The larger the settlement, the greater the importance of WASH because of the number of people affected and because of the impact of deficiencies in WASH provision. Very large settlements such as urban areas and large camps create particular problems for WASH: it is more difficult to control environmental health risks, establish community-based hygiene promotion activities and promote community participation in the management of facilities. Very large settlements may also place unsustainable demands on limited natural resources, including water resources, and create a large burden of waste to be managed in the local environment. Data should be collected from key informants in the camp management and camp coordination cluster. The figure for number of people on the site may be verified with data used by the shelter and nutrition clusters for distributions, and estimates from surveys. Figures in the score range may need to be adjusted to reflect national or local norms and patterns of settlement.