ALTRINCHAM. 



HISTORY. 



No reference is made in any text-book or report, 

 so far as I am aware, to this farm. It was started 

 about 1870, and in all probability the population 

 served gradually increased and thus threw a grow- 

 ing burden on a small area of land. 



REPORTS TO THE ROYAL COMMISSION. 



Conservancy. — It is stated in 

 The Sewage, the Engineering Report (Part 

 IV., page 24) that " water-closets 

 are in use over the greater part of the town ; there 

 are, however, a few privies, the contents of which 

 are not dealt with at the sewage farm." I am 

 informed that there are 2,325 privies, 1,440 wet 

 ashpits, 1,221 dry ashpits and 1,464 water-closets, so 

 that it would appear that the sewage does not con- 

 tain all the human excrement. The sewerage system 

 is on the Combined method, all street, roof, and back- 

 yard water being admitted to the sewers. During rain- 

 fall large fluctuations occur in the sewage flow, and 

 very frequently the outfall sewer is too small there- 

 for. The roads are principally macadam. There 

 is practically no manufacturing effluent; the sew- 

 age is therefore Domestic in character. Subsoil 

 Water. — The population per acre of drainage area 

 is small — viz., thirty-six — and consequently the 

 subsoil leakage to the sewers per head is propor- 

 tionately more than would be the case in a thickly 

 populated district; further, two small ditches run 

 into the main sewer where it passes by a syphon 

 under the Bridgwater Canal. The average Dry- 

 weather Flow is 800,000 gallons per diem. The 

 Storm Flow must approximate to that theoretically 

 possible — namely, 1,800,000 gallons per twenty-four 

 hours. The Water Supply is derived from the 

 Wood-Head source. The Rainfall is 37 in. per 

 annum, and the Drainage Area is about 500 acres. 

 Flushing. — With the exception of the main gravi- 

 tation outfall sewer the general lines of sewers 

 have fairly good falls throughout. They are not 



flushed at any time. Stay in Sewers. — The average 

 time taken by the sewage to reach the farm is about 

 three and a half hours, the Distance being about 

 2 miles. Sewer Capacity. — A 21 -in. sewer is laid 

 to the farm at a gradient of about 1 in 2,174, 

 having a theoretical capacity, running full, of about 

 1,800,000 gallons per day. The outfall sewer being 

 at such a flat gradient has not a self-cleansing 

 velocity, and has a tendency to silt up rapidly in 

 consequence. Storm Overflows. — Near West Tem- 

 perley station two ovoid brick sewers discharge 

 into a chamber provided with a storm overflow sill 

 and iron flap valve opened during storms by the 

 head of sewage and storm water. It discharges by 

 a 3-ft. 9-in. circular brick culvert into an adjoining 

 stream, which eventually flows into the brook re- 

 ceiving the farm effluent. At present this main 

 storm overflow works at less than one of storm 

 water to one of sewage, or less than twice the 

 dry-weather flow. There are, in addition, two 

 other local storm overflows. It is from this cham- 

 ber that the outfall sewer to the farm starts. 

 Detritus Chamber. — About 150 yds. from the storm 

 overflow chamber the sewage passes through a small 

 catchpit 20 ft. by 2 ft. by 2 ft. deep, and any ac- 

 cumulation of silt or sand (such as that caused 

 by laying a new sewer) is extracted here when 

 necessary. There is one Settling Tank, 70 ft. by 

 6 ft. by 3 ft. 9 in. average depth, formed with a 

 circular bottom. Owing to the small capacity of 

 the tank but little appreciable settlement is effected. 

 The Stay in Tank is very short, being under twenty 

 minutes. The Sludge is drawn off about once a 

 week by means of a chain pump into an adjoin- 

 ing sludge bay 68 ft. by 18 ft. by 2 ft. 6 in. When 

 it has dried sufficiently it is mixed with farmyard 

 manure and ploughed or dug into the land where 

 required. The Analyses, both chemical and bac- 

 teriological, of the sewage will be found at the end 

 of this section compared with those of the efiluent 

 and of the stream. 



17 



