NOTE UPON THE 
ACTION OF THE DIBDIN CONTACT BEDS 
CONSTRUCTED BY THE CORPORATION 
OF LIVERPOOL AT WEST DERBY 
The following account of the Sewage Farms at West Derby and Walton, 
and of the subsequent construction of Storm Water Filter Beds, and of Dibdin Bed*, 
has been kindly furnished by the City Engineer. I desire to express my thanks 
both to the City Engineer, the Assistant Engineer (Mr. Cooper), and the Farm 
Bailiff (Mr. Smith), and more recently to Mr. Edge, for their cordial co-operation in 
enabling me to conduct the bacteriological investigations. 
The interest attaching to the experiments lies in the comparison of the sand 
effluents with the Dibdin effluents, and with the action of the rough storm water filter 
beds, which have been in use since April, 1896. The bacteriological analyses have 
been made by Drs. Hill, MacConkey, and Miss Chick. 
RuBERT BOYCE. 
COPORATION SEWAGE FARMS AT WEST DERBY & WALTON 
The system adopted on these Farms is broad irrigation, and filtration without 
chemical treatment. On the West Derby Farm special contact beds have been 
constructed. 
The West Derby Farm has an area of 207 acres, which, at the present time, 
takes the sewage of about 35,000 inhabitants, spread over an area of about 2,000 
acres. The sewage is conducted on to the Farm by means of two sewers, one a 
high-level brick sewer, 5ft. 3m. by 3ft. 6in. in size, outlets at the highest point of the 
land, whence, if desired, the sewage could be carried to any part of the Farm. It 
is a gravitation sewer throughout, with a ruling gradient of 5 feet per mile, or 1 in 
1,056. The second sewer, which is also of brick, but 4 ft. 6 in. by 3 ft. internal 
dimensions, with a gradient of 1 in 1,120, serves the low-lying portion of the district, 
and discharges into a tank some 1 3 feet below surface level at the lowest part of the 
land. It has here to be raised by pumping to a height of about 10 feet above the 
ground level, to permit of its distribution over the land by gravitation. This distribution 
is effected both for the high and low level sewers by means of open carriers (or conduits), 
