The times. [volume] (Richmond, Va.) 1890-1903, 1902-04-27
90
10000 70
$1,000 "
$4,000 90

Note-At rate Of cur pr@ent consump-
ton, annual expense S31,5::.
DIR. WALLETS INVESTIGATION.
Dr. J. w MaIlet. than whom there Is
no higher authority in America, reports
that the principal lines in which the re-
search has been directed are the follow
ing:
/. To ascertain to what extent and at
what rate the James River water will
GEAR itself by simple subsistence in 2
storage basin. and whether during the
time required for such subsistence the
water will become chemically or bacter-
iologically impure.
- To ascertain how far simple fltracs
ton through bed Of sand. as practiced
In England Gotten referred to as the Eng
lish system. though in use elsewhere).
can be relied upon to render the James
River water clear and good within reas-
enable limits of time and cost.
3 To ascertain how far the American
system of coagulation by means Of alum
or aluminium sulphate. followed by pas
cage through q mechanical sand filter ar
ranged for frequent cleaning, is adapted
tc the Qualification of James River water;
T. To ascertain whether any other, and
II SO what. coagulants can be with adj.
vantage substituted for alum or alumni
mum suIphate
KID
DR.. Mallet concludes a full and exhaus-
tive report with the following practical
suggestions based upon this investiga-
ton:
sEDI1lENTATIoN
81 have no hesitation an recommend
ing that, whatever further actAon may be
decided upon afterwards, the first step
taken should be the construction OF a
large storage reservoir. in which the river
water may be allowed to clear itself as
far as possible by simple natural sedi-
mentation. The value Of such reservoir
would at the outset consist in its allows
inc the influx Of river water to be cut Off
whenever the muddy condition is very
bad. the reservoir holding enough to sup
ply the city for some time, and being q f.
forwards filled up when the river gets
into better condition. During the period
CT storage the water would continually
improve in clearness, depositinS its
coarser slit first. while provision would
he made for the removed OF the deposit
at (probably quite long) intervals by a
division Of the reservoir into two COM
partments. of which one could be cleaned
out while the other was full. The pipes
for taking off the water for use would be
so arranged as always to draw from near
the top Of the mass OF stored matter.
Chemically the water would be improved
during storage by the gradual progress
of oxidation Of organic matter. and the
dtIth not being too great to allow Of free
access Of sunlight as well aus atmospheric
oxygen. the conditions would favor the
de. truction Of harmful bacteria. Possibly
these same conditions might at times
bring about growth OF algae. but their
presence is far less to be deprecated. Is
usually quite .unobjectionabGe, and might
at the worst but occasionally be detect
able in the case of a few species by a
little temporary taste or smell, without
injury to the wholesomeness of the water.
II the supply mains Of the city We're to
he fed from such a reservoir, without any
further Qualification, 1t might be safely
counted upon that relief would be afforded
II ON the gross nuddiness which now,
during a part Of each year. renders the
water unfit for ordinary bathing or wash
ing: a tolerably clear water would be Sc
cured at. all times. such as would obviate
much at least OF the complaint now made.
And il better. more nearly complete, clari-
fication should be demanded, the estab-
lishment OF such a standardization reser-
yoir is beyond doubt the essential pre-
requisite to the adoption Of any successful
and reasonably economical system OF
treatment, whether by means OF hltrat1
or ccagulants or BOTH
COAGQ lLtA44S1ss
go. Assuming the construction OF The
large storage and standardization reser-
syoir5 to have been decided on. I would
suggest as the second step that another
hut much smaller basin be provided, also
divided into two compartments for alter
nate cleaning. in which coagulants-
preferably iron compounds. II the cost
prove to be sufficiently noderate-may
be added to the water received by gravity
from the large storage reservoir, and
reasonable time allowed. to be counted.
however. by hours instead OF days. for
further deposition Of tho coagulated
matter thrown down. It would be de.
sirable to make each compartment OF
this basin large enough to hold twenty
four hours supply; IL madA' smaller tho
water would OF course have less time to
clear itself OF the coagulum. Taking
the present consumption Of the city to
be about 1o.0 900 gallons per day. mr..
Boiling estimates the cost Of such q
basin. In two compartments. each hold
ing 10. COX. 600 gallons. at one hundred and
forty-two thousand dollars fsl42, 0ool. and
he puts tho cost at one hundred thou-
sand dollars Is l0o, 900 it each compart-
|s1nent should DO made to hold hut $, ooo. 900