Water Jargon Buster

Water Jargon and Industry Terminology Explained

At Crown Energy, we’re passionate about making utility connections simple. But within the water industry, sometimes there’s no escaping the jargon! We’ve put together a handy “Water Jargon Buster” to help you sail through the minefield of complicated terms and energy acronyms, so you’re never left in the dark.

Adoption agreement

An arrangement where a water company takes ownership (“adopts”) newly installed mains or infrastructure from a developer once it meets the required standards.

Backflow

The unwanted reversal of water flow. which can cause contamination if non-potable water enters the drinking supply. Preventing the use of backflow devices.

Boundary box

An underground chamber, usually at the edge of a property, housing the external stop tap and meter (if fitted).

Building water supply

A temporary water connection is used during construction before the permanent supply is installed.

Communication pipe

The section of pipe owned by the water company that runs from the water main to the property boundary stop tap.

Connection charge

The fee charged by a water company or utility provider to connect a property to the mains water supply.

Developer services

The department within a water company that handles applications for new connections, diversions, and supply alterations for housing and commercial developments.

Decommissioning

The process of permanently cutting off a water supply at the main or boundary, often when a building is demolished or a supply is no longer needed.

Distribution main

A large-diameter water main that carries treated water from service reservoirs to smaller local mains.

Diversion

The process of moving existing water mains or pipes to make way for building works or infrastructure projects.

Domestic water supply

A water connection that serves residential premises, providing potable (drinking-quality) water.

Dual supply

Two separate water supplies serving the same premises, for example, one for potable water and one for process or recycled water.

External stop tap

A valve fitted in a boundary box that allows the water supply to be turned on or off externally, typically used by water companies or plumbers for maintenance.

Fire main / fire hydrant

Dedicated pipework and access points are designed to supply large volumes of water for firefighting purposes.

Fittings Regulations (Water Supply (Water Fittings) Regulations 1999)

Legal standards governing how plumbing systems are designed, installed, and maintained to prevent contamination, misuse, or wastage of water. These regulations apply to any plumbing system that connects (or could connect) to the public water supply. (See The Water Supply (Water Fittings) Regulations 1999 to learn more.)

Groundworker

A contractor responsible for excavation and reinstatement when installing new water or sewer connections.

House supply

The internal plumbing system that distributes water from the point of entry (stop tap or meter) to appliances and outlets within the building.

Jointing

The process of connecting sections of pipe using couplings, flanges or fusion welding.

Lead pipe replacement

The process of upgrading old lead service pipes to modern plastic pipes for health and safety reasons.

Main

The principal pipe carrying water in a public network, from which smaller service pipes branch off to individual properties.

Meter installation

Fitting a water meter to record consumption for billing and leak detection purposes.

Meter serial number

A unique identifier engraved on the water meter body, used to link the meter to a specific property and billing account.

New connection

A new pipe connection linking a property to the public water main for the first time.

Non-potable water

Water not suitable for drinking, often used for industrial or irrigation purposes.

Off-site works

Infrastructure installed beyond the property boundary, such as water mains extensions or diversions.

On-site works

Water infrastructure is installed within the development site boundary.

Point of connection (POC)

The location on the existing network where a new service pipe or main will connect.

Potable water

Water that is safe and clean enough for human consumption.

Private supply

A water supply not provided by a regulated water company, often sourced from boreholes, wells, or springs.

Service pipe

A general term for the entire pipe run connecting a property to the water main. It includes both the communication pipe (owned by the water company) and the supply pipe (owned by the customer).

Service reservoir

A large storage tank that holds treated water before it’s distributed through the local network.

Site survey

An inspection carried out to determine where new water connections or meters can be safely installed.

Stop tap (internal)

A valve inside the property that allows you to turn off the water supply in an emergency or for maintenance.

Supply pipe

The section of pipe owned by the property owner, running from the external stop tap or boundary box into the building. (This is the customer-owned part of the service connection.)

Temporary builders’ supply

A short-term water connection installed to provide water during construction before the permanent connection is complete.

Two-part tariff

A type of water billing structure combining a standing charge (fixed cost) with a volumetric charge (based on water usage).

Wastewater

Used water that drains away from homes and businesses, sent to sewer systems for treatment.

Water main

A large public pipe that distributes water throughout a local area.

Water undertaker

A company (like United Utilities, Severn Trent, or Yorkshire Water) legally appointed to provide public water supply services in a given region.

Water regulator

The official body responsible for overseeing water services in England and Wales, known as Ofwat. (See OFWAT to learn more)

Water Regulations Advisory Scheme (WRAS)

An organisation that ensures plumbing products and fittings comply with the Water Supply (Water Fittings) Regulations, preventing contamination of the public water supply. (See the WRAS Approvals website to learn more.)

Water safety plan

A structured approach to identifying and managing risks to the safety and quality of a water supply.

Wholesaler

A water company that owns and operates the physical network and sells water services to retailers under market competition rules.

Wholesaler / retailer split

A regulatory model where the company owning the network (wholesaler) is separate from the company that bills and manages customer accounts (retailer).

WRAS approval

Certification that a plumbing product or fitting complies with water supply (fittings) regulations and is safe for use with drinking water. (See the WRAS Approvals to learn more.)