Evening star. [volume] (Washington, D.C.) 1854-1972, 1951-08-16
Air Conditioning
Puts Burden on
Water System
Situotion Not Critical,
But Safety Margin
Is Declared Thin

ing here is constantly adding new
burdens to Washington's water
system. .
The system becomes increasing
1y sensitive to the heat with each
extension of cooling facilities. Upt
to 1000 air-conditioning units.
large or small. now demand as
much as 40 million gallons of
water on the hottest days.
The drain on the water supply
continues to mount each year by
some 3 million gallons, despite
technical Improvements and the
fact that huge cooling plants in
the Federal Triangle, on Capitol
Hill and at the Pentagon have in
dependent sources of water.
The situation is by no means
critical. but it offers disturbing
possibilities. The demand is sol
close to supply that the balance
could be upset by a protracted
heat spell, or even a very hot
Monday wash day. These are fac
tors quite apart from a possible
breakdown at the pumping stations
or breach in the dikes along the
restored C & o Canal.
Safety Margin Thin.
Two or more of these posi-
bilities occurring together would
be heavy blow at a system now
operating well above design ca
pacity during the peak consump-
ton month of August. The safety
margin lis little too thin for
comfort" according to Water
Supt., David v. Aud.
During July and August, Wash
ington has been using an aver
age of 100 million gallons daily.
Arlington County and Falls
Church, Va, are receiving some is
million gallons a day, with an
additional Ala million going to
nearby Maryland communities.
This midsummer output of some
210 million gallons fluctuates as
much as 20 per cent because of
weather alone.
In addition, there are day-to-
day and hour to-hour load diff
ferentialS, as between Sunday and
Monday wash days, for example.
or the beginning and end of
business days.
The Districts two big filtration
plants. Dalecarlia and Mcmillan.
were designed for a normal out
put OF only 1875 million gallons a
day, although engagements now
In progress should boost that fig
ure to 234 million gallons by next
summer.
Output Only Briefly Expansible.
The 185-million normal out
put is expansible only for brief
periods. With present facilities,
the pumps can deliver up to 230
million gallons a day for Short
haulS" of up to five days. They
might be called upon in a pinch
for 248 million gallons, but more
than two days of this maximum
output would be an invitation to
q major breakdown, it was said.
Fortunately, the postwar ex-
tension OF cooling equipment has
gone along with technical i'm
provements for saving water.
Modern plants now use from ITO
to 1870 of the water once needed
for the same result.
The water is circulated through
cooling towers or evaporation
condensers and used over and
over again.
Only few of the big, wasteful
pre-war unitS-which use water
only once for its direct cooling
and pump it into the sewers-re-
main in Washington.
At least 80 per cent of the big
apartments erected since the war
are conditioned throughout.
This applies also to new office
buildings, big chain groceries and
shopping centers in the outlying
sections.
Home Cooling Lays.
The use of water for cooling
private homes remains, generally
speaking, several years in the fu-
ture. This factor, however, must
be taken into account in long
range planning.
Demand for water as a cooling
factor probably will be 8 or mil
lion gallons higher this time next
year.
Consumption in this category
now varies from 40 million on days
of maximum heat to Is million
Or a summertime average of
around Is per cent of the total
water output.
The Government, despite it's in
dependent sources, uses about
eight or nine million gallons a
day from District mains to cool
its buildings in the summer.
Meanwhile, the Capitol, House
and Senate Office Buildings, Su-
preme Court and some sections cf
the Library of Congress draw their
cooling water from the Anacostia
River.
Buildings in the Federal tri-
angle have refrigeration units
connected with the Tidal Basin,
and the Pentagon pumps its water
from the Potomac.
Principal bottlenecks in the Dis
trict system are raw water con-
duits leading from Graeat Falls to
Dalecarlia filtration plant. The
inadequate facility is supplement-
ed by water pumped up from the
c. & o. canal.
This is a temporary expedient at
best, in view of the fact that the
rebuilt bikes along the canal are
sometimes preached during high
water in the Potomac.
The current extension of Dale
carlia is expected to be completed
next summer, along with the gen.
eral overhaul of the Mcmillan
plant and improvements al
Caoroatou,po PpSaryoir