HKAES TechTalk – Metallurgical Issues in Water Supplies in Hong Kong
June 26 2024 (Wednesday) 4:00-5:00pm
Water supply in Hong Kong began more than 170 years ago in 1851. Initially, only fresh water was supplied but serious droughts in the 1950s-60s led to the development of one of the world’s first SWFT – “seawater for toilet flushing” systems, which continues today and covers around 85% of the Hong Kong population. This talk will focus on the metallurgical issues encountered in the supply of both fresh and sea water in Hong Kong. For fresh water, excess lead (Pb) was reported in a newly completed housing estate in 2015 and since then, measures have been taken to tighten the control of materials used in pipes and solder joints. Yet, potable-water grade copper-alloy materials allowable by international standards are still not entirely Pb-free, and this talk will report a scientific study on the metallurgical pathways for Pb-leading from such materials. For seawater supply, using the SWTF system for more than 60 years is met with increasingly frequent pipe bursts due to seawater-induced corrosion of the ferrous pipe materials. This talk will report an on-going study on a type of corrosion inhibitors which, if added to the seawater, can potentially lengthen the lifespan of the pipes. The research reported here is supported by the Research Impact Fund of the Hong Kong Research Grants Council and the Water Supplies Department of the HKSAR Government.