Sewage Disposal. 371 



taken to apply the sewage intermittently in a thin stream or in the 

 form of drops or spray. 



The filters on this system which are being tried at the present 

 time are the " Scott Moncrieff," the " Ducat," the " Whittaker-Bryant.'' 

 the '• Corbett " and the " Stoddard " filters. 



Without going to the length of describing the methods uiX)n 

 which these different filters are constructed I may state generally that 

 these filters are used in conjunction with the septic tank and are 

 capable of dealing with a greater amount of sewage than the contact 

 beds. The " Ducat '" filter is said to deal with sewage at the rate 

 of 1,000,000 gallons per acre per diem; one of the largest plants on 

 the intermittent continuous system — a " Whittaker-Br}ant"' plant erect- 

 ed at Church near Accrington — is dealing with sewage at the rate of 

 2,000,000 gallons per acre per diem and the purification is said to be 

 good, while a small " Stoddard "" filter erected near Bristol has been 

 nmning successfully at the rate of 5.000,000 gallons per acre per 

 diem. 



The construction of these filters, with the exception of the last 

 named, is more costly than that of contact beds, and owing to the 

 special means that have to be taken to ensure complete aeration the 

 cost of maintenance is considerable. 



A brief description of the Sewage Purification works on the 

 Contact system which have been constructed at the Native Location, 

 Maitland, may be of some interest. 



The sewage is brought from the various parts of the location to 

 the sewage works in iron trolleys running on an 18 inch gauge tram- 

 way, where it is emptied into a screening chamber and from thence 

 it passes over a weir into a septic tank. This is a covered tank with 

 a capacity of 6.000 gallons, which is estimated to be the quantity of 

 sewage that will be treated daily when the various sanitar}- conveni- 

 ences in contemplation have been constructed. The septic tank is 

 fitted with partitions or scum boards at a distance of one foot from 

 each end. which extend from above water line to within two feet six 

 inches of the bottom, an arrangement which causes the liquid passing 

 from the tank to be drawn from the middle portion, leaving undisturb- 

 ed the sediment which is deposited at the bottom and the thick crust 

 or scum which forms at the top ; a weir is formed at the outlet similar 

 to the one at the entrance extending the full width of the tank and 

 over this the effluent passes in a thin film to a collecting tank 

 designed to contain 1,000 gallons; in this tank there are fixed two 

 syphons set to discharge the whole of the contents of the tank when 

 the liquid reaches a certain level ; these two syphons work automatic- 

 ally and discharge alternately on to two bacteria beds which are 

 constructed immediately below the tank. 



The bacteria beds are designed to contain 1,000 gallons in 

 addition to the filtering material so that each time one of the syphons 

 discharges the contents of the collecting tank one of the bacteria beds 

 is filled while the other bed is being aerated preparator}' to coming 

 into work at the next filling of the collecting tank. 



