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.

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    It should be understood that these suggested standards are provisional, and for the guidance of local authorities as average requirements. Nuisance may not only be caused in a stream by second- are fermentation of the organic matters in a sewage effluent, but the effluent may cause the growth in the stream of lowly vegetable organisms, which often give rise to nuisance- and difficulty. Even the best effluents contain a certain- amount of plant food in solution, and therefore tend to promote vegetable growths. In the case of a stream re- ceiving well-purified and nitrated effluents these growths are green, from the presence of chlorophyll, and are un- productive of nuisance until they become detached and accumulate in sufficient quantities to give rise to nuisance from decomposition. In streams receiving imperfectly oxidised effluents, grey growths of the sewage-fungus order may arise, and tend to choke up the bed of the stream, at the same time causing an offensive nuisance when decomposition occurs. The Commissioners, however, are not at present in a position to state exactly what effluents will, and what effluents will not, cause objectionable growths in streams. The Biological Characters of Sewage Effluents The question of the biological purity of sewage effluents is an even more difficult one than that of chemical purity, as it is so intimately related with the life processes of the enteric fever bacillus, and of other disease organisms that are occasional inhabitants of water ; such knowledge as we possess on this subject being scanty, and liable to revision with every advance made by bacteriological 9