The Report, by Professor Frankland, on the analysis of the waters
supplied by the Metropolitan Water Companies during the several months of
the year, is, on the whole, somewhat more favourable than usual. As
regards “temperature,” he notices the wide variation in the waters
derived from riverian sources, as compared with the narrow range in the
deep well water of the Kent Company, derived from the chalk. The
temperature of the Thames water varied from 36° Fahr. in February to
68°–9 in June, a range of 34°; while the range in the water of the Kent
Company was only 7°–9 Fahr., viz., from 51–l° in May to 59° in September
and October. The total solid impurities—composed of a great variety of
substances, some of which are organic and very objectionable, and at
times eminently noxious, while others are either entirely or
comparatively harmless—was rather less than in previous years, the
progressive increase in the quantity which had been noticed during the
years 1871–2–3 having apparently ceased. The maximum was observed in
January, and the minimum in July. The character of the Thames water, in
respect of organic impurity—as represented by its two most important
constituents, carbon and nitrogen—was practically the same as in the
previous years. The maximum pollution occurred in March, April, and
December, when the river was in a very objectionable condition. In
December the Chelsea Company supplied this foul water in an unfiltered
condition, and contaminated with fœcal matter. The subjoined table shows
the maximum, minimum, and average quantity of organic matter in the
water, the amount of organic element (organic carbon and organic
nitrogen) in the Kent Company’s water being taken as unity, or the
standard of comparison:—
Name of Company. Maximum. Minimum. Average.
Kent 1.0 1.0 1.0
West Middlesex 4.3 2.0 3.0
Grand Junction 4.9 2.4 3.3
Chelsea 7.1 2.3 3.7
Professor Frankland remarks that the water of the Thames is at its source
as free from pollution as the chalk well water, but on its downward
course becomes largely and progressively contaminated by sewage and the
washings of cultivated land, especially during winter.
The average hardness of the Thames water—or the weight of carbonate of
lime, or its equivalent of other soap-destroying substances, found in
100,000 parts of water was 21° or parts in 1873, and 19.7° in 1874.
Large quantities of soap or soda are required to soften the water before
it is used for washing; but this process could be accomplished for a
small portion of the expense by substituting lime for soap or soda, as
practised on similar waters at Aylesbury, Canterbury, Caterham, and
Tring. The following table exhibits the degree of efficiency of
filtration of the waters:—
Name of Company. No. of occasions No. of occasions No. of occasions No. of occasions
when clear and when slightly when turbid. when very
transparent. turbid. turbid.
Chelsea 6 5 0 2
West Middlesex 12 1 0 0
Grand Junction 7 5 1 0
The exceptional occasion on which the water supplied by the West
Middlesex Company was slightly turbid was in December, when the condition
of the Thames was bad for a lengthened time, so that even the large
storage of the Company proved insufficient to render them independent of
flood water; it being impossible, moreover, to separate by filtration the
whole of the finely divided clay to which the turbidity of the water was
due. The Kent Company’s deep well water, having already undergone
natural filtration through an enormous thickness of chalk, is always
clear and transparent, without artificial filtration. The appliances of
the Companies supplying river water are, excepting in the case of the
West Middlesex Company, unequal to the filtration work required of them.
The microscope is called into use in the examination of potable water,
and it always reveals numbers of living and moving organisms in the
sediment deposited by turbid water on standing. The annexed table
exhibits the results of such microscopic examinations during the past six
years:—
Name of Company. Number of occasions when living
organisms were found.
1869. 1870. 1871. 1872. 1873. 1874.
Chelsea 3 2 2 3 2 5
West Middlesex 0 0 0 0 0 0
Grand Junction 4 1 1 2 3 5
To Professor Frankland’s valuable report, the main features of which I
have thus summarised, are appended numerous tables setting forth, in
detail, the various information condensed in the text. I subjoin, as of
greatest general interest, Table M, which exhibits the
AVERAGES FOR 1874.
(The numbers in this Table relate to 100,000 parts of each Water.)
NAMES OF COMPANIES. Temperature in Total Solid Organic Carbon. Organic Ammonia. Nitrogen, as Total Combined Previous Sewage Chlorine. Total Hardness. Proportionate
Centigrade Impurity. Nitrogen. Nitrates and Nitrogen. or Animal Amount of
Degrees. Nitrites. Contamination. organic
(Estimated.) Elements, that
in the Kent
Company’s Water
being taken as
1.
THAMES.
Chelsea 11.8 26.46 .211 .039 .001 .155 .196 1250 1.87 19.3 3.7
West Middlesex 12 5 26.62 .176 .028 .001 .124 .153 930 1.83 19 4 3.0
Southwark 12.7 26.68 .192 .030 .001 .125 .155 940 1.83 20.0 3.3
Grand Junction 11. 4 27.00 .186 .033 .001 .129 .164 990 1.83 20 0 3.3
Lambeth 12.0 27.88 .196 .037 .001 .144 .181 1120 1.87 20.0 3.4
OTHER SOURCES.
New River 12.2 26.02 .087 .015 .001 .146 .162 1150 1.67 20.1 1.5
East London 11.8 27.13 .153 .027 .001 .076 .104 560 2.04 19.3 27
Kent 12.4 40.36 .057 .012 .000 .371 .383 3 40 2.48 28.1 1.0
But it is not to Professor Frankland alone that we are now indebted for
information respecting the water we drink, many very interesting facts
being supplied by Major Bolton, R.E., the water examiner appointed by the
Board of Trade, under the provisions of the Metropolis Water Act, 1871.
Major Bolton’s reports, which, by his courtesy, I receive every month,
afford information on all points relative to the machinery for water
supply, and to the provisions already made, or in progress, for giving a
constant supply, the main object of the Act; and which, I suppose, we
may, at some remote future, hope to obtain. As the information in
question is not generally accessible, I make no apology for presenting a
_resumé_ of it on this occasion. And, first, with respect to the
constant service, we learn that the West Middlesex Company are giving
constant supply to a number of houses, on the application of the owners,
and are fully prepared to extend the supply when called upon. Extensive
works and additional engine power of 120 horse power are in course of
construction at Hampton.
The Grand Junction Company have formed a high service reservoir near
Kilburn, to contain 6,000,000 gallons, for constant service, and are
completing the line of main pipes to connect up this reservoir with the
works at Campden-hill; they are likewise erecting boilers and works at
Hampton, for which place an additional 70-inch engine of 125 horse power
is being constructed, and an extra 30-inch main from Hampton to Kew has
been ordered to be laid down. The Chelsea Company does not appear to
have taken, as yet, any steps in this matter, having, as we shall see,
other and more pressing work in hand. The Act of 1871 provides power to
compel the companies to give a constant supply as and when the “public
authority” may see fit to move. The authority (Metropolitan Board of
Works) has not seen fit to move in respect of the companies supplying
this parish, nor is it probable that any steps will be taken until the
stringency of the water regulations, to which I have already referred,
has been modified.
The number of miles of streets in the Metropolis which contain mains
constantly charged, and upon which hydrants could at once be fixed, is
666—including 67 in the West Middlesex, 41½ in the Grand Junction, and 50
in the Chelsea Company’s district. The companies are prepared to affix
hydrants thereon when required by the authorities; but, in fact—although
hydrants might be used for street watering—of 2,531 hydrants already
erected, 1,996 are for private purposes, and only 535 for public
purposes, including 267 for street watering, in the entire Metropolis.
The companies supplying this parish obtain water exclusively from the
Thames, viz., the West Middlesex and Grand Junction Companies at Hampton,
and the Chelsea Company at Ditton. The bad state of the water supplied
by the last-named company in December appears to have been caused by the
intake being “below the filthy outflow of the rivers Mole and Rye.” The
total volume which may be supplied daily by each company is 20,000,000
gallons. The average daily supply during the month of December was—West
Middlesex, 8,600,000; Grand Junction, 10,200,000; and Chelsea, 7,200,000
gallons—eleven to fourteen per cent. of the water (exclusive of waste, an
enormous but unknown quantity!) being delivered for other than domestic
purposes. The number of houses supplied in the several districts is—West
Middlesex, 46,404; Grand Junction, 35,144; and Chelsea, 28,395. Only 401
houses in the West Middlesex district have a constant supply. The
estimated population supplied is—West Middlesex, 348,000; Grand Junction,
316,000; Chelsea, 210,000. The West Middlesex Company possess eleven
engines of 1,341 horse power; the Grand Junction, eleven of 1,820 horse
power; and Chelsea, eight of 1,025 horse power. The number of miles of
mains possessed by these companies in the Metropolis is—West Middlesex,
248; Grand Junction, 200; Chelsea, 170. The West Middlesex Company have
three subsiding and storage reservoirs for unfiltered water—area, 20½
acres; available capacity, 57,000,000 gallons: and three covered
reservoirs for storing filtered water, of an aggregate capacity of
10,922,000 gallons. This company, by means of its large reservoir
capacity, avoids taking in water during floods. The Grand Junction
Company have four subsiding and storage reservoirs for unfiltered
water—area, 7 acres; available capacity, 19,500,000 gallons: the number
of covered reservoirs for filtered water being three, their capacity
18,000,000 gallons. This company requires additional impounding and
subsiding reservoirs. The Chelsea Company have no reservoirs for
unfiltered water, and only two (capacity, 11,000,000 gallons) for storing
filtered water. The filter beds of the several companies are as
follows:—West Middlesex, five in number, area 8 acres, depth 5 feet,
viz., Harwich sand 1ft. 9in., Barnes sand 1ft., and gravel (screened to
different sizes and arranged in layers) 2ft. 3in. The average rate of
filtration per square foot of area was, during December, 1½ gallons per
hour. (It may be here observed that the quality of the water is improved
by a slow rate of filtration—the rate should not exceeded 2½ gallons per
square foot of filter bed per hour: this will give 540 gallons per square
yard each 24 hours, and at this rate filtration should be effectual.)
Grand Junction: Number of filter beds, 4; area in acres, 7¾; depth, 5ft.
6in.—viz., Harwich sand, 2ft. 6in.: Hoggin, 6in.: fine gravel, 9in.:
coarse gravel, 9in.: boulders, 1ft.: average rate of filtration, 1⅓
gallons per square foot of area per hour. Chelsea: Filter beds, 7; area,
6¾ acres; depth, 8ft.—viz., Thames sand, 3ft. 3in.: shells, &c., 3in.:
gravel, 4ft. 6in.; rate of filtration, 2⅓ gallons per square foot per
hour. It will be observed that notwithstanding the greater depth of the
filter beds of the Chelsea Company, the water supplied by the Company in
all times of difficulty arising from a flooded state of the river is
unfit for drinking, although the rate of filtration is slower than that
deemed sufficient by the water examiner. This is due to the total
absence of impounding and storage reservoirs for unfiltered water, to the
exceptionally bad quality of the water taken in by the Company, owing to
the improper situation of the intake at Ditton, and to the impossibility
of filter beds removing suspended matter when in any large quantity;
that, moreover, being a principal object of the subsiding reservoirs.
The disgusting condition in which the water of the Company was sent out
during parts of the months of November and December formed the subject of
many complaints, both in the public press and in communications addressed
to myself, and was referred to in my reports, dated December 16th, 1874,
and January 13th, 1875. I had, on former occasions, reported specially
on the subject, and particularly in February, 1872. The dissatisfaction
which the condition of the water at the latter date gave rise to induced
the Company to take steps to improve their means of supply by enlarging
their storage. The scheme submitted to Parliament in the Session of 1873
included the embanking of the Thames at Hampton Court, and was defeated
by a strong public opposition, on what I described at the time as
æsthetical grounds. No further attempt appears to have been made by the
Company to put their supply on a proper footing until the great outcry
referred to arose. On the 18th December, however, at a special meeting
of the proprietors, a resolution to the following effect was passed:—
“That the directors be authorised to take such steps as in their
judgment may be necessary or expedient to obtain a fresh intake, with
reservoirs and other works connected therewith, and lay the necessary
main pipes from the site of such proposed intake to the works at
Seething Wells, with the least possible delay.”
The measures taken by the directors to secure the land—an area of 50
acres, near Molesey—for the construction of impounding reservoirs, were
approved and adopted, and the directors were authorised to apply to
Parliament in the now current Session for the necessary powers. This
they have done, and there is every probability that their Bill will pass,
and that with the completion of the contemplated additions to their works
this Company will be able, at no distant time, to supply its customers
with water as clear and transparent as any derived from the River Thames.