ISO 5667-22:2010 give guidelines for the design, construction and installation of groundwater quality monitoring points to help ensure that representative samples of groundwater can be obtained. Within the guidance consideration is given to: a) the impact of installation materials on the environment; b) the impact of the installation on sample integrity; c) the impact of the environment on the installation and the materials used in its construction.These guidelines allow the impacts to be considered and accounted for when designing a groundwater sampling programme. They also allow an informed assessment of data and results obtained from existing installations, the construction of which can potentially have an impact on sample integrity.These guidelines are intended for installations and monitoring in different environments including those where background or baseline groundwater conditions are being established or monitored and those in which impacts of contamination are being investigated.