significant modification and/or rehabilitation of existing water supply systems. the extension of significant areas forming a coherent part of an existing water supply system the design and construction of new water supply systems The requirements of this standard apply to: requirements for installation, site testing and commissioning. general requirements for inclusion in product standards which may include specifications which are more stringent general requirements for water supply systems outside buildings (see Figure 1) including potable water mains and service pipes, service reservoirs, other facilities and raw water mains but excluding treatment works and water resources development
