DRAINAGE OF TOWNS.

Evening Star, Volume VIII, Issue 2294, 13 September 1870, Page 2

DRAINAGE OF TOWNS.

The following letter, which we extract from the Ayr Advertiser, of June 26, is of some interest at the present time. The writer is referring more particularly to the drainage of Ayr:— I am aware that Riuch has been written and many suggestions advanced in regard to this much vexed question, but thus far, no practical solution has been arrived at. I have seen from your columns that various schemes have been introduced ; but none of them seem to he generally approved of—some being objectionable on the score of great outlay, while polluting the river ; and others that they retain the unsightly pipes on the beach, and pour their contents amongst the sea-bathers. lam about to propose no pet theory of my qwp,, but a nlqq which has drained atonn quite' as level as Ayr, and drained it to the entire satisfaction of the inhabitants.

In dealing with the drainage of Haddington (for tint is the town to which I refer), throe difficulties had to be overcome—viz., want of water, want of level, and ah outlet liable to be interdicted if a nuisance were created. Those difficulties puzzled engineers for upwards of thirty years. Plan after plan was proposed, each to be abandoned as more objectionable than its predecessor, until the double of separate system was adopted, which entirely overcame all objections, and effectually drained tlje towp. In a}l the leading streets this system has been followed —a double line of sewers has been laid along the same track, the one sewer for the reception of kitchen, street, well, and storm water, which is carried direct to the river; the other sewer for the reception of all watercloset and like offensive matter, which is carried to a water-tight tank near to the river, but sunk 18 feet below the level of the river. The contents of this tank are emptied by means of a steam-pump, carted away, aud mixed m)d sold with the ordinary street manure Hitfcprto’towns Have beep drained upon the principle of mixing all kinds of sewage, valuable and the reverse, and then afterwards erepting and keeping up expensive works for the separation of sewage so mixed, Tho plan at Haddington has always

been, followed of never mixing what; is value* less and inoffensive with what is valueable and offensive, by carrying a double sewer to every house, connecting the one with the kitchen, the other with the water-closet: thus complete separation is secured from the commencement. The liver by this means escapes pollution, because all the offensive matter is retained in the tank, and what is inoffensive flows perfectly clear and pure ; into the river—so pure that people may be seen carrying it away in buckets for washing purposes. One objection that will be raised to this kind of drainage, no doubt, will be that it is expensive. The reverse is the case. In all drainage the cutting of the ground is the most expensive item—that expense must be incurred, whether one or two sets of pipes are laid—and all the former plans for draining Haddington showed a cost involving an assessment of from Is 6d to 2s per £, while the present system has been carried out at a cost of only 2|d par £. These facts speak for themselves.

The great objection to the system of having only one largo drain, into which all the sew» age is conducted, is, that the rain and face water take with them into the sewen^^

the fine sand or other material from the street. This accumulates inside the sewers, especially where the gradients are low; and becoming impregnated with other matter, forms a clammy mass at the bottom of the sewer, and from its weight is never completely washed away, even in winter, and hence arises the ever-eecumng nuisance of a “stopped-up” drain. Besides, if all the sewage be amalgamated, the valuable part becomes so diluted by the rain and surface water that it is practically useless, and costly machinery has to be erected to separate the sewage so n.ixed. - The whole Drainage Question is ably discussed in a report by Lieut.-Col. C. B. Ewart, Royal Engineers, Loudon district, on the “ Proper principle of drainage to be adopted in the towns of Oxford, Eton, Windsor, and. Abingdon.” In this report Lieut-Col. Ewart strengly recommends the “separatesystem,” viz,, the system I have been advocating, and one that has been successfully car-ied out in a town where the tank into which the sewage was deposited, had to be sunk 18 feet below the line of the river to allow a proper fall for the drains. What can be accomplished in one town can be accomplished in another, provided there be equal zeal and hear tine'fl displayed in tho effort.