Water quality - Sampling - Part 21: Guidance on sampling of drinking water distributed by tankers or means other than distribution pipes ((ISO 5667-21:2010))
This part of ISO 5667 establishes principles to be applied to the techniques of sampling water provided for drinking and for use in the manufacture of food and beverage products. The guidance given in this part of ISO 5667 is generally confined to those circumstances where water is drawn from municipal or similar public or private abstraction, treatment or distribution systems for which prior treatment or quality assessment has resulted in the water being classified as suitable for drinking or potable process purposes. Specifically, this part of ISO 5667 is applicable to water that is supplied by tanker or other non-contiguous bulk means, but not contiguously as part of a piped distribution system, during any stage of use up to and including the point of consumption or transfer to a piped distribution system. This part of ISO 5667 is also applicable to the distribution and bulk storage of water on aircraft, trucks, trains, ships, and other vessels and vehicles, as well as to sampling situations that can arise during the investigation of system defects, initiation of new systems, re-initiation of systems that have been unused for long periods or emergency situations where the safety of sampling operatives is not compromised. This part of ISO 5667 does not provide guidance on: a) the sampling of source water, e.g. groundwater and impoundments; b) the sampling of potable water supplies derived from contiguous piped supplies covered by ISO 5667-5; c) the sampling of beverage products (including bottled waters) or food containing potable water used in its preparation; d) the sampling of drink vending machines.