Question No. 3
REPLY BY THE SECRETARY FOR HEALTH AND WELFARE TO A QUESTION BY THE HON. ANDREW SO, OBE, JP, IN THE LEGISLATIVE COUNCIL ON WEDNESDAY, 7 AUGUST 1985
Question: Will the Government inform this Council about the
extent to which sludge discharged from water treatment plants is causing pollution to the major streams in the New Territories, particularly the Shing Mun River, and what measures are being taken to tackle the problem?
Sir,
The Government operates 15 water treatment
plants. The process at five of them leaves a sludge which
is subsequently discharged to rivers or streams and carried
away to the sea.
2.
The sludge
-
known properly as alum sludge
contains a high level of suspended solids as well as
elements, such as aluminium, which are potentially toxic.
As regards the latter, I must emphasize that water quality
monitoring has not indicated concentration levels reaching
anywhere near those which would represent a direct or
indirect threat to people. These sludges also contribute to
a reduction in the amount of oxygen in rivers and the marine
receiving waters.
/3.