Land Treatment of Sewag^e. 



1 in 400, and a capacity, when running full, of 

 210c.f.m. ;* the Wellington Lines sewer is a 12-in. 

 pipe, and passes under the Basingstoke Canal by 

 an inverted syphon just before entering the farm ; 

 and the Marlborough Lines sewers are 12 in. and 

 15 in., with a combined capacity when running full 

 of 246-6 c.f.m. There is one Detritus Chamber on 

 the Stanhope Lines sewer, where a good deal of 

 sand collects — it is cleaned out every six weeks 

 or so, from 5 to 8 tons being removed. Screens. — 

 As the sewage is very fresh the paper and faeces 

 are easily removed. The screens are made of |-in. 

 galvanised iron bars, set | in. to | in. apart, at an 

 angle of 45° to the flow — they are cleaned every 

 hour. Settling Tanks. — The Stanhope tanks are 

 in duplicate, each 64 ft. by 12 ft., with an average 

 depth of 1 ft. 6 in. Each is used in turn for a 

 period of two to three weeks, and the sludge is run 

 into the sludge bed. The tank is then brushed 

 perfectly clean. The Wellington Lines tanks are 

 70 ft. by 10 ft. by 1 ft. 8 in., and the Marlborough 

 Lines tanks 80 ft. by 12 ft. by 3 ft., and they are 

 worked in the same way. Stay in Tanks. — The 

 capacity of the Stanhope and Wellington tanks 

 is about 6,500 to 7,000 gallons each — this, with a 

 flow of one-third of a million gallons for each set, 

 gives a stay in the tanks of about thirty minutes. 

 A single new Marlborough tank holds 18,000 gal- 

 lons, and the sewage takes approximately one hour 



end of this section, compared with those of the 

 efiluent and of the stream. 



Soil 

 and Subsoil. 



Originally the Soil was an 

 almost pure sand — there is now 

 a siu'face soil of 4 in. to 12 in., 

 produced by sewaging and by ploughing in sludge, 

 incorporated with farmyard manure. With the 

 exception of one field 20 tons of chalk have been 

 applied per acre as a dressing. The Subsoil con- 

 sists of a little gravel in parts, but is mostly of 

 very fine sand, with a tendency to pug.* An 

 impervious pan,t at a depth of 2 ft. to 4 ft., is 

 noticeable, though it has now in great measure 

 been broken up by under-draining. Under-drain- 

 age. — The land has a slight slope eastwards to the 

 river Blackwater, but there is not sufficient fall 

 to create a good draw in the drains. The 3-in. 

 agricultural pipes are laid at an average depth of 

 3 ft. 3 in., and generally about 12 yds. apart. They 

 communicate with larger pipes (up to 15 in.), which 

 discharge into an efiluent chamber. Subsoil Water 

 and Floods. — In winter during rainfall there is 

 some subsoil water, but as a rule when the tank 

 effluent is taken off a plot the under-drains run 

 dry. The land is not subject to flooding. 



The Mechanical Analysis shows the following 

 percentage composition of the ignited soil and sub- 

 soil : — 



and twenty minutes in its passage through it. 

 The Screenings (about two wheelbarrow loads per 

 tank per day) and the Sludge (about 20 to 30 tons, 

 wet, at each emptying of the tanks combined) are 

 deposited together in beds formed with a fender 

 of long stable manure, and eventually are applied 

 to the farm. The Analyses, both chemical and 

 bacteriological, of the sewage will be found at the 



♦ Cubic feet per minute. 



The approximate number of particles in 1 gramme 

 was, for soil, 154,373,990; subsoil, 1,142,111,850; 

 and in 1 c.c, for soil, 226,466,640 ; subsoil, 

 1,677,742,900. 



The Lime (parts per 100,000) dissolved by water 

 in twenty-four hours is, for soil, 0-004; subsoil, 



• By pug is meant a tightening of the surface sand and consequent 

 obstruction to filtration. 



t Sand cemented together with iron oxide. 



12 



