Supply pipe

Definition and what it excludes[edit]

The definition is short and its precision is easy to lose. It does not say the supply pipe starts at the boundary of the property, at the external stop tap, or at the water meter. It says the supply pipe is the part of the service pipe not vested in the undertaker.^[1] Vesting is the test; the boundary, the stop tap and the meter are commonly used as markers for where vesting changes, but none of them defines it.

This distinction matters when a leak is found near the boundary. The position of the external stop tap is a strong practical indicator and is what most parties will refer to, but where responsibility is disputed the question is what the undertaker owns, not where the tap happens to be.

Obligations on the owner[edit]

Because the supply pipe is not the undertaker's, the requirements of the Water Supply (Water Fittings) Regulations 1999 fall on the person installing or using the water fittings.^[2] Regulation 4 requires that water fittings are of an appropriate quality and standard and suitable for the circumstances in which they are used.^[2] Schedule 2 sets out detailed requirements including those for materials, backflow prevention and stopvalves.^[3]

Certain installation work must be notified to the water undertaker in advance under regulation 5, and the undertaker may consent with or without conditions.^[4] Regulation 3 sets out the circumstances in which the Regulations apply to a water fitting.^[5]

Leaks and detection[edit]

A leak on a supply pipe is one of the more common subjects of underground leak detection, because the pipe is buried, often long, and frequently runs beneath a driveway, garden or outbuilding. It is also the case that continuing water loss through a leak can engage section 75 of the Water Industry Act 1991, which deals with waste, misuse and contamination of water and gives undertakers powers where water is being wasted.^[6]

Many water undertakers operate discretionary schemes offering a free or subsidised first repair on a customer's supply pipe. These are policy rather than statutory duty and their terms differ between companies, so the existence of such a scheme in one area says nothing about another.

Materials[edit]

Supply pipes in the United Kingdom have historically been laid in lead, galvanised steel, copper and, since the later twentieth century, polyethylene. Modern replacement is generally in blue medium-density polyethylene to BS EN 12201,^[7] which is specified for water supply and for drainage and sewerage under pressure. Lead supply pipes remain in service in many older properties and are a drinking water quality concern separate from leakage.^[8]