SEWERAGE IN NELSON.

Gisborne Times, Volume XXVII, Issue 2691, 22 December 1909, Page 6

SEWERAGE IN NELSON.

an unfortunate experience UNTREATED SEWAGE IN THE HARBOR.

At last meeting of the Nelson City Council Dr. Valintine, Chief Health Officer, wrote covering the report of Dr. Frengley, District Health Officer, on the effectiveness of the sewerage scheme. Dr. Valintine added: “I reoret to see that what ’ should have proved a good system of drainage has been marred by inefficient construction and supervision. I look, therefore, to your Council to rectify the obvious defects commented upon by Dr. Frengley, and thus provide the residents of Nelson with a system of sewerage and sewage disposal such as they have a right to expect,” Dr. Frengley forwarded detailed reports' of the Department’s inspector and together with his own report, as follows: — , ■ _ Conclusion. —(1) To the City Council’s question: “Whether the new system of drainage which has been inaugurated in this city will prove effective for idle proper sanitation of the city r —the answer must emphatically be that it is impossible to have any effective system with such evidence of extremely bad construction and mdiffei - ent supervision in parts thereof. (2) The evidence is conclusive that at the time of my- visit such sewage as was passing down the newly inaugurated system did not even pass into the septic tank/ but was being “by-passed”, and deposited into the harbor without any attempt at treatment whatever, anil further demonstrates the proba>dity that this state of things has existed for some time.

(3) The analysis show that just, as much sewage is massing down the old as the new system, for the amounts of saline and free ammonia, albuminoid ammonia, and'oxvgen absorbed are fair indicators of the “sewage content” and the average tests from the new sewers iml from the old sewers are as folloWS~ New- Old * outfall outfall

sewer, sewer. Ammonia free and saline 1.23 1.03 Ammonia Albuminoid .11 -10 Oxygen absorbed in 4brs. at SOdegs. Fahr. " 1.03 1.0

In view of these results it is not surprising to me to have heard it said in Nelson that near the foreshore offen. sive smells are frequent. On the occasion of my visit, as I have indicated, probably—to the best of my belief—for a long time the septic tank has been “by-passed;” therefore no stigma can attach to that feature of the scheme as a smell-producer.- A still more obvious danger to health is in this, htat while I held, in the past, that oysters should not be allowed inside the Boulder Bank, I learn that this is now being permitted. I suppose the facetious contention is advanced that sewage is’ being “treated” before its discharge into the harbor. How far this is from being the actual truth I need not reiterate.

(4) Leakage in the Sewers.—This is manifestly, most marked- • in.. ‘ ‘The Wood” area. I am not prepared to. state that Cambria Street drain is entirely at fault, since it is impossible to judge the condition of other sewers in the lower Collingwood Street area, on account of the backing-up that was noted. If all the leakage be due to thecondition' of the Cambria Street sewer between the “septic” manhole referred to and Collingwood Street, it can only be said there must have been gross mismanagement in the . laying of that sewer. • •. ■ i •'. . ..'

(5) The nature of the water gaining entrance to the sewers.—lt; has been suggested to me that an underground stream may have unfortunately -been tapped at this point and thus cause the abnormal floif. The analysis of the sewage ', makes it, however, only too clear that this underground! spring is saline in character or that much more positively it may be said that e.xcess water is mainly sea water. It will be noted that the amount of chlorine in chlorides averages about 22 times as much in the new sewers as in the old, 51 though the actual sewage .content is about the same. . This .chlorine, in my. opinion, comes from the sodium chloride. (salt) of sea water. It is to be feared, then, that if on account of bad construction and insufficient supervision, subsoil salt water has not been adequately kept out in Cambria Street, such leakages in smaller degrees wil be found elsewhere m “The Wood.” Before expressing further opinions on this point, I am desirous of ascertaining the results of the repairing work in progress in Cambria Street.. (6) The Working of the Septic Tank. —The evidence pees to show that the sub-soil leakage from ‘‘The Wood” end

•' ‘ . alone would be -sufficient to fill-: the septic tank with (diluted) sea water and nothing else in 24 hours. It is not surprising to learn, that the screening bed at the end 1 of the septic tank quickly blocked. . shortly after starting the system. , To deal with, such enormous volumes of fluid as have been passing down the system a tankage of four to- six times the present capacity would be necessary, and then only if fresh water, not sea water, were the abnormal element in the sewage. The obvious cause of the blockage was that the excessive flow through the tank' washed undisintegrated sewage into the interstices of the screen. JL beg to recommend : —■ (1) That investigation be duly made by this Department to ascertain the result of the repairs now being made to the Cambria Street sewer.

(2) That the screening material be taken out of the end chamber of the septic tank and be allowed to remain out until the flow of sewage us reduced to that capacity for which the general scheme and septic, tank were adequately designed. * (3) That the by-pass valve be sealed down under the seal of the City Council, and he not removed except by request in writing, under the hand of the engineer, stating the reason for which the valve is desired to be opened. Resealing to be performed after the conclusion of. any such operations. (4) That,/ notwithstanding the fact that the septic tank cannot bo expected to disintegrate and; dissolve the sewage in an adequate manner under the present and immediate future conditions. it is advisable that the City Council enforces the provisions of section 216 of “The Slunicipal Corporations Act,” with a view to the prevention of the pollution of the foreshore in the vicinity of the old sewer-outlet. (5) That for the present notices to connect to the system be not sent regarding premises which would be required to connect to any sewer leading to the Collingwood Street ejector. (6) That steps! be taken by this Department to prohibit oysters being stored inside the Boulder Bank. (This has already been undertaken). JOS. P. FRENGLEY, District Health Officer.

After a short discussion the Council decided to consider the report at a special meeting at which the City Engineer was invited to make an explanation. One Councillor said the principal indictment was against the City itself in not allowing Mr. Mestayer to supervise the work due to the personal differences that had arisen.