Connecticut. State Board of Health.

Annual report of the State Board of Health for the fiscal year ending November 30 .. online

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on ignition found in any sample during the second year, is that of
the Thomaston sample of September, which gave 25.5 parts per
million, or 1.49 grains per gallon of organic matter.

Some waters contain at times such large numbers of floating
algae, as to give the impression of large amounts of organic
matter. In order to obtain data for the estimation of the amount
really contained in these forms, a quantity of blue-green algae,
consisting almost wholly of Clathrocystis and Anahcena^ in about
the proportion of 3 to 1, was filtered out of the water in which
they occurred, and suspended in distilled water. Measured
quantities of this mixture were used for determination of the
solid residue and of the total nitrogen. The residue diied at
100° C. was found to contain 6.3 per cent, of nitrogen.

The sample containing the largest amount of suspended matter
was that of New Britain for September, 1890. It was very
turbid, and gave 0.420 parts of nitrogen of albuminoid ammonia
in the filtered, and 1.296 parts in the unfiltered water, leaving
0.876 for that derived from the suspended organisms.

The organisms most abundant were groups of Anahoenay and
assuming for them the composition given above, this amount of
nitrogen of albuminoid ammonia corresponds to the presence of
27.8 parts per million, or 1.62 grains per gallon, of dry organic

The amounts of dissolved and suspended organic matter in the
examples cited are very exceptional, and have a most marked
influence on the character and appearance of the waters, still
1.49 and 1.62 grains of organic matter are in themselves very
small quantities of material when it is considered that they are
diluted to one gallon. We cannot, however, doubt that these
amounts and even much smaller quantities may have much san-
itary significance.

* See methods of analysis.




It is a matter of common observation that certain waters pro-
duce diarrhceal and other disturbances in persons in good health,
but unaccustomed to their use. The somewhat indefinite charac-
ters of the symptoms alleged to be thus produced, and their
common production by other causes, make it difficult to fix with
certainty their relationship to the water in certain cases. But
it is easy to believe, that causes that certainly do produce distur-
bances in healthy persons at certain times, may also be the cause
of illness in feeble persons even though they habitually use the
water. Cases have been reported in which large groups of per-
sons have been made ill by the use of water, or ice made from
water, highly contaminated with organic matter of vegetable
origin, and which as far as could be ascertained, was not contam-
inated with sewage or other animal matter.*

While we may not cite cases in our own State, in which such
gross contamination of a water has existed as to have caused ill-
ness in a large proportion of those using it, still it would seem
certain that an impure water supply may be the cause of illness
in a community, quite independent of the causation of typhoid
fever or other infectious diseases.

We can conceive of two ways in which the organic matter in
water may have an injurious effect on those using it ; i. e. by the
direct effect of the material itself, acting as would a drug ; and
effects produced by products incident to the biologroal changes
in the water, which are induced in part by the organic matter.

When the organic matter is simply the extractives of unde-
composed vegetable matter, it is difficult to see how the amounts
which are found in waters, which would be considered potable,
can have any injurious effect. It is well known that many peaty
waters having much deeper color, and containing much more or-
ganic matter than any in use in our State, are in common and ap-
parently successful use elsewhere. Highly colored waters from
old woodland and swamps are not free from the accusation of in-
jurious effects on those using them, but this form of organic mat-
ter appears to be rather stable, and such waters give little trouble
from those causes attributable to the processes of decay.

The waters which have caused the most complaints from con-
sumers in this State, are those more nearly colorless, which have
derived most of their organic matter from the debris of water
plants, or at least those in which there are large annual growths

♦See CoDn. State Board of Health Report, 1888, p, 289.




of snch plants, examples of which may be found in reservoirs of
Thomaston, New Britain and Middletown.

That the albuminous matter from such sources has a special ten-
dency to decompose we cannot assert, but the fact that in waters of
the kind mentioned, the plants grow and decay in the water, is a
safficient explanation of the much greater changes that are ob-
served in the chemical composition of these waters. In growing,
the plants assimilate the organic matter, the ammonia and nitrates
of the water, and for the time hold these nitrogenous elements in
an insoluble form. If they could then be removed the water would
be purer than before, but as they are not removed it receives the
products of their decay, and the total organic impurity is much

While it is very desirable to keep the water plants from devel-
oping in our reservoirs, it is difficult to do so, as the conditions
affecting their growth are not all known. Two objects to be
aimed at in the construction of reservoirs, as of value in this
connection, would appear to be obvious ; first, to make them
of moderate depth, that the water may not be overheated
as it is in shallow places by the action of the sun ; and
second, to construct and maintain a well cleaned bottom, that the
plants may not there attach themselves and find nourishment.
Reservoirs so covered as to be dark do not support the most nox-
ious vegetable growths. The same may be said concerning
waters in rapid motion, consequently, supplies taken directly
from large atreams are not liable to troubles of this sort.

Sewage furnishes abundant nourishment for plants, and its
presence in water must be a potent factor in their development.
This would appear to be true, whether the sewage is added di-
rectly or whether it reached the reservoir after percolation
through the ground. For in the first instance there are abun-
dant ammonium salts, in the second, there are nitrates, and either
of these is an excellent plant food.

Aside from the unsavory organic contamination caused by sew-
age, and its influence on the development of objectionable forms
of plant life, the presence of sewage in water is especially noxious
because of its liability to contain the contagium of infectious
diseases, notably, typhoid fever and cholera. These are living
organisms, bacteria, which are capable of increasing in number
by reproduction, and although they may not find in a given
water, the conditions favorable to their reproduction, they are




yet capable of retaininp^ their vitality for considerable periods,
certainly long enough to be transported several miles from the
place of infection and to be distributed in a virulent form by
the ordinary methods of water distribution. This has been
demonstrated far too many times to admit of doubt.

The Free Ammonia, — The sources from which bodies of water
may derive their ammonium salts are, the rain, sewage, and the
decomposition of organic matter in the water, or on the collecting

The amount of ammonia in rain water is large and variable, but
the results of analyses of rain water collected in New Haven, as
given on another page, show much greater amounts of ammonia
than is found in the rain in the country districts, in which the air
is free from the contaminating influences of a large city. Al-
though rain water contains notably larger quantities of ammonia
than reservoir waters usually contain, it does not appear that the
rainfall at any one time perceptibly influences the proportion of
anmionia in the reservoir. The sudden melting of large masses
of snow, however, may do so.

As is shown in the analyses of sewage, quoted on page 371,
high free ammonia is a characteristic of sewage. Direct addition
of sewage may, therefore, notably increase the proportion of free
ammonia in a water; especially is this true during the cold
months when vegetation is much less active in removing the ex-
cess of this compound. It is believed that none of the reservoirs
included in this report are subject to direct sewage contamina-
tion, so that we must look to the decomposition of vegetable
matter in and about our reservoirs as the source of their free am-

The term, free ammonia, is applied to that ammonia which is
evolved when the water is distilled in the presence of a trace of
sodium carbonate. We do not believe that it exists as ammonia
dissolved in the water, but that it chiefly comes from the decom-
position of ammonium carbonate during the process of boiling.
That a part of it may be evolved from the organic matter during
the process, is shown by a comparison of the free ammonia obtained
from filtered and unfiltered water. The amount from the unfil-
tered water is greater, and although it is usually only slightly
greater, the difference may be considerable, as in the Thoroaston
sample of August, 1890, in which the free ammonia of the filtered
water was 0.114 and of the unfiltered water, 0.340 part per million.




Excluding the three reservoirs in which there were marked
irregularities in the amount of ammonia, it is seen that on the
whole the quantity of free ammonia is very small in our sur-
face waters, the average amount being about 0.020 part per mil-
lion. This shows that in general the assimilation by plants keeps
pace with the development of ammonium salts by the processes
of decomposition. High free ammonia, or marked irregularity
in this factor, is then an indication of excessive decomposition
changes in the organic elements of the water. It is these unsta-
ble waters, that cause the greatest complaint from the consumers.

In those reservoirs in which large quantities of plants grow and
decay, there is likely to be an accumulation of mud, rich in organic
matter, and prone to undergo putrefactive changes. The charac-
ter of such accumulations is shown in the following example : A
quantity of mud was collected on August 26, 1891, from the bot-
tom of the Middletown reservoir at a point where the water
plants grew abundantly. Quantities of the moist substance were
mixed with distilled water and examined with the following re-
sult :

Analysis op Mud from a Reservoir.

Mud taken 1,000,000. parts by weight.

Nitrogen of Free Ammonia 21. " "

Nitrogen of Albuminoid Ammonia 1,046. '* "

Total Nitrogen 1,869. " ♦♦

This amount of nitrogen would require the presence of 1.17
per cent, of albumin, if it were all in that form. The mud was
greenish black in color, contained many diatoms and rhizopods,
and emitted a foul odor. Such material readily undergoes putre-
factive changes and communicates the products formed to the
water in contact with it. When the water is stagnant, it may thus
become very highly charged with ammonia, ill smelling gases, and
other products of decay. It has been shown by the researches
instituted by the Massachusetts Board, that the wind may set
the water into circulation to a depth of twenty feet. And thus,
this foul water may, from time to time, be mixed with and con-
taminate the superficial and purer water of the reservoir. The
stagnant water in reservoirs of a greater depth than twenty feet
also rises and disseminates its impurities in the fall, owing to
temperature changes that then take place. In Massachusetts the
temperature of the water at a depth of forty feet or more, is
found to be about 45° F. Water is heaviest at a temperature of




40°, consequently the lower layers of water, below the influence
of the wind, are practically stagnant, until by the cooling of the
surface water, on the approach of the cold months, this sinks and
the relatively lighter water l)elow rises. Not until the surface is
lowered below 45° would the whole mass of water be set in motion.
That these conditions of stagnation, pollution and dissemination
do take place as described, has been abundantly shown by the
work done in Massachusetts. The following determinations of
free ammonia^ at different depths, in Jamaica Pond, may be
quoted from the Report before mentioned to illustrate the change
that takes place in the fall.

Depth in feet.





SO Average.

On Oct. 22, 1889... 0.068




4 200

5.920 0.773

On Nov. 27, 1889... .640





.612 .619

The figures represent free ammonia in parts per million. In
calculating the average, due allowance was made for the volume
of water at each depth.

Nitrogen as Nitrites and Nitrates, — Nitrogen as ammonia does
not long persist in this form .in water, but is either assimilated
by living plants, becoming a part of their organic constituents, or
it is converted into nitric acid by the activities of certain bac-
teria. This nitric acid unites with sodium or calcium and exists
in the water as nitrates of these bases. This is an oxidizing pro-
cess, and where water is subjected to it under the most favorable
conditions, as in intermittent filtration through sandy soil, it is
found that its nitrogen exists almost wholly in this form. This
is true of the purest well and spring waters. The nitrates, then,
are to be considered as the products of the complete oxidation of
other forms of organic matter.

The nitrites contain less ogygen than the nitrates ; they are
the products of incomplete oxidation, or they may be considered
as an intermediate form between the other nitrogenous bodies
and the nitrates. They are mot stable bodiea but tend to pass
quickly into the form of nitrates. Their general significance,
therefore, is the same as notable quantities of ammonia, that is,
their presence indicates a condition of change or instability in
the water. They do not, however, seem to be as much affected
by season as the ammonia, and they are especially abundant in
water receiving sewage. The amount of nitrogen as nitrites in
our reservoir waters is always very small, Ihe average of all de-
terminations being 0.0011 part per million. The lowest annual




aTerage in aoy reservoir is 0.0003, and the highest, in Lake
Whitney for 1889-90, 0.0028 part per million. Many samples
contained no nitrogen in this form ; the largest amonnt found
was in the Thomaston sample of November, 1890, namely, 0.008.
Lake Whitney shows their presence most constantly, and this
is to be attributed to the fact that this supply undoubtedly
receives a larger proportion of drainage from inhabited areas
than any of the other reservoirs.

The nitrates are much more constantly present than the nitrites
and in larger, though still, small, amounts. The average amount
of nitrogen in this form in all of the analyses is 0.06 part per mil-
lion, the largest amount is 0.24, some of the samples, especially
during the warm months, were quite free from it. As is shown
in the chart of averages, there is a notable increase during the
cold months. This is to be ascribed to the diminished activity
of plants during this period. The nitrates are entirely with-
out effect on the health of those using a water containing them,
even when they are present in very much larger quantities than
in any of our waters. Nevertheless they are of much importance,
for they give information concerning the history or source of the
water containing them, and they serve as food for water plants.

The nitrogenous matter of sewage is almost entirely converted
into nitrates, when it is allowed to percolate through a porous
soil. It thus happens that the ground water of inhabited regions
contains nitrates, sometimes in very large amounts ; for example
the water of the well on the Green in New Haven, contains an
average amount of about 12 parts per million of nitrogen of
nitrates, although it is of good organic purity; some other
wells in the city yield as much as 30 to 40 parts per million. On
account of this connection with sewage, nitrates are taken as a
measure of the previous sewage contamination, as free ammonia,
nitrites and albuminoid ammonia, are taken as the measure of
recent sewage contamination. The relationship in the two cases
is to be taken with about the same limitations, for while ammonia
and its companions may exist in waters entirely independent of
any sewage contamination, so may nitrates, but it is true that
waters receiving sewage contamination show high average ni-
trates, particularly are they high during the winter months when
plants are less active in removing them. The nitrates in Lake
Whitney are not high, but that they are higher than in the other
reservoirs examined, is to be explained by the character of the




drainage area. While the nitrates derived from sewage must be
regarded as entirely harmless in a sanitary sense, it unfortunately
has not been demonstrated that the processes which are efficient
in effecting this purification of sewage are also effective in free-
ing it from pathogenic bacteria, which constitute the worst
elements for evil in sewage. It has also been shown that an
amount of filtration that will prove effective, in the sense of
complete nitrification, under ordinary conditions, will fail at
times, as when the filtration is too rapid or the admixture of sew-
age too great. A water therefore, that is subjected even to past
sewage contamination must be regarded with suspicion, although
it may ordinarily be safe.

Aside from the evil effects that may rise from the direct action
of sewage, waters containing nitrates have in them a favorite
food supply for the development of plants. The disagreeable
consequences which arise from excessive growth of plants due to
this cause, have been particularly observed in the case of ground
waters, pumped from wells and stored in reservoirs. The
practical remedy for this trouble has been found to be to cover
the reservoirs, thus keeping .the water dark and cool. This
remedy cannot be applied in the case of large storage reservoirs,
consequently this constitutes another reason for excluding from
these reservoirs, waters coming from inhabited areas.

Odor and Taste, — Waters coming in contact with the material
in swamps, wood mould, or other accumulations of vegetable
matter, commonly acquire an odor more or less characteristic of
the source, and which may be described as swampy, woodlike, etc.
These are common in our ponded waters, but are usually slight
and of little moment.

The grass-like and vegetable odors noticed in waters appear at
times to be due to the presence of diatoms and green algaB.
Prof. iJrown states that some samples of water from which these
organisms have been removed by filtration, present no odor on
being boiled, whereas, if they are not removed, the odor increases
on boiling, thus indicating that the odor is dependent on the

The odors which are troublesome, are those which are de-
veloped from time to time in some of our reservoirs, and which
are strong and frequently of a disgusting character. Most com-
monly the odors are described as fishy, but other terms are also
used. Popularly, they are ascribed to putrefactive decompo-




sition, and sometimes erroneously to the decomposition of fish
lodged in the pipes. Regarding the true causes of these disa-
greeable odors, it must be said that the conclusions of different
observers are not in accord, but it would appear that there are
two distinct classes of them ; one class including those odors
which are the products of putrefactive changes, and the other
including those which pertain to organisms entirely independent
of any putrefaction.

Under the head of free ammonia, mention has already been
made of the putrefactive character of the mud at the bottom of
some reservoirs, and it has been stated that the water lying
stagnant in contact with this mud, becomes at times highly
charged with free ammonia, foul smelling compounds and the
other evidences of decay. When this foul water is set into cir-
culation it imparts its character to the water of the reservoir
and the odor thus caused may be sufficiently marked to cause
much complaint.

The blue-green alg» produce very offensive products of de-
composition, as I have convinced myself by experiment with
CUUhrocystis and Anabasnay and they may be present in reser-
voirs in sufficient quantities to notably affect the odor of the
water, producing the so-called pigpen odors. Apparently also
bad odors in water have in certain cases been attributed with
justice to the decomposition of sponges.

It would appear to a chemist, that those biologists, who have
reached the conclusion that foul odors in water are usually the
result of putrefactive changes, have not given sufficient weight to
the entire lack of evidence of the presence of other products of
decay in the results of chemical analyses in many cases in which
the odor has been most marked. Others have reached the con-
clusion which appears to the writer to be most in accord with his
observations and knowledge, namely, that frequently, perhaps
nsuaUy, in those cases most complained of by the consumers, the
odors in the water are the specific odors of certain organisms.
This assumes, what one by analogy may readily admit, that some
of the lower organisms contain or excrete strongly odorous
principles, just as certain of the higher organisms do, for ex-
amples the gariics and mints among plants and certain bugs
among animals.

As is mentioned above, many of the algae seem to possess a
grass-like or vegetable odor that is not disagreeable ; among the




organisms to whiob disagreeable odors have been ascribed, are
particularly UveUa^ Vroglena, Vblvox, Dinohryony and Aste-
rionella, Uroglena has appeared in sufficient numbers to cause
trouble in several of the reservoirs in this State, as in the Cooke
St. reservoir at Waterbury, and in the reservoirs at Meriden,
Middletown and Wallingford. This organism is very fully de-
scribed by Prof. Williston in his Report, and is referred to here
only to present such evidence as has been observed as to whether
the odor is due to putrefactive changes or not.

In each case where this organism has been observed in notable
numbers, the odor complained of has been a nauseous fish-like
odor. When the odor was most marked in the water drawn
from the taps at a distance from the reservoir, it has been slight
in the water of the reservoir, even when the sample was taken
directly at the inlet to the mains, as was the case at Wallingford.
The odor has disappeared from the sample as it stood in the
laboratory in from one to three days.

In May, 1891, the water delivered to consumers in Wallingford
caused much complaint. Samples were taken from the reservoir
at the entrance into the mains, from the gatehouse, 800 feet away,
and from a tap in the borough. They were delivered at the
laboratory from five to six hours after collection. The samples
from the reservoir and from the gatehouse contained many colo-
nies of Uroglena and but little of the peculiar odor, which was
marked in the sample from the tap ; this, however, contained
very few of the colonies, though there were some fragments
visible under the microscope. Chemically the samples were
almost identical. The reservoir was visited and about ten
gallons of water collected near the surface were filtered through
loose layers of absorbent cotton. The pieces of cotton were put
into a wide-mouthed quart bottle and gently mixed with water
in sufficient quantity to fill the bottle to about three fourths of
its capacity. The mixture presented little of the fish-like odor,
although it was distinctly perceptible. On arriving at the rail-
road station after a carriage drive of about half an hour, during
which the mixture in the bottle was constantly agitated, the sam-
ple was found to present the nauseating odor in a high degree.
This was again noted during t^e evening of the day of collection ;

Online LibraryConnecticut. State Board of HealthAnnual report of the State Board of Health for the fiscal year ending November 30 .. → online text (page 30 of 46)