MR CLARK'S DRAINAGE SCHEME.

Globe, Volume IX, Issue 1272, 16 April 1878, Page 3

MR CLARK'S DRAINAGE SCHEME.

The following correspondence has been handed to the " Press " for publication!:— Christchurch District Drainage Board, Hereford street, April 6th, 1878, W. Clark, Esq., C.E., The Club, Wellington,

Sir, —Herewith I send you newspaper extracts having reference to your scheme for the drainage of the Christchurch district. You will observe two questions raised therein, viz. : Is it a matter of sanitary necessity that the excreta should be removed by sewers ? And, Are you aware that the normal wind of Christchurch is easterly, and that for four or five days each week (on the average) the wind blows from the Sandhills direct to the town ?

The town clerk informs me that heretofore the pans have been emptied on an average about once in ten days; by a new contract, which has just been concluded, they will be emptied not less than once a week. You are already aware that pans are used over only a portion of the district. May I ask you to favor the Board with your answer to the above questions at your convenience.

I remain, &c, (Signed R. J. S. Habmah, Acting Chairman.

To R. J. S. Harman, Esq., Acting Chairman Christchurch District Drainage Board.

Sir, —I have the honor to acknowledge receipt of your letter of the 6th inst., and with reference to my report on the drainage of Christchurch requiring my opinion, 1. Whether it is a matter of sanitary necessity that the excreta should be removed by the sewers ?

A simple assent to the question so put would ignore all other modes of dealing with this matter, which I do not desire to do, for there are many possible ways of treating and removing it, but in my opinion if economy, completeness (with the absence of nuisance), and possible return for the outlay in the future, be taken into consideration, then I say iu the case of Christchurch there is a necessity. I have pointed out in my report that the system of sewers for subsoil drainage and the removal of house slops is necessary, and that no extra expense will be incurred in the construction of the sewers by their use for this purpose also. 2. As to the prevailing wind which blows from the Sandhills towards the city? When I state that the utilisation of the sewage, if properly regulated, will produce little or no nuisance at the Sandhills, I scarcely expect it to be credited ; but it must be borne in mind that the filth will be removed and absorbed by the land while in a fresh condition, it will not stop from the moment of production to that of absorption, and certainly not more than three 'or four hours would be occupied in its journey from the most distant part of the city, during which if; will not have time to decompose. This, however, is a matter a right understanding of which is of so much importance, and so few persons have had the opportunity of visiting a sewage farm, that I must endeavor to put the case in a form which may be better appreciated than by a mere statement of my own opinion. Imagine then a row of twenty or thirty pan closets at the Sandhills, with their one week old and decomposing contents —what the nuisance arising from these places and the still worse cesspits amounted to the inhabitants of Christchurch are familiar with—imagine this now at the Sandhills, and I will guarantee that if any ordinary precautions be taken to keep the sewage flowing over the land, it will not produce one-half the nuisance due to the closets. How far then will the nuisance from the closets travel on the wind ? or, it may be asked, how far does it travel from the 1500 or 1600 of these pans in Christchurch ?

Any inquirer can thus estimate for himself, and I think most will agree with me that a few hundred yards of distance would bo quite sufficient to render the supposititious nuisance of the twenty or thirty pan closets at the Sandhills inappreciable. I was not aware that the wind, probably for five days in the week, blows from the Sandhills towards the city ; but now I am so informed, I am of opinion that, at, say, one quarter of a mile from the point of utilisation, or from the point of its discharge from the iron conduit which conveys it to the Sandhills, its presence could not possibly be detected.

3. Regarding the suggestion that the estimate I bave formed for carrying out the works may be considerably exceeded, I would remark that I am familiar with the difficulties which will have to be overcome, and the means of overcoming them. I have consulted with Mr Bell on the matter, and the estimate has been formed from my experience, aided by his knowledge of tho locality and rates of labor and material; to this we have added 10 per cent, for contingencies, and to the best of my belief the work will not exceed the estimate so formed. I have the honor to remain, Your obedient servant, (Signed) W. Olaek. Wellington, April 11th, 1878.