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 Lewisham Borough]
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Table 16
Average results of the chemical and bacteriological examination of the water supply to the Borough of Lewisham for 1964 milligrams per litre (unless otherwise stated)
Description of the Sample | No. of Samples | Ammoni acal Nitrogen | Albuminoid Nitrogen | Nitrate Nitrogen | Chlorides as C1. | Oxygen abs. from KMnO4 4 hrs. at27ºC. | Turbidity units | Colour (Burgess) scale | Hardness (total) | Hardness (non-carbonate) | pH value | Phosphate as PO4 | Silicate as SiO, | Sulphate so4 | Magnesium as Mg. | Natural Fluoride as F. | Surface active material as Man 0X0/ OT | Electrical Conductivity (micromhos) |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Bexley | 0.005 | 0.019 | 5.6 | 18 | 0.08 | Nil | Nil | 314 | 68 | 7.2 | 0.1 | 570 | ||||||
Darenth | 4 | 0.003 | 0.019 | 5.1 | 18 | 0.08 | 0.1 | Nil | 272 | 40 | 7.3 | 0.2 | 490 | |||||
Deptford | 4 | 0.007 | 0.026 | 6.0 | 37 | 0.14 | Nil | Nil | 362 | 118 | 7.2 | 0.2 | 680 | |||||
Wilmington | 6 | 0.010 | 0.031 | 8.3 | 24 | 0.12 | 0.3 | Nil | 288 | 50 | 7.2 | 0.15 | 550 | |||||
Merton Abbey | Not in supply during the year. | |||||||||||||||||
Thames-derived | 159 | 0.031 | 0.075 | 5.0 | 34 | 1.06 | 0.1 | 11 | 264 | 64 | 7.6 | 1.4 | 9 | 60 | 5 | 0.25 | 0.09 | 550 |
South of River |
Table 17
Bacteriological Results—Yearly Averages, 1964 of water supplied to the Borough of Lewisham
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 22º C | Per cent, samples negative in 100 ml. | Per cent. samples negative in 100 ml. | |||
Bexley | 253 | 0.1 | 12 | 100.0 | 100.0 | — | 257 | 0.3 | 2 | 99.61 | 100.0 | |
Darenth | 251 | 0.2 | 6 | 98.80 | — | 98.80 | - | 248 | 0.1 | 4 | 100.0 | 100.0 |
Deptford | 254 | 0.2 | 7 | 99.21 | - | 99.61 | - | 257 | 3.0 | 61 | 99.61 | 100.0 |
Wilmington No. 1 | 61 | 0.1 | 114 | 100.0 | - | 100.0 | — | 189 | 0.1 | 16 | 100.0 | 100.0 |
Wilmington No. 2 | 127 | 0.2 | 141 | 97.64 | 0.1 | 99.21 | - | |||||
Thames-derived South of River | 1 ,883 | 10.6 | 99.95 | 100.0 |