Water supply systems assessment

Testing the potential of pipe materials to promote biofilm growth is needed because it may affect the taste, odor or turbidity of drinking water and may cause non compliance with microbiological water quality parameters and a risk to consumers health. Because EU Drinking Water Directive (98/83/EC) controls the water quality at the consumers tap instead of the point of supply, it is important to be assessed if the pipe material in drinking water supply systems release substances that may enhance or inhibit attached microbial growth. 

An area of water quality assessment, either an entire or a part of a water supply system. 

The WHO Guidelines (2004) devote an entire chapter to the topic of drinking water safety planning. It is recommended that a risk assessment and risk management approach should be implemented in the design and operation of water supply systems, additional to the verification of water safety by sampling. The risk assessment and risk management approach should extend from source to tap , that is, the entire water supply chain. This is considered further in Chapter 6 in the context of risk assessment in plumbosolvency control. 

Risk assessment and risk management strategies, including improvement plans, are put in place in the management of water supply systems. 

In the US, this is achieved by periodic surveys at consumers taps with sample numbers reflecting the population of the water supply system being assessed (Table 3.1). Whether the system complies or fails the LCR is clearly defined on the basis of observed 90th percentile concentrations. Water quality monitoring points must also include both the entry points to the distribution system, as well as locations in the distribution network itself. 

In the EU, a minimum number of samples must be taken each year from consumers taps, again dependent on the size of the water supply system being assessed. The frequencies for comphance monitoring for lead are given in Table 3.2. 

In the assessment of plumbosolvency changes in a water supply system, it is advisable to monitor a minimum of 6 suitable properties. The main problem with the approach is that householders tire of repeated sampling visits, move away or die, such that the ability to monitor at an individual property may be lost. 

Wieczysty A. others 2001. Methods for assessing and improving the reliability of the municipal water supply systems, PAN Monographs, vol. 2, Cracow. 

Zimoch L, Szymik-Gralewska J. 2014 (in press). Risk assessment methods of water supply system in terms of reliability and operation cost, Conference Urban Water 2014, 27th to 29th May 2014, Algarve, Portugal. 

ABSTRACT In the era of informatization databases and information systems are an essential source of risk analysis and risk assessment of collective water supply systems. The functioning of the water distribution system is associated with the risk of occurrence of undesirable events. The result of these events may be deterioration of the water quality parameters, reduction of water pressure in the water network or total lack of water. 

Rak X Tchdrzewska-Cieslak, B., 2006. Review of matrix methods for risk assessment in water supply system. Journal of Konbin, 1 67-76. 

Zimoch, I. Lobos, E. 2012. Method of safety analysis of water supply system. Proc. 11th International Probabilistic Safety Assessment and Management Conference and the Annual European Safety and Reliability Conference, Helsinki 25-29 June (2012), vol. 7 5816-5823. Helsinki lAPSAM ESRA. 

Rak, J., 2003. A study of the qualitative methods for risk assessment in water supply systems. Environment Protection Engineering, Wydawn. Politechniki Wroclaw-skiej, z. 3—4 123 134. 

Tchorzewska-Cieslak B., 2007. Method of assessing of risk of failure in water supply system. European safety and reliability conference (ESREL), Risk, reliability and societal safety, Taylor Francis, (vol. 2) 1535-1539. 

A full system assessment to determine whether an existing or planned drinking-water supply is capable of meeting health-based targets. 

Specified technology National authority specifies processes to adequately address constituents with potential health effects (e.g. generic water safety plans for an unprotected catchment) Constituents with potential health effect in small municipalities and community supplies Compliance assessed through system assessment and operation monitoring (see GDWQ Chapter 4)... 

Operational monitoring involves planned observations or measurements to assess whether the critical components of a safe water supply are operating properly. If the components are operating properly collectively, the system should be able to meet water quality targets. 

Logistics. The committee observes that the supply chain provides a delivery mechanism for surreptitious chemical or biological attack. Our nation s recent experience with anthrax delivered through the U.S. mail system provides a relevant illustration of the disruption and psychological response that such an attack can cause. Food and water supplies offer similar delivery opportunities. Attacks by such means should be considered within the context of an overall risk assessment, since they could significantly degrade operational readiness. 

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