To mark the World Water Monitoring Day 2009, 120 secondary school students from Pui Kiu College gathered at Tai Tam on 18 September and carried out tests on the quality of water sampled from Tai Tam Tuk Reservoir. This year, the educational event was held in conjunction with the ceremony for declaration of waterworks monuments in Hong Kong. The programme started with a clear demonstration by a chemist from Water Supplies Department regarding the test procedure. Students were then divided into small groups and each group was required to conduct three sampling tests by the use of a standard test kit. With the guidance of teachers and chemists, test results including temperature, acidity (pH), clarity (turbidity in JTU) and dissolved oxygen (DO in ppm) from each group were successfully taken and submitted. The test results showed that the surface water from Tai Tam Tuk Reservoir reached the temperature of 36 ℃ high. The average values of pH and dissolved oxygen level of water were 8 and 4 ppm respectively while the turbidity stayed at 0 JTU in general. It can be concluded from these results that the quality of water was free from serious pollution. Selected photos of the event are available in the Photo Gallery.