Rock Island Argus. (Rock Island, Ill.) 1893-1920, 1899-07-12
REPAIRS.
Engineers Final Report Says
They Can Be Made for
$44.l73.
COUNCIL TAKES PROMPT ACTION.
Have the Great System Completed
at the Earliest Date Possible-An-
other Meeting to Further Consider the

report of the engineers. Messrs. Mead
Tanning and Betzenb berg, ON the con-
| ditions of the incompleted Rock ISL
and reservoir plant BY report
printed below it will be seen
that the plant can be put in
the best possible shape for $44, 173,
which addition cost is much lower
than MANY were led to anticipate, and
on the whole will not bring the aggre-
gate cost of the system completed up
to what was the common impression
it would amount to at the outset, or to
what plant of this magnitude would
ordinarily cost. All the advantages
peculiar to the system adopted for
| Rock Island are to be preserved and
the unanimous determination of the
city council to go ahead and make the
| reservoir system what it should be
without delay, will prove source of
sincere satisfaction and qualification
to all our people. The report of the
engineers follows:
The Report In Full.
To the Hon. Mayor, Water Committee and
City Council. Rock Island. Illinois.
GentlemeD:-In response to your resolution
of June 10th VIC have examined the Settling
Basins and Filter System as partially con
4
pressure and have considered methods OF
their repair and completion, and respectfully
report thereon follows:
SETTLING BASINS.
In order to attain satisfactory results in
water without the use of coagulent. it is
necessary to allow the water to remain quiet
in the settling basins for not less than TWEEN
ty-iour CAD hours Such daily Sedimentati IN
of three million gallons of water Will require
an available capacity in the settling basine
Of about sin million gallons.
Ma. /. settling basin. constructed can no va
its water drawn down from the full flow
line. at elevation Of one hundred and seventy
nYe 115) to the center of the outflow pipe at
an elevation of one hundred and sfxty-six
and sixty-seven hundreths Q66.67), a depth
OF s33 feet, which gives a capacity OF L. So
Ooo eaiIons- NO. :, settling basin can in like
manner be drawn down to elevation I65 n
depth OF ten feet, which gives a capacity Of
The combined available storage capacity of
both settling basins above their lowest out
water. -
After the water has remained quiet durine
its term of sedimentation the clearest water
is near the surface and its cIoudipe.s in
creases from the surface downward. The out
flow pipes leading water from the settling
Easins TO the filters are at a depth of eight
and one third and or ten feet respectively be-
low the fun water surface and therefore, viii,
draw water that has had only limited and
partial standardization.
when the water is srawn off from the sete-
ing. the water should at all times be drawn
from near the surface.
In each settling basin there was an upper
outflow pipe at an elevation of 81 when
is one and one-third feet below the full water
surface These outflow pipes would be Liable
to obstruction by ice in winter. and the up
moved. Above the remaining upper pipe in
No basin the storage capacity is only
rangement of outflow pipes therefore limit,
the effective capacity of the settling basin,
IN In their supply to the filters of water that
sedimentation TO the above amount.
In view of the above condition we con-
no hn
ment of pipes advisable for drawing off
the water from the settling to the filter
In the partition between basins Nos ami
there is a weir intended for the overflow
only in mild weather when the weir would
not be obstructed by ice. This weir is now
basins are used in series by flow from No. /
to No. 2 and then to the filters the period
water would take in passing from the in q.
to and over the weir and to the outlet, ana
proper precipitation of suspended matter in
the water Considering the limited use anc
purpose of this weir and its present condition
We believe the removal of the weir is ad-
visablc rather than its repair. The
hest results of sedimen alton in the e
two basins can be obtained by using
them alternately and by allowing the water
in each, after it has been filed to staud
quiet as long as possible until it is necessary
of the settling basins above suggested an /.
also to reduce the number of pipes in the
accompanying them and also to avoid pipe
openings through the basin Innings the foI-
lowing changes in the construction OF the
two settling basins are recommended.
l. The removal OF the portions of the inlet
and outlet pipes that exist so far a.
they approach the concrete lining of the
basins and to the extent that they can be
lions of these pipes may be disconnected
and remain abandoned within the embank-
made as harmless as SI possible. We con conside der
the presence of these pipes within the en-
info l,,tt r-af1
pense would continue the use of the main |
pipe which delivers unsettled water, with |
slight necessary notifications.
p The construction of inflow chambers in the |
angles formed by the junction of the North |
OF the settling basins. In these basins there
should be proper spill ways over which the |
delivered into the settling basins and these |
spillways might be similar to those in the !!
filter basin chambers.
The construction of new outflow apparatus |
in the angles formed by the junction of the 1
South embankment of the basins with the /
iyering water from the settling basins to the !
filters should be automatically adjusted 80 1
IS 70 deliver water always. as the water ii /
he basins lowers from near the water sur
lace or from Immediately under the ice II l
ion OF these outlets will be shown in detail /
Ira wings
4 For facilitating the cleaning of the mud
rom the settling basins We would place a
our inch pipe with hose connection in eac-.
" the new inflow chambers Water il this
pumps and would aid in washing out sedl- |
nent from the settling basins when they are
)eing cleaned
Since We have reason to fear that neither |
he overflow nor waste pipes from the sett:- |
ng basins To the sewer drain are in safe con- |
iitiou we advise that these pipes be uncov- |
red as far as they readily be reached |
nd that concrete stop-wails be placed about |
hem and that puddle be carefully raInmei
bout them
Since the mud valves now in place at the
ioors OF the settling basins are defective in |
heir operations We advise the substitution
or each OF them two valves at different
Elevations. The lower OF the two valves at
he floor, may be standard gate valves and
be upper may be positive acting disc valves
IN the repair OF the lining OF basin No. 2
Fe advise the removal. construction pro-
--esses, CT the defective concrete floor lining
md Of such portions of the slope lining :
re nof In good condition. Inasnuch the
arffl apor of No basin is moist. soft and ,
poBgy we advise that the material Of tbs
emcved concrete Innings be broken up to