Evening star. [volume] (Washington, D.C.) 1854-1972, 1931-02-16
DISTRICT ASSURED
|. OF WATER SUPPLY
IF DROUGHT LASTS
War Department Engineer
'for Capital Foresees
Ample Supply.
CITY TAKES ONLY HALF
OF RIVERS LOW FLOW
Potomac Higher Now and New
Dalecarlia Plant Fills Needs
Until 1850.

Even If the present drought should
continue through the coming Summer,
Washington's water supply will be
ample for all needs that can now be
foreseen, according to Maj. Joseph D.
Arthur, jr., District Engineer for the
War Department for the Washington
area, who has charge of the produc-
ton phase Of the water supply system.
The minimum flow of the Potomac
River has never been less than twice
what we need to I'LL our conduits,"
Maj. Arthur said, in explaining that
Washingtons water supply comes from
the river, near Great Falls, and is
brought down to the Dalecarlia plant,
just within the District, in giant pipes.
River Flow Higher.
In general, We use $40 second-feet
(3l0 cubic feet each Second) in our
condu1ts. The lowest flow Of the river
IN history has been approximately $50
Second-feet. This minimum, according
to the records. was not reached during
the past Summer. OF the $40 second
feet that We bring down through our
conduits the City Of Washington used
az the maximum, approximately two
thirds, the remaining one-third bein
used by us for generating electricity fo
pumping operations. In an emergenc
we would not have to use any Of tn
water for pumping purposes.
The Potomac River is now appreci.
ably above the minimum flow of tn.
past Summer. It would be most un
usual II it dropped to 200 second-fect
but 1t can drop that low and not re.
ouce the flow below the amount re-
quired by the City Of Washington.
The water Is still excessively hard, "
Maj. Arthur continued. "It has a loi
of calcium carbonate in it, due to it
coming down through limestone coun-
try and not being diluted by surface
run-off.
Mud Added Before FiItering.
I'VE are trying to maintain a bal
arce between the alkalinity and ths
hardness, so that neither will cause diff
f1culty in the pipes. Excessive hardness
is likely to cause trouble in small water
heaters that are used for q capacity
greater than that for which they were
designed. To remove entirely that diff
f1culty would result in excessive aka
Unity, which would become apparent
throughout the city in the form Of rec
water through the taps. caused BY the
rusting action on the pipes.
The hardness during the past Sum
mer was approximately twice the nor
NAL found in Potomac River waite
Because of the lack Of rain, the wat(
was so free of mud that difficulty We
experienced in the operation Of tn
filters, which operation is basicall,
dependent on the formation of small
particles resulting from the adhesion
OF alum to mud carried in the water
Conditions were so bad that a cor
receive was supplied by actually addin
mud to the water, prior to sending j
through the filters.
Had the new conduit and the new
filtration plant at Dalecarlia not been
available during the past Summer the
consumption of water by individuals
would have been limited, because or
many days during the Summer actu2
consumption exceeded the capacity
the old conduit and filter plant.
Plant Ample Till 1850.
This Office (the United States e..
gineer'S off1ce) has made studies as [
the probable increase in consumptiCn
for number Of years, and on the bass
of this predicted consumption recon-
mendations were submitted in ample
time for the construction of the new
plant
Similar studies" Mai. Arthur as
serted, will continue to be made, and
plans have been tentatively prepared
for increased capacity In ample time to
meet the demand of the District.
IF the growth in the future parallels
that of the past, 1t can be stated that
present installations should be suffi-
Gent to serve the community until ap-
proximately 1880"