientific literature puts a clear emphasis on the view that quantitative risk analysis and assessment methods of water supply system failure form the basis upon which to manage security of a WSS [18][19][20][21][22][23][24][25][26][27][28][29], in the context of belonging to critical infrastructure [30].Natural waters are very rarely of a composition allowing their safe use as drinking water. Almost alwa...