437 



TEEATMENT OF LIQUID SEWAGE IN GREAT BRITAIN. 



The first report of tbe British Association Sewage Committee states, 

 that at fifteen places which are seAvered wholly or partially the liquid 

 sewage is subjected to treatment either by allowing it to remain for a 

 time in settliug tanks, from which the deposit is occasionally removed, 

 as at Burton-ou-Trent, Birmiugham, Epsom, Fareham, and Andover, or 

 by filtering, as at Uxbridge and Ealing. In eight instances deodorizing 

 materials are added to the sewage : Lime and carbolic acid are used at 

 Carlisle and Harrow; lime aloue is used at Leicester; lime and chloride 

 of lime at Luton; perchloride of iron at Cheltenham; perchloride of iron 

 and lime at Northampton ; ferruginous clay, treated with sulphuric acid, 

 at Stroud. At Leamington the lime treatment has lately been super- 

 seded by a method by which the sewage is clarified and a deposit sep- 

 arated, which is sold as manure. In regard to the effects thus produced, 

 it is stated that at Leicester the sewage runs off as pure as ordinary rain 

 water ; at Ealing it is free from smell, colorless, and harmless to vege- 

 table or animal life ; at Stroud and Luton the effect is stated to be sat- 

 isfactory ; at Harrow the nuisance is somewhat mitigated, and at 

 Abergavenny the stench is said to be abated by the treatment of the sew- 

 age; at Bury St. Edmunds upward filtration, through charcoal and 

 gypsum, has been abandoned as too costly, and in favor of irrigation ; 

 at Banbury treatment of the sewage has failed, and irrigation is now 

 resorted to ; at Hereford, where it was proposed to be adopted, it has 

 not been tried on the score of expense ; at Tunbridge it is about to be 

 tried; and at Hastings and Cambridge experiments are being made. 

 The cost of treatment amounts to £1,200 i)er annum at Leicester, for a 

 Ijopulation of 89,000, discharging into the sewers. At Ealing, wath a 

 population of 7,500, the annual cost is £300. At Luton, with a popula- 

 tion of 18,000, the annual cost is £500; at Cheltenham, with a popula- 

 tion of 36,000, it is £350 ; at Uxbridge, with 7,000 population, it is £200; 

 and at Alton, with 3,000 population, it is £46. The solid deposit ob- 

 tained by treating liquid sewage is sold at prices varying from 6^. to 

 2s. 6d. per ton. At Leicester as much as 5,000 tons is produced. At 

 Luton the deposit is mixed with night-soil ; at Banbury with street-sweep- " 

 ings ; and at Stroud it is made the basis of a manure that is said to be 

 sold at £7 10s. per ton. 



In only fifteen places out of the ninety-six Avhere the water-carriage 

 system of removing excreta! refuse is adopted, either generally or par- 

 tially, is the sewage applied for irrigating land. Of these places eight 

 are completely sewered ; in eleven of them water-closets are general, and 

 in two they are partial. The remaining seven towns are only i:>artially 

 sewered and in three of these towns water-closets are general, while 

 privies are general in the other four towns. At most places the applica- 

 tion of the sewage to land has been found to exercise a most beneficial 

 influence on the condition of the streams receiving the drainage of the 

 district. Even w^here only the solid portion of the sewage is separated 

 by filtration or precipitation, the state of the rivers receiving the dis- 

 charge is to some extent improved. Generally speaking, no objeetions 

 appear to have been made to the application of sewage for irrigation ; 

 and where such objections have been urged, on the ground that the ap- 

 plication was offensive and injurious, they do not appear to have been 

 supported by ULedical authority. In most cases the application of 

 sew^age for irrigation has not been attended with any apparent change 

 in the sanitary condition of the districts, but there is said to be a marked 

 improvement at Braintree. The number of acres irrigated by the sewage 



