Doncaster Scientific Society
“River Pollution and Purification.”

There was an exceptionally large attendance at the meeting of the Scientific Society, which was held in the Old County Court Room, Guild Hall, on Wednesday evening.

The lecturer, Mr. J. Corbett, is a brother of the learned president of the Society, who occupied the chair, and the subject, that of “River Pollution and Purification,” was one of considerable importance in this locality.

Mr. Corbett, who hails from Salford, where he holds the position of Borough Engineer, is a authority on the subject he was handling, having been engaged in the study and treatment of sewage in the industrial district of Lancashire for many years.

He showed that the problem of artificial river purification was of quite modern growth, for in 1801, with the exception of the Thames and its Metropolitan tributaries, there was no large foul river in the country. About 1820 river pollution became a serious question owing to the invention of coal gas lighting, as all the foul by-products of the manufacture of gas were dumped into the rivers.

The progress of chemistry soon found such good uses for these by-products that they became very valuable, and were seldom run into rivers; but there were other pollutions not so easily made profitable, especially the sewage from dense populations. So long as the population of the watershed of any river was small in proportion to the river’s flow, the natural processes of oxidation, fish and plant life would transform the polluting substances into inoffensive forms, and thus natural rivers had a great power of self-purification.

Mr. Corbett gave some figures showing the great increases in population during the last century, and the consequent increased pollution of rivers, dealing particularly with the watersheds of Lancashire, where he said, the work of river purification was being vigorously pursued, so that notwithstanding the enormous population the rivers were not now deteriorating.

He mentioned that many of the rivers in the West Riding urgently needed vigorous purification, and instanced the case of the Irwell reiver in Lancashire to show that even in an extreme case such purification was quite practicable.

Coming to methods, the lecturer said that the first and best method was discovered in very early times, irrigation, or sewage farming, having been practiced around Jerusalem in its best days. Coming to modern times, the celebrated irrigation meadows at Craigentinny, near Edinburgh, were established about 1825, and were still flourishing and very remunerative.

There was throughout the country numerous successful sewage farms, which had been worked for 30 of 40 years with continued prosperity, and it was safe to assert that whatever there was near a town an adequate area of light sandy soil available at a modest price, a sewage farm could be used to purify and utlise the sewage of the town with economy and efficiency.

Mr. Corbett described as a serious blunder the idea, once very prevalent, that by the use of sewage tanks the well known manurial qualities of liquid sewage became concentrated in the precipitated “sludge.” In reality only about 15 per cent. of the manurial and putrescible matter of the sewage remained in the sludge, and 85 per cent. flowed away in the innocent-looking tank effluent.

Meanwhile the exponents of the science of bacteriology discovered that the purification of sewage in suitable soils was due, not to the processes of vegetation, but to the operations of innumerable minute life organisations of various types, and as a result of their enquiries there were now in use all over the world a great variety of arrangements for carrying out the bacterial purification of sewage.

The lecturer himself had succeeded in carrying out, what he believed to be, the most concentrated sewage purification works in the world, those at Salford, where the sewage of a population of about 240,000 was satisfactorily treated on eight acres of bacteria beds.

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Passing on to the question of the disposal of the trade refuse, Mr. Corbett said that the most bulky and most troublesome form of refuse was some years ago, the burnt cinders and ashes from the furnace of steam boilers were now found to be one of the best materials for forming bacteria beds for sewage purification. Cinders and coke also formed a good medium for catching greasy substances found in sewage, and when hoked with grease, could be used as fuel for furnaces, etc. Grease from sewage was being dealt with in various ways, as for instance in the Yorkshire woolen manufactories, the wool grease which had been one of the greatest difficulties hitherto, could now be recovered in a marketable form.

Mr. Corbett went on to speak of the purification of rivers which had to provide the domestic water supplies of large towns, and quoted as the most wonderful instance of success in that difficult and risky process the County of London, which was less subject to cholera, enteric fever and other such diseases than most towns in the country, and yet drew about half its water supply from the Thames. In this direction also the science of bacteriology had proved of great service in regard to aerated filter beds.

In conclusion, he declared that the Americans had “gone one better” than the country in regard to some of the processes he had mentioned, and declared that in this phase of public duty we must endeavour to hold a leading position if we wished to remain a prosperous nation. Above all things we must maintain ample supplies of pure water for domestic and trade use, and it was quite time that the past careless toleration of ever-increasing river pollution should be brought to an end by more drastic legislation and by a strong public sentiment leading to effective action for the general carrying out of river purification throughout the country.

(Applause)

The discussion was opened by Mr. J. E. Johnson, the local inspector of the West Riding Rivers Board, who gave some interesting particulars of the difficulties met with in the treatment of trade refuse in the Ridings. Others joined in the discussion, and at the close, a hearty vote of thanks was passed to Mr. Corbett for his address.

From the Doncaster Gazette