1953 - Construction of the Clay Lane

Construction of the water treatment plant at Clay Lane begins in 1953.
This new water treatment plant just outside London has the same capacity as eight previous smaller sites would have had.

It is the first stage in what, in 2001, will become the largest ultrafiltration plant in the world, supplying 750,000 inhabitants with high quality clean drinking water.

Ultrafiltration occurs at the end of the water treatment process. Micro-organisms, viruses and bacteria are eliminated as they pass through porous straws (the size of a pencil) each one containing 9,300 membranous fibers with pores 0.03 micron (the size of a pore in human skin) in size.