London's Pulse: Medical Officer of Health reports 1848-1972
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Hints from the Health Department. Leaflet from the archive of the Society of Medical Officers of Health. Credit: Wellcome Collection, London
Twickenham 1957
[Report of the Medical Officer of Health for Twickenham]
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35
AVERAGE RESULTS OF THE CHEMICAL AND BACTERIOLOGICAL EXAMINATION OF THE WATER SUPPLY TO THE BOROUGH OF TWICKENHAM
FOR 1957
Milligrammes per litre (unless otherwise stated)
(a) Chemical
| Description of the Sample | Number of Samples | Ammoniacal Nitrogen | Albuminoid Nitrogen | Oxidised Nitrogen (Nitrate ) | Chlorides as C1 | Oxygen abs. from Permanganate 4 hrs. at 27°C. | Turbidity in terms of Silica | Colour, mm. brown 2 ft. tube Burgess's Tintometer | Hardness (total) | Hardness (Non carb.) | pH. Value | Phosphate as P.O 4 111 | Silica as SiO2 | Sulphate as SO4 | Electrical Conductivity (gemmhos.) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Hampton | 236 | 0.020 | 0. 076 | 3.9 | 29 | 1.20 | 0.4 | 12 | 260 | 58 | 7.9 | 0.95 | 10 | 58 | 550 |
Table 7
(b) Bacteriological, after chlorination (water passing into supply)
| Description of the Sample | Number of Samples | Plate count (average per millilitre) Colonies counted on agar. | Coliform Test Percentage Samples Negative in 100 ml. | ||
|---|---|---|---|---|---|
| 3° C. 20-24 hrs. | 22°C. 3 days | ||||
| Coliform | E.Coli | ||||
| Hampton | 801 | 3.7 | 99.50 | 99. 75 | |