Hints from the Health Department. Leaflet from the archive of the Society of Medical Officers of Health. Credit: Wellcome Collection, London
[Report of the Medical Officer of Health for London County Council]
II—EXPERIMENTAL BACTERIAL TREATMENT OF CRUDE SEWAGE AT
THE NORTHERN OUTFALL WORKS (BARKING).
1.—TABULATED LIST OF THE EXPERIMENTS AND OF THE BACTERIA-BEDS.
The various experiments carried out at the Northern Outfall Works in connection with the
bacterial or natural treatment of sewage are included in the following list.
The bacterial treatment of effluent from chemically treated and sedimented sewage in a
coke-bed of one acre area.
The treatment of raw sewage in bacteria-beds, with and without previous settlement.
(a) Without previous settlement.
In beds of Kentish ragstone and of coke, from September 22nd, 1898, to April 15th,
1899. (Series I.)
In coarse and fine coke-beds, from July 4th, 1899, to May 19th, 1900. (Series II.)
(b) With previous settlement.
In coarse and fine coke-beds, from November 7th, 1900, to August 10th, 1901.
The one-acre coke-bed, as originally constructed, was three feet in depth, and it was
composed of unsifted pan breeze. In 1898 it was increased in depth to 6 feet, by placing on
the top of the old bed 3 feet of sifted coke fragments about the size of walnuts; it has not
undergone further alteration in depth.
It was first used as a 6 foot coke-bed, on April 29th, 1898, and since May 12th, 1898,
it has been dealing almost continuously with effluent from the chemically treated and sedimented
This coke-bed has been reported upon in the Third Report, pp. 13 and 14, and the analytical
results are given on pp. 25 to 34 of the same Report. Later details of the work of this coke-bed
are given on pp. 9, 10, 24, 28 and 29 of this Report.
For the purpose of carrying on other experiments on the bacterial or natural process of
sewage purification, four galvanised iron tanks were used. In order to facilitate the use of
these tanks in pairs, for the treatment of sewage in two consecutive coke-beds by so-called
'"double contact," two of the tanks were fixed at a higher level than the other two; by this
arrangement the effluent from a higher tank could be allowed to flow into a lower tank bv
The following table indicates the various uses to which these tanks have been put during the whole of the bacteria-bed experiments—
|Date.||Upper tanks.1||Lower tanks*|
|No. 1.||No. 2.||No. 1.||No. 2.|
|1898. 22nd Sept.||Kentish ragstone-bed, primary||Coke-bed, primary ...||Kentish ragstone-bed, secondary||Coke-bed, secondary.|
|1899. 15th April.||End of Experiments of Series I.|
|1899. 4th July.||Primary, coarse coke-bed||Primary, coarse coke-bed||Secondary, coarse coke-bed||Secondary, fine coke-bed|
|1900. 19th May.||End of Experim ents of Series II.|
|1900. 7th Nov.||Settling tank A||Settling tank B||Single coke-bed A ( coarse")||Single coke-bed B ("fine")|
|1901. 10th Aug.||End of Experim ents of Series III.|
2.—SUMMARY OF THE PREVIOUSLY REPORTED DETAILS OF THE EXPERIMENTS
IN THE BACTERIAL OR NATURAL TREATMENT OF SEWAGE AT THE
NORTHERN OUTFALL WORKS, WITH SUCH ADDITIONS AS ARE NECESSARY
IN ORDER TO COMPLETE THE INFORMATION UP TO THE END OF 1901.
(a) The One-acre Coke-bed dealing with the Effluent from Chemically Treated and Sedimented
The one-acre coke-bed has been dealing almost continuously with effluent from the
chemically-treated and sedimented sewage since May 12th, 1898. Full particulars of the
working of the bed up to April, 1900, and details of the chemical analyses of the liquid supplied
* Each tank was originally 4 feet square and 6 feet deep.; they were afterwards increased to 10 feet deep.