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 London, City of ]
This page requires JavaScript
METROPOLITAN WATER BOARD — Water Examination Department BACTERIOLOGICAL RESULTS - YEARLY AVERAGES, 1963 CITY OF LONDON
Source of Supply | BEFORE TREATMENT | AFTER TREATMENT | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Number of samples | Agar plate count per ml. | Coliform count | Escherichia coli count | Number of samples | Agar plate count per ml. | Coliform count | E. coli count | |||||
20-24 hours at 37°C. | 3 days at 22*C. | Per cent, samples negative in 100 ml. | Count per 100 ml. | Per cent. samples negative in 100 ml. | Count per 100 ml. | 20-24 hours at 37 °C. | 3 days at 22°C. | Per cent, samples negative in 100 ml. | Per cent. samples negative in 100 ml. | |||
Stoke Newington | 256 | 5.0 | 100.0 | 100.0 | ||||||||
Thames-derived, south of river | 1,873 | 12.5 | 99.41 | 99.47 |
AVERAGE RESULTS OF THE CHEMICAL EXAMINATION OF WATER SUPPLIED TO THE CITY OF LONDON FOR 1963. (MILLIGRAMMES PER LITRE (unless otherwise stated)
Stoke Newington | Thames-derived South of river | Stoke Newington | Thames-derived South of river | |||
---|---|---|---|---|---|---|
No. of Samples | 52 | 156 | Phosphate as P04 | 1.0 | 1 | |
Ammoniacal Nitrogen | 0.092 | 0.20 | Silicate as Si02 | 11 | 11 | |
Albuminoid Nitrogen | 0.061 | 0.079 | Sulphate as SO4 | 58 | 62 | |
Nitrate Nitrogen | 5.2 | 3.8 | Magnesium as Mg. | Natural | 5 | 5 |
Chlorides as C1. | 37 | 32 | Fluoride as F. | 0.25 | 0.25 | |
Oxygen abs. from KMn04 4 hrs. at 27°C. | 0.61 | 1.18 | Surface-active material as Manoxol OT | 0.07 | 0.08 | |
Turbidity units | 0.1 | 0.3 | Sodium as Na | 29 | 25 | |
Colour (Burgess) scale | 6 | 10 | Potassium as K | 4.9 | 5.2 | |
Hardness (total) | 306 | 266 | Electrical Conductivity (micromhos) | 620 | 550 | |
Hardness (non-carbonate) | 68 | 66 | ||||
pH value | 7.9 | 7.8 |