Annotated Summary

International Organization for Standardization. (2019). Service activities relating to drinking water supply, wastewater and stormwater systems — Guidelines on alternative drinking water service provision during a crisis (ISO/DIS Standard No. 24527). Retrieved from https://bsol-bsigroup-com.proxy4.athensams.net/Bibliographic/BibliographicInfoData/000000000030364931

In the industry standard, International Organization for Standardization (ISO, 2019) stated the guideline for the fundamental concepts, designs and execution of alternative drinking water service (ADWS) provision in the event of a prolonged stoppage of water supply.It says that the first consideration in deciding an approach for providing an ADWS is to acquire adequate knowledge of the affected facility’s regular water service during non-crisis situations. This is because the ADWs needs to fulfil sanitary and fire-fighting purposes. Failure to do so may lead to repercussions like loss of ADWS efficiency and reliability and increase in monetary cost.The standard also said that, based on the planning established from a risk assessment during the facility's ordinary operation, a method for ADWS can be chosen between; a temporary connection from the existing distribution network, or water from external sources.This standard supports the methods that PUB uses to provide temporary water supply relief when a mass-discolouration event occurs in the municipal mains. Currently, Singapore's water agency, Public Utilities Board (PUB) most commonly employs one of two options. The first option is a hosed connection from a neighbouring unaffected mains into the affected receiving party's connection. This allows users to continue receiving fresh water. This method, however, only works if discolouration happens in a local area. For most situations, discoloured water affects a whole distance in the entire mains, which requires the second method. As described in the standard, PUB deploys water tankers full of fresh water from another location as an external source of temporary supply.