The Providence news. (Providence [R.I.]) 1891-1906, 1893-01-16
A WATER MILLENNIUM.
Advocates Of Filtration and Aeratlon
Hope for One.
THE SPECIAL COMMITTEE.
II Will Report to the City Council ON
Some Matters OF Purifying fawtuxet
Water by the Above-Named Methods
What its Advocates Say of It.

months ago BY the City Council has ex
amined the SUBJECT of pure water SUP
ply aud reports that it finds 1t not onl.
possible but practicable and that too a
the expense only Of very few months o
time and a very small sum of money.
The universal demand for pure water
has it's origin in no less an abstruse and
scientific subject than tie germ
theory of dis ase. There was time not
many years ago when peope knew al
most nothing of these deadly germs.
They saw the drop of marsh water mag
nified and looked with amusement at the
little animals swimlng about In the
stereopti, on view thrown on the scene.
they knew that every day they were
drinking this. But few knew that the
powerful microscope would reveal more
wonderful things yet-namely that water
is the most common bearer and source OF
almost every disease. People can't see
the germs but they abound In every drop
of water that they drink. After having
discussed this fact scientists set To work
TO arouse public opinion ia favor of puri-
Tying water.
Work of the Committee.
The special joint COMMITTEES OF the City
Council has not only considered this
question theoretically but they have visit
ed other cities whore various systems
of filtration are in operation. Recently
they took a trip to Long Branch, Phila-
delpbia and Wilmington. They have
also visited various cities in New England
notably Lawrence, where the so-called
system OF natural filtration is being in
troduced. The full result of their in
quiries will soon be made public in their
report Co the council. 1t is probable that
they will recommend some special sys-
tenn aud give pre- w accurate figures AS TO
the probable cost OF Construct on hot only
OF a filter plant but also OF system by
which the water will be subjected to a
process Of aeration.
Natural Filtration.
The committee has found as n result OF
It's work that there are two systems of
fiitration-the so-called natural and me-
chanical. Natural filtration is accom-
pished by preparing shallow reservoir
sometimes as large rs two or three acres
in extent. The bottom of this is covered
with layers OF various kinds of stone aud
sand. Through this the water filters into
drains, aud through them into storage
reservoir. whence 10 is pumped into the
mains. Such system. II maintai ned in
perfect condition. is good. But 1t is ry
likely TO get out of order. The
VI tuO NdltT frequently
causes small leaks. and very quick
~ an opening Is formed which
may be undiscovered for long time.
Meanwhile filtration ceases, and all the
impurities OF the water are carried into |
the mains. Then comes the difficulty of
rep ,ring the leaks. We know from
some recent experience with the Fruit |
Hill reservoir how diflicnlt it is to attain |
q psrfect construction apd how almost |
impossible it is to repair reservoirs where |
defects have been found, The repair of "A |
natural filtration bed would be of |
a similar kind. IL would be costly |
tedious-in fact almost impossible.
I'll ration system lies in the difficulty |
Of cleansing it. All filters need to be
cleansed frequently ana thoroughly. TO |
cleause the nat ural filter bed all the
W 'tsr must be drawn off and the top
surface must be scraped. Obviously
the labor and the time required for sucn
y process every day or two would be
great. And even at best such cleaning
could only be partial.
(. Strangely enough, too, it was found
that when the woras at the Sockanosset
pumping station were erected provision
vas made for system of natural filtra-
ion. After few Intellectual tests. how
'ver the system was abandoned as OF no
Talue. For the reasons above mentioned
the committee has virtually given up the |
Idea OF natural filtration.
Mechanical Filtration.
Having reached the conclusion that
'atural hltrat ion was ut best Ques ion
lble process, the various mechanical pro.
esses We're examined All OF these are
practically upon the same lines Some
consist OF tanks OF various sizes into
which the water is pumped aud i'm the
'ottom of which are the fitering medi-
inns. In some the water is allowed 10
liter by its own weight. In others tho |
vater is forced through by pressure.
again In others the filter is placed direct
y in the mains
In all these the fltering material being
4 composite nature, of mechanical
obstruction aud covering only small
PAGES each a leak or imperfection is al
nost inposeible. The cleansing is
lechanical process. IL simply reauire,
'ater to be reversed aud forced backward
hrough The filters. The wash wafer is .
hen drawn OF and the filter is at once . .
eady for use again The cleansing being !
D simple and rapid n process can be and
suaily IS done once every few hours. !,
hus the chances of cloggcd filters and /.
IMPURITIES being forced through them ,
re reduced to a minimum. :
Aeration.
a further process. and one 10 be used In I
onneciion with filtration is that of aera- v
on. Water naturally contains some y
Ir. BY aeration four or five times the !,
sual amount Of air is forced by pressure i
lto given bulk of water and the i'm .
nre gasses contained in it. When the
ressure is removed the air escapes and
Ikes with IL nearly all gaseous impuri-
es. i
Results of the Systems
As to the perfection Of the results TO he
'tained by these processes it might be {
id that It is claimed that the water will n
} more pure than any mineral or spring :;
ater now sold in the city. Members Of ST
'e committee say that they have seen | n
ater as dirty a. that found in the ordi- "
iry cesspool, put through the filtration %
'ocess and come out AS clear and spnrk. Ii
ng as crystnl-so clear In fact hat tba M
'ople exhibiting the filter drank n as O,
adily as IL IL had been ordinary spring dI
ater. M
The advocates Of the system claim thar Lt
ese methods OF filtration will remove "a
acticallg all OF the solid substaners I,
tue water aud render IL perfectly free b-
ON all matter held in suspenslon and
at they will also remove from g5 20 az
I'LL