I am delighted to hear that you are publishing a book about
sewage treatment.
The sewage farms at Aldershot and the Royal Military College
afford ample proof of what a sensible practical man can do.
But it is not every one who knows what those farms were
before you took charge of them, nor do I think that any one
seeing them now could conceive their previous condition. It
is to that I can testify; you have turned putrid sewage bogs
into fertile fields. You will confer an immense benefit on
the country if, by your book, you can only teach sanitary
authorities generally that the crux of the whole question is
the necessity for practical commonsense measures against
sewage stagnation, and if those measures are taken nature
will do the work of purification without the assistance of
expensive patents or artificial devices.
Yours very truly,
(_Signed_) REDVERS BULLER.
_To_ COL. A. S. JONES, V.C., C.E.
It must not be gathered from the foregoing account that the War Office
authorities are prejudiced in favour of the _natural_ treatment of
sewage, for, like many other sanitary authorities, they have been
bewildered of late years by the numerous forms of “_artificial_”
treatment in vogue, and I know of more than one experimental
installation for barracks where good available land has been
neglected, for I read last summer of ghastly failures among the
bacterial arrangements in some of those.
[Sidenote: Success mainly due to activity of farm bailiff, foremen and
other workers.]
I cannot quit the above account of the vicissitudes of the Camp Farm
in fourteen years’ growth from a sandy waste to a condition which
tempted a tenant to pay a rent of 3_l._ odd per acre in 1880—its
retrogression to its primitive waste during the following fifteen
years—and restoration to its present measure of fertility, without
expressing the belief that Mr. Blackburn’s success and my own have
been mainly due to our good fortune in obtaining the willing services
of excellent intelligent foremen and workers who, one and all, have
taken a real interest in their several tasks.
Mr. Cameron and other engineers may boast of their labour saving (?)
automatic appliances for opening and shutting valves on sewage works,
but practical workers, responsible for dealing with a million gallons
a day and upwards average, in hourly varying flow of town sewage, will
agree with me in hesitation as to placing entire confidence in the
substitution of automatic machines for any large proportion of their
manual labour.
[Sidenote: Education and encouragement of sewage employees advocated.]
I have for many years advocated education of sewage farm managers and
watermen, to be selected from the rapidly decreasing class of
agricultural labourers by the tender of high wages, houses and good
gardens, with other profit-sharing allowances which it will well pay
sanitary authorities to hold out to their sewage employees.
In this sense I am glad to note the recent formation of “_The
Association of Managers of Sewage Disposal Works_,” Secretary, Charles
H. Ball, 5 Fetter Lane, London, E.C., as a Trades Union move from
within well calculated to raise the status of the class of men upon
whose exertions the community must mainly rely if there is to be any
hope of improving the condition of our streams and rivers.
[Sidenote: Evidence and Reports of Lord Iddesleigh’s Royal
Commission.]
Two large Blue Books containing the evidence taken by Lord
Iddesleigh’s Royal Commission have been published since the Interim
Report, and their contents more than warrant the opinion expressed in
the latter; indeed it must surely be admitted that the case for each
of the artificial systems was very fully gone into before that
Commission expressed the guarded conclusion, “We doubt if any land is
entirely useless.”
I do not believe that the surface purification obtained by
distribution over even the densest of clay lands was _effectively_ put
in evidence, and too much weight was given to the difficulty of
increasing the effective top soil on such land; but on the whole I
think that the Interim Report is very satisfactory to the reasonable
advocates of a preference being given to the adoption of a large area
of land, where available, over any artificial treatment on a small
area, other things being equal.
At the time when the Interim Report was issued, however, a very full
and careful examination of a select number of sewage farms was still
in progress, and Appendix 22, with a casual mention by Dr. M’Gowan,
affords the only glimpse to be had in the bulky Blue Books, of any
results of that examination having been as yet adduced in evidence.
The Commission’s officers, to my knowledge, were engaged for many
months in examining, surveying and taking numerous samples of sewage
and effluent at the Camp Farm, and, as they doubtless had equal
opportunities of independent observations on the other selected sewage
farms, the further reports of Lord Iddesleigh’s Royal Commission
cannot fail to be interesting and instructive.
On one point Appendix 22 to the Blue Book abundantly supports an
opinion I have so often expressed, namely, that a good strong loamy
surface is a more efficient purifier of sewage than many feet of
barren sand.
I refer to the curves in Appendix 22, showing the greatly superior
purification effected at Nottingham with the best soil as compared to
that of the sandy one at Aldershot, which, in its natural character,
is about the worst for purification and for producing crops to be
found in England.
My experience, however, all points to the extreme importance of
studying local conditions from the first inception of plans in each
particular case, to their completion with the best available
materials.
But when the engineer has done his best, the sanitary authorities,
having borrowed the funds to pay for the work, will take no further
trouble about its sewage, and will often engage careless ignorant
workpeople at inadequate wages to carry on the hourly varying labour,
on efficient performance of which success depends.
[Sidenote: Automatic appliances for sewage and effluent discharge.]
It may seem idle to complain of boards and their employees showing
little interest in the work of sewage disposal, but it is worse to
pander to their failings by selling them automatic machines under the
pretence that all the thought, and fertility of resource, required for
efficient sanitary sewage disposal can be supplied by ingenious
applications of hydraulics on the principle that sewage is a fluid,
and, as such, will behave like clean water.
Of course, when the aerobic treatment is carried out on a bare level
surface of cinders or coke growing only weeds, the lack of interest is
very excusable, but in the natural system the growth of crops and
contouring a sloping surface with carriers so that every part shall
have its trickling water alternating with dry periods for cutting the
crops or hoeing out weeds, should be a matter of constant interest to
an agricultural worker, and, if he knows his business, good crops and
purity of effluent must go together.
[Sidenote: Managers should have a free hand.]
In order to attain this happy result, a manager must know his business
and be given a free hand, not pestered by members of a committee
(farmers, butchers, gardeners or town tradesmen) coming to give their
advice or orders. The river authority should take samples as often as
they like and send the manager as soon as possible the analyses with
day and hour of sampling as a guide for future working.
He will then have to explain any defect from average purity of
effluent, due to one of the hundred contingencies which may arise in
practice, after he and the river authorities have agreed about what
that average analysis should be for his particular farm or works; and
it will be for the advantage of all parties not to try and enforce a
fixed standard for a whole district, as some river authorities usually
attempt to do, because it is easier to lead than to drive a good
manager, and nothing at all can be done with a bad one.
It must not be supposed that I think river authorities should be easy
going, quite the contrary, but they should trust their inspectors’
reports, and “run in” those sanitary authorities who are careless
about the management of their sewage farms and trying to cut down
working expenses and capital.
In precipitation or other artificial sewage works it is easy to judge
this, but more difficult for any one except the good farm manager to
know whether the land is being made the most of for profit or for
purification; still the rivers authority ought to get to know if they
and their officers take pains.
[Sidenote: Purification and profit.]
It is a common idea that working a sewage farm for profit, and for
purification of the sewage, are two incompatible things, whereas, the
good manager with sufficient working capital (double or more what
would be enough for the same acreage in ordinary agriculture) and a
good market for produce will attain the two together in due proportion
in all ordinary seasons, when a fair allowance has been made him for
the necessary sanitary work.
It is easy to see how the popular idea of incompatibility has arisen
in a case like that above stated of the Camp Farm tenant, eating up
year by year all the fertility stored up in the land during the
previous period, and letting nearly all the sewage run to waste,
because its scientific application would cost much in thought and
labour. In much the same way district councils have been, all over the
country, stinting their labour bills and interfering with their
managers’ purchases and sales in order to make as small a demand on
the rates as they can—each year bringing some change of system—to the
end that nobody is responsible or has any confidence in master or man.
With such a state of things up and down the country the way was
prepared for preachers of microbe agency to say, why should you buy
all that land when a septic tank, a few acres of coke or burnt
ballast, and a patent automatic opener and shutter of valves (which
you see working so nicely with tap water and model at some exhibition)
will give you “no more troublesome sludge,” and a first class effluent
with hardly any labour bill? if you only agitate against that
arbitrary Local Government Board, which insists upon land!
But those gentlemen neglected the fact, that in a few years’ time
their filters would have to be pulled to pieces, washed and put back,
while the land remains as efficient as ever, and a valuable asset, in
some cases saleable at building value, if it becomes desirable to move
the outfall further at some future time.
[Sidenote: Sludge treatment.]
In the above comparison between natural and artificial treatment
reference has been had chiefly to the aerobic branch of the business,
but the anaerobic, breaking down _some_ of the solid organic matter
and the sanitary disposal of the remainder in the state of sewage
sludge (containing fully 90 per cent. of moisture) must not be
overlooked or shirked as beneath the attention of the scientific
bacteriologists and chemists whose analyses of effluents, and often of
what they call crude sewage, are made from the liquid which has passed
through a filter paper in their laboratory before their “oxygen
absorbed” or “ammonia processes” are proceeded with.
On the contrary, I have always maintained that sludge, being the
foulest part of town sewage, ought to receive primary and earnest
attention if we desire to improve the condition of our watercourses.
When town sewage is pumped through a long rising main, it can often be
spread on the land in its really crude state, and if the soil is clay
ploughed up to receive it the sludge is most beneficial to its
texture.
But in every other case we must face the nuisance of extracting the
sludge, and its desiccation in one of the following ways.
1. On a farm at some distance from roads and houses, the cheapest plan
is to form a bank of earth about 18 inches high, enclosing a
rectangular area into which the wet sludge can be run or pumped out of
depositing tanks, and left alone until dry enough for cartage, when it
can be used on the farm or sold to neighbouring farmers for a shilling
or two a load.
2. A wall of farmyard _long_ manure may be used instead of earth, and
trench 5 feet wide dug on each side of the longer sides of the
rectangle, leaving 3 feet of ground between the wall and trench, on
which men can stand to scoop the sludge over the wall when it has
consolidated a little in the trench; the latter is then ready to
receive the sludge from another tank emptying, which is again scooped
over the wall on to a thin coating of farmyard manure, which has been
scattered over the last layer of sludge in the rectangle; and thus in
a year’s time a solid mass of the mixture is raised four or five feet
high, and is in capital order for putting in drills for a crop of
mangold wurtzel.
This is the plan in use at the Camp Farm; it occupies little ground
and smells only like rotten dung does during the few days carting to
the mangold field.
3. Pressing by compressed air forcing a liquid mixture of sludge and
lime into the interstices between cloths supported by vertical iron
plates on a horizontal frame; and such pressing is a very expensive
process, only resorted to when the sewage works are in a confined
populated district where no accumulation of sludge can be tolerated.
[Sidenote: Expert examination of neighbourhood a very necessary
preliminary to any sewage scheme.]
Before any sewage scheme is conceived a very careful survey of the
neighbourhood ought to be made by a person who knows the requisites of
a site for sewage disposal, especially if land irrigation is intended,
because natural advantages of site both for tanks, main carriers,
roads, etc., may make all the difference in the world in expense and
efficiency not only in first cost of works but also in their use
afterwards.
And if land is to be acquired for sewage farming it will be very
desirable to include in the purchase some neighbouring high lying
area, not required for sewage disposal but for growing straw crops to
be used on the farm.