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6
I may summarise as follows the results of the topographical enquiry made by the Council's
inspectors. The best beds were, generally speaking, found upon a bottom of hard clean gravel.
Such beds are regularly cleansed, and in some instances a light dressing of lime is used at each cleansing
in order to destroy organisms deemed to be injurious to the watercress. On the other hand, there were
beds found in sluggish streams or backwaters having muddy bottoms and receiving the drainage of
grazing lands.
The water supply was found to be derived from various sources, such as rivers, canals, natural
springs and artesian wells. In one case, however, the effluent from a sewage farm provides the only
water supply.* Some beds receive their water from a combination of any two or more of the abovementioned
sources of supply.
The condition as regards maintenance of the several beds varies considerably, and in one or two
instances it was found that altogether exceptional precautions were taken to prevent risk of contamination.
As an illustration of a case of this kind the following extract from the inspector's report
may be cited—
Case 1.†—"The sides of all the beds are boarded, and the paths between covered with
clean gravel. The farmhouse and workmen's cottages are provided with earth closets. Slop
water is discharged into the stream below and clear of the beds. The drainage of the
surrounding fields is carried away by a separate channel The stubble and refuse from
cleansing are at once removed by a cart to the fields, and are chain-harrowed into the ground.
It is worthy of note that the workmen are not allowed to smoke on the premises so as
to keep down the habit of spitting."
These precautions are quite exceptional, though in a number of instances the position of the beds
is such as to render it unlikely they can be exposed to pollution. As a typical instance of such watercress
beds, the following extract from the inspector's report may be given c—
Case 2.—" On the high ground on a hillside where a tiny stream is formed by
springs, the watercress is grown in the bottom of the stream. The sloping sides of the hills
are hopfields. The sides of the cleft and the bottom of the beds are steep. To dam up the
water a little and prevent the cress from being washed away, rows of stones are placed at
intervals across the beds. The conditions are the most primitive possible, but there is nothing
to suggest pollution."
The causes of pollution were found to be many and various. Surface drainage from grazing lands
is often allowed to enter the beds. In some instances, too, house drainage and the drainage from trade
premises are allowed to aggravate the mischief caused by want of proper cleansing, and the unchecked
growth of rank vegetation. Even the process of cleansing itself contributes to pollution when the scum
and weeds drawn from the beds are left to decompose upon their banks. The rapid growth of large towns,
too, is another factor tending towards possible pollution. In a case to be mentioned hereafter, it was found
that a bed had been laid down some twenty-five years ago in a rural district under altogether favourable
conditions, but the neighbouring town had expanded, extending its area of smoke, sewage, contaminated
watercourses, and noxious businesses until the rural district was wholly absorbed. Under these circumstances
the carrying on of the business of a grower of watercress had necessarily become increasingly
difficult.
It does not follow in all cases where the watercress is grown under conditions which render it
liable to pollution that analysis of the samples of water taken by the Council's inspectors revealed
in marked degree the presence of deleterious matter; it is, however, an open question whether the
unfavourable surroundings would not under particular climatic circumstances cause serious pollution,
especially in low-lying beds.
As examples of some of the defective conditions found I append some extracts from the reports
of the Council's inspectors.
Case 3.‡—" These beds cover an area of about three acres At the north end
of the beds is a small engine-house in which a steam pump is worked, pumping about 400
gallons of water per minute near high tide from the river The water is discharged into
an open ditch reservoir from whence it is conveyed to the beds by pipes and open channels.
At low tide the river is nothing less than semi-liquid black filth giving off sickening
and offensive odours Within 20 yards of the north-west portion of the beds is situated
an artificial manure works, which gives off most unpleasant odours, polluting the atmosphere.
Within 200 yards of the beds a gut-scraper's business is carried on Within 300
yards of the beds fish-skin dressing is carried on and the waste liquids from these
various premises drain into the river. Within 10 yards house refuse of all kinds is deposited.
There is also a piggery in the brickfield attached to this rubbish shoot. There
are some 25 or 30 houses in the neighbourhood for which there is said to be no sewer accommodation.
The effluents from two sewage farms also discharge into the river. The storage
reservoir and channel are lined with black putrescent mud, and the beds are almost in the same
condition The cress has a bright green appearance, and looks even better than that
grown under more favourable conditions. The proprietor states that he has cultivated these
beds for upwards of 25 years, and that the surroundings when he established the beds were
of a totally different character from the existing conditions"
* This bed has since gone out of cultivation.
† From these beds samples of water VII. and VIII. (Table I.) were taken for bacteriological examination,
‡ Samples of water I., II. and IV, (Table I.) were taken from the beds for bacteriological examination.