Evening star., 1899-03-10
CITY WATER SUPPLY
Colonel Miller Preparing to Execute
Recent Legislation.
THE FEASIBILITY OF FILTRATION
Investigation to Be Made and
Report to Be Submitted.
CLEANING OUT THE TUNNEL,

| Col. A. NJ Miller the engineer officer I'm
| charge Of the Washington aqueduct, has
| made arrangements for the prompt execu-
| tlon OF the legislation OF the last Congress
| Tor the repair and Improvement Of the
| water supply system of the city OF WASH
| ington. The District APPROPRIATION act pro-
| Vlded as follows: To enable the proper
\ officer of the government, having charge OF
| the Washington aqueduct and the water
| supply Of the city of Washington. to make
an investigation of the feasibility and pro-
| prtety of hltering the water supply at
| Washington and TO submit to Congress a
| full and detailed report thereon, and to
| meet all necessary expenses OF said investi-
CATION. $1,000. Said report shall he accom-
| panied by a detailed estimate OF the cost
of the work required. and in making the
| investigation and in the preparation Of this
| report the chief of engineers. L. :. A, shall
he associated with the proper officer of the
| government in the charge Of the aqueduct
| as consulting engineer"
| Col. MillrI made a project for the ex-
penditure of these funds which WAS app
! proved by the chief OF engineers as fol-
| lows: 1T is proposed 10 make the required
| investigation of the subject of tiltering the
water supply Of Washington and submit the
required detailed report al early n date
! as possible. As this important subject will
require time and careful study, the date at
/ which the report Will be made cannot be
definitely stated. The subject Is being
studied and investigated with view to pre-
| pairing a report"
The condition of the water at various
| parts of the aqneduct system during the
month of February is reported as follows:
At Great Falls-Nery turbid days. turbd
! days, slightly turbid day, and clear IL
| days
At Dalecarlia reservoir, efluent gate
| hcuse-Nery turbid days, tur5id days,
slightly turbid , days, and clear Is days.
At distributing reservoir, efiluent gate
| house-Very turbid days. turbd 3 days,
slightly turbid days and clear II days.
The water in the distributing reservoir
! varied during the month between 1A"so and
| 1f455 above the datum plane. The mouth
of the conduit and the boats at Great Falls,
and the mouth of the shaft at the Dale
| carlia reservoir. were protected and kept
clear of running ice during the high water.
Snow drifts Were cleared from the Conduit
road and the culverts under the Conduit
road. 1t is proposed to repair the Conduit
road near the Dalecarlia reservoir during
the present month.
Repairing the Tunnel.
The project for the expenditure of tho
| appropriation for the completion OF the
Washington aqueduct tunnel and the How
ard University reservoir under the District
appropriation act is as follows: The pre-
limlnary steps in undertaking this work Will
be the stoppage of the water leak into tho
tunnel unde~ Rock creek. 1t is proposed TO
accomplish this by constructing cons
crete covering over the tunnel where IL
passes under Rock creek While this work
is in progress preparations VIII he made 10
pump out the tunnel through the shafts,
The tunnel will then be pumped out ana
inspection made and the force organized for
carving out the plans of the board OF eA-
perts, as set forth in its report dated Janu-
airy II, 1896. which plans have been APP
proved by the chief of engineers and the
Secretary of War"
Good progress has been made in the ex-
ecution of this project. During the past
month cement shed was built at Foundry
branch shaft; snow drifts were removed
from the New Cut road between the shaft
and Both street: coal was hauled TO the
shaft, and the work of eXcavating stone
and muck, trimming the sides and bottom
of tunnel and cleaning out tOOthlng or
brick work, where holes were cut through
the arch was prosecuted with good results.
At Rock creek shaft cars were repaired.
an extension to engine house built and snow
was removed from the road between the
shaft and street An ice gorge which
formed near the shaft and raised the water
so as to very much increase the leakage
into the tunnel was removed.
Experimenting with a Model.
Colonel Miller says that in order to ascer-
tain what would be the effect of grouping
the backing of the tunnel lining, where the
backing was dry stone, a model was built
representing the extrados of the arch,
around WnlCn was packed lOOse stone Ol
random sizes varying in weight from to
~ pounds. The moueI was OF actual size,
representing twenty feet IN length OF the
actual tunnel; the amount of dry packing
used was $50 cubic feet, the amount OF
VoidS by trial 9l0 cubic feet.
The grout " as prepared in the proportion
of one OF round top hydraulic cement,
two of sand. by volume, and as much wafer
as would make the grout sufficiently huid
to pass readiy through the pump. Tfa
volume of water was about 9-lOO in excess
of the volume of cement. Holes were buried
ten feet apart horizontally and about four
feet apart vertically. through which the
grouting was pumped. The grouting was
completed December l., and the Tagging
tahen down to examine the effects March i.
1t was found that the Volds were completes
ly filled. thus demonstrating the fact, says
Colonel Miller. that this method OF grouting
could be successfully accomplished. Blue
prints were made showing the results of the
experiment. Considerable stone and muck
were removed from the tunnel at the differ
ent shafts
The cleaning out of the toothing in the
east heading at Champlain avenue shaft
has been completed. Since the commence
ment of the work 10 ,269 cubic yards of ma
terial have been removed from the tunnel,
2U.599 feet OF track laid and 5,S92 feet OF
.-s.,