THE WATER SUPPLY OF THE CITY OF NEW YORK 
E. Waller ~Ph. D. 
1 desire, in the first place, to present the results of complete an- 
alyses of the Croton water made at different times. The various 
denominations of salts quoted have been given in order to literally 
quote the different analysts. For the three first, double columms 
are given, representing the result, in grains per English (Imperial) 
gallon of 70,000 grains, and also in grains per United States gal- 
lon of 58,318 grains, the first columns in each case being the form 
in which the analysts have recorded their results, to judge from the 
context. In Nos. 4 and 5, the magnesium and calcium bicarbon- 
ate have been calculated back to mono-carbonates, and the results 
given brackets. Another table of the same results, calculated 
to parts per 100,000, is appended. 
There is probably less difference in the results than the figures 
would seem to indicate, the mode of stating the results in the ear- 
lier analyses rather suggesting different methods of conducting the 
examination, and calculating the results to those at present in use. 
Next, permit me to call your attention to a chart showing graph- 
ically the variations found in the constitution of the Croton water 
by Dr. C. F. Chandler during the Summer months of 1867 and 
1868, representing some fifty examinations, and my own results, 
made in a similar manner every week, from the latter part of 1872 
to the middle of 1879, representing about 350 examinations. The 
average results may be thus stated : 
Average of results of tests made on Croton water (Parts per 
100,000) : 
Mineral 
matter. 
Org. and 
volatile. 
Total 
solids. 
Hardness 
Ox’u absor- 
bed from 
Perman - 
ganate. 
Summer of 
1867 
6.72 
1.12 
7.84 
4.32 
0.181 
U 
1868 
5.66 
1.97 
7.63 
0.168 
Last 2 mos. 
1872 
7.48 
0.44 
7.92 
3.553 
0.131 
Y ear 
1873 
6.23 
1.59 
7,82 
3.395 
0.135 
U 
1874 
5.83 
1.76 
7.59 
3.332 
0.166 
1875 
5.656 
1.835 
7.491 
3.293 
0.211 
u 
1876 
5.416 
1.682 
7.098 
3.159 
0.185 
u 
1877 
5.603 
1.823 
7.426 
3.260 
0.253 
u 
1878 
5.299 
1.904 
7.203 
2.846 
0.183 
First 5 mos. 1879 
Average from Nov. 
5.424 
) 
0.912 
6.336 
2.811 
0.072 
1872, to May,1879, 
inclusive 
- 5.702 
1.678 
7.380 
3.210 
0.180 2 
THE AVATER SUPPLY OF THE CITY OF NEW YORK. 
The “ Total solids” AArere determined by weighing the residue 
obtained by evaporating a measured quantity ; the “ Organic and 
Volatile ” by igniting this residue, moistening Avith carbonic acid 
Avater, drying and weighing again ; ‘‘Hardness” by standard soap 
solution as usual, the results being expressed in the Equivalent of 
calcium carbonate, AAdiile the “ Permanganate ” test Avas that of 
Miller. (J., Lond. Chern. Soc., 1865, p. 117 ; see also R. Angus 
Smith, Watts’ Dictionary, v. 1039 ; Wauklyn’s Water Anal., Ist 
Ed., 1868, p. 43. &c. and others), acidifying with H2 S 04, adding 
standardized solution of permanganate, until the color held for 
half an hour at the ordinary temperature of the laboratory. 
In addition to these, several other examinations made at irregu- 
lar intervals, and at other times than those specified above might 
be given, but as they present no marked deviations, I will not oc- 
cupy your time with them. 
As a sample of similar determinations made on samples of the 
Croton, taken from different parts of the city at the same time, I 
would present the results obtained in April of last year, when the 
odors in the water caused suspicion that it contained some com- 
pounds dangerous to health. 
No. 
Locality. 
Mineral matter. 
Organic & Vol. 
Total Solids. 
Oxygen absorbed 
from 
Permanganate. 
1 
West 33d St. 
6.6 
2.2 
8.8 
0.064 
2 
East 34th St. 
6.0 
1.5 
7.5 
0.060 F 
5 
West 131st St. 
4.4 
1.3 
5.7 
O.064F 
8 
East 122d St. 
5.7 
trace 
5.7 
0.062 
The samples marked F were clarified by subsidence or filtration 
before examination, as they contained varying amounts of muddy 
sediment, and were therefore not fair samples of the water as or- 
dinarily used. It may be mentioned that about a pint of No. son 
standing half an hour in a cylinder, some inches in diameter, de- 
posited a sediment fof an inch in depth. When this sediment was 
distributed as evenly as possible through the water and a portion 
was examined, the results Avere 
No. 
Mineral. 
Org. and Vol. 
Total. 
Oxygen from 
Permanganate. 
2 
75.7 
21 
96.70 
0.366 
5 
69.2 
15.1 
84.30 
0.455 tHK WATER SUPPLY OP THE CITY OF NEW YORK. 
3 
A portion of the sediment was examined separately. Shaken 
with ether it afforded as soluble in that menstruum, a minute pro- 
portion of vegetable wax having a slight greenish-brown tinge, pro- 
bably from the presence of chlorophyll. 
A small amount was obtained for analysis. The results were 
Loss on ignition. 23.31 
Silica 43.61 to 51.00$ 
Lime 0.63 =CaCo3 1.12$ 
Magnesia 3.16 =MgCo3 6.64 
Ferric and Alurainic oxides 20.92 
As to other determinations on the Croton Water, the following 
results are offered. 
Parts per 100,000. 
Date. 
Free Ammonia. Albuminoid Ammonia. Remarks. 
August, 1874. 
0.00095 0.0145 
average of 6 
December, 1877. 
0.0010 0.0102 
“ of 2 
Nov. 16th, 1878. 
0.0015 0.0130 
July 11th, 1879. 
0.0008 0.008 
April 4th, 1881. 
0.0020 0.0110 
“ 22d, “ 
0.0016 0.0117 
average of 10 
u u u 
0.019 to 0.031 
Total NH3on very 
turbid samples. 
May 16th, 1881. 
0.001 0.007 
Nov. 8th, 1881. 
0.002 0 012 
Nitrogen in Nitrates. 
July 29th, 1881. 
0.0198 
Nov. 8th, “ 
0.0181 
The results obtained on free and albuminoid ammonia do not in- 
dicate any material alteration in the proportions of those constitu- 
ents yielding nitrogen in those forms since the examinations began 
to be made. The investigation of last April shows that the qual- 
ity of the water does not vary very much in different parts of the 
city at the same time, unless the sediment is mixed in, when the 
amount of nitrogen obtainable as ammonia by distillation may 
reach nearly thrice the amount obtainable from the sample when 
fairly clear. 
The amounts of nitrogen in nitrates so far as they go give no 
indications of sewage contamination in the water. 4 
THE WATER SUPPLY OP THE CITY OP YEW YORK. 
About the end of last year a paper by Prof. Leeds on “ Relative 
purity of city waters in the United States,” was published in the 
Chemical JShews (xnv p. 265), in which the Croton water was con- 
demned as contaminated. 
The analytical results were given as follows: 
Croton, June 23d, 1881. (Results in parts per 100,000) 
Free Ammonia 0.0027 Chlorine 0.350 
Albuminoid “ 0.027 Hardness 3.30 
Oxygen required 0.81 Total Solids 11.80 
Nitrites none Mineral Matter 5.00 
Nitrates 0.8325 Organic & Vol. 6.80 
These results I strenuously object to as misleading. 
The term “ nitrates ” is indefinite, and when so many chemists 
calculate their results to “ nitrogen in nitrates,” &c. a false impres- 
sion is readily created by the above statement in that regard. The 
“ oxygen required,”! have learned was obtained by Kubel’s method 
—by the action of potassium permanganate on the water strongly 
acidified with sulphuric acid at the boiling temperature. Inasmuch 
as most chemists (at least in English speaking countries), use the 
permanganate test at ordinary temperatures,such a statement as the 
above, without specifying the method used, is calculated to convey 
a false impression of the quality of the water. Moreover the tes 
performed in that Avay isopen to serious objections. 
Under those circumstances the chlorine in the water would affect 
the results, and Prof Leeds himself has shown us that the reagents 
used invariably contain impurities which would affect the test to 
the prejudice of the water tested, the permanganate containing 
chlorine compounds, and the sulphuric acid (which is used in con- 
siderable amount) containing lower oxides of nitrogen and sulphur, 
so that where a line is drawn on comparatively small amounts of 
oxygen absorbed from permanganate, the impurities in the reagents 
would make a great difference in the conclusions to be drawn. 
Prof. Leeds’ results on Total Solids and Free and Albuminoid am- 
monia are very high, indeed higher than any results I have obtained 
during the past fourteen years, except when—as last spring—the 
samples of water were so charged with sediment as to render them 
by no means fair samples of the Croton Water as ordinarily obtain- 
able. The conclusion would seem to be that his sample was turbid 
with sediment. The water supply of the city of new York. 
5 
With regard to other determinations they either agree with the 
preceding examinations, or the methods employed were different 
from those of which I made use, and therefore preclude a compari- 
son between them. 
In commenting on the results, Prof. Leeds remarks: “New York 
and all the places mentioned lower on the list receive their water 
from contaminated sources. The feeders which empty into Croton 
Lake, the principal reservoir of the New York water, pass through 
a settled country, with numerous tanneries, factories, &c., along 
their banks. Analyses of the Croton water, made at different 
times during the past five years, have shown that it is to be classed 
among contaminated water supplies,” A quotation of this state- 
ment was sent to Mr. Isaac Newton, Chief Engineer of the Croton 
Aqueduct Department. His reply was briefly to the effect that he 
had comparatively recently examined the Croton Avater-shed, and 
that Prof. Leeds’ assertion with regard to it was altogether erro- 
neous. 
From other sources, I have been able to ascertain, first, that with 
regard to the population of the water-shed: for its area of 339 
square miles the population is from 17 to 20,000, or about one man 
to every ten acres. Permit me to quote the table given by Mr. D. 
M. Greene in the 23d annual report of Water Commissioners of 
Troy for 1877, p. 120. 
Population of water sheds for city supplies ; 
City. Population per square mile. 
Rochester, N. Y. . . .36 
New York, N. Y. . . . . 65 
Albany, N. Y. ... . .77 
Poughkeepsie, N. Y. . . . 86 
Schuectady Cohoes, )g, from Mo. 
J roy, | River. . . . 103 
Brooklyn, N. Y. . . . .119 
Boston, Mass., ... . . 229 
London, England, . . . . 270 
/Second.—As to industries in the Croton water-shed. But few 
tanneries now exist in that region for the simple reason that the 
most of the trees yielding the necessary bark have been cut down, 
and tanning is no longer profitable in that section. As regards 
other industries the region contains but few factories of any kind, 
and those are on a small scale. 6 
THE WATER SUPPLY OE THE CITY OE NEW YORK. 
To sum up, I desire to express a most emphatic dissent from 
Prof. Leeds’ conclusions for the following reasons: 
1. The proportion of chlorides existing in the water has not in- 
creased of late years so far as the records extend, and hence no in- 
dications of contamination by sewage or manufacturers can be assert- 
ed to exist. 
2. The amounts of oxygen absoi-bed by permanguate test for a 
number of years, (serving to compare the water with itself at differ- 
ent times) show no changes in the quality of the Croton water. The 
same may be said for the results on Free and Alluminoid Ammonia 
and Organic and Volatile matter. 
3. The Croton water-shed is not crowded either with population 
or with manufacturers as Prof Leeds seems to imagine. 
4. The health of the community is not, and has never been, such 
as to indicate the presence of any contamination in the water sup- 
ply. THE WATER SUPPLY OE THE CITY OF NEW YORK. 
COMPLETE ANALYSES OF CROTON WATER 
RESULTS IN GRAINS PER GALLON. 
Number 
1 
1 
2 
2 
3 
3 
4 
5 
6 
7 
Professor 
Analyst 
J. C. Booth. 
Dr. J. R. Chilton. 
C.F. Chandler. 
E. Waller. 
August, 
Sum’er 
May,' 
May, 
Nov. 
1843. 
1843. 
1859. 
I860. 
1872. 
1879. 
1881. 
Gallon used 
Eng 
U. S. 
Eng. 
u. s. 
Eng. 
U. S.* 
Sodium chloride 
.... 1 
0.44 
0.367 
4.404 
0.336 
0.402 
0.284 
0 205 
0.205 
Calcium sulphate 
... ) 
0.353 
0.294 
0.158 
0.024 
0.723 
0,193 
0.161 
0.179 
0.205 
0.188 
0.201 
0.260 
0.024 
0 200 
0.216 
0.828 
0.690 
0.90 
0.270 
0.225 
0.054 
.... I 
0.84 
0.750 
0.147 
0.122 
.... [ 
0.104 
0.087 
Magnesium carbonate.. 
0.939 
0.782 
1.52 
0.700 
0.390 
0.325 
(1.101) 
(0.770) 
0.918 
0.685 
Calcium carbonate 
2.293 
1.910 
1.266 
0.836 
0.696 
(1.648) 
(1.439) 
1.650 
1.319 
1.913 
1.3:38 
2.670 
2.331 
0.110 
0.092'] 
0.058 
0.175 
0.045 
Silica 
0.339 
0.299 I 
0.46 
0.383 
0.170 
0.142 
0.621 
0.222 
0.274 
0.210 
Organic and volatile 
0.276 
0.240 J 
0.916 
0.763 
0.670 
0.874 
0.560 
0.233 
3.590 
2.990 
6.873 
Solids by evaporation... 
4.998 
4.174 
4.16 
3.466 
3.705 
3.087 
4.780 
3.849 
4.893 
3.168 
0.296 
0.243 
0.172 
0.124 
0.124 
ABOVE RESULTS GIVEN IN PARTS PER HUNDRED THOUSAND. 
1 
o 
3 
4 
5 
6 
Analyst . 
Booth. 
Chil 
ton. 
Chai 
idler. 
Waller. 
1843. 
( 
1843. 
1859. 
1869. 
1872. 
1879. 
1881. 
0.629 
0.690 
0.487 
0.351 
0.351 
( 
0.504 
0.272 
0.041 
1.239 
0.276 ' 
0.309 
0.351 
0 322 
0 345 
0.449 
0.041 
0.343 
0.371 
1.183 
) 
0.386 
0.092 
1.286 
0.210 
f 
0.149 
1.341 
1.200 
0.557 
(1.888) 
(2.826) 
3.280 
(1.320) 
(2.467) 
2.294 
1.575 
1.174 
3.276 
2.171 
0.194 
2.830 
2.262 
4.578 
trace. 
3.996 
0.100 
0.157 ) 
.... 1 
0.243 
0.300 
0 078 
0.513 y 
0.657 ( 
0.394 ) 
1.060 
0.380 
0.470 
3.360 
1.309 
1.150 
1.500 
0.960 
0.400 
Total 
5.129 
11.788 
9.190 
Solids by evaporation 
Chlorine 
7.140 
5.943 
5.293 
0.508 
8.200 
0.416 
6.600 
0.294 
8.390 
0.213 
5.432 
0.213 
Nos. 1 and 2. Illustrations of the Croton Aqueduct. F. B. Tower. N. Y., 1843, p. 135, 
No. 3. Report of Water Commissioners of Albany for 1865, p. 50. 
Nos. 4 and 5. Report of Board of Health for 1871, New York, p. 371. 
No. 6. Report on Croton Water, New York, 1881, p. 45. 
* U. S. gallon of 231 cubic inches (58,318 grains).