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
Lewisham 1956
[Report of the Medical Officer of Health for Lewisham Borough]
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Average results of the chemical and bacteriological examination of the water supply to the Borough of Lewisham for 1956
parts per million (unless otherwise stated)
| Description of the sample | No. of samples | Ammoniacal nitrogen | Albuminoid nitrogen | Oxidised nitrogen (nitrate) | Chlorides as CI. | Oxygen abs. from permanganate (4 hrs. at 27°C) | Hardness (total) | Hardness (non. carbonate) | PH value | Sulphates as SO, | Conductivity |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Bexley Well | 5 | 0.006 | 0.022 | 5.6 | 17 | 0.06 | 282 | 54 | 475 | ||
| Darenth Well | 3 | 0 005 | 0.027 | 5.0 | 16 | 0.06 | 262 | 38 | 7.1 | 14 | 425 |
| Darenth Bore Hole | 3 | 0.007 | 0.030 | 5.5 | 16 | 0.12 | 280 | 54 | 7.2 | 22 | 450 |
| Shortlands No. 1 | 4 | 0.001 | 0.024 | 4.8 | 16 | 0.08 | 282 | 74 | 7.2 | 40 | 475 |
| Shortlands No. 2 | 4 | 0.005 | 0.025 | 5.1 | 16 | 0.06 | 282 | 72 | 7.2 | 40 | 500 |
| Wilmington No. 1 | 4 | 0.012 | 0.027 | 6.6 | 22 | 0.18 | 284 | 56 | 7.1 | 22 | 400 |
| Wilmington No. 2 | 4 | 0.004 | 0.026 | 8.4 | 21 | 0.18 | 292 | 62 | 7.2 | 22 | 425 |
| Deptford Well | 3 | 0.003 | 0.025 | 7.3 | 34 | 0.12 | 362 | 134 | 7.1 | 100 | 600 |
| River Thames . derived filtered water | 1598 | 0.036 | 0.086 | 4.3 | 30 | 1.16 | 258 | 72 | 7.7 | 58 | 500 |
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(b) BACTERIOLOGICAL Table 19
| BEFORE CHLORINATION | AFTER CHLORINATION (WATER PASSING INTO SUPPLY) | |||||||
|---|---|---|---|---|---|---|---|---|
| No. of samples | Plate count (average per ml.) Colonies counted on agar 37°C. (20.24 hrs.) | Bact. coli test | No. of samples | Plate count (average per ml.) Colonies counted on agar 37°C. (20.24 hrs.) | Bact. coli test | |||
| Percentage samples neg. 100 ml. | Average number per 100 ml. | Percentage samples neg. 100 ml. | Average number per 100 ml. | |||||
| Bexley Well | 467 | 0.2 | 100.0 | . | 257 | - | 100.0 | - |
| Darenth Wells | 421 | 0.02 | 99.5 | 0.01 | 255 | - | 100.0 | - |
| Shortlands Wells | 499 | 0.01 | 1000 | - | 255 | - | 100.0 | - |
| Wilmington Wells | 366 | 0.3 | 96.5 | 0.09 | 244 | - | 100.0 | - |
| Deptford Well | 199 | 0.1 | 99.5 | 0.03 | 201 | - | 100.0 | .. |
| River Thames . derived filtered water | 7066 | — | 61.2 | 4.43 | 3736 | 5.0 | 99.9 | 0.002 |