Water quality

Why we test your water

Most of the drinking water in your taps comes from surface water sources, such as reservoirs and rivers. Some of the water comes from underground pools or groundwater sources. These water sources contain naturally occurring substances.

Before it reaches you, your water is treated to remove any harmful substances or make them safe, including bacteria.

Drinking water quality in the UK is governed by strict laws set by the Government.

We regularly take samples of cold kitchen tap water to make sure your water is safe and drinkable.

Water sampling

What to expect from a water quality test

We’re required by our regulator to visit a certain number of properties each year to carry out samples.

We must carry out these visits at random and we can’t let you know in advance if your home has been selected. You don’t have to let us into your home if you’re comfortable.

The inspector will fill bottles from the kitchen tap, while also carrying testing for temperature, chlorine, appearance, deposits, taste and smell. They will need to flush the tap for a couple of minutes after filling the first bottle to ensure accurate results. The whole visit usually takes less than 15 minutes.

We won’t be in touch with you after our visit, unless we need to do more tests.

A woman washes her hands at the kitchen tap

Water sampling

How we test your water

We use an independent laboratory called ALS Global to test our water samples and the results are compared to the legal quality standards.

What we test your water for

We check the levels of more than 50 substances using the following measures:

  • mg/l = milligrams per litre or parts per million
  • µg/l = micrograms per litre or parts per billion
  • Bq/l = becquerel per litre unit of radioactivity (equal to one disintegration or nuclear transformation per second).