[Report 1971] / School Medical Officer of Health, Exeter.

Exeter (England). City Council.

Date:: 1971

Catalogue details

Licence: Attribution 4.0 International (CC BY 4.0)

Credit: [Report 1971] / School Medical Officer of Health, Exeter. Source: Wellcome Collection.

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Pynes Water Works, Exeter. Chemicals in Parts per Millic >N Analysis Raw Water Sample 12.3.71 (a.m.) Final Treated Water 12.3.71 (a.m.) Raw Water Sample 17.8.71 (a.m.) Final Treated Water 17.8.71 (a.m.) Bacteriological Examination : Nutrient Agar at 37°C. 48 hours 560 0 2.560 0 Coliform Organisms, per 100 mis. 3,500 0 16,000 0 Bact. Coli. Type 1, per 100 mis. 3,500 0 16,000 0 Physical Characters : Colour (Hazen) 15 <5 17.0 5 Turbidity 3.5 Nil 20.0 0.2 pH 7.20 8.0 7.4 8.35 Conductivity 25°C. (umhos) .... 180.0 210.0 134.0 175.0 Temperature 7.5° C. 9° C. 16° C. 15.5° C. Chemical Analysis (in mgm. per litre) : Free Carbon Dioxide (CO2) 2.0 1.6 1.2 trace Total Alkalinity (CaCOs) 21.0 38.0 18.0 25.0 Caustic Alkalinity (as CaCOa) .... Nil Nil Nil Nil Ammoniacal Nitrogen 0.066 0.06 0.112 0.072 Albuminoid Nitrogen 0.100 0.06 0.310 0.112 Nitrite Nitrogen 0.006 Nil 0.003 Nil Nitrate Nitrogen 2.42 2.42 1.1 0.73 Oxygen Absorbed (4 hrs. at 26.7°C.) 1.0 0.25 2.3 0.65 Carbonate Hardness (E.D.T.A.) 21.0 38.0 18.0 25.0 Non-Carbonate Hardness (E.D.T.A.) 37.0 34.0 19.0 2S.0 Total Hardness (E.D.T.A.) .... 58.0 72.0 37.0 53.0 Total Solids (dried at 1S0°C.) .... 114.0 132.0 83.8 111.0 Calcium (Ca) 16.8 22.4 11.6 17.2 Magnesium (Mg •) 3.84 3.84 1.92 2.40 Sodium (Na) 1 1 as Na 9.35 9.85 5.75 6.35 Potassium (K) j r 2.0 2.0 1.75 2.03 Carbonate (CO3 12.6 22.8 10.8 15.0 Sulphate (SO4) 13.9 21.6 20.2 27.4 Chloride (Cl) 13.5 15.6 u.o 13.5 Nitrate (NO3) 10.5 10.5 4.8 3.2 Fluoride (F) 0.12 0.11 trace 0.06 Silica (Si02> 9.4 6.25 11.5 5.5 Phosphate 0.20 0.14 0.5 0.3 Aluminium (A1 0.025 0.04 0.06 0.06 Manganese (Mn) Nil Nil trace Nil Iron (Fe) 0.50 0.1 0.34 0.15 Residual Chlorine : Free — 0.55 — 0.5 This water is chemically and bacterio- logically satis- factory. This water is chemically and bacterio- logically satis- factory. PRIVATE DOMESTIC WATER SUPPLIES There are eleven properties still supplied by well water and there is little hope of these being connected to a mains supply in the foreseeable future. One of these properties has been unoccupied throughout the year and is not likely to be used again. SEWERAGE AND SEWAGE DISPOSAL The City Engineer and Surveyor (Mr. J. Brierley, o.b.e., f.i.c.e., m.i.mun.e., M.T.p.i., f.g.s.) has kindly supplied the following information :—