In places where unlimited water is obtained by merely turning a tap these estimates are very liable to be exceeded, especially when those who turn a tap on are too forgetful or lazy to turn it off.
I feel certain that anyone who experiments on this matter as I have done will be simply astounded at the small amount of ground which is necessary.
Critics of the plans which I have advocated, and am now about to advocate, sometimes hint that the whole curtilage of one's house must be unwholesomely sloppy.
Such a statement shows a complete ignorance of the whole subject.
Few, if any, of the writers of hygienic text-books seem to have really studied the life-history of slop-water, and it is matter for regret that in some of these books the chapters devoted to domestic hygiene deal more with patents than with principles, and are illustrated more by woodcuts culled from tradesmen's catalogues than by any practical knowledge possessed by the writer.
Principles of Slop-Drainage
If domestic slop water is to be dealt with successfully it is necessary—
1. That all waste pipes terminate well above the level of the ground.
This is a point too much neglected by architects, who are very prone to carefully put all waste pipes below ground level, so that any purification of slops without pumping is impossible.
Allowing a fall of, say, 1 in 10, it is evident that for every foot above ground at which a waste pipe terminates it is possible to deliver the waste on to the surface of the ground at 10 feet from the house. Thus the bedroom sink waste at a height of 10 feet above ground level might be made, if so desired, to deliver its waste 100 feet from the house. It is often necessary to take the waste pipes from the first floor over the path surrounding the house. This is easily accomplished without causing any unsightliness by placing an arch over the path. Such arches may be of galvanised iron for a cottage, or of masonry for a mansion, and are soon hidden by creepers.