House-drainage, sewerage and sewage disposal in relation to health / by Louis C.Parkes.

  • Parkes, Louis Coltman, 1857-1942.
Date:
1909
Catalogue details

Licence: In copyright

Credit: House-drainage, sewerage and sewage disposal in relation to health / by Louis C.Parkes. Source: Wellcome Collection.

Provider: This material has been provided by London School of Hygiene & Tropical Medicine Library & Archives Service. The original may be consulted at London School of Hygiene & Tropical Medicine Library & Archives Service.

    105/160 (page 93)
    THE DISPOSAL OF SEWAGE It will be unnecessary to discuss the question of whether sewage should be purified before discharge into streams and water-courses, as this has long ago been answered in the affirmative ; and it is now an established maxim in sanitary administration that crude sewage should never be allowed to flow into non-tidal waters, and may only be discharged into the sea or estuarial waters if there is no likelihood of damage being done to fisheries or oyster beds, and if the discharged sewage is certain to mix rapidly with large volumes of sea or estuarial water, and is not in danger of being carried along the sea fronts of coastal towns, where solid floating matters might be deposited on the foreshores. The purification of sewage has been the subject of an immense amount of investigation, experimentation, and discussion during the past forty or fifty years; but we need only consider at the present moment the chief methods, which have survived the tests of actual practical applica- tion, and which are more or less in use at the present day. These are (1) Precipitation ; (2) Surface irrigation of land, with which is usually combined, (3) Filtration through land, and (4) Bacterial treatment by septic tanks and artificial bacteria beds, which last include intermittent contact-beds, and continuous or trickling filter-beds. It will first of all be necessary to consider briefly what constitutes sewage. The sewage of all communities of persons in this country is water, containing, both in solution