The evening times. [volume] (Washington, D.C.) 1895-1902, 1901-05-10
PURE WATER In PROSPECT
Plans for Washington's ProposeJ
Filtration Plant.

( The English System, TO De Adopted
Sixty Million Gallons to lie Sup
| piled DafEy-PrccautiOus in Case Of
Accidents - waiting or Congress
/ It begins TO look now as if one would
/ soon lie able TO see daylight through the
muddy waters Of the Potomac River. For
/ the past twenty years or more tests of
/ the waters turhidity have been made
I accompanied with appeals to Congress for
/ the necessary appropriations 10 secure TO
/ Washington clear and wholesome water
/ To these appeals, however, Congress~has
/ given but slight attention. although
/ enough to determine a system Of fltra-
! ton which shall be not only efficient but
practical. This system is one that has
( been in successful operation in England
! and various places in this country. and is
/ known as the English system.
/ The English plan of filtration has finally
| been approved by a board of engineers
| as the one most practicable. Already
| site for the filtration plant has been Sc
| IeCted and excavating begun. The site
! chosen adjoins the grounds Of the Sol
| diers Home and Howard University The
! SreCifcations call for i series of seven
| teen hlteT-basins, communicating one with
! the other. The partially filtered water
J from one basin enters the next one ad-
Jacent and so on until the maximum fl
/ tTation Of the entire plant is realized.
At the bottom of each filter basin is
| 70 be layer. of coarse gravel overlaid by
gravel of a smaller size, both to serve as
/ uHdcrdrains, This will be about eight
inches OF ten inches deep and upon this
/ VIII be laid layer of carefully washed
Potomac River sand. the real flteriag ma
nj ar1
viii be supplied also with the necessary
pipes. valves meters. and other apparatus
to admit the turbid water, control its
velocity through the filter, and dispose
OF the Uttered water. Upon the top Of
the hltering sand the water will be ad-
mltted to a depth of three feet
Inc inferred water from the underdrains
At the bottom of the filters is to be COL
iected III clearwater well. and thence
passed through meter to the efHuent
pipe A-verticaI scale viii be erected on
the exterior OF the tanks, on which point
ers. connected with floats at the surface
Of the water in the filter and with the
surface Of the water in the clearwater
" ell, viii serve to Indicate the level of
these two surfaces The water in the
filter VIII be kept at a certain level. or
constant head This system of filtration
viii supply the city of Washington with
upward Of 100000 gallons Of clear water
a day.
The filters are to located on land in the
Immediate vicinity of the Howard. or new
reservoir They are to be laid out to
agree with the plat of the ground. and will
average about L6 acres each. They are
designed as large as is practicable in
order to save masonry They viii be rec
tanguIaT OF tTapeZOIdaI in form accord
Ia
a depth Of three feet, supported on one
foot OF gravel, with the proper under
drains, collecting cOnduits, inflow and
outflow pipes, and regulating apparatus
As the filters should be worked at a
consta,I rate, 1t will be necessary to pro-
vide for the varying hourly demand. This
neCessitates a filtered water reservoir, ana
II has been provided for by setting apart.
by masonry dam with proper gatehouse /
and valves, q portion of the Howard res
ervolT- This filtered water reservoir viii
contain 3o,od0.oe0 gallons at the normal eIe-
walton Of 144 feet above mean tide The
dam IS given such a height as to allow
an excess over this quantity as a compen- |
sation for the varying demand.
It mas been decided to adopt a rate Of
filtration from the English method OF
3,6J1,e59 gallons an acre day. In order to
supply 0,005000 gallons at this rate con
slant dIteTing area of twenty acres must |
be in operation, and the acreage must also !
be placed in use during the period of !
cleaning any filters and in case Of acct
dent, or on any occasion when the plant /
: out Of use For this purpose q reserve
OF ~ per cent OF the acreage in active or
Grafton viii be set aside In other words
when three-qUaTters Of the whole plant is |
al active operation, one-quaTtsr viii be !
out OF use undergoing cleaning, renuing !
with sand, or any Of the necessary opera |
tons TO keep the plant in an efficient |
working condition
To operate under th=se conditions TWEEN
ty-Seveu acres OF hltcring surface viii be
required This is merely the actual sur
face of the sand in the filter beds. The /
necessary buildings, the masonry Of the !
hiters, the space occupied by commUnica-
tons. and washers will add about eight
acres TO the required area Altogether |
about thiTty-fIve acres Of land viii be re-
CURED TO erect such q plant
The location CT the plant viii be as
near the new reservoir. located near the |
Soldiers Home grounds, as possible The |
site selected Hes adjacent to the reservoir. |
and IS bounded on the north by the Sol
dieFs Home grounds, on the east by North |
SaDltOI street, on the south DE Detroit |
Street, and on the west by the new reser- !
vOir. This plot contains, exclusive OF
First Street west 1858 acres or J. sol 1856 !
Frankfort, and EmpoTia Streets, contain
ing 4i29So square feet. there are IIlII75 !
square feet laid out in building lots which |
are available for the plant.
The Washington water supply is partly |
4 gravity supply, and any system Of fl |
tration adopted should be so arranged
that no loss of head viii result This |
requires that the filter beds be above the
delivery level and shat the filtered water |
be delivered a the same level To accom-
plish this ii viii be necessary to raise the |
water TO the nlter beds by pumping The !
pumping plant must be able 20 deliver Sc |
90, 90 gallons Of water a day with a maxi |
mum lift Of thirty feet In case o. acct |
dent to this plant which would be a very |
serious matter, as il would stop the SUP
ply Of filtered water, and for necessary I!
repairs. there will be a reserve. A re |
serve. therefore. of 50 per cent has been f!
adopted, and the plant divided into three !
units Of 100000 gallons each two in con |
slant use and one in reserve.
About once in a month or forty days |