Monitoring the quality of your water supply

Posted: 28 May 2024


Over the last couple of weeks, there has been increased media coverage about drinking water quality following an outbreak of a parasite in Devon which has affected South West Water residents.

Firstly, we can confirm the water being provided to Cambridge Water customers is completely safe to drink and there is no requirement to boil your water.

We’re committed to delivering high-quality drinking water to our customers and take multiple water samples to ensure the quality of your water is not compromised.

To help answer some further questions we have received about water quality, our Head of Water Quality, Kara Sadler, outlines how we look after the water you drink.

How much water we treat

On an average day, we supply 83 million litres of water to over 138,000 homes and 8,000 business customers. Our treatment processes ensure that our water is clean and tastes nice to drink.

How your water is treated

Before we can supply your water, we must meet strict drinking water standards. To do this, all of our water goes through a treatment process.

First, we pass water through huge sieves, removing large debris such as leaves, twigs and rubbish.

Smaller particles such as dirt and bacteria are then removed by adding carefully controlled quantities of chemicals to the water. This causes the particles to stick together, forming a dense layer that sinks to the bottom. This settles as sludge and is removed.

The clear water then flows through layers of gravel and carbon, filtering the water. The carbon also removes traces of organic material such as pesticides.

Finally, to make the water safe to drink, it is disinfected with chlorine. This removes any remaining germs or bacteria and ensures the water remains safe as it travels through our network of pipes and out of your tap.

Every year we take nearly 16,000 samples from across our raw water sources, treatment works, storage assets and at customers taps. These samples are tested against a number of parameters as set out by our drinking water regulator, the Drinking Water Inspectorate. These include microbiological parameters to ensure that the water is safe for you to drink.

If any samples fail those tests, we immediately contact our customers and give advice to protect their health, and they are kept updated until our samples show that water is once again safe to drink.

Monitoring the quality of water in Cambridge

How do we combat microparasites like Cryptosporidium?

The outbreak of Cryptosporidium, which has taken place in Brixham, Devon recently, poses a challenge to water treatment because of its small size and resistance to chlorine.

Most investigations of outbreaks show that they happen only when some aspect of water treatment is inadequate, or on rare occasions where contamination enters the distribution network.

Cryptosporidium is particularly prevalent in surface water and we can confirm that our treatment works and treatment process provides a very high level of protection against exposure to the parasite.

Our surface water works also have ultraviolet (UV) disinfection in place, which inactivates Cryptosporidium oocysts at the UV dose applied. We also have a risk-based monitoring programme in place for Cryptosporidium.

Furthermore, as part of our regulatory requirement, our risk assessments are kept under continual review.

To find out more about your water supply, click here.

For advice and further information on water quality, click here.