TRIPLE PROBLEM.

Auckland Star, Volume LXVI, Issue 198, 22 August 1935, Page 8

TRIPLE PROBLEM.

THE TAMAKI "DRAIN." CRUDE SEWAGE IN RIVER. OTAHTTHTJ'S THREE OUTFALLS. A triple nuisance in the Tamaki River provides yet another facet to the manysided drainage problem of Auckland. Into that shallow tidal inlet , of the Ilauraki Gulf three outfalls of the Otahuhu borough sewe'iage system, several trade outfalls and, it is stated, a number of minor private outfalls in Hie I'aninure township road district, daily pour contaminated matter, including a percentage of crude sewage.

The result is a condition of things very .similar to that which prevails in Maniikau Harbour —mudflats impregnated, with noxious . matter, unclean waters and soiled beaches. The final discharge, it is believed (or rather hoped) finds its way out through Motukorea, Channel, between Motutapu and Motuihi Islands, but il is probable that some of it joins with the. discharge from Orakei to contaminate the beaches about St. Helior's Hay.

For all this no blame can lie attached except to a condition of divided control which permits the solution of various drainage problems by the creation of others. Otahuhu has done all which it is financially able to do to remove from the borough the drainage discharge of a population of r>2oo people. Septic tanks at each of its four outfalls, one into the upper reaches of the Manukau, and three others into the Tamaki, remove a good deal of the nuisance that might otherwise exist, but it is beyond the resources of the borough to deal with the problem adequately. Financial Obstacle. 'Tor years we have been wanting to clean the Tamaki," said the Mayor of Otahuhu, Mr. C. l<. Petrie. The volume of water ebbing and flowing in the river was, lie admitted, inadequate for the proper dispersal of sewage and sewuge effluent. The discharge must taint the water, and the mud of the river bottom must become impregnated with contamination. There was at the present time an agitation for a fresh water bath, due, he felt, to the fear the people had that their beaches were not in a sanitary condition. There was no proof of that condition, but complaints were mado from time to time that crude sewage was found in the water. The Borough Council fully approved of the proposal to consolidate the drainage system of Auckland, though the financial aspect worried them, and their district was too small to take the initiative. Fertiliser in Mud. " Referring to the Mahnkau side of the problem Mr. Petrie recalled that some years back a welfare association had made endeavours to have the upper reaches of the harbour where it touched "the borough reclaimed. A chemical analysis of the mud showed that it contained enough fertiliser to last 100 years. That was the stretch on to which trader wastes from Westfield and the effluent discharge of the Otahuhu outfall were deposited.

Until a few years ago Otahuhu had two outfalla on the Tama.ki side, one at Cracroft Street and one in Otahuhu Creek. A third was then installed at Stringer's Point, to meet the needs of the growing population. The upper one at Cracroft Street caters for a population of 1500, Stringer's Point for 200 or 300, and the Otahuhu outfall for 2000. Septic tanks at each deal efficiently with the discharge from the sewerage system, and it is only the effluent which finally reaches the river. They begin discharge one hour after high water, and are allowed to work only for one hour.

Fofir years ago the overtaxing of the Otahuhu Creek outfall b}' storm water led to a nuisance which was a source of continuous complaint by residents. This outfall, which has a pipe line down Awatui Creek into the larger creek, had been in operation since 1!)12 ail<l it ivas not acting as efficiently as the more modern equipment. As a result of •these complaints the council had a spillway,/Or by-pass, erected behind the septic tank, which took surplus water directly into the stream through mesh screens which guarded against the introduction of any crude sewage.

Nuisance Persists. In spite of this precaution a nuisance still persists, and It is stated authoritatively that crude sewage in some quantity enters the Otalmhu Creek and from there into the Tamaki. The trouble lies not with the sewerage system or the efficiency of the outlail to deal with the resultant discharge, but in the disposal of sewage from the unreticulated area of the borough. The "dump" for this sewage is on the city side of the septic tank and periodically it is tipped into the septic.tank for dilution. The authority stated that the consequent tax on the tank is too great, and that as a result a percentage of the sewage is passed out in an undigested state, to pollute the lower stream.

The problem of the. pollution of the Tamaki has other important factors. As the. Westfield trades district outfalls on the Manukau cause serious contamination of the harbour so other similar outfalls are the cause of trouble on the Tamaki. The flow is not , so big, and the matter discharged not of the same obnoxious quality, but nevertheless it is a serious factor in the present position, and a continuous source of concern to the Health Department and the Harbour Board. These outfalls are under license from the Harbour Board, which annually makes an inspection. The conditions, are known to be insanitary, b.ut until some better scheme is available the licenses could not in justice be refused. They are, however, revocable whenever such a system is available.

Illegal Installations. The saniL' position mil's in regard to other licensed private outfalls into the Tamaki. Sir. I). Holderness, engineer to the Harbour Board, stated yesterday that very lew private licenses have been granted for discharges into the Tamaki. Vet yachtsmen say that through the Paiimure township house after house on the river frontage lias a patent installation with a discharge of crude sewage into the Tamaki. PaiiDiure has no sewage scheme and these installations—even though they are illegal—appear, in present conditions, to be a fuiiher necessary evil.

From these three sources, the Otahuhll outfalls, the trade outfalls and the private Outfalls. ! here pours daily into the Tamaki a stream of contamination. Point England and Ulendowie beaches on the city side of the mouth and JJuckland'a Beach on the eastern side stand in the way of the flow and there danger exists. The district is particularly attractive as a residential urea and in all likelihood will become considerably developed within the next few years. At present a serious drainage problem stands in the way—as it does in that of nearly every waterfront suburb of Auckland.