New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1906-01-14

roadway merely screened off huge underground
reservoirs of water undergoing treatment for
publication. The entrance 10 the filter has a
door large as that of stable. iron OPEN
ing it one looks into great cavern in which a
rather graceful effect is given by the numerous
arches supporting the roof. In the roof are
glazed openings through which The sunlight
streams in the daytime. These resemble man.
hole coverings in city streets. They may be
lifted off that fresh supplies of sand may be
poured in to be distributed along the floor each
time the beds are cleaned. At night the vaults
Illuminated with electric lights The en-
tire filter is practically one block Of waterproof
honeycombed concrete From its floor the pillars
supporting the domed roof are built at intervals
of about ten feet. The height from n.o- to roof
is ten feet When the filter covering of rock
and sand is laid along the floor there is. there
fore. a space available for water of about five
feet. Thick concrete walls shut in the filters
every side outside of it earth is placed
The object in inelosing the filter beds is To pro-
tect the surface of the water from outside dust
and especially to prevent as much possible
the freezing of the water in winter
Washington uses on an average 6S00'o0o elI-
Ions of water a day Each of these filters strains
an average of 3.O6Oo0O gallons a day There
fore twenty-three filter beds can strain the
amount absolutely required. leaving SIX beds 70
be used for reserve and as a surplus 90 allow
for taking each bed in turn to be cleaned The
Washington city reservoir. alongside of which
the filters are built. has capacity of 1"d-std10
gallons. this being the final reservoir az the
three used for bringing the water down from
the Great Falls of the Potomac, sixteen miles
away The first great reservoir at p-,a.aria.
ten miles below the Falls has "a clra,i-y of
o-.'-l''to gallons This acts not only as O. slor-
age reservoir but also as Il sediment p basin
The next reservoir is about two miles from
w Washington, on the heights above George town.
ard Is connected with the receiving reservoir by
Il continuation of the conduit. From the J;e ~se-
town reservoir it comes TO the Washt----rr lis
trioutins basin at the filter plant throu-h nine
loot conduit The combined capacity os the
three basins is 30o0OoOoO gallons T. has been
found that the water steadily improve LIS ss,!i-
mentation in it's passage through The three
basins From the last reservoir. SUI In its
muddy state, though benefited by The settling
that has taken place there the water IS jumped
through I2-inch and 52-inch rising mains with
Zeinch branches onto the filter beds IL filters
slowly through the three feet of SAM M the
rate OF about three vertical inches an hour. is
collected in an undertakings system and car
ried through pipes to the regulator house con-
tanning the valves for regulating The rates and
operating the filter. and from there to the
filtered water reservoir with a capacity OF L.
100000 gallons from which it is distributed to
the city
1t is the cleansing of the filters which 70 the
lay mind presents a difficult feature in the OPP
Grafton of the plant That this is prac ticable
and can be done with little difficulty has been
effectively shown in the operation OF the Wash