Last week, third year students in the department of environmental sciences took part in a study tour as part of their course on the subject of treatment processes of drinking water. The topic of the tour was the water supply to ancient Jerusalem in comparison to the modern water supply today in Israel. Some of the treatment processes of modern day drinking water actually go back thousands of years. The Jerusalem water supply has always been a challenge to the water engineers due to its height above water level and the few streams in the area. Up and until today the security of the ongoing water supply to Jerusalem and in times of crisis, keep the Israeli water authorities busy.

The tour starts in the morning at the Gihon Company that supplies water to about a million residents in Jerusalem and the surrounding areas including settlements like Abu Gosh and Mevasseret Zion. Mr Adiel Gecht, the Microbiologist in charge of the laboratories of the Gihon Company guides the tour. He is also alumni of the department of environmental health from the Hadassah College. The students were shown the drinking water supply lines to Jerusalem by the Mekorot Water Company and mainly the drinking water reservoirs, including the largest water treatment reservoir in the middle east, and received explanations about the monitoring of the drinking water systems in the city and the maintenance of the drinking water reservoirs as well.

The water supply in Jerusalem during the ancient times was described in detail, including a discussion on the different ways water was brought to Jerusalem in those times, and during the period of the pilgrimage to Jerusalem in the Hasmonean times, when Herod ruled. The way the Ottoman rulership used the ancient water systems was also demonstrated on the tour.