The integrated water cycle

Water quality

The laboratories ensure that the water quality is suitable for its proposed subsequent use.

In order to guarantee the quality of our drinking water, we adhere to a strict drinking water surveillance programme, from the source of the supply up to its delivery to the consumer. We also control the quality of purified waste water in the same way.

The programme is designed to monitor the quality of water intended for human consumption, before and after the treatment process and during its distribution to users. We have a permanent system of alerts, through a network of automatic surveillance stations (ASSs). This type of installation is also used to control the purified water that passes the strictest quality controls from entering a WWTP until it is returned to a river.

Read a PDF about water quality

Relevant data

More than 6,000,000drinking water analyses a year

More than 600,000reclaimed water analyses a year

21water quality laboratories

40drinking water ASSs

15reclaimed water ASSs

Did you know …?


Each year we carry out more than 6 million analyses in order to guarantee the quality of the drinking water that arrives at your tap and those of all our customers.

The first water filter for domestic use was patented in 1746; it was designed by French scientist Joseph Amy.

At Canal we analyse a water sample every 5 seconds.

The main waste water laboratory is in Majadahonda and it was inaugurated in 2010.