Sewerage and Sewage Disposal / by Henry Robinson.

Date:
1896
Catalogue details

Licence: Public Domain Mark

Credit: Sewerage and Sewage Disposal / by Henry Robinson. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    of Berlin (hereafter referred to) from one to two and a half tons of waste lime per acre have been spread over fields which had previously been drenched with sewage, and the result was most beneficial. The land in this case had a sandy subsoil. The most unsuitable soils for sewage purification are stiff tenacious clays, peaty or boggy land, and certain conditions of coarse gravelly soils, which contain hard conglomerate layers often very dense and impervious. Clay lands can be rendered more fitted for filtration by specially preparing the surface to some •depth by ploughing or digging in ashes or other materials. These will convert the impervious surface into a more open one through which the sewage can sink, and the nitrifying processes can be set up. Clayey lands, besides being too dense for sewage to pass through under ordinary conditions (as when wet and waterlogged in the winter months), are liable to crack to considerable depths in periods of long continued dry weather, when unpurified sewage can pass untreated into the subsoil. In many cases clay lands have been deep drained by cutting trenches, laying agricultural drains at the bottom, and filling up with burnt clay, ballast, or other porous material. This has resulted in serious failure, as the crude sewage has passed down the trenches unpurified and away in the underdrains. Where this can possibly