28 HISTORY OF COLCHESTER CORPORATION WATER WORKS
Analyses of Chalk-water are given in the Appendix to this
paper.
From personal observations, my impression is that the Chalk
discharges freely into the river Stour in the neighbourhood of
Sudbury. There might, however, be times when the river is
discharging into the chalk at periods of low rain-fall, and these
are matters which local geologists might set themselves to deter-
mine. No. 1 is an analysis of the chalk water by Dr. Foster,
M.A., F.C.S., from the new well, before it was reconstructed in
1889. No. 2 is an analysis of water from the same source in
1894, by Mr. W. Chattaway, Analyst to the Borough, after the
reconstruction of the well, and No. 2A from the same source by
Dr. Thresh, M.D., D.Sc, in 1898.
It should, however, be noted, when there is water to spare
from the Lexden springs, or when the engine which pumps that
water is not at work, it is run into the well in order to assist the
underground source; this may have some slight effect on the
chemical constituents of the pure chalk water when analyses are
taken in the future. No 3 is an analysis of the chalk water from
the Sudbury Corporation Water Works well, and No. 4 is an
analysis of chalk water from Halstead Urban District Council well
Comparing the analyses of the chalk water at Sudbury
and Halstead with Colchester, about twelve miles apart, it will
be observed that the water at Sudbury and Halstead is tpyical
hard chalk water with 21.5 and 18 degrees of hardness respectively
and only 3.18 and 4.2 grains of chlorine per gallon, whereas at
Colchester the chalk water is comparatively soft, and contains
about 10 degrees of hardness, but has from 21 to 22 grains of
chlorine per gallon; otherwise the chemical characteristics of the
Colchester water compares with the deep well water common to
this part of Essex, and which have been so exhaustively treated
and recorded in the Club's transactions by Dr. Thresh. The
chief characteristic of the Colchester well water is the chlorine
in the chalk, but, that has been practically constant to my know-
ledge for the last 23 years. As to the origin of the chlorine, I
believe no definite decision has been arrived at, but as we
approach the coast in certain directions it goes up by leaps and
bounds. To my mind the only rational conclusion one can come
to to account for it is the process of diffusion through ages of
time.