The Providence news. (Providence [R.I.]) 1891-1906, 1896-01-29
Filtration Plant on Paw
tuXet River.
City Fathers Will Take Imme-
date Action.
Difference Between Natural and
Mechanical Plants.

ecullng 10 the IuIlest eAlenl All NlOihNlohS
of the law relative TO the dedlement of the
Pawtuxet river and also the immediate
adoption OF some suitable system of I'LL
tration. Acting on the latter suggestion,
tire committee on city engineers depart
ment got to work at once on the hltration
scheme and it is announced that the
matter will come 10 a head very quickly.
The plan in favor is To construct a natural
filtration plant ome here on the banks
Of the river. The matter has agitated the
public mind for a long time. Away
back In 1868 when City Engineer shedd
worked on a plan for a water system, in
GLIDING a pumping station that should
last long after he dies, he had in mind
the construction, some day, OF a filtra-
tion plant. II has bobbed no more or less
frequently ever since, and now, I've says,
the prospects are good for its consumma-
tion. In this connection the report Of a
Joint special committee relative 30 filtra-
ton, and a resolution providing for a sys-
tenn Of natural gravity filters, and appro-
priating $40, 600 therefor, has been resur-
rected. The resolution was tabled Aug.
2, 1894.
The report deals thoroughly with the
matter. 1t gives the analysis Of samples
OF sane taken from opposite the pumping
station and from the bank near the Cor
liss works. The results were extremely
satisfactory, according to ii. w. Clark,
who made the tests.
The mechanical analysis of fltering
materials at the Lawrence, Mass, expert
ment station, where the natural system
is used, is also given. Then follows a
report from Norman N. Mason, showing
the sand from east of Corliss, to be even
better for fltering purposes than Law
renee sand. The city engineer then gives
his opinion. In which he says among
other things:
The city of London has been able to
supply Thames water to its inhabitants
and maintain their healthy condition by
passing the water slowly through sand
filters OF large area. Success has attended
this method now for more thar 40 years
and no change in the process appears to
be desirable. Many large cities on the
continent OF Europe have adopted the
London plan, and have practiced it for
long periods with satisfactory results.
In Massachusetts,, In the last few years,
much attention has been given to the
subject of purifying public water sup
plies. Extensive experiments have been
carried on by the board of health for
about seven years, and careful and
eofanffHr nhaaryotfana houa hoan pnada
on the effect upon water of filtration
through sand. Their results have led
the board TO approve slow filtration as a
proper means OF purifying water for do
mcstic use In large quantities.
TIE city of Lawrence had long suffered
excessively from typhoid fever caused
by drinking the water Of the Merrimac
river, which received the ewage OF Low
ell, that in It's turn suffered from the
effects OF excavations Of typhoid patients
turned into the river above tina city.
Under the advice OF the State Board OF
Health aud under direction OF Mr.. Mills,
the engineer member of the board, the
city OF Lawrence constructed q sand filter,
having an effective area OF two and one
halt acres and intended to filter five
million gallons OF water daily. This filter
has been In active and successful opera
tion since the 20thof Soptem Der last year
(1S93), having an effect upon the health
OF the citizens which is marked, and
causing expressions OF satisfaction with
its effectc which are hearty and general
throughout the city. Where 80 deaths
from typhoid fever might have been ex-
pected to occur, only seven occurred.
Mr.. Shedd estimated that a sand hitter
for slow filtration could be constructed
Tor s2OS, 900, whereas II had been found
that q mechanical filter was likely TO cost
e2si, 900, and Everson q Liddle agreed TO
build a sand filter for $500, 900, complete.
AS stated in The NEWS the other day.
doctors and experts contributed their
opinions IS to the need OF purifying the
water and It's being unwise to attempt
Its publication by the use of chemicals.
These latter were Drs. /. w. sawin, J.
g. Budlong, Ssyer Hnsbrouck. Edward b.
Knight, Mary ID. Moss Matthews and
George ID. Wilcox.
1t being understood that superintendent
Chaplin has some pronounced and well
sssim Hated notions on the subject he was
asked a few general questions.
In the first place il was suggested that
he might be able TO furnish some figures
showing the comparative cost Of the two
plans. lie replied hat he could not, but
In his opinion IL a mechanical and a
natural plant Of equal efficiency were con-
stracted the former would be fully ns
cheap II not cheaper not only to build
but 10 maintain. IL is also his opinion
that a mechanical plant would he more
eficacious than the other and 10 attain
anything like a similar efficiency the
natural plant would have TO be large
enough to warrant a very low rate OF m.
tration or a slow nltration and cared for
most .ralously.
In bis opinion, too, any system OF grayity
filtration should he housed although the
city engineer differs in that point.
Natural nlt-aiion, simply stated. is flow
ing water over beds 81 sand through