Glossary – Severn Trent Searches

Map keys glossary for the residential CON29DW and commercial drainage and water report.

Sewer Record


Public Combined Gravity Sewer		A public sewer that is in the ownership and control of Severn Trent Water that drains by gravity and receives both foul and surface water flows from more than one property.
Public Foul Gravity Sewer		A public sewer that is in the ownership and control of Severn Trent Water that drains by gravity and receives foul water flows from more than one property.
Public Surface Water Gravity Sewer		A public sewer that is in the ownership and control of Severn Trent Water that drains by gravity and receives surface water flows from more than one property.
Combined Use Pressurised Sewer		A public sewer that is in the ownership and control of Severn Trent Water through which both foul and surface water flows are pumped and receives drainage from more than one property.
Foul Use Pressurised Sewer		A public sewer owned and operated by Severn Trent Water through which foul water flows are pumped and receives drainage from more than one property.
Surface Water Pressurised Sewer		A public sewer that is in the ownership and control of Severn Trent Water through which surface water flows are pumped and receives drainage from more than one property.
S104 Pressurised Sewer		A private sewer through which foul water flows are pumped which is subject to a sewer adoption agreement (usually an S104). This sewer will remain the responsibility of the developer until it is adopted by Severn Trent Water.
Abandoned Gravity Sewer		A sewer no longer in use that formerly received drainage by gravity and is still in existence.
Private Gravity Sewer		A sewer which historically was plotted as a private sewer but should now have transferred into public ownership (Severn Trent Water) since the sewer transfer legislation in October 2011, providing it connected into the public sewer network . The sewer drains by gravity and receives either foul or surface water flows from more than one property.
Section 104 Gravity Sewer		A private sewer which is the subject of a sewer adoption agreement (usually an S104) and will remain the responsibility of the developer until the sewer is adopted by Severn Trent Water. The sewer drains by gravity and receives either foul or surface water flows from more than one property.
Transferred Gravity Sewer		A sewer that transferred into public ownership (Severn Trent Water) as a result of the sewer transfer legislation in October 2011. The sewer drains by gravity and receives either foul or surface water flows from more than one property.
Highway Drain (Not STW)		A pipe that is used to drain surface water from highways which (if maintainable at the public expense) are in the ownership and control of the highway authority.
Vent Column		A vertical above ground column used to take odours arising from the sewerage system away from ground or street level.
Waste Water Storage		A tank used for the temporary storage of waste water in a sewerage system.
Culverted Watercourse (Not STW)		A natural watercourse that has been enclosed within a pipe or culvert and is not a public sewer.
Protective Strip		A strip of land over the line of a sewer or lateral drain within which no buildings should be placed or ground levels altered in order to protect the integrity of and access to the pipe.
Sewage Pumping Facility		This is usually an underground facility which may be accommodated in an above ground building and pumps from a low-lying area to a higher one. Foul sewage and/or surface water flows from a sewerage system by gravity into the pumping station and the flows are then pumped into another sewerage system or to a sewage works.
Sewage Pumping Facility – Private		A private pumping station – not the responsibility of Severn Trent Water.
Sewage Pumping Facility – Awaiting Adoption		A private pumping station which is subject to a sewer adoption agreement (usually an S104). This pumping station will remain the responsibility of the developer until it is adopted by Severn Trent Water.
Sewage Pumping Facility – Transferred		A formerly private pumping station that has now transferred into public ownership (Severn Trent Water) under the Private Sewer Transfer Regulations (2011).
Sewage Pumping Facility – Abandoned		A pumping station no longer in use that formerly received drainage by gravity and is still in existence.
Sewage Pumping Facility – Highway Drains		A highway drainage pumping station which (if maintainable at the public expense) is in the ownership and control of the Highways Authority.
Sewage Facility Connection inlet / outlet		A connection to or from a sewage pumping facility.
Hyrdrobrake		A device that limits the volume of a discharge to the sewerage system to a preset flow rate.
Lamphole		A small vertical shaft between sewer manholes that can be used to illuminate sewer lengths for visual inspection.
Outfall		A discharge point from the end of a sewer usually into a watercourse.
Overflow		A chamber enabling the overflow of sewage and/or surface water to spill (over a weir wall) into another system.
Penstock		A gate, valve or sluice used in controlling the flows in sewerage systems.
Petrol Interceptor		A device that traps oil, petrol and other hydrocarbons and prevents the discharge of those substances into a sewerage system.
Sewage Treatment Works		A site that receives flows from a sewerage system and which contains all the necessary plant and machinery for the treatment and disposal of sewage.
Sewer Blockage		A point in a sewerage system where the sewer is blocked.
Sewer Collapse		A point in a sewerage system where the sewer has collapsed.
Sewer Chemical Injection Point		An access point in a sewerage system used to inject chemicals into or “dose” the contents of the sewerage system.
Sewer Junction		Device used to slow the speed of sewage and or surface water in a gravity sewer.
Sewerage Air Valve		A valve used for venting air from a sewer that is pressurised.
Sewerage Hatch Box Point		A pressurised sewer inspection fitting that may be located in an access chamber.
Sewerage Isolation Valve		A valve used to isolate one part of a sewerage system from another.
Soakaway		A below ground structure into which surface water is discharged to allow infiltration into the ground.
Surface Water Manhole		A vertical access shaft from ground level to a surface water sewer to allow cleaning, inspection, connections and repairs
Blind Shaft		Chamber or small hole giving access to a sewer but not for man entry.
Combined Use Manhole		A vertical access shaft from ground level to a combined sewer to allow cleaning, inspection, connections and repairs.
Disposal Site		Where sewage sludge is disposed of after being treated at a sewage treatment works.
Flushing Chamber		A chamber found at the head of a sewer designed to allow water to be pumped down to flush out the sewer.
Foul Use Manhole		A vertical access shaft from ground level to a foul sewer to allow cleaning, inspection, connections and repairs.
Grease Trap		A device that captures grease and oils entering a drainage system before they reach the sewer. Grease traps are normally used in commercial applications such as restaurants or cafeterias.
Head Node		Access point at the head of a sewer.
Public Combined Gravity Sewer		A public sewer that is in the ownership and control of Severn Trent Water that drains by gravity and receives both foul and surface water flows from more than one property.
Public Foul Gravity Sewer		A public sewer that is in the ownership and control of Severn Trent Water that drains by gravity and receives foul water flows from more than one property.
Public Surface Water Gravity Sewer		A public sewer that is in the ownership and control of Severn Trent Water that drains by gravity and receives surface water flows from more than one property.
Combined Use Pressurised Sewer		A public sewer that is in the ownership and control of Severn Trent Water through which both foul and surface water flows are pumped and receives drainage from more than one property.
Foul Use Pressurised Sewer		A public sewer owned and operated by Severn Trent Water through which foul water flows are pumped and receives drainage from more than one property.
Surface Water Pressurised Sewer		A public sewer that is in the ownership and control of Severn Trent Water through which surface water flows are pumped and receives drainage from more than one property.
S104 Pressurised Sewer		A private sewer through which foul water flows are pumped which is subject to a sewer adoption agreement (usually an S104). This sewer will remain the responsibility of the developer until it is adopted by Severn Trent Water.
Abandoned Gravity Sewer		A sewer no longer in use that formerly received drainage by gravity and is still in existence.
Private Gravity Sewer		A sewer which historically was plotted as a private sewer but should now have transferred into public ownership (Severn Trent Water) since the sewer transfer legislation in October 2011, providing it connected into the public sewer network . The sewer drains by gravity and receives either foul or surface water flows from more than one property.
Section 104 Gravity Sewer		A private sewer which is the subject of a sewer adoption agreement (usually an S104) and will remain the responsibility of the developer until the sewer is adopted by Severn Trent Water. The sewer drains by gravity and receives either foul or surface water flows from more than one property.
Transferred Gravity Sewer		A sewer that transferred into public ownership (Severn Trent Water) as a result of the sewer transfer legislation in October 2011. The sewer drains by gravity and receives either foul or surface water flows from more than one property.
Highway Drain (Not STW)		A pipe that is used to drain surface water from highways which (if maintainable at the public expense) are in the ownership and control of the highway authority.
Vent Column		A vertical above ground column used to take odours arising from the sewerage system away from ground or street level.
Waste Water Storage		A tank used for the temporary storage of waste water in a sewerage system.
Culverted Watercourse (Not STW)		A natural watercourse that has been enclosed within a pipe or culvert and is not a public sewer.
Protective Strip		A strip of land over the line of a sewer or lateral drain within which no buildings should be placed or ground levels altered in order to protect the integrity of and access to the pipe.
Sewage Pumping Facility		This is usually an underground facility which may be accommodated in an above ground building and pumps from a low-lying area to a higher one. Foul sewage and/or surface water flows from a sewerage system by gravity into the pumping station and the flows are then pumped into another sewerage system or to a sewage works.
Sewage Pumping Facility – Private		A private pumping station – not the responsibility of Severn Trent Water.
Sewage Pumping Facility – Awaiting Adoption		A private pumping station which is subject to a sewer adoption agreement (usually an S104). This pumping station will remain the responsibility of the developer until it is adopted by Severn Trent Water.
Sewage Pumping Facility – Transferred		A formerly private pumping station that has now transferred into public ownership (Severn Trent Water) under the Private Sewer Transfer Regulations (2011).
Sewage Pumping Facility – Abandoned		A pumping station no longer in use that formerly received drainage by gravity and is still in existence.
Sewage Pumping Facility – Highway Drains		A highway drainage pumping station which (if maintainable at the public expense) is in the ownership and control of the Highways Authority.
Sewage Facility Connection inlet / outlet		A connection to or from a sewage pumping facility.
Hyrdrobrake		A device that limits the volume of a discharge to the sewerage system to a preset flow rate.
Lamphole		A small vertical shaft between sewer manholes that can be used to illuminate sewer lengths for visual inspection.
Outfall		A discharge point from the end of a sewer usually into a watercourse.
Overflow		A chamber enabling the overflow of sewage and/or surface water to spill (over a weir wall) into another system.
Penstock		A gate, valve or sluice used in controlling the flows in sewerage systems.
Petrol Interceptor		A device that traps oil, petrol and other hydrocarbons and prevents the discharge of those substances into a sewerage system.
Sewage Treatment Works		A site that receives flows from a sewerage system and which contains all the necessary plant and machinery for the treatment and disposal of sewage.
Sewer Blockage		A point in a sewerage system where the sewer is blocked.
Sewer Collapse		A point in a sewerage system where the sewer has collapsed.
Sewer Chemical Injection Point		An access point in a sewerage system used to inject chemicals into or “dose” the contents of the sewerage system.
Sewer Junction		Device used to slow the speed of sewage and or surface water in a gravity sewer.
Sewerage Air Valve		A valve used for venting air from a sewer that is pressurised.
Sewerage Hatch Box Point		A pressurised sewer inspection fitting that may be located in an access chamber.
Sewerage Isolation Valve		A valve used to isolate one part of a sewerage system from another.
Soakaway		A below ground structure into which surface water is discharged to allow infiltration into the ground.
Surface Water Manhole		A vertical access shaft from ground level to a surface water sewer to allow cleaning, inspection, connections and repairs
Blind Shaft		Chamber or small hole giving access to a sewer but not for man entry.
Combined Use Manhole		A vertical access shaft from ground level to a combined sewer to allow cleaning, inspection, connections and repairs.
Disposal Site		Where sewage sludge is disposed of after being treated at a sewage treatment works.
Flushing Chamber		A chamber found at the head of a sewer designed to allow water to be pumped down to flush out the sewer.
Foul Use Manhole		A vertical access shaft from ground level to a foul sewer to allow cleaning, inspection, connections and repairs.
Grease Trap		A device that captures grease and oils entering a drainage system before they reach the sewer. Grease traps are normally used in commercial applications such as restaurants or cafeterias.
Head Node		Access point at the head of a sewer.

Water Record


Distribution Main		A local water main that distributes water supplies to premises within a geographical area.
Trunk Main		A water main that provides water supplies to distribution mains or transfers water between water sources, water treatment works and reservoirs.
Strategic Main		A water main that conveys water in bulk between strategic water assets such as from a borehole to a reservoir.
Fire Supply Main		A pipe that supplies water to one property solely for the purpose of extinguishing fires.
Fire Main		A pipe that supplies water into an area to enable connections to be made solely for the purpose of extinguishing fires.
Non-Domestic Customer Service Pipe		A water service pipe that is not owned by Severn Trent Water and which supplies the premises of a non-domestic customer.
Domestic Customer Service Pipe		A water service pipe that is not owned by Severn Trent Water and which supplies the premises of a domestic customer.
Abandoned Main		A water main no longer in use that formerly supplied water and is still in existence.
Elevated Main		A water main that has been constructed above ground level.
Aqueduct		A large diameter pipe that carries water from a water supply source to a water treatment works or reservoir.
Duct		A conduit that carries a pipe or other apparatus.
Pre-1937 Properties		Properties that were constructed prior to 1st October 1937.
SSSI Area		A Site of Special Scientific Interest.
Protective Strip		A strip of land over the line of a water main within which no buildings should be placed or ground levels altered in order to protect the integrity of and access to the pipe.
Pumping Facility		Building or chamber housing a pump or series of pumps to induce or increase pressure and consequently a flow rate of water.
Booster Facility		A pumping station that boosts water supplies into a geographical area.
Potable Water Storage		A connection to a potable water storage facility.
Water Tower		A large elevated tank or reservoir that holds potable water for the distribution of drinking water supplies to a geographical area.
Well / Borehole		An underground water supply source.
Intake		The point at which water is abstracted from a water supply source.
Water Treatment Works / Chamber		A facility that treats raw water from a water supply source to make it suitable for drinking.
Draw-off Tower		The point at which water is drawn off from a reservoir through a tower containing pipes and valves.
Bowser Point		A point on a water supply system where it is planned to put one or more water bowsers in the event of disruption to normal water supplies.
Water Facility Connection		Inlet to a water pumping facility or outlet from a water pumping facility.
Pipe Support Structure		An above ground structure that supports a pipe which is crossing an obstruction.
Open Pipe		Open end of a pipe used to abstract water from a spring.
Discharge		A point where water can be flushed from a water supply system into a watercourse.
End Cap		The capped end of a pipe.
Water Isolation Valve (Closed)		A valve used to isolate one part of a water supply system from another – valve in closed position.
Water Isolation Valve (Open)		A valve used to isolate one part of a water supply system from another – valve in open position.
Water Isolation Valve (Partially Open)		A valve used to isolate one part of a water supply system from another – valve in partially open position.
Water Air Valve		A valve used for venting air from a water main when bleeding the main or allowing air to enter the main when draining it.
Pressure Reducing Valve		A valve used to reduce pressure in a water supply system.
Pressure Sustaining Valve		A valve used to sustain pressure in a water supply system.
Non-Return Valve		A one-way valve that allows water to flow through it in one direction but prevents its movement in the opposite direction.
Float Valve		A valve that automatically opens or closes as the level of water changes in a reservoir.
Hydrant (Single/Double)		A valved outlet on a water main which allows water to be drawn off by the emergency services, flush out the network or to allow a temporary connection by authorised users.
Washout (Single/Double)		A valve that allows water to be flushed through a water supply system for maintenance purposes.
Bulk Meter		A device fitted to measure the rate of flow or volume of water passing in a pipe.
Water Hatch Box		A fitting allowing access to a water pipe or aqueduct that may be located in an access chamber.
Pressure Tapping		A fitting point on a pipeline for attaching equipment used to measure the pressure inside.
Insertion Flow Meter Point		A point at which a flow meter can be installed in a water supply system to measure the rate of flows.
Change in Characteristic		Symbol that indicates the point where there is a change of characteristic to that asset.
Marker Post		Above ground posts or markers that indicate the position of fire hydrants, valves, water mains or other underground assets.
Cable Junction		A junction of cables where other equipment may be connected.
Anode		A device for the protection of steel water mains against the risk of external corrosion.
Boundary Box		A box that is usually in the pavement outside premises and which contains a stop tap and often a meter belonging to Severn Trent Water.
Stop Tap		A control valve located on a service pipe to a property which is used to isolate the water supply to the property.
Cross Piece		Connecting pipe work.
Strainer		In line filter for the removal of large particles and the protection of equipment.
Listening Post		A metal pole attached to a pipe, used in leak detection by listening to noise transmitted to ground level.
Revenue Meter		A meter used to assess charges for water supplied to premises.
Housing, Building		A structure in the form of a building that houses equipment.
Housing, Kiosk		A structure in the form of a kiosk that houses equipment.
Housing, Other		A structure of an unspecified form that houses equipment.
Quality Sample Point		A point on the water supply network where samples can be taken to test water quality.

Water Hardness

Water hardness can be expressed in various indices for example the hardness settings for dishwashers are commonly expressed in Clark’s degrees, but check with the manufacturer as there are also other units. The following table explains how to convert mg/l calcium and mg/l calcium carbonate classifications.

TO CONVERT FROM:	TO CLARK DEGREES	TO FRENCH DEGREES	TO GERMAN DEGREES
mg/l calcium	multiply by 0.18	multiply by 0.25	multiply by 0.14
mg/l calcium carbonate	multiply by 0.07	multiply by 0.10	multiply by 0.056