2
3.
About three quarters of all the sludge produced at
the five treatment plants arises at Sha Tin where it is
discharged into the upper Shing Mun River. Without
attempting to minimize the significance of the sludge
produced at Sha Tin, I would point out that it accounts for
about 10 to 15 per cent of the total pollution load,
measured in terms of oxygen demand, on the Shing Mun River.
This, together with the sludge from a plant at Tai Po,
represents about four per cent of the overall daily
pollution load on Tolo Harbour.
4.
The Government is actively planning alternative
starting with the plant
disposal schemes for these sludges
at Sha Tin. The main options which are being considered
are:
(a) direct discharge through the sewerage system to
(b)
sewage treatment plants, or
dewatering and thickening of the sludge prior to
disposal.
Within the second option, we would also need to consider
whether the treated sludge should be dumped at sea or in
controlled tips.
5.
Meanwhile, on a broader front, comprehensive plans
for the disposal of all sludges are being drawn up so that
sludge management can form an integral part of Hong Kong's
waste disposal strategy.