Affinity Water

Affinity Water Limited is the largest water only supply company in the United Kingdom, owning and managing the water assets and network in an area of approximately 4,515 square kilometers split over three supply regions in the South East of England.

The company provides 900 million litres of water each day to a population of more than 3.5 million people in parts of Bedfordshire, Berkshire, Buckinghamshire, Essex, Hertfordshire, Surrey, the London Boroughs of Harrow and Hillingdon and parts of the London Boroughs of Barnet, Brent, Ealing and Enfield. The company also supplies water to the Tendring peninsula in Essex and the Folkestone and Dover areas of Kent.

Above ground assets collect water from groundwater or river sources and deliver it to 96 treatment works where raw water is converted into high quality wholesome drinking water. Below ground network of assets takes water from treatment works and deliver it to homes and commercial premises through more than 16,600km of mains.

Sundon Water Treatment Facility (2024)

A novel water treatment plant constructed on the site of an upgraded reservoir to aid Affinity Water’s environmental sustainability commitments

Affinity Water Metaldehyde Removal Project (2020)

Affinity Water own and operate a crucial and long-standing water treatment works which is situated to support the north London water supply infrastructure. Any shortfall in the production of treated water leads directly to the need for importing water from a neighbouring water company. Four groundwater sources are combined and treated at site, all of […]

Hedges Farm River Restoration Project (2020)

The River Ver is a chalk river tributary of the River Colne in Hertfordshire. Chalk rivers are a globally rare habitat, with around 240 existing worldwide. There are approximately 160 chalk streams in England with 10% located within the supply area of Affinity Water. The Environment Agency placed targets (through the Water Industry National Environment Programme) […]

Woodhall Park River Restoration (2020)

The River Beane is a chalk stream that flows through the county of Hertfordshire and is 30.3km in length from its source at Roe Green. As a tributary of the River Lea, it rises to the south-west of Sandon, in the hills northeast of Stevenage, and joins the Lea at Hartham Common in Hertford. Chalk […]

Manor Road Park River Restoration Project (2019)

Affinity Water (AW) is the largest water-only supply company in the UK, providing on average 900 million litres of water each day to a population of more than 3.6 million people in parts of Bedfordshire, Berkshire, Buckinghamshire, Essex, Hertfordshire, Surrey, the London Boroughs of Harrow and Hillingdon and parts of the London Boroughs of Barnet, […]

Affinity Water Metaldehyde Removal Project (2018)

One of Affinity Water’s long-standing water treatment works (WTW) is to be upgraded following successful completion of industry leading research and development trials. By utilising a pioneering new technology, Affinity Water will be able to continue to deliver a high quality supply of water for customers and communities whilst continuing to operate a robust treatment […]

Uttlesford Bridge WTW (2018)

Originally built in 1965, Uttlesford Bridge Pumping Station near Saffron Walden consisted of two boreholes, a contact tank, booster pump suction tank and treatment by marginal chlorination. The licence at Uttlesford Bridge is a combined group licence with Springwell Farm of 13.64MLD. There are times during peak demand that up to 5MLD compensation flow is […]

Affinity Water Pesticide Removal (2017)

Affinity Water’s largest water treatment works (WTW) is being upgraded as part of their AMP6 business plan to ensure they continue to provide a robust treatment solution for the removal of pesticides from water abstracted from the River Thames. The scope of the works is to increase the granular activated carbon empty bed contact time […]

The PIONEER Optimiser (2017)

At the 2014 Price Review in England & Wales, the economic regulator Ofwat (2013) gave water companies a challenging set of objectives in preparing their business plans. These included a major shift towards outcomes-based regulation, with all business plan investment requirements being justified on the basis of outcomes for customers and the environment, and with […]

Mid River Colne & Lakes (2015)

Investigating the impacts of Affinity Water’s groundwater abstraction on the Mid River Colne and Lakes

Three Valleys Water - Sludge Treatment & Handling (2009)

A £2.2M Sludge Treatment System Upgrade

Chertsey WTW (2005)

First submerged membrane plant for Three Valleys Water

Iver WTW (2005)

Adding a third clarifier stream & 10Ml/d reservoir

Drellingore Pumping Station (2004)

New micro-filtration membrane system & plant upgrade

Chertsey WTW Microfiltration Plant (2003)

Two water sources brought together for final treatment

Egham WTW (2002)

Forward flow to waste & filter refurbishment

Lye Oak Pumping Station (2002)

Membrane filtration system for borehole sites