Lead

The use of lead in water pipes has been banned since the 1970s. Exposure to large amounts of lead can be harmful to health, especially for unborn babies and young children.

If you own an older property, you may be worried about lead levels. However, as the water in our region is hard, limescale is likely to build up within your pipes. This helps to prevent lead from dissolving into the water, helping to keep levels low.

We also add a small amount of phosphate to most of our water, which acts like limescale. This reduces lead levels even further. Phosphate at such levels is not harmful and is about 500 times lower than the phosphate levels in milk.

We’re replacing the lead pipes we own in areas where they’re most common. We remove the communication pipe, which usually runs from our water main to the property boundary. We then install a new plastic pipe.

The water pipe that joins our water main to your property is called your service pipe. This is split into two parts.

Pipework that’s our responsibility

We own the communication pipe that starts at our water main and usually runs to the outside stop valve at your property boundary. We’re responsible for fixing or replacing these pipes.

Pipework that’s your responsibility

As well as your internal pipework, you own the supply pipe that starts at your outside stop valve and ends at your inside stop valve. These pipes can either be separate (one pipe per property) or shared (two or more properties fed by a single supply pipe).

Many older properties are served by a shared supply pipe.

If you have a separate supply pipe, you're responsible for maintaining or, if needed, replacing it.

If you’re on a shared supply pipe, you and your neighbours are jointly responsible for maintaining or replacing it. You’ll be individually responsible for any branch of pipe that solely feeds your property.

To separate your clean water pipework from your neighbours’, you’ll need to apply for a new water connection. If you’d like your own supply pipe, get a quote for a new water connection now.

Inside your home: Check the pipe leading to the internal stop valve. This is often under the kitchen sink, behind the kitchen cupboards or sometimes in the cupboard under the stairs. Find out more on how to find and use your inside stop valve.

Outside your home: Open the flap of your outside stop valve and look at the pipe running towards your property. Find out more about how to find and use your outside stop valve.

• Check the colour: Unpainted lead pipes are a dull grey colour
• Look at the joints: Lead joints are rounded and swollen where two pipes meet
• Scratch the pipe gently: Scratches on lead pipes will reveal a shiny metal that's silver in colour
• Tap the lead pipe with a metal object: Lead makes a dull thud rather than the clear ringing produced by a copper or iron pipe

If you have lead pipes, we advise flushing out your pipes to reduce lead levels each day, especially in the mornings or if you’ve been away for a few days.

It’s easy to flush your pipes. Just leave your cold kitchen tap running for about two minutes before you drink or cook with the water. This will help to clear any standing water that’s been sat in your lead pipework for long periods of time. You can then use your cold kitchen tap as normal.

You can collect the water you flush and put it to good use, such as watering your plants or washing your car.

We test our water at every stage of the treatment process, including regular lead monitoring at randomly selected properties. If we ever find traces of lead above the standard in your home, we’ll inform you and your local authority’s environmental health department straight away. We’ll let you know what we plan to do and share advice on how you can reduce lead levels in your water.

If you’re replacing lead pipework you are responsible for, under our free replacement scheme we can also replace any lead pipework that belongs to us, providing the application is approved. We’re responsible for pipes running from the edge of your property boundary to our water main.

Under the lead pipe replacement scheme, a replacement pipe will be the same size as the existing pipe. If the existing pipe is smaller than the industry-standard 25mm diameter, it will be replaced with a 25mm diameter pipe. 

We can’t install a pipe with a larger than 25mm diameter under the free lead replacement scheme. For more information about having a larger pipe installed, including costs, please contact our Developer Services team.

Check if you can apply for the lead replacement scheme

You can apply for the lead replacement scheme if: 

• Your property has an existing water supply and you have a Thames Water clean water account. If you are unsure if we are your supplier, you can check on the Water UK website.

• You know that you have lead pipes, and have arranged for either an approved or independent plumber to replace your lead pipework in the next few months. Please make sure that: 

• The work is in line with the Water Supply (Water Fittings) Regulations. You can also read our guide on how to install a new water connection.     
  

• If you use an approved plumber listed on the WaterSafe website, you keep the certification of work they provide. 

• If you use an independent plumber, please leave the trench open and contact us before burying the pipework, as we’ll visit to inspect the work.

• You have established that you are either on a single or common supply. 
  • If you’re on a common supply, you need to consult with your shared neighbours. You can either have a joint replacement of your shared supply pipes, or you can arrange to lay a new supply pipe from your property to the point where the old supply joins our communication pipe (usually it is an outside stop valve located in the pavement). 
  • You’ll be responsible for disconnecting your old branch pipe, which may involve crossing your neighbour’s property. Make sure you have permission to do this before you start any work.

Apply for lead pipe replacement

What happens next? Our team will process your application. 

If you opted for an approved plumber to carry out your pipework replacement, we will ask you for the certificate covering the work from the approved plumber. 

If you have opted for an independent plumber, you will need to let us know when you are ready to conduct the reconnection survey. 

Once you have either provided the certificate, or the reconnection survey has passed the team will then let you know if your application has been successful. 

Please note, we will aim to complete our replacement work within 3 months from the date we approve your application. This timescale depends on the layout of your street, its traffic management requirements and local authorities permits to work.

If your house was built before 1966, make sure you’ve checked your earthing connection before you replace any pipes. In older properties, a lead pipe sometimes provides the main electrical earthing, which is an essential safety measure for your home’s electricity supply.

If you’re unsure, we recommend contacting your electricity supplier or a qualified electrician. They may recommend that you have your earthing checked, and they could charge for this service. In most cases, they’ll only need to take a quick look at your wiring.

To find a trusted local electrician, check out the Association of National Inspection Council for Electrical Installation or the National Professional Inspectors and Testers.