Richmond dispatch. [volume] (Richmond, Va.) 1884-1903, 1898-08-25

1
/ TO $4,000 per acre; II rooted with concrete.
about $4,000 to 10000 per acre. Each one
will filter from two to two and half mil
| lions of gallons per day. Total cost OF such
! filtration. including interest at per cent.
| on cost OF original plant with sinking
| fund. from s. TO 81 per million gallons OF
| water filtered.
The other largely-used method for filter
ing water on the great scale consists In
adding alum In small quantity 10 promote
cCagulation of suspended matter, and then
altering. usually after partial clearing by
subsistence. using but small amount or
sand or other altering material, and
forcing the water rapidly through by pres
sure. There are many patented arrange
ments for this. OF which the cost IL va
riable. but commonly claimed TO be con-
sderably less than for the use OF filter
beds. as above described. / have no doubt
that the habitual use OF alum in drinking
water Is unwhOlesome even when the
quantity present Is very small. There Is
a good deal OF truth in the claim that
most. II not all. Of the aluminium added
Is thrown down IN the sediment formed,
and filtered out, but It Is not easy TO Sc
cure the assurance that this is always ac-
cOmplished. I'm n suit. in which ! was q
witness some years ago, involving the use
OF alum in filtering the water supply OF
Eau Claire. Wis, there was evidence OF
the grossest carelessness in the manner |
OF using the alum. and consequently great /
irrcgularity in respect TO the quantity |
used. If any coagulant be employed, j |
should greatly prefer a salt Of iron to |
one Of aluminium. Iron chloride was sat
isfactorly applied TO water from the Mis-
sissippi at New Orleans many years ago.
As,I ~ ba M =
sage Of the water through revolving cy-
finders containing turnings of metallic
iron IS an expensive way Of using iron
hydroxide formed during the agitation by
the action Of air and water on the metal. |.
There are still other ways of dealing |
with the problem Of rendering clear and
wholesome the water supply Of a city,
such as hltering tunnels. parallel to the
course Of n stream and separated from it
by sufficient thickness Of natural soil
TO act as a iltering medium but the two
| have indicated are most worthy of
1t cannot be too strongly
emphasized that no system of filtration I
will satisfactorily run" itself; II must
be carefully watched and carefully man
aged by intelligent people to be useful
and safe.
1t would be easy to construct. at very
|,
experiment. on practical scale. one capa-
Die of delivering, say, 100000 or 10000
gallons of water n day. On the other
land an experiment with one or more
II the mechanical fltering plants would
probably have to be made under agree
nent with the holders of patent rights !
or such plants.
I am afraid 1 have drawn out this COM
TO an undue length for your
olumns and for the patience Of your
eaders. Allow me but word more in ! {
onclusion. Whatever the people OF Rich |
1Ond decide TO do about the muddy
'ater of James river or whether any {
hing be done or not, the most serious
eed should be given TO the warning {
sounded by you some time ago. {
ot to drink of the water of the {
arious old wells and natural springs c
catered within the city limits. Better q
wallow any amount Of good, honest. red,
irginia clay than the water though 7
lear and sparkling, which comes from i
ne inevitably polluted-often, foully pol +
ted-soil underlying any large city.
am, sir, your obedient servant. a
J. w. MALLET. I
The bottle of filtered James river water
D which Professor Mallet refers has y
cen received. and as he says, shows a
etter result than the sample of Char n
water he sent US last week 0
20 community could desire a clearer Z
'ater than the James river sample.
Professor Mallet seems to be under
lisapprehension as to the purport OF s.
ne paragraph in our article Of Saturday.
tut that is immateral. His communica- d
lon IS most valuable and enlightening -
contribution to the discussion of a ques- a.
on vital to our people, and we again
hank him for the interest he is taking Of
that question. G.
What Professor Mallet says about the I"
lreless use Of alum in clearing water in ri
rye quantities would seem to Justify
he popular prejudice against the alum fl,
ethod as applied TO municipal water II
lpplies, and is exactly in line with what @,
G some time ago pointed out as among NJ
lie greatest and soundest objections 10 y
at method. His warning on the subject g.
drinking city well and spring water IN
timely, and entitled to the weightiest Il,
while the general informa- ey
on he gives as TO systems of water
tration and publication emphasizes the
ct that in solving RichmOnd's water II
oblem we should make haste slowly.
nat is to say, it shows that there arc WI
any things to be considered in solving !.
e problem, and that there is a wide ba
Id in which to experiment. That the be
oblem should be solved goes without gr
ying. Aside from any question OF "
alth and comfort a clear, pure water No
pply would be yearly worth thousands tn
dollars to Richmond in the matter OF mi
eaking down the prejudice against our
y due 10 the muddy condition of the mi
tier during certain seasons. The only ca
~ to meet the issue satisfactorily is to wi
Ike, as we have suggested. an APP sh
opriation Of from $1,000 to $4,000 for
series OF exhaustive experiments to
end of securing. as a permanencv the ly,
st method of filtration and publication Del
ch an appropriation would prove w
'nomy in several directions, and the hi
irge would be one which we believe lS''
taxpayers would cheerrully bear. OH
bel
he tenth statistical report of the In
state Commerce Commission has been