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the impervious strata, yielding many thousands of gallons of clear, sparkling and bacteriologically
pure water. Each of these wells is operated by the respective owners or occupiers of the premises
in which they are housed and they provide an adequate supply of water for all purposes.
When the 1945 - 1948 Water Acts came into force, a restriction was imposed on new borings
as the water table was known to be falling, and since that time no new bore holes have been
allowed in this area. Disused wells are sometimes brought into operation and improved by means
of acidisation. This process enlarges the interstices in the chalk strata and allows the subterranean
water freer access and is accompanied by some nuisance to the surrounding users.
This was realised when a large City building contractor carried out the operation earlier in the
year and a complaint was received from an adjoining premises about the colour and taste of the
water,.
Mr. Welldon and Mr. Camsey are the responsible inspectors for the regular sampling of these
supplies and this is carried out by arrangement with the Ministry of Health's Bacteriological
Laboratories at Colindale.. The samples are forwarded to the laboratories within a matter of
hours in insulated containers and results are known within 4 to 5 days.
During the year, 118 samples were taken, the water in each case was satisfactory. These
samples were subject to a coliform examination and only two showed a verv minor plate count.
This was not Bact. coli type 1 (Escherichia coli). As the later supplies were adequately
chlorinated no further action was taken. The temperature of this water is remarkably constant
averaging 57°F summer and winter.
Of the total number some 121 are treated at source, thus providing an additional safeguard.
Most supplies are chlorinated but some have adopted the ultra-violet method of sterilisation.
Most wells are supplied with an electric submersible pump which is lowered into the bore and
operated at a depth of about 400 ft.
There are several sources of contamination which makes constant sampling necessary. These
fall roughly into three classes
1. Improvement works to artesian supply.
2. Flooding of surface water into bore hole.
3. Improperly sealed off disused wells.
The Metropolitan Water Board has supplied the following information:-
"The water supplied to the City during 1964 was generally satisfactory both as to quality
and quantity. The supply is derived from two sources in varying and unpredictable proportions
viz:-, River Thames derived water from the Thames Valley filtrations stations above Teddington,
and New River derived water from the Board's works at Stoke Newington.
During the year 948 yards of service mains were laid but no trunk main. All new and repaired
mains are chlorinated before being brought into use or restored to service, and samples of water
from them are tested bacteriologically to ensure that the quality is satisfactory.
The Board's waters are not plumbo-solvent.. Samples are collected daily at each stage of
purification and in the distribution system. Immediate action is taken in respect of any form of
contamination or variation in quality."
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