Hints from the Health Department. Leaflet from the archive of the Society of Medical Officers of Health. Credit: Wellcome Collection, London
[Report of the Medical Officer of Health for Coulsdon]
This page requires JavaScript
The results of two chemical and two bacteriological examinations
of the water in public supply are given below and these are
fairly typical of the reports received:—
Chemical Analysis.
Sutton District Water Company. | East Surrey Water Company. | |||
---|---|---|---|---|
Parts per Million. | Grains per Gallon. | Parts per Million. | Grains per Gallon. | |
Total solid matter (dried at 180°C.) | 175.0 | 125.0 | - | |
Chlorine present as chloride | 14.5 | 16.0 | - | |
Ammonia, free | 0.00 | 0.03 | - | |
Ammonia, albuminoid | 0.002 | 0.002 | - | |
Nitrate nitrogen | 5.3 | - | 5.3 | - |
Nitrite nitrogen | trace | - | 0.04 | - |
Oxygen absorbed from permanganate solution in 4 hours at 27°C. | 0.09 | _ | 0.06 | _ |
Hardness —Temporary | 93.0 | - | 31.0 | - |
Permanent | 32.0 | - | 40.0 | - |
Total | 125.0 | 8.75 | 71.0 | 5.0 |
Iron and other metals | absent | - | absent | |
Residual chlorine at time of receipt | 0.03 | 0.21 | ||
pH | 7.4 | 8.4 | ||
Electric conductivity at 20 °C. | 255 units | 165 units |
Bacteriological Examination.
Probable number of coliform bacilli,
MacConkey 2 days, 37°C. 0 per 100 ml. 0 per 100 ml
There are no private wells in use in the District; all houses
are provided with a mains supply laid into the house, and there
are no standpipes for common use.
Forty-six samples were taken from the supplies of the two
Companies and examined for hardness by the Department, all of
which were satisfactory in that adequate softening had been carried
out.
RAINFALL.
The rainfall registered by the automatic rain gauge installed
at Alderstead Heath was 29.54 inches, this being an increase of
3.05 inches compared with the previous year. The monthly totals
throughout the year were as follows:—
inches.
January 1.43
February 2.42
March 2.08
April 0.38
May 2.70
June 3.33
July 2.68
August 3.14
September 2.20
October 2.04
November 5.12
December 2.02
36