Drinking water

The UK water industry treats just under 16 billion litres per day and supplies it directly to almost every household across the country. This water is treated to some of the strictest levels in the world and passes over 99.97% of tests. 

The UK’s drinking water is sourced from many locations including rivers, groundwater aquifers, reservoirs, and in some unique places, directly from the sea. Cleaning water from each of these "raw water sources" poses different challenges, often including removing contamination from the atmosphere, industry or agriculture. Overseen by the independent Drinking Water Inspectorate (DWI), the water industry is constantly investing and adapting its processes to ensure that standards remain exceptionally high. Yale University ranks the UK in joint first position for its measures to provide safe drinking water and sanitation.

At each treatment works in the country water is treated to a very high standard. We ensure that:

• water looks and tastes as best as it can. This includes controlling its temperature, Ph levels, clarity, and colour.  
• water is treated for chemicals such as pesticides and other synthetic chemicals (such as PFAS), phosphorous, nitrates, medicines and organic chemicals. We achieve this through multiple stages of treatment including filtration, activated carbon treatment, ion exchange, reverse osmosis, and membrane filtration.  
• all kinds of bacteria, viruses, and other pathogens which pose a threat to human health are removed or destroyed. To eliminate this risk and provide wholesome water to customers, treatment plants make use of several processes including, screening, pre-treatment oxidation, clarification, filtration, UV disinfection and a final chlorination stage to perform disinfection and establish a chlorine residual ensuring the water will be safe to drink all the way to the tap.

Clean water is delivered to customers through expansive network of pipes, underground storage tanks, and water towers. The storage tanks and towers act like rechargeable batteries of clean water that allows us to treat water overnight, ready for when the UK wakes up and takes a shower each morning.

Supplying the water the country needs is a complex and important job. The industry constantly monitors its performance through an intensive sampling program including over 3.6 million samples a year. This sampling helps us assess any emerging risks and design our responses such as; changing treatment processes, installing new state of the art treatment equipment, or even bringing water from alternative sources.  

Climate change means we will need to continue to respond to rising temperatures, increasing amounts of toxic algae in surface water sources, and more intense rainfall that washes more contaminants into rivers. Future industry plans set out the new treatment processes, water storage, and water resources investments needed to maintain high quality drinking water for decades to come.

The safety of supplied drinking water has always been a top priority of each and every water company, and each is incredibly proud that the water they provide is some of the highest quality in the world.