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from the material of water piping particularly when it is newly installed; this
applies to copper, zinc, iron and also to lead."
3 a) During the year, 38 samples of swimming bath water were taken from the
six public pools in the Borough and were submitted for bacteriological examination
to the Public Health Laboratory Service. The recommended standard
is that 75% of samples should have a colony count of less than 10 per ml.,
the remainder less than 100. 31 samples were satisfactory and 7 were below
the recommended standard. Repeat samples produced satisfactory results.
(See page 66 — Swimming Pools).
b) Fifteen samples of swimming bath water were taken from school or privately
owned pools. Five were below the recommended standard but repeat samples
proved bacteriologically satisfactory.
c) Six samples of mains water thought to be causing illness or to be abnormal in
taste were submitted for bacteriological examination. One was below the
recommended standard but a repeat sample proved satisfactory.
SEWERAGE & SEWAGE DISPOSAL
I am indebted to (a) Mr. M. S. Hebron, B.Sc., C.Eng., M.I.C.E., A.M.I.Mun.E.,
Borough Engineer and Surveyor, and (b) Mr. A. J. Berry, B.Sc., M.I.W.P.C., M.I.Biol.,
Regional Engineer, Greater London Council for the following reports: —
“(a) Sewerage
The replacement of compressed air ejectors by electric pumps has been completed
at Sandy Lane and Lower Teddington Road, Hampton Wick and similar work is commencing
shortly at two further pumping stations in Hampton Court Road, Hampton
Wick. Design is in hand for the conversion of two pumping stations in Hampton Court
Road, Hampton.
Work will be starting shortly on the provision of relief sewers for both the foul and
surface water sewers in Hampton Road, Twickenham.
The sewer survey for the Richmond area will be completed in the summer of 1972
and a start made on the Barnes area of the Borough".
"(b) Sewage Disposal
Sewage for the Borough is treated at two Treatment Works of the Greater London
Council.
Kew Sewage Treatment Works receives sewage from the 11 square miles south of
the Thames, (with the exception of parts of Ham). The Works treat an average daily
flow of million gallons before discharging to the River Thames, between Kew and
Chiswick bridges.
Work commenced in 1970 on improvements to the aeration plant, in order that
treatment standards keep pace with the increasing load on the Works. These improvements
are nearing completion and will be commissioned in 1972.
Sewage from the remainder of the Borough flows to the Mogden Sewage Treatment
Works, which deals with some 99 million gallons per day from the whole of the former
West Middlesex area. The effluent is discharged into the River Thames at Isleworth.
An automatic pumping station at Ham commissioned in June, 1970, conveys sewage
to Mogden, and replaces the former station which pumped to Kew.
The standard of effluent as required by the Port of London Authority was maintained
throughout the year. In spite of the marginal increase in flow to the Mogden Works, the
average effective oxygen load imposed on the river by the effluent (including storm water)
was further reduced to 15.3 tonnes (metric tons) per day from 22 tonnes per day in 1970.
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