The Wheeling daily intelligencer. [volume] (Wheeling, W. Va.) 1865-1903, 1876-12-27
Intercepting sewers.


The engineer who Is charged with the
design Of works Of sewerage should pay
particular attention to the principle Of
interrogation. II may often happen that
the financial success Of u scheme for dis
posing Of the sewage Of district will
depend upon the construction Of proper
lntercepting sewers, that is, certain por.
lions Of the sewage should DO intercepted
in the higher portiona of tho district, and
not allowed to gravitute downto the love
cat lsvsl; and SO tho sewage Of consiieF-
able portion Of such district may often be
conveyed BY direct gravitatidn to Sdita.
bio outiall, leaving only the sewage OF the
lowest zones to DO dealt with by artificial
power. Not unfreQuently the intercept:
Ing sewer will form the only outtall OF
the district, as the sewage Of the lower
district may be pumped into it., Iu dis
tricts Ii, which there Is buta small longi-
tudinal fall, and comparatively great
lateral falls, the work OF interception will
form an essential feature in the
scheme Of sewerage, In large towns
the.work Of interccption may be carried
out with advantage, and thereby often
reduce the cost of the system Of sewer
age, 40 when this principle is fully car
ried out large town is divided by inter
cepting sewers into number OF smaller
areas, and as II is well known that u IS
much cheaper proportionulely To me pop
ulation and areas, to drain a snall .owI
han large one, 30 large town ulViueu
into districts by intCrcepIing sewers can
often be drained more eiiectuailJ ana
cheaply than II all the sewers were Al
lowed 10 flow 10 one common level. In
fact, branch sewer may be compared 10
a cone, the b. Of whichr rests in the low
eat portion OF the district, and the apex
terminates in the highest. A system oil
intercepting sewers would cut this cone,
and the saYiug in cost would be repre-
scented by the difference in cost OF con-
structing that portion OF the branch
sewer represented by the fsustum oil
the cone below the linterceptins
sewer, and the construction OF an
other smaller cone, the apex oil which
would commence n the intercept.
ing sewer, and the base reat at the lowest
level of the district, due allowance oil
course being made for any extra sewer
that may be required in carrying out the
principle OF interception. In large dis
tricts The principle Of interceptiOn forms
an essential element OF safety: by diyid'
ing the drainage area into smaller dis
tricts the volume OF sewage or rainfall Ia
broTpht moro under control than in dis
tricts where the volume oil sewage is
large, and is allowed to fall down to the
lowest level OF the district. In sea.coast
towns the principle Of interccption is also
OF great Importance. The low:levcl sew,
ers in such districts are often Lide.lockcd
therefore il is of manifest advantage &c
intercept the sewage OF the higher por'
tions OF the district, and TO lead it away
together With the rainfall, by district
outlalI, no rs not TO interfere, with The
tide.lockcd sewers OF the district. The
principle Of interceptiou in well under
stood in the great drainage works
that have been carried out in the
fen districts Of England, These large
areas are entirely surrounded by inter
cepting drains, which catch the rainfall
OF the higher districts, and lead II OF b!
gravitation 10 the natural streams, lOav
Ing only the rain falling on the low land
TO he dealt with by artificial means. II
many towns this principle otintercePtior
has formed main feature in the scheme
OF sewerage, as in the case Of London i
has received ita full development. Thu
author has seen many cases in which
towns after being severed have increased
80 rapidly in size ard population thatth'
original scwers have become too small
the consequence Of which has been tha
the lowcr;porIiona Of the district hav'
been frequently inundated. by the in
PRODUCTION into these overgrown town
OF system OF intcrceptingscwers, cutting
the sewers already constructed, the sew
age Of the upper portion Of tho diStric
may often be harmlessly conveyed away
leaving the sewers OF the lower dlstric
ample in size to deal with the volume o
sewage which is locally due them, and, 80
alta comparatively small cost, tho-efti
cheney OF tie original sewerage work.
NAV bercstored. n.t Es H.6HS