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47
the lock it is a foul stream with a fermenting bed. The river is much used for pleasure purposes, and the
state of affairs is much to be deplored. The litigation on the matter between the Lee Conservancy and
the Enfield District Council has resulted in the latter body being admonished by the County Court Judge
to do all they can to push forward improvements at their works; but it does not appear that a permanent
improvement in the effluent may be expected for three or four years.
The condition of the River Wandle has also called for some attention.
At the Outfall Laboratories in addition to the systematic daily examination of sewage treated
thereat and the resulting effluent and sludge, the river water lying off each outfall is examined daily at
high and at low water. The examination of the tideway of the Thames and of the estuary, as far as
the sludge-depositing area, has been continued. The opportunity afforded by the return to more
normal staff conditions at the Central Laboratory and offices has allowed of a more complete
examination of the results obtained in past years than was possible during the war, and, on the basis
of this statistical work and of special experiments, it has been possible to suggest a means of temporary
relief by carrying out an examination on a reduced scale which will afford useful results of a fair order
of accuracy. It does not appear that any other public body makes a systematic examination of the
tidal river, the condition of which, apart from this work, is a matter of surmise only.
The Main Drainage Committee, as a result of their visit to various provincial cities have decided
to experiment on various modifications of biological treatment of sewage. Some work on one of these
modifications has been going on for some time and the requisite structural work for the other experimental
plant is being proceeded with.
An investigation has been made on the gases dissolved in the feedwater. Examinations have
been made of the gaseous contents cf the water throughout the whole circulating system from hotwell,
through the economisers, boilers, turbine condenser and again to the hotwell. The presence of dissolved
oxygen in the water or of free oxygen in the steam is a potent cause of corrosion both of the steam
raising plant and of the blades of the turbine itself. This has led to proposals for degassing the water,
and experiments with a small plant designed by the electrical engineer are now in progress. The efficiency
of the water softening plant has been greatly increased as shown by systematic tests, which enable
the supply of chemicals to be controlled.
The routine examination of waters, etc., has been extended to include samples of the coal burnt
each day at the station, deliveries supplied to the station still being examined at the Central Laboratory.
Other necessary investigations are being made.
River Wandle
Outfalls
Biological
treatment of
sewage
Greenwich
power Etation