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 1957
[Report of the Medical Officer of Health for Lewisham Borough]
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30
Average results of the chemical and bacteriological examination of the water supply to the Borough of Lewisham for 1957
Darts Der million lunless 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 2VC) | Hardness (total) | Hardness (non-carbonate) | pH value | Conductivity |
|---|---|---|---|---|---|---|---|---|---|---|
| Bexley Well | 3 | 0.007 | 0.018 | 6.5 | 17 | 0.06 | 304 | 66 | 7.1 | 575 |
| Darenth Well | 4 | 0.001 | 0.020 | 4.6 | 16 | 0.06 | 255 | 22 | 7.2 | 500 |
| Darenth Bore Hole | 4 | 0.006 | 0.020 | 5.0 | 17 | 0.11 | 272 | 36 | 7.2 | 525 |
| Shortlands No. 1 | 3 | 0.005 | 0.026 | 4.3 | 17 | 0.03 | 275 | 54 | 7.2 | 525 |
| Shortlands No. 2 | 2 | 0.002 | 0.010 | 4.5 | 18 | 0.02 | 278 | 57 | 7.3 | 525 |
| Wilmington No. 1 | 4 | 0.002 | 0.025 | 6.2 | 22 | 0.14 | 278 | 44 | 7.2 | 525 |
| Wilmington No. 2 | 4 | 0.001 | 0.030 | 7.4 | 22 | 0.10 | 286 | 49 | 7.2 | 550 |
| Deptford Well | 3 | 0.005 | 0.021 | 6.1 | 32 | 0.14 | 358 | 121 | 7.3 | 725 |
| Thames-derived filtered water | 1882 | 0.027 | 0.074 | 3.9 | 29 | 1.16 | 260 | 56 | 7.9 | 550 |
(fa) BACTERIOLOGICAL Table 21
| No. of samples | BEFORE CHLORINATION (RAW WATER) | AFTER CHLORINATION (WATER PASSING INTO SUPPLY) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Plate counts (average per ml.) Colonies counted on aear | Coliform test | No. of samples | Plate counts (average per ml.) Colonies counted on agar | Coliform test | ||||||
| Percentage samples neg. 100 ml. | Percentage samples neg. 100 ml. | |||||||||
| 37° C. (20-24 hrs.) | 22° C. (3 days) | 37° C. (20-24 hrs.) | 22° C. (3 days) | |||||||
| Coliform | E. Coli | Coliform | £. Coli | |||||||
| Bexley Well | 321 | 0.2 | 4.3 | 99.10 | 100.0 | 252 | 0.02 | 4.3 | 100.0 | 100.0 |
| Darenth Well | 239 | 0.2 | 7.5 | 94.98 | 100.0 | 255 | 0.4 | 5.4 | 100.0 | 100.0 |
| Darenth Bore Hole | 209 | 1.6 | 14.8 | 95.69 | 99.04 | |||||
| Shortlands No. 1 | 161 | 0.04 | 4.9 | 100.0 | 100.0 | 256 | 0.2 | 3.6 | 100.0 | 100.0 |
| Shortlands No. 2 | 92 | 0.1 | 2.2 | 100.0 | 100.0 | |||||
| Wilmington No. 1 | 236 | 0.8 | 57.4 | 88.98 | 99.58 | 255 | 0.1 | 2.8 | 98.82 | 100.0 |
| Wilmington No. 2 | 225 | 0.1 | 14.5 | 88.80 | 99.56 | |||||
| Deptford Well | 244 | 0.1 | 217.0 | 99.59 | 100.0 | 248 | 0.1 | 4.6 | 98.39 | 100.0 |
| Thames derived filtered water | - | - | - | - | - | 3438 | 6.4 | - | 99.33 | 99.91 |