Waterbury Democrat., 1900-12-18
DISPOSAL OF SEWAGE.
Another Report Prepared by Engineer
 Aldermen Table It.

ing, submitted to the aldermen last night, and ordered laid on the table, is as followS:- r- "---
 To the Board of Aldermen of the City
 of Waterbury, Conn:
 Gentlemen: In August, 1896, 1 pre- scented to you. at your request, a report on an investigation made into the best means of disDosing of the sewage Of your city, resulting in the formulation of two projects: one, chemical preclp- itation of the solid matter with sub sequent land filtration of the. liquid matter near Platt's Mills, the other, a filtration of the raw sewage upon land situated near Beacon Falls.
 Neither project was given an unQual- flied preference over the other. The chief unfavorable characteristics of both projects was the great expense necessary in either case.
 Final action upon the adoption of plan was postponed; partly. it may be presumed. on account of the proSpec- tive heavy financial burden and partly because, in view of recent develop ments in sewage puriication in Eng land. it was desired to make sure that so large sum of money as that which would be required, should be invested in the best practicable plan. England was talking much about the so-called septic process. which had been intro duced in several towns with the hope of very materially cheapening the pur- itica ton of sewage. Ii seemed there fore. reasonable and proper to await the results there to be obtained before making q final move in your city. The present year appeared to war rant an examination of these novel works. several having been in opera | 1it | engineer. R. A. Cairns, was instructed to visit them for such a purpose. and. as I was going to Europe about the same time you asked also me to give you an opinion re egartlinG the applica- : tion of the new methods to the case you have in hand.
 | Nr Cairns and 1 accordingly met in i England and either separately or to- i gethcr examined the more important works. and exchanged our views re- garCling their merits and demerits.
 To understand the chief features of | the new process for our present pur- pose. it may be well first tO briefly review the essential features of sewage puritication. as known to-day.
 Sewage. containing organic matter. partly suspended and partly dissolved in a large amount of water, is a rich
 
 sorts of bacteria. They are supplied to the sewage chiefly through eNcreta and convert the organic matter, through different processes. into inor- ganic. or, from q sanitary point Of l view, harmless substances. This con. l version can take place only when the matter is in a liquid state. The first important step necessary is. therefore
 to change the solids into liquids; ill other words. to get all the organic matter into solution. The second ster
 is to change this liquid matter, by the
 oxidation of the nitrogen and carbon
 compounds. into nitriteS, nltratcS, car 1 bnnic acid and water.
 When there is plenty of air. l. O. ONy
 gen, present both steps are taken by
 the single process of oxidation. accom-
 plished chiefly through the action o1
 aerobic bacteria, and finally results i,
 the production of carbOnic acid and nj
 trltcs. none of which are offensive il
 anDearance CT smell. Pari Dassu witt
 this conversion of the organic matter
 gees also the disappearance of the bac
 teria As an example, observe tho
 inoffensive gradual disappearance o' ! dead VeCetahle matter in forest ant
 field or of dead animal matter Whel ! continually exposed to strong current:
 of air.
 On the other hand. when there is bu
 little oxygen or none at all present
 the conversion is less simple. The frs
 step is accomplished by anaerobic O IiGIlifying bacteria and therefore i called hydrolysis. These bacteria pro duce chiefly hydrogen compounds b. a process of putrefactiCn, the result
 of which. particularly with highly nj trocenous or animal matter are ot fensive both i'll appearance and smell ] Instance the foul smells of decaylh I vegetables and especially Of anima
 matter. when contained in small CT
 closed spaces with no circulation of al
 and particularly when no dampnesS Q present. When these hydrogen con : bounds are then exposed to q sufficien r. quantity of oxygen, they are again al . tackled by bacteria. but this tune II the aerobic class. which causes q COT ;. version into inoffensive products c T oxidation. A buried animal body. r is well known. first putrenes and the , the nrctlucts oXidize. with the final r'
 siIlt that only mineraliZed bones an 'i salts ale left.
 Il In the first process, the oxidation = tGe raw sewage is accomplished pra , tically by slow filtration throug . i porous soilrhc Saweg is applied |! " termittently, so that at intervals e thorough aeratiCn can furnish the so $ with the necessary oxygen to tran q form the liquid sewage matter into Il
 organic compeunds. This is the pr
 cess of s0-c3lled' intermittent filtration Il extensively applied since 1870 for seV T. age purification i'll Europe and Amer s. ca; and it Is also the process Whlt V was recommended to you to be co . ducted at Beacon Falls and nnon u n sandy territory near Platts Mills. Ill The other process emhodles. frs n hydrolvSis of the solid matter. quick V. produced hv anaerobic bacteria. aI to then. oxidation of the liuIIi1 matte
 Thus the sewage is transformed ill | simpler substances at a more rapid r:l ts tl,an is possible if the usual Quant rs of solid matter is held i'll susDensio 10 This embodies the new So-cal}ed 'se - 1 lie process" recently much talked S and eyperimented with in Europe. id ranuires less land than intermitte C. filtration. because without solid matt ls an increased speed of percclation ,+ possihle. It is also less expensive = oneration than the chemical precfpit ie tion. process. because there is le Id sludae to handle. For these reaso