The Portland daily press., 1895-04-02

on my feet only short time, and now do
all my work for my family of hve.h
above maximum quantities, the interoeptor
would run but half full, which allows fer
the admission of an amount of rain-water
equal at least TO the greatest quantity of
Sc wage, and therefore a corresponding dit
rion of the same, lwhen it escapes into the
IsGoye for a slprt time during rain storms.
Under the circumstances do not consider
this escgnesof diluted sewage to lie at all
ohleo tlona bleasst such Tines. particularly if
1.-The overflow pipes are extended into the
ldeep water Chan eel nRt Il tanned by the
United states government.
m order 10 economic as much as nracti-
cable il tile slope and depth of The inter-
ceptoi, bave assumed the shape of its
cross-sectlon o be circular, and it's centre
line continuous. In other words, when rum
ming half full the slope of the water surface
in the sewer represents ire hydraulic gr;-
Idient Tor Whit o he sizes have been campG-
Etcd. y can see no advantage IN using an egg
shape in this case. US the flow will be rela-
ltiyaly great at all times. and d circular
Eslape requires less Aeight and less slope
Tor given velocity.
In order TO obtain the dimensions Of the
tank sewer proposed to lead from the end
of the intsrceptor TO the outf III, and in
which The sewage is to lie retained during
the incoming Tide, II is necessary to aseer-
tnin what STORAGE capacity it ahould have
/ tligh tide. II the sewer is to dis barge dur
Ing three hours, then he capacity should
be SUFFICIENT 10 hold The sewage gradually
accommodating during nine hours and TWEEN
.ty five minutes, because the duration of one
tdaily tide is twelve hours and TWEEN ty-tye
minutes. The greatest accumui afion of sew
Eeubio feet, exclusive Of rain or ground
water.
70 satisfy this requirement. have as
THE TANK SEWER
has width of sixteen feet in The clear, and
hat lis average depth of water is 5.25 feet
below high wafer mark, with slope towards
the outfall. 1t should be given o reetangu-
lar shape will slight depression in the mid
die and built OF timber. J he top should be
level and least one foot atove high wat
er level.
The tank sewer leading to the temporary
outfall at The bridge need not lave rs much
storage capacity because the amount of
sewage to be stored now is not rs great as
that which is assumed fer he tank sewer
leading TO tile permanent outfal1 1t Is we'll
| to place screen near the end of the INFER
lceptOr I o prevent floating matter from es-
Gaping from the temporary outlet and DRIFT
ing back to the shores.
Ii eoDne6 ting tie OLD sewers with the in
| terceptor, care should be taken that no re-
Tar dation of tne flow is caused at the juno
Etions. and that rs little rain water as posi-
Eble tends to enter it.
/ IL the separate system is USeu IO1 Une low
TERRITORY, the liar drainage should if pos
sible lie turned into the storm water sewers
Ior drains, and not into the interceptor.
On a., secouRt 81 q the slight yeloeities OBJ
to provide ample means for flushing. For
instance. by gates. at suitable points to
Temporarily store the sewage and to let it
Suddenly rush out; or. the lower part of
the sewer can be flushed by storing the
water at high tide and discharging it sud-
denly at mean tide.
1t has been suggested that the Back Cove
be transformed into
A WATER PARK
with marginal boulevard. In connection
with the sewage question / consider this
an excellent proposition, as such park is
only feasible if the sewage is excluded from
the Cove. 1t is an error to suppose that this
body of water is able to receive the sewage
without.objec tionable consequences. For
several hours during every tide the velooi-
| ty is too slight TO prevent deposit. This
| would cause putrefac tiOn in warm weather,
| whether the bottom is exposed OF slightly
| of sewage, such rs would enter during
| rain storms might be admitted without
| harm.and then only II the Cove is improved
| SO that the flats are we'll covered with wat
En- Such Improvement seems necessary
| also TO prevent the present nauseating
| doors from the extensive beds Of dead
4 MuSSelS, WHICH uye uRcOVereu ut low Tue.
These nDjectlonala features can be obv-
ated by the proposed park, as it is suggest
| ed to have at least three Ieet Of water COW
ering the beds at the lowest tide. There
are ways in WHICH this may be economical
| " done, and still allow. Of free navigation
during several hours OF high tide. Il neces-
sary requirement for the harbor 1t is there
| fore to he hoped that such pr oject may be
favora bly, considered by the United States
engineers who have charge of the navigable
wal eTs of the Cove.
| The following is an estimate Of cost for
the proposed interceptor in it's different
sections as referred TO on the profile of the
same. It was m; de by the city engineer,
Mr' George N. Fernald, after a consul alton
| witn me, and the totals received my APP
| nrdval. The estimate for the tank sewer
fefars 10 the temporary optfall at the Grand
| 4 rink railroad bridge. No estimate of cost
is included for The permanent ontfall and
! for the branch @@:sewer in Green straet to
| cnnneot the Deering system with the inter
| cen,or Estimate of cost for proposed north
| side interceptor:
| TANK sewer, AGO feet, $50, SOC 90
| Seetion one, 1850 feet, 81 .s06.6 s.:
Ssction two. 4S65 feet. so $50. 9G
| Section three. 2,26b feet. 1905, "a
| Ssction four, 1910 feet, 1891 50
Section i've, ~ feet, lSl.dl
| Section six. 2.040 feet, 5,l23. 08
Estinated cost OF connecting later
al sewers with in eIceptor and re-
| huilding where required, say, 4.000.0L
! Land damages, say, 10000. 90
S133. 656. 81
| plan is also presented herewith, show
| ;,a tbe location of the interceptor. the
1a1k sewer ard The sautfalls as described
ana finally profle.Sf tie interceptor, show
III Which plan and moale have been pre-
rarea h. he citySeagineer..
HRsf pdHPSa Herring.