SEWERAGE OF THE CAPE PENINSULA. 73 



method of the disposal of the sewage. To this question there 

 can be, in my opinion, only one possible answer, and the plan 

 I have prepared will, I submit, best and most briefly supply 

 it. To begin with, my scheme would be to construct: (i) A 

 main intercepting sewer along the lowest lines of the Liesbeek 

 River Valley; (2) a main intercepting sewer along the Black 

 River Valley; (3) a main intercepting sewer from Woodstock; 

 (4) a short intercepting sewer from Maitland, all to gravitate 

 to and form a junction at the most suitable point obtainable 

 in the vicinity of Montagu Bridge, where it will be necessary 

 to construct a pumping station to lift the sewage through a 

 rising main to disposal works, to be constructed on a suitable 

 site on or near Paarden Island. The method of treatment I 

 would recommend would be the Bacterial, a^ follows: — The 

 sewage w^ould first pass through a screening chamber, thence 

 into and through a series of sufficiently large Anaerobic tanks 

 of an united capacity sufficient to hold rather less than a day's 

 volume of sewage, thence by a continuous flow over a suffi- 

 cient area of aerobic filter beds, the effluent from which would 

 be collected and conveyed by means of a stoneware and C.I. 

 pipe of sufficient diameter to a point well below the low water 

 ordinary spring tide of Table Bay. This system of disposal 

 would produce an excellent effluent, and its discharge into 

 Table Bay would not create the slightest nuisance or smell 

 whatever. One of its great advantages would be that the whole 

 of the Sewage Disposal Works could be enclosed within a very 

 small area of land. Any proposal to discharge crude sewage 

 into Table Bay would be no doubt strongly objected to, and 

 rightly, by the Table Bay Harbour Authority. Some people 

 might advocate the pumping of the crude sewage on a pre- 

 pared_ area for irrigation purposes on the Cape Flats. This 

 idea is of course worthy of consideration, but I believe the 

 most satisfactory and economical method of its disposal will 

 be found in the bacterial system I have briefly indicated. 



With regard to the branch or street sewers, these should 

 all be laid with glazed stoneware spigot and socket pipes of 

 standard thickness and suitable diameters, with straight lines 

 and even gradients from manhole to manhole. Ventilation 

 should be secured by tall cast-iron shafts placed in suitable 

 positions, and special attention should be made for the auto- 

 matic flushing of all branch sewers. 



The house drainage should be properly disconnected from 

 the street sewers, and every soil pipe should be not less than 

 4'' m diameter and carried up well above the roof for ventila- 

 tion. 



Time and space prevent my dealing more fully with this im- 

 portant and interesting problem, but if I have in the slightest 

 degree succeeded in drawing public attention to and creating 

 an mterest in this subject, which has an important bearing 

 upon the comfort, cleanliness and health of manv thousands 

 of residents in the Cape Peninsula, I shall feel amply rewarded 

 for any little trouble I have taken. 



