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 Westminster, City of]
This page requires JavaScript
Table 19.—Chemical Examination of Water Supplied to City of Westminster—Average Results Milligrammes per Litre (unless otherwise stated)
Analysis data | Source f Supply | |
---|---|---|
Stoke Newington | All Thames derived | |
Ammoniacal Nitrogen | 0.017 | 0.024 |
Albuminoid Nitrogen | 0.063 | 0.089 |
Nitrate | 5.2 | 4.1 |
Chlorides as CI. | 35 | 30 |
Oxygen abs. from Permanganate 4 hrs. at 27°C | 0.56 | 1.12 |
Turbidity units | 0.0 | 0.1 |
Colour (Burgess units) | 5 | 12 |
Hardness (total) | 312 | 282 |
Hardness (non-carbonate) | 77 | 73 |
p.H. Value | 7.9 | 7.9 |
Phosphate as P04 | 1.4 | 1.9 |
Silicate as Si02 | 10 | 10 |
Sulphate as S04 | 64 | 64 |
Natural Fluoride as F | 0.30 | 0.30 |
Magnesium as Mg. | 5 | 5 |
Sodium as Na | 28.9 | 22.5 |
Potassium as K | 4.8 | 5.1 |
Surface active material as manoxol | 0.01 | 0.01 |
Electrical Conductivity (microhms) | 660 | 590 |
Table 20.—Bacteriological Examination of Water Supplied to City of Westminster—Average Results after Treatment
Source of supply | Number of samples | Agar plate count per ml. | Coliform count | E.coli count | |
---|---|---|---|---|---|
20-24 hours 37°C. | 3 days at 22°C. | Per cent. samples negative in 100 ml. | Per cent. samples negative in 100 ml. | ||
Stoke Newington | 254 | 6.5 | _ | 99.61 | 99.61 |
All Thames-derived | 3,578 | 12.2 | — | 99.75 | 99.97 |
Lead Content (mg/1.Pb) Water from Main Taps in Consumers Premises
Number of samples | Per cent | |
---|---|---|
Less than 0.01 | 64 | 66.7 |
0.01 | 22 | 22.9 |
0.02 | 3 | 3.1 |
0.03 | 4 | 4.2 |
0.04 | 2 | 2.1 |
0.05 | 0 | — |
0.06 | 1 | 1.0 |
96 | 100.0 |