Perspectives are different frameworks from which to explore the knowledge around sustainable sanitation and water management. Perspectives are like filters: they compile and structure the information that relate to a given focus theme, region or context. This allows you to quickly navigate to the content of your particular interest while promoting the holistic understanding of sustainable sanitation and water management.
A factsheet on slow sand filters work compiled by the WHO. It includes a paragraph on how sanitary inspections of rapid sand filters should be conducted.
WHO (1996): Rapid Sand Filtration. (= Fact Sheets on Environmental Sanitation , 2 / 14 ). Geneva: World Health Organization (WHO) URL [Accessed: 15.02.2012]