The water coming from the WTP for distribution to the consumers is safe for drinking and it meets the existing sanitary regulations. The water of Athens is of the best quality. It is one of the best in Europe given that in Europe bottled water is used quite often.

Potable water is the water, which is free from certain physical, chemical, biological and microbiological parameters and can be consumed without any risk to the human health.
Potable water must be colorless, odorless, fresh and with a pleasant taste. It shouldn’t have a lot of hardness because of the problems caused by its daily and industrial use. It must not contain large quantities of organic substances, pathogens or bacteria, nor heavy metals or other substances hazardous to man. Its temperature must be stable at 10o - 15o C. In the course of the quality control, water is basically analyzed for the following parameters:

•  Odor - taste
•  Color
•  Turbidity 
• Temperature
•  Alkalinity - Acidity - Ph
•  Bacteria 
•  Hardness

Some times analyses of many chemical substances like chloro-compounds and sulphur compounds are also carried out.

CHEMICAL LABORATORIES

Every WTP has its own chemical laboratory equipped with the most modern analytical instruments and equipment. In these labs water samples taken from every part of the Water Supply System are analyzed. Every year, over 20,000 laboratory tests and approximately 180,000 parameter determinations are performed to ensure that international standards on water quality are upheld. The newest and most modern laboratory is the chemical and biological laboratory of Polydendri. This lab is a real jewel for EYDAP S.A. The main purpose of the Polydendri lab is the analysis of metals in water samples. The lab has an ultra-modern system for analyzing metals and it can detect 30 different metals in one water sample.
At the Biological Laboratory of Polydendri, water samples from the raw water reservoirs are analyzed to make sure that the reservoirs meet the E.U. guidelines concerning the biological and immunological parameters. The main biological parameter investigated at the biological laboratory is the reservoir’s phytoplankton that shows the general condition to the lakes and their stage of eutrofication.