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 Chigwell]
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Water Samples
(a) Average results of Chemical Examination. Milligrammes per litre (unless otherwise stated):-
| Lee Valley -derived | Chingford Mill | Waltham Abbey | |
|---|---|---|---|
| No. of samples taken during the year | 104 | 4 | 4 |
| Ammoniacal Nitrogen | 0.017 | 0.230 | 0.190 |
| Albuminoid Nitrogen | 0.092 | 0.030 | 0.22 |
| Nitrate Nitrogen | 8.5 | 0.8 | 0.6 |
| Oxygen abs. from KMnO4 4 hours at 27 C | 1.28 | 0.30 | 0.50 |
| Hardness (total) CaCO3 | 306 | 288 | 278 |
| Hardness (non-carbonate) CaC03 | 95 | 72 | 58 |
| Magnesium as Mg | 6 | 17.0 | 22.0 |
| Sodium as Na | 34.6 | - | - |
| Potassium as K | 7.3 | - | - |
| Chloride as C1 | 47 | 27 | 25 |
| Phosphate as PO4 | 3.7 | - | - |
| Silicate as SiO2 | 10 | - | - |
| Sulphate as SO4 | 72 | - | - |
| Natural Fluoride as F | 0.17 | 0.45 | 0.43 |
| Surface-active material as Manoxol OT | 0.02 | - | - |
| Turbidity units | 0.1 | 0.1 | 0.2 |
| Colour (Burgess Units) | 14 | 6 | 9 |
| pH value | 7.9 | 7.3 | 7.5 |
| Electrical Conductivity (micromhos) | 670 | 550 | 550 |
/(b)
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