Authorisation numbers for self-lay providers

Find out when and how we provide authorisation for Self-Lay Providers (SLPs) working on our existing assets.

What is an authorisation number and why is it required?

Any self-lay provider carrying out connection work on existing water mains requires an authorisation number.

Under the Health and Safety at Work Act 1974, we’re legally required to make sure there are adequate systems of planning, organising and controlling work, and that all risks are identified and controlled.

We issue an authorisation number for each job planned by a WIRS-accredited Self-Lay Provider (SLP). This is part of our ‘permit to work’ system, which authorises certain people to carry out specific work within a specified time frame. It sets out the precautions required to complete the work safely, based on a risk assessment. It describes what work will be done and how it will be done, in the form of a ‘method statement'.

Your authorisation number also legitimises the work you’re carrying out if you’re challenged – for example, by a highway authority or maybe even a Thames Water employee who may not recognise your company as working with us.

Are there occasions when we won't provide an authorisation number?

As noted in the Code of Practice, we won’t allow you to carry out construction when we assess that it significantly heightens either the risk of damage being caused to our existing assets or risks interrupting supplies to existing customers in the event of an unplanned incident.

You can find more detail on this in the document below.

We’ll need you to follow the requirements of this document as if they formed part of the Code of Practice.

What information is required from an SLP prior to an authorisation request?

We’ll require a construction schedule, as well as a site risk assessment. You’ll also need to provide a site-specific method statement, which your operational team must follow when carrying out the work.

What if an SLP is working on a trunk main?

If you’re working within three meters of a trunk main, we’ll need to provide you with a ‘contingency pack’. This includes details of how we’ll isolate the main and lessen the impact on customers if something goes wrong – for example, if the main bursts.

We define trunk mains as those with a diameter of at least 300mm (12 inches) in London or 229mm (nine inches) outside the capital.

How long does it take to receive authorisation?

Approval should take no more than 14 calendar days from the date of submission. However, it will take longer in cases where we need to provide a contingency pack, as we’ll need to understand the impact of an unexpected problem occurring.

For how long is the authorisation valid?

They will typically be valid for two months, with the dates depending on the type of activity. The authorisation period can generally be extended by request.

What should an SLP do when they start work, and during their construction work?

On the day you start work, you must call our Network Management Control Centre to seek permission before breaking ground. In rare cases – for example, if a local main has burst – we may ask you not to start.

You’ll also need to call to advise them when the day’s shift has finished.

For each subsequent day of your construction schedule, you must call in at the start and end of each shift. The number to call is 0800 009 3909.

What should the SLP do when work is completed?

As above, you must call our Network Management Control Centre, and again when the whole job is completed – i.e. the hole has been backfilled and reinstated.