It is a recently recognized but an
old and universal truth, that human life involves
the production of refuse matters, which, unless proper
safeguards are taken, are sure to become a source of
disease and death. The danger is not confined
alone nor chiefly to that element of household waste
which is most manifestly offensive, but in almost equal
degree to all manner of organic refuse. It is
true that faecal matters are often accompanied by
the inciting agent of the propagation of infectious
diseases. For convenience, and as indicating the
more probable means for disseminating infection, we
may call this agent “germs.” It has
not yet been demonstrated with scientific completeness
that a disease is spread by living germs whose growth
in a new body produces a corresponding disorder; but
all that is known of the circumstances of infection,
and of the means for preventing it, may be fully explained
by this theory. Typhoid fever, cholera, epidemic
diarrh[oe]a, and some other prevalent diseases, are
presumed by the germ theory to be chiefly, if not
entirely, propagated by germs thrown off by a diseased
body. So far as these ailments are concerned,
there is therefore a very serious element of danger
added in the case of faeces to the other evil effects
which are produced by an improper disposal of any
refuse organic matter. That any one or all of
these diseases can originate from the decomposition,
under certain circumstances of faecal matters, is
not clearly determined. There is, however, good
reason for believing that one common effect of the
gases arising from improperly treated matters of this
kind is to debilitate the human system, and so to
create a disposition to receive contagion, or to succumb
to minor diseases which are not contagious.
The same debilitating effect and the
same injurious influences often result from the neglect
of other organic wastes. The refuse of the kitchen
sink is free from faecal matter; but it contains, in
a greater or less degree, precisely the kind of organic
material which has gone to make up the more offensive
substance. If its final disposition is such as
to contaminate the water that we drink or the air that
we breathe with the products of their decay, the danger
to life is hardly less than that from the decomposition
of faecal accumulations.
It is proposed now to set forth, in
the simplest way and without much discussion of principles
(which may be studied elsewhere), the methods and
processes by which village households and communities
may be protected against the influences that come
from an excess of soil-moisture, from damp walls,
and from imperfect removal or improper disposal of
organic filth.
We will assume that a village has
a water supply sufficient to admit of the use of water-closets
in all houses, and to furnish a good flushing for
kitchen sinks, &c. A necessary complement of this
work indeed, it should properly precede
it is the establishment of a system of sewers
by which all of this liquid outflow may be carried
safely away. It would be out of the question
in a small or scattered community, especially where
roadways are unpaved, to establish any system which
should include in its working the removal of surface
water. The moment we undertake to make sewers
of sufficient capacity to carry away the storm water
of large districts, then we enormously increase the
scale and cost of the work.
So far as the removal of house sewage
alone is concerned, the work need by no means be very
costly. If a tolerable inclination can be given
to the line of sewers, say a fall of one
in two hundred, a six-inch pipe will have
a capacity quite up to the requirements of a village
of two thousand inhabitants using one hundred gallons
of water per day per head. It will, however,
be safe to use a pipe of this size only when it is
true in form and carefully laid, so that there shall
be no retarding of the flow at the joints from the
intrusion of mortar, or any other form of irregularity.
Unless the joints are wiped quite smooth, the roughness
remaining will serve as a nucleus for the accumulation
of hair, shreds of cloth, and other matters which
will hold silt and grease, and form in time a serious
obstruction. Nothing smaller than six-inch pipe
should be adopted for a street sewer. Unless the
work is to be most carefully done, for all but the
branch lines, for a population of five thousand, or
less according to the fall of the sewer, it will be
safer to use eight-inch pipes. These pipes must
be laid with great accuracy as to grade and direction.
All corners should be turned with curves of large
radius and regular sweep, and with an additional fall
to compensate for the increased resistance of curves.
The weight of the pipe should not be supported upon
the sockets, partly as a question of
strength, and partly because any irregularity of form
or thickness of the socket would change the inclination
of the sewer. The bottom of the trench being
brought exactly to the required grade, let there be
dug out a depression greater than the projection of
the socket, the pipe resting upon its finished bottom
for its whole length. Too much
care cannot be given to the thorough filling with
cement of the space between the socket and the pipe
inserted into it; the whole circle being well flushed
and wiped, so that there may be no possibility of
leakage.
The objection to leakage is twofold:
sewage matters escaping into the soil might contaminate
wells and springs; and it would also rob the flow
through the pipes of water needed to carry forward
the more solid contents. The continued efficiency
of these small drains for carrying away the solid
or semi-solid outflow of the house is dependent very
largely upon the presence of sufficient water to create
a scouring current. While eight-inch pipes are
admissible as a safeguard against imperfect laying,
they are liable to the grave objection, that, where
the service to be performed is greatly less than their
capacity, the stream flowing through them will not
be sufficiently concentrated to carry forward the
more solid parts of the sewage. Up to the limit
of their capacity, six-inch pipes properly laid are
greatly to be preferred, as insuring a deeper stream
which will more generally attain the velocity of three
feet per second, needed to move the heavier constituents
of the sewage. The difference in cost between
six-inch and eight-inch pipes will be sufficient to
cover any extra cost of the most careful workmanship.
However much attention may be given to the cementing
of the joints, it will be impossible to prevent the
running into the pipes of a certain amount of mortar;
and the workman should have a swab or a disk of India
rubber of the exact size of the bore of the pipe,
with a short handle attached to its middle, to draw
forward as each joint is finished, and so scrape away
any excess of mortar before it hardens.
Wherever it is, or may probably become,
necessary to attach a house-drain or land-drain, there
should be used a length of pipe having a side branch,
oblique to the direction of the flow, to receive such
connection. The location of these branches should
be accurately indicated on the plan; and they should
be closed with a flat stone or a bit of slate, well
cemented in place.
It will at times be necessary to use
larger conduits than even an eight-inch pipe.
Up to a diameter of fifteen inches, it is cheapest
to use pipes, but for eighteen inches or more, brick-work
is cheaper; and at that size a considerable
regular flow of water being insured the
slight roughness of brick-work offers no serious objection.
The use of oval or egg-shaped sewers will rarely be
necessary under the circumstances that we are considering;
but there may be exceptional conditions where the
covering-in of a brook, or storm-water course, cannot
be avoided; and in such cases the volume of water may
vary so greatly that there will at times be a mere
thread of a stream, and at times a torrent. Here
the oval form is the best, as concentrating a small
flow within a narrow and deep channel, and still giving
the capacity needed for exceptionally large volumes.
All bricks used for sewers, man-holes, &c., should
be of the very hardest quality, and true in form.
The general rule is to be kept in mind, that the thickness
of the wall of a brick sewer should not be less than
one-ninth of the inner diameter; that is to say, that
up to a diameter of three feet the thickness of the
wall should equal the width of a brick, four
inches. This applies to circular sewers only:
the oval form, being less strong, calls for a wall
of a thickness equal to one-eighth of the largest
diameter.
Connecting drains leading from houses
to the sewer are to be made at private cost; but they
should be made in accordance with plans furnished
by the public authority, and by a workman acceptable
to that authority.
The householder might be permitted
to take the responsibility of the finishing of his
drain, but for the fact that the working of the public
sewer calls for the largest amount of water in proportion
to the amount of solid matters that it is possible
to secure, and thus makes it imperative that this
drain should be absolutely tight, so that the liquid
parts of the house outflow shall not trickle away through
its joints, leaving only the more solid parts to flow
into the public sewer.
Properly graded and smoothly jointed,
a four-inch pipe will carry more water than even the
largest boarding-house or country hotel is likely to
discharge. There is, however, a tendency in all
house-drains to become filled in the early part of
their course by the accumulation of grease and solid
matters caught in the grease. Where no form of
grease-trap is used, there is a certain argument in
favor of the use of six-inch pipes for the upper part
of house-drains. The use of a grease-trap, however,
should always be insisted upon; and with its aid these
obstructing matters will be retained, and the outflow
may be perfectly carried by a four-inch pipe.
So far as the public sewer is concerned,
it makes little difference what is the size of the
house connection drain through the greater part of
its course; but the junction with the sewer should,
under no circumstances, where six-inch sewer-pipes
are adopted, be more than four inches. I should
even insist on four-inch connections with an eight-inch
sewer. Through neglect, or by reason of improper
management, many kinds of rubbish find their way into
house-drains; and a four-inch opening will admit as
many of these into the sewer as it will be able to
carry away. If, by reason of bad construction
or neglect, an obstruction is to be caused at any
point, it should be in the drain, which the person
responsible for it must cleanse or repair.
The grease-trap referred to above
may be any form of reservoir which will retain the
flow from the kitchen sink until it has time to cool,
when its grease will be solidified, and will float
at the surface. The outlet from this trap should
be at such a distance below the surface of the water,
that there will be no danger of its floating matter
passing in with the discharge.
From a trap of this sort the flow is constant whenever
additions are made to its contents.
When filled, any sudden addition of
a few quarts of water, as from the emptying of a dish-pan,
brings into action a siphon whose entrance is near
the bottom of the tank; and this siphon rapidly discharges
all of the contents above its mouth in a flow having
sufficient force to carry forward not only any solid
matters which it may contain, but also any ordinary
obstructing accumulations in the drain below.
The soil-pipe, carrying the discharge of water-closets,
should not be delivered into the flush-tank, but at
a point farther down the drain, so that any solid
matter it may deposit shall be swept forward by the
next action of the flush-tank. The more often
the flush-tank is filled, and the greater the proportion
of its water to its impurities, the more efficient
will be its action. Therefore the slop closet
waste leading from the upper story, and even the outlet
pipes of bathing-tubs, may with advantage be delivered
into it.
Although the flush-tank may receive
no faecal matter, and even though the housemaid’s
sink may not deliver into it, it will contain in the
discharge from the kitchen alone an amount of organic
matter which will produce offensive and dangerous
gases by its decomposition. To provide for the
safe removal of these gases, a ventilating pipe should
be carried up to some point not near to any window
or chimney-top.
From the time the sewers are ready
for service no accumulation of faecal matter or other
organic household waste should be allowed to remain
in the village. All old vaults and cesspools
should be filled with earth, and disinfected by the
admixture of lime with the upper layers of the filling.
The use of water-closets in all houses should be made
imperative; and the construction and arrangement of
soil-pipes and of all outlets should be regulated
by the health authorities.
It is not worth while here to discuss
the details of the construction of water-closets and
other interior plumbing work, except with reference
to soil-pipes and such drains as may deliver the outflow
of soil-pipes to the public sewer. The soil-pipe
should be of cast iron, carefully jointed with lead,
not less than four inches in diameter, and carried
by the straightest course possible up through the
roof and generally higher than the ridge-pole.
Its open top must not be near any window, and if within
ten feet of a chimney it should be at least one foot
below the level of the top of that chimney. There
should be no trap in the soil-pipe, and no trap in
a private drain between the outlet of the soil-pipe
and the sewer. The reasons for this rule are twofold:
1. No matter what amount of water
may be used for flushing out the soil-pipe, its sides
will always be more or less coated with organic filth;
and, however slight this coating, there will be a certain
amount of decomposition. The decomposition of
all such matters must be rapid and complete, not slow
and partial. A necessary condition of complete
destructive decomposition is an abundance of atmospheric
air to supply the oxygen which complete decomposition
demands. If the soil-pipe is closed at its top,
or if it is obstructed by a trap in the lower part
of its course, there can be no such circulation of
air as safety requires.
If there is an opportunity for the
free admission of air from the well-ventilated sewer
to feed the upward current almost constantly prevailing
in a soil-pipe open at both ends, the gases resulting
from the decomposition will be of a different and
less injurious character than where the air is confined, and
by the mere volume of air passing through the pipe
they will be so diluted that even were they originally
poisonous their power for harm will be lessened.
The gases formed by the decomposition
of organic matter in the sewer itself, or in the soil-pipe,
have a certain expansive force which is greatly increased
by the elevation of temperature, caused, for example,
by the discharge of hot water into the pipe or sewer.
If the soil-pipe is open at its upper end this expansion
will be at once relieved; but if the top of the pipe
be closed there will always be danger of the forcing
of the feeble barrier offered by the ordinary water-seal
trap of a branch pipe leading from a wash-basin or
sink. Then, too, the sealing-water of the trap
readily absorbs any foul gases presented at its outer
end, toward the soil-pipe, and gives it off in an unchanged
condition at the inner or house end. Such traps
retard, but do not prevent, the entrance of sewer
gases into the house. Water-seal traps which
are unused for any considerable time are emptied by
evaporation, and thus open a channel through which
the air of the soil-pipe may find its way into the
house.
It is usual in modern plumbing to
relieve the pressure of gas in the soil-pipe by what
is called a “stench-pipe.” This is
a pipe from one to two inches in diameter, leading
from the highest point of the soil-pipe to the outside
of the roof, where it is bent over to prevent the
entrance of foreign matter, or is closed at the top
and perforated with holes to allow the gas to escape.
This small stench-pipe is inadequate for the necessary
work. It is very important that there be the freest
possible channel for the movement of air; and nothing
will suffice for this save the continuing of the pipe,
at its full size, to its very outlet. Indeed,
angles and bends in a pipe by increasing friction form
a serious obstruction.
The arrangement of the soil-pipe here
indicated, although excellent and efficient, is susceptible
of further improvement by the use of a ventilating
cowl or hood at its top. There are many forms
of such cowls in use which are effective whenever
there is a sufficient current of wind; but most of
them require a certain force to bring them into action,
and when this force is absent they usually retard the
flow they are intended to increase. This is true
of a recent invention known as “Banner’s
ventilating cowl,” which so long as the wind
blows is a most effective device. When the air
is perfectly still, however, it offers by its curved
air-way a certain resistance to the current, and in
the case of baffling winds and flaws the air may blow
directly into its opening.
Among the various inventions of this
sort nothing seems so free from objection as the old
arrangement known as the “Emerson” ventilator. This gives a straight outlet,
protected by a disk far enough above it not to prevent
its delivery of air; and it becomes an effective suction
cowl, with the least movement of the wind from any
side or from above or below. No eddy caused by
the angles of gable roofs can give it a backward draught;
and if a pipe armed with it be held toward the strongest
gale a puff of smoke blown into its other end will
be instantly drawn through. As the patent for
this invention has run out, it is competent for any
tinsmith to make it, and it is a common article of
manufacture.
2. What is said above concerning
the ventilation of the soil-pipe from end to end relates
to the interest of the private owner. The interest
of the public gives an equally strong argument in
its favor. The sewer should be as far as possible
removed from the condition of an “elongated
cesspool.” There must be no halting of its
contents, and no deposit of filth or silt at any point.
Within the shortest time possible, every thing received
into the sewer must be passed on and delivered at
its outlet. Still, however perfectly this may
be accomplished, there will always be a certain adhesion
of slime to the walls of the sewer; and this slime
must always be in a state of decomposition, a constant
source of offence and possible danger. The only
way to avert this danger is to give the sewer such
a thorough ventilation that the decomposition shall
be rapid and safe, and that the resultant gases shall
be at once diluted with fresh air.
This may be measurably accomplished
by the simple ventilation of the sewer itself, through
open-topped man-holes; but such ventilation is less
effective in the case of small sewers than of large
ones. In the case of either large or small sewers,
it will be vastly increased if we compel every householder
who makes a connection with the sewer, to carry a
drain and soil pipe, nowhere less than four inches
in diameter, from the point of junction with the main
line to the open air above the roof. Where houses
are near enough to make the use of a public sewer
advisable, the aggregate of these soil-pipes, having
almost constantly an upward current, will make such
a draught upon the sewer, to be supplied by a downward
current through the man-hole covers, as will maintain
a perfect and continuous ventilation.
Important as it is to secure the proper
arrangement and construction of sewers and house-drains,
it is still more important to provide for the safe
disposition of the sewage.
We must begin at the outset with the
understanding that all sewage matters not only are
of no value to the community, but that it will cost
money to get rid of them.
There is hardly an instance, after
all the efforts that have been made, of the profitable
disposal of the outflow of public sewers. The
theoretical value of the wastes of human life
is very great, but the cost of any method for utilizing
them seems at least equally great. The question
of cost is so much more important (to the community)
than the question of agricultural value, that the
practical thing to do is to make such disposition
as will cost the least, while fully meeting the best
sanitary requirements.
So far as village sewage is concerned,
there are three means open for its disposal:
to discharge it into running water or into deep tide-water,
to use it for the surface irrigation of land, or to
distribute it through sub-irrigation pipes placed at
little distance below the surface of the soil.
Experiments are being made with more or less promise
of success in the direction of the chemical treatment
of this liquid so as to purify its effluent water,
and retain in a solid form, and in combination with
certain valuable added ingredients, all of its undissolved
impurities. None of these processes can as yet
claim consideration in regulating public works.
The cheapest way to get rid of sewage
is to discharge it into a running stream or into tide-water.
So far as the community itself is concerned, this
is often the best way; but there will very often arise
the objection that the community has no moral or legal
right to foul a stream of which others make use in
its further course. Where the amount of water
constantly flowing is very large, and where the discharge
is rapid, any given part of the sewage
reaching the open air within a few hours from the
time of its entering the pipes, and where
it flows in moving water for a considerable distance
before reaching others who may have occasion to use
the stream, no practical danger is to be apprehended.
But where the sewage is more foul, more sluggish, or
exposed in the open current for a shorter time, the
danger may be serious. The pouring of sewage
into tide-water is always admissible where floats
show that there is no danger of a return and deposit
of solid filth; but the delivery at all stages of
the tide, in the immediate neighborhood of salt marshes
and mud flats, and in land-locked harbors, is to be
avoided.
Where an unobjectionable natural outflow
cannot be provided, the irrigation of agricultural
lands affords the best relief. The action of
vegetation, the oxidation which takes in the upper
and well-aerated layers of soil, and the well-known
but not yet fully explained disinfecting qualities
of common earth, are effective in removing the dangerous
and offensive impurities, and in converting them into
a more or less important source of fertility.
Precisely how far this system may be available during
winter, it is not easy to say. While the earth
is locked with frost, there must be very little, if
any, infiltration; but, as an offset, the action of
a low temperature upon the sewage matters will clearly
be antiseptic; and it is only necessary to provide
against an undue washing away of the surface of the
ground during thaws, and against the flowing of the
sewage beyond the proper limits.
Generally in the neighborhood of villages
it will be easy to find lands over which the delivery
may be carried on throughout the year without objection.
The sewer, or some form of covered channel, should
lead far enough from any public road to avoid offence.
From this point it may be led by open gutters to the
land over which it is to be spread, or
rather through such a system of surface gutters as
will enable us to deliver it at different parts of
the field, according to the requirements of the crops,
and so as to use fresh land at frequent intervals,
leaving that which has been saturated to the purifying
processes of vegetation and atmospheric action.
The gutters having been made, it is
easy, by the use of portable dams, of thin
boiler-iron, like broad shovels, which may
be set in the course of the flow, to divert the current
into any branch channel, or to stop it at any desired
part of this channel. All the gutters having
sufficient descent to lead the sewage rapidly forward,
it is usual to set a dam near the far end of the gutter,
and allow the sewage to overflow and run down over
the surface until it has reached as far as the formation
of the ground and the quantity of the liquid will allow
it to spread. This portion having received its
due amount of the liquid, the dam is moved to a higher
point, and the overflow is allowed to spread over
a second area. In this way, step by step, we irrigate
all that may be reached by a single gutter. Then
the moving of the dam in the main line turns the water
into another gutter, and this is proceeded with in
like manner. In practice it is found best to begin
the overflow at the farthest end of the lowest-lying
gutter, working back step by step until the higher
parts of the field are reached. It would be better
that there should be land enough to require the irrigation
of any given area not oftener than once in one or
two weeks. The amount required for a given population
cannot be determined by any fixed rule, so
much depending on the amount of water used per
capita, and on the absorptive character of the
irrigated soil. In the case of villages, one
acre to each five hundred of the population would generally
be found ample.
There are several instances of the
successful use of a much smaller area than is here
indicated, by the use of intermittent downward filtration.
The most noted success in this direction is that at
Merthyr-Tydvil in Wales, a large mining town, where
the allowance is only one acre to each two thousand
of the population. There are two filter-beds of
light loam over a gravelly subsoil thoroughly underdrained
with tiles at a depth of six feet. One of these
beds is cultivated with some crop like Italian rye-grass,
which bears copious irrigation; and the other by some
crop like wheat, which, in the absence of irrigation,
will thrive on the fertility left over from the previous
season. The volume of sewage is very great, but
the action of the six feet of earth in removing its
impurities seems to be complete; the water flowing
out from the drains having been proved by analysis
to be really far purer than the standard fixed by
the Rivers Pollution Commission.
It is an important condition of this
system that the sewage, where its quantity is small,
shall be stored in tanks until a large volume has
accumulated, and that it then be rapidly discharged
over the soil. There is no objection to an actual
saturation of the ground, provided the soil is not
of such a retentive character as to be liable to become
puddled, and so made impervious. The tanks being
emptied, the flow ceases until they are again filled.
During the interval, the liquid settles away in the
soil, by which its impurities are removed. Its
descent is followed by the entrance of fresh air,
and the oxidizing action of this, accompanied during
the growing season by the purifying effect of the
growing crop, leads to an entire decomposition or destruction
of all organic matters.
The third system the distribution
of sewage through irrigation-pipes laid at a depth
of ten or twelve inches below the surface of the ground has
its efficiency attested by numerous instances in private
grounds. I have adopted this system for disposing
of the sewage of the village of Lenox, Mass., where
there was no other means available short of cutting
an outlet, at great expense, through a considerable
elevation. This method is an extremely simple
one, and is available in every instance where even
a small area of land lying slightly below the level
of the outlet is to be commanded. The arrangement
of the sub-irrigation pipes is easily made: Suppose
that in land having an inclination of about one in
two hundred, occupied by grass or other growth, a
trench be dug twelve inches deep, that there be laid
upon the bottom of this trench a narrow strip of plank
to insure a uniform grade, and that upon this plank
is laid a line of common agricultural land-drain tiles,
say two inches in diameter. However carefully
these tiles may be placed, there will be at their
joints a sufficient space for the leaking out of any
liquid they may contain; the tiles being laid either
with collars around the joints, or with bits of paper
laid over them, to prevent the rattling in of loose
earth during the filling. The excavated earth
is to be returned to its place, well compacted, and
covered with its sod. Suppose this drain to have
a cross-section equal to three square inches, and
a length of one hundred feet, its capacity will equal
about sixteen gallons, or a half-barrel. If this
amount of liquid be rapidly discharged into the drain,
the inclination being slight, it will at once be filled
or nearly filled for its whole length, and the liquid
will leak away in tolerably uniform proportion at every
joint along the line, and will saturate the surrounding
earth. The plan adopted at Lenox, and recommended
for all small villages which cannot secure a better
outlet, is simply a multiplication of these drains
to a sufficient extent.
A description of the manner in which the Lenox work is
arranged will illustrate the adaptation of the system to its circumstances. As
circumstances vary, the adaptation must be modified.
The main outlet sewer delivers at
a distance of about one-half mile from the last junction
with a branch sewer. It is a six-inch pipe five
feet below the surface of the ground, and it delivers
into a flush-tank, but
having a capacity of about five hundred cubic feet.
This tank stands at the upper side of a field having
an inclination of seven in one hundred. There
is a branch from the main sewer, above the tank, supplied
with a stop-cock, by which, in case of need, the sewage
may be carried on down the hill without going into
the tank. The outlet from the chamber below the
siphon leads off in another direction down the hill,
and has a stop-cock and a branch which will allow
its flow to be diverted. The discharge of this
diverted stream and the discharge through the branch
of the main above the tank, both deliver into a horizontal
surface gutter to be well grassed, and lying at the
top of the land to be irrigated. By this arrangement,
should repairs become necessary in the tank, the flow
may be turned into the gutter; or, should it be desired
for any reason to use the outflow of the tank for
surface irrigation, the second branch outlet will
deliver it into the same gutter, where, the outflow
being uniform along the whole length of five hundred
feet, the stream will pass in a thin sheet off on
to the descending ground. The hill-side, immediately
below the gutter, is brought to a true grade and covered
with grass. As its inclination is much greater
than would be admissible for sub-irrigation drains,
these are laid obliquely in parallel lines at
intervals of six feet from one end to the other over
the whole graded slope. These drains are connected
at their upper ends with the direct outlet-pipe leading
from the siphon chamber. They have an aggregate
length of about ten thousand feet. The method
of operation is as follows:
The capacity of the tank is supposed
to equal about two days’ discharge, or about
thirty-five hundred gallons; and the whole capacity
of the drains is about half that of the tank, so that
the rapid emptying of the whole volume into them will
insure their being pretty thoroughly filled from end
to end. This arrangement will provide for the
saturation of the soil about once in two days, and
will leave a sufficient interval between the periods
of saturation for the thorough dispersal and aeration
of the filth.
The extent to which this system will
be interfered with by frost, it is impossible to say.
This will probably be less than would be supposed,
for the reason that the ground would often be covered
with snow, and that the sewage will have sufficient
warmth to exert considerable thawing influence.
Whenever the discharge of the liquid through irrigation
pipes is shown to have become obstructed by freezing,
it will only be necessary to divert the flow, and
turn it into the surface gutter to be distributed
over the ground.
It is possible that in this case,
as in the one which has been under my observation
for six years past, there will be no interruption of
the working because of cold; but, should the interruption
become serious, I shall propose the planting of evergreen
trees in parallel rows midway between the drains.
The protection that would thus be afforded, both by
the trees and by the drifting snow which they would
gather, would probably keep the ground free throughout
the winter. Incidentally to the chief advantage
of this system, there will be, so long as the land
is in grass, quite an addition to its product.
There are hundreds of villages, with
and without a water supply, where the houses are too
scattering and the street lengths too great to make
it advisable that the cost of any form of public sewerage
should be assumed. In all such villages, the
public authority or the active influence of the village
improvement association should be exerted to secure
a regular and systematic adoption of some more perfect
system for the private disposal of household drainage
than is usual. Fortunately, the best system is
the cheapest.
No form of cesspool, no leaching vault,
and no cemented tank, should be allowed under any
circumstances. Neither should there be permitted
any form of the old-fashioned out-of-door privy with
a vault. Every household should be supplied with
water-closets or well-arranged earth-closets, to which
reference will be made below.
The foul water discharge of kitchen
sinks, or of whatever form of slop-sink is used for
the water of bedrooms, should discharge into a flush-tank,
and should be led from this by a tightly cemented four-inch
drain to a tight settling basin in the ground beyond.
If water-closets are used, the soil-pipe should deliver
into the drain between the flush-tank and the settling
basin. The settling basin should be constructed; and this, as well as the flush-tank,
the soil-pipe, and the connecting drains, should be
amply ventilated. The outlet from the settling
basin should be carried by well-cemented vitrified
pipes (four-inch) to the connection with the subsoil
irrigation pipes. The flush-tank discharging at
each operation of its siphon about thirty gallons
of liquid, two hundred feet of drain, unless the soil
is very compact, will dispose of the whole discharge
with sufficient rapidity. The tank being emptied,
the flow ceases; and within a very short time the
drain becomes empty of its contents, which are absorbed
by the sponge-like action of the earth, and are subjected
to the combined influence of the roots of plants, and
of the concentrated oxygen contained among the particles
of the soil. They will soon have their character
entirely changed, so that the earth will become purified,
and will be ready to receive the next discharge from
the tank. In the case of my own drains, after
five years of unremitted use, the gradual accumulation
of bits of grease and more solid matters obstructed
the drains, and there appeared undue moisture about
their upper ends. All that was then necessary
was to re-open the trenches, and remove, wash, and
replace the tiles. This operation cost, for a
length of two hundred feet, less than three dollars.
For any ordinary household of six
or eight persons, where the water-closet is not used,
two hundred feet of drain of this sort will be sufficient.
If there are water-closets, it may be well to duplicate
the length; and, to provide for the necessary connections
to lead the liquid to the drains, we may assume that
in all five hundred feet of length will be required.
The cost of two-inch tiles at the works, in small
lots, and where collars are furnished, is about three
cents per foot; and we will suppose that transportation
will increase the cost to five cents per foot, making
the cost of this item twenty-five dollars. The
strips of board (three inches wide) will cost, at a
very liberal estimate, five dollars more, and the
cost of digging and laying not more than another five
dollars; so that the establishment of this means of
disposal, under the most liberal allowance of prices,
will not exceed thirty-five dollars. Ordinarily,
especially where neighbors combine to buy their material
in larger quantities, it will hardly exceed one-half
of this amount. This, be it understood, is for
a complete and permanent substitute for the expensive
and nasty cesspool now so generally depended upon
in the country.
A piece of ground fifty feet square,
having ten rows of tile five feet apart and fifty
feet long, will suffice for even a large household
with an abundant water supply.
The leaching drains may safely begin at a distance
of even ten feet from the back of the house, requiring
for the whole a clear area of only fifty feet by sixty
feet. With small households, the length of drain
may be very much shortened. In my own case, where
water-closets are not used, the total length of irrigation
drain is, as before stated, only two hundred feet.
The earth-closet was invented by the
Rev. Henry Moule, vicar of Fordington, in
England, more than ten years ago. Its progress
in England has been considerable, and its introduction
there has resulted in a profit to the company undertaking
it. In this country it has met with less general
favor. Two companies with large capital, after
expending all their resources, have been obliged to
abandon their attempts to build up a profitable business.
Having been actively interested in the enterprise
from its inception, and having given constant attention
to the merits of the system, I am to-day more than
ever convinced that the solution of one of the most
difficult problems connected with country and village
life is to be sought in its general adoption.
The public reports of sanitary officers in England,
who have investigated the subject to its foundation,
fully confirm every thing that has been claimed by
the advocates of the earth-closet, unless perhaps in
connection with the incidental question of the value
of the product as a manure.
The only thing which now deters the
authorities of some of the larger manufacturing towns
of the North of England from adopting the dry-earth-system
as a means of relief, under the sharp exaction of the
law that prohibits their further fouling of water-courses,
is the belief that the labor of bringing into the
town the enormous amount of earth required to supply
such an immense number of closets, and the labor of
removing the product at frequent intervals, would be
so great as to constitute an insurmountable obstruction.
Prof. Voelcker, in a paper published
in the Journal of the Royal Agricultural Society,
shows pretty conclusively that even the use of the
same earth four or five times over, although perfectly
successful in accomplishing the chief purpose of deodorization,
fails to add to it a sufficient amount of fertilizing
matter to make it an available commercial manure.
Extended experience in small villages and public institutions
seems to confirm his view, that, if the earth-closet
is to be adopted by towns, they cannot depend either
on farmers buying the manure, or undertaking the labor
of supplying and removing it. It is estimated,
that, for a population of one hundred thousand persons,
there would be required seventy-five tons of earth
per day, to say nothing of heavy refuse matters which
would be thrown into the closets, and would increase
the amount to be removed. Even the quantity required
for a village of a few hundred inhabitants, if it
were to be brought in and carried out, would entail
a considerable cost for handling.
I have recently concluded an experiment
of six years’ duration, the result of which
seems to show that this objection to the adoption of
the earth-closet system may be set aside, or at least
reduced to such proportions as to make it unimportant.
In the autumn of 1870 I had brought to my house, where
only earth-closets are used, two small cart-loads
of garden earth, dried and sifted. This was used
repeatedly in the closets; and, when an increased
quantity was required, additions were made of sifted
anthracite ashes. I estimate that the amount of
material now on hand is about two tons. We long
since stopped adding to the quantity, finding that
the amount was ample to furnish a supply of dry and
decomposed material whenever it becomes necessary to
refill the reservoirs of the closets.
The accumulation under the seats is
discharged through simply arranged valves into bricked
vaults in the cellar. When these vaults become
filled, about three times in a year, their
contents, which are all thoroughly decomposed, are
piled up in a dry and ventilated place with a slight
covering of fresh earth to keep down any odor that
might arise. After a sufficient interval these
heaps are ready for further use, there being no trace,
in any portion, of foreign matter nor any appearance
or odor differing from that of an unused fresh mixture
of earth and ashes. In this way the material
has been used over and over again, at least ten times;
and there is no indication to the senses of any change
in its condition.
A sample of this material has recently
been analyzed by Prof. Atwater, at the Connecticut
Agricultural Station at Middletown. The analysis
shows that it contains no more organic matter than
Prof. Voelcker found in fresh earth prepared
for use in the closet, say about two hundred
pounds, nearly all of which organic matter
it undoubtedly contained when first made ready for
use. In my case, there was an addition, at a
moderate calculation of at least, 800 pounds of solid
dry matter during the six years’ use by an average
of four adult persons. Prof. Voelcker’s
analysis showed that the unused earth contained about
twelve pounds of nitrogen. Prof. Atwater’s
analysis shows that my two tons contained only about
eleven pounds of nitrogen. By calculation, the
800 pounds of solid dry matters added in the use of
my material contained 230 pounds of nitrogen.
Doubtless the constitution of Prof.
Voelcker’s sample was somewhat different from
the original constitution of my own; but practically,
except perhaps for the addition of a trifling amount
of residual carbon remaining after the decomposition,
they were about the same; and, after being used ten
times over, the whole of the 800 pounds of organic
matter added, including 230 pounds of nitrogen, seem
to have entirely disappeared.
It becomes interesting and important
to know what has become of this added matter.
That it was absorbed into the particles of the earth,
is a matter of course; and the result proves that
after such absorption it was subjected to such a chemical
action of the concentrated oxygen always existing
in porous dry material as led to its entire destruction.
Porous substances condense gases air, oxygen,
etc. in proportion to the extent of
their interior surface. The well-known disinfecting
action of charcoal the surface of the interior
particles of which equal from fifty to one hundred
square feet to each cubic inch of material, and all
of which surface is active in condensing oxygen is
due not simply to an absorption of foul-smelling odors,
but to an actual destruction of them by slow combustion,
so that the same mass of charcoal, if kept dry and
porous, will continue almost indefinitely its undiminished
disinfecting action.
The earth used in the closet is a
porous material, sufficiently dry for the free admission
of air or of oxygen. The foulest materials when
covered with dry earth at once lose their odor, and
are in time as effectively destroyed by combustion
(oxidized) as though they had been burned in a furnace.
The process is more slow, but none the less sure;
and it is clear that in the case of my dirt-heap the
foul matters added have thus been destroyed.
The practical bearings of this fact are of the utmost
importance. Earth is not to be regarded as a vehicle
for the inoffensive removal beyond the limits of the
town of what has hitherto been its most troublesome
product, but as a medium for bringing together the
offensive ingredients of this product, and the world’s
great scavenger, oxygen. My experiment seems
to demonstrate the fact that there is no occasion
to carry away the product from the place where it
has been produced, as after a reasonable time it has
ceased to exist, and there remains only a mass of
earth which is in all respects as effective as any
fresh supply that could be substituted.
The quantity necessary to be provided
can be determined only by extended trial. My
experiment proves that the amount needed does not exceed
one thousand pounds for each member of the household,
and that this amount once provided will remain permanently
effective to accomplish its purpose.
With a suitable public supply of water
for the purpose, and with a suitable means of disposal,
nothing can be better and nothing is more easily kept
in good condition than well-regulated and properly
ventilated water-closets. Where these are available,
with enough water for their flushing, their use is
to be recommended. Where there is not sufficient
water, there a well-regulated system of earth-closets
seems to be imperatively demanded. By one process
or the other we must prevent the fouling of the lower
soil, and the consequent tainting of wells and springs,
and the ground under houses and adjoining their cellars.
With a system of sub-irrigation pipes which deliver
foul matters into earth that is subject to the active
operation of oxidizing influences, we need fear no
contamination of the deep and unaerated soil.
It would be better, however, where this system is
used for the disposal of the outflow of soil-pipes,
to avoid the use of wells. As a general rule,
it is safer not to use for drinking purposes the water
of any well near a house or a stable: practically,
it is better not to use wells at all as a source of
water for domestic supply. Filtered cistern-water
is greatly to be preferred.