Pleasantville weekly press. (Pleasantville, N.J.) 1890-1911, 1895-12-18

Ground Water, sOcn as mat from we1is
and springs, is largely used in Europe
Paris is supplied from springs for do
mestic use, and from the river for other
purposes. Vienna, Munich and large
number Of French and English cities are
also supplied by springs. London gets
her water from grossly polluted streams,
vet by scientific filtration has as pure
water to drink as any other city in the
world.
Statistics relative to deaths due to
water diseases are appalling. At Plym-
outh, Pa, population 5000, in 1885.
one case Of typhoid reaching the water
supply caused 1,104 cases and ia
deaths. The histories of the Lausanne,
Switzerland; Montciair, Chicago, Buf-
falo and (recently) Stamford epidemics
are familiar to every one and carry out
the statements made above and are but
examples of human negligence to hu.
man rights. In 1866, 3,400 people died
Of cholera in London because one Of the
water companies failed to filter the sup
ply from the river. One such expert
ence should prove the efficacy Of filtra-
tion.
FILTRATION as carried on under the
latest improved methods is not costly
matter. It is vastly cheaper than sick
ness and death to community. It il
commonly thought that if filtration clar-
.ifes water that is sufficient. This is a
great mistake and can readily be under
stood to be so when it. is known that
1000, 900 or more bacteria may be pres
ent in glass Of clear water and yet not
affect its clearness. The filtration of
water means straining it through sub
stance which removes all or most i'm
purities, and it is not properly done un-
less the etraining is go hne as to remove
the infnitesimals called bacteria, which
measure one-thousandth Of an inch,
more or less.
"It is the only absolutely safe method,
as far as is known at the present time,
for domestic purposes when the supply
comes from the surface, as from rivers.
The latter water supply is more likely
to be wholesome than the others, for tho
reason that large reservoirs afford time
for water to settle, and any pathogenic
bacteria which may be present have an
opportunity to sink to the bottom or be
destroyed by the beneicent bacteria.
There is also more or less benefcent ac-
tion upon the water by the sunlight, but
even this protection is not considered
entirely sufficient in the light Of recent
experiments Filter beds are unanimous
ly agreed upon by almost all expert en-
gineers as the only true way Of filtering
water for public supplies.
"a filter bed consists Of horizontal
layer Of rather fine sand supported by
gravel and underdrained, the whole be-
ing inclosed in suitable basin or tank.
The water in passing through the sand
Leaves behind upon the sand grains the
extremely small particles which are too
fine to settle out in the settling basin,
through which the water first passes di-
rect from the river for the purpose Of al
lowing the mud to settle, and is quite
clear as it goes from the gravel to the
drains and pumps which forward it to
the reservoir or city. The coarser mat
tiers in the water are retained on the
surface Of the sand, where they quickly
form layer of sediment which itself be-
comes filter much finer than the sand
alone, and which is capable Of holding
back under suitable conditions even the
bacteria Of the passing water.
"When the layer of sediment becomes
30 deep as to prevent the proper strain
ing Of the water, the rate Of pressure
and other features being regulated by
expert superintendent, the layer is
scraped or cleaned off, This is done at
regular intervals. This sediment layer
fs valuable element in aiding perfect
Filtration. 1t becomes sort Of jellylike
mud, formed Of the bacteria and other
particles, which affords not only an al
most solid mass, which holds back the
infinitesimals, but is kind Of battle
field where the opposing armies of bac-
terra slaughter the harmful kind, thus
cleaning out those we would be rid Of.
So valuable is this sediment layer that
after filter bed has been scraped clean
a new thin layer is allowed to form be-
fore the water passes into the basin.
Filtration in any way cannot be done
rapidly. The process must be so slow as
to be scarcely more than an oozing out
between the very small interstices."