Rock Island Argus. (Rock Island, Ill.) 1893-1920, 1899-07-12

proper sizes and that it be rammed into the
sponsy earth door until the floor is sufficient
~ haro &c receive the new concrete lining,
and also that much OF this broken concrete
he rammed into the lower portions of the
side slopes as is necessary TO make the
slopes firm and adapted TO receive their new
Innings over the floor thus PREPARED in
basin No. we advise the placing of layer
We advise making the junction of the side
slopes with the floor by curved surface in
of the clay puddle would therefore at the
junction have surface curve with radius of
s In replacing the concrete lining of basin
No. would advise first the constr uctioa
of concrete abutment wall at the foot of the
slope to resist the sliding pressure Of The
would extend short concrete ribs on each
side across the curve. These ribs would be
built upon the rammed broken concrete floor
above described and would be twelve inches
thick and placed at about twelve feet centers
and their top surfaces would conform to tbs
curved surface OF that part of the pdyins
uniting the floor and slope Innings. Between
these ribs the clay puddle would b. rammes
and formed to receive the new concrete
we advise that the new concrete lining
the floor and portion OF the sides of No.
towards the mud valves and also that The
upper portion OF the slope paving shall be
surfaced with four inch layer Of
hard paving bricks placed edge ON four
inches of concrete. This brick paving should
extend from two feet below the level OF the
low water in the settling basin to the top n
the embankment and there be finished with
concrete coping. This brick paving should
be bedded in and its joints filled full OF the
best Portland cement mortar
9 In the repair OF the concrete lining iubasi
No. 1 we advise the placing of ribs at the
foot OF the slope as described for basin No.
.. except that the ribs be placed top OF
the present concrete floor and a portion O.
the slope be covered with an additional lIyer
OF concrete, four inches in thickness gsne,-
ally. That portion of the slope extendins
from. two feet below low water line to tho
top of the embankment should be covered
with four inches thickness of hard pavIne
ed with strong mortar described for basin
No. p The surface of the old concrete lin.
OF concrete and bricks, should be roughsned
by picking that the new covering may
oesive parts of the new coverings are placed,
the surface of the old concrete, as roughenei
fine cement mortar and the new GOVERNS
placed thereon before the thin mortar has
in part project above the concrete lining and
tho brick paving will have concrete coping.
curb on edge, with eight inches thickness
and thirty inches dep.h art should be sc;
puddle and should be built in connection
with the top of the concrete pavings
10 We note that the full water surafce in the
settling basins, when free from ice, is at Gle
walton 1I5, which is six feet only above the
full water surface in the filter basins. Thi
permits a dTaught OF less than six feet depth
of water to the settling basins TO the filter
basins when both are fun and also whenever
the filters are most clcsged by use. This
Il
of the water in the settling basins canot be
drawn to the filters The settling basins
at least six feet deeper below surface water
in the filters than present conditions necas-
state would warrant. These facts sug-
gest that the available draught capacity of
each settling basin is but 1,1G9,010 gallons CT
water and that to secure continued success
full sedimentation with this plant. and with
out the aid of coagulant, when the river is
most roilly and the filters most clogged an
additional settling basin will socn be re-
uuired. Such settling basin should at
have least four million gallons available
capacity above the level of the full fl ter
water surface in addition to the 2,33S, 900 now
available from the combined two preselt
FILTER BASINS.
AS has been heretofore partially stated.
when the water from the settling basins is
drawn to a level with the lowest outlet pipe
in basin No. there will be one foot of water
above the sand in the filters and but two
feet fall from that level to the lowest notch
of the outflow weir, which in turn is enc
foot below the level of the water in the clear
water distribution reservoir when fun
Hence when the distribution reservoir is fun
there is but foot difference between the
elevation of the water in it and the low water
line in the settling basins.
1t will therefore be readily that when
the filters, partly silted, requiring a high
head of water TO maintain a reasonable rate
of filtration, the water in the settling basins
cannot be drawn off as low as at other times
And the sedimentation in the settling
basin is not likely to be even approximately
complete, il is reasonable to expect that the
filter will rapidly and frequently silt up AMI
because Of the small margin of available |
head. require constant and careful attention.
Under these conditions a rate of liberation
not to exceed 1900. 600 gallons per acre can
be expected at any time and during much OF
the time not even that rate can De MAN tam
ed. At the rate of :, 800 Coz per acre the three
filters VIII not supply more than 3,OO00oc |
gallons of filtered water per day. Hence the |
early day in order to meet the requirements Il
Of consumption. In this connection we con- /
slider it proper to call your attention 20 three
imprtant points.
/. THAT a uniform, good and satisfactory |
efiuent from these filters, at any rate of fill /
tration, cannot alwaysbe obtained unless they /
are operated with the greatest attention, care,
intelligence and skill
That even partial neglect of the filters
will soon result in an unsatisfactory water
and possibly in the entire failure of the
efficient action of the filtering material. T.
is doubtful, even with the arrangement of
the present work as herein suggested and
With the most careful supervision, that sat
sfactory results can be obtained at all times
until additional settling basins and filter No.
3 are completed.
.. In order to obtain the best possible e.
huent from these filters the different layers
Of sand and gravel used should be of uni
form size and free from all organic and other
foreign substances. and
j. To prevent the water from freezing |
possibly to a depth reaching the sand VIXEN
the head is low, the filters should be covered |
BY TOT as a protection against frost as
was 4sinally contemplated. Our examina- 4
ton OF the filters at different times revealed L
the fact that while one of the filters was fl
ID or partially filled. containing at times no
more than one and one half fot of water
which would barely cover the gravel a con-
siderable flow Of water from this filter into
the adjacent empty filter occurred. Further
examination developed that this flow took
place through and in under the fcting of
he partition wall, the water coming up
through the joints in the concrete floor of tn.
litter. This water communication Is so free
that when the first filter was drained the
or from he h..
the first When the filter was full of water Il
leaks were discovered through the 4
partition walls for some distance above the
ioor. Notwithstanding these walls hal re-
.ently been well covered with a good cnat 81