6 AMERICAN MUSEUM (HIDE LEAFLETS 



of this immense mass of liquid amounts to 800 tons; and this is approxi- 

 mately the amount of organic matter discharged into New York Harbor 

 every day. 



The organic matter in sewage, which is the principal source of embarrass- 

 ment in its disposal, is made up for the most part of imperfectly oxidized 

 unstable molecules which may undergo one or the other of two different 

 series of changes. First, it may decompose or putrefy in the absence 

 of oxygen, with the production of offensive gaseous compounds. Or 

 secondly, under the influence of oxygen it may undergo another process 

 that of nitrification, a slow burning or combustion which converts the organic 

 matter into nitrates or other mineral substances, without the production 

 of foul odors and in a wholly innocuous way. 



Where sewage is discharged without due precautions into the nearest 

 watercourse, the first sort of change is likely to result. If the volume of 

 the sewage in relation to the stream lie small, there may he enough oxygen 

 present to care for tin- organic matter. If, on the other hand, the volume 

 of sewage exceeds the purifying capacity of the stream (which may be 

 taken as ahout one part of sewage in fifty parts of water' the whole process 

 changes: instead of self-purification, there is putrefaction. Decomposable 

 organic matter accumulates on the bottom and the whole stream or pond 

 i- turned into a fermenting pool, the odor from which may produce a serious 

 nuisance for considerable distances from its banks. Conditions like these 

 now exist within the limits of Greater New York in such places as the 

 estuaries of the Gowanus (anal and Newtown (reck. 



CONDITIONS IN NEW YORK HARBOR 



New York is more fortunate than most cities in its insular position and 

 in the large bodies of water which wash its shores. Even here however, 

 the present methods of disposal by the haphazard discharge of some 

 sewers at the piers or bulkhead lines is manifestly unsatisfactory. So fat- 

 as the harbor waters as a whole are concerned, it must he noted that the 

 amount of diluting water available is much less than would at first sight 

 appear. The hourly variations are great. Over 3000 million cubic feet 

 of water pa>s through the Narrows in a single hour at the maximum period 

 of Hood.' The total ebb at this point is 12,213 million cubic feet; but the 



> Data in regard to conditions in New York Harbor are quoted from the Report of the 

 Metropolitan Seweragi Commission, I910 s 



