Changes

*Where drainage or conveyance to a downstream facility is a greater priority, the base of the reservoir and the underdrain pipe may have a gradient of up to 1-2%.

*Where drainage or conveyance to a downstream facility is a greater priority, the base of the reservoir and the underdrain pipe may have a gradient of up to 1-2%.

==Maintenance and inspection==

==Inspection and maintenance==

[[File:45 degs.PNG|thumb|Schematic of pipes and connectors]]

[[File:45 degs.PNG|thumb|Schematic of pipes and connectors]]

[[File:Jet cleaning.jpg|thumb|Diagram of hydrojetting cleaning apparatus]]

[[File:Jet cleaning.jpg|thumb|Diagram of hydrojetting cleaning apparatus]]