The Portland daily press., 1889-08-08
DEERINc'S SEWERS.
The Report of Civil Engineer ). Her
bert Shedd.


bert Shedd.
Mr.. j. Herbert Shedd, civil engineer, Of
Providence, r. l., has submitted to Mr..
Luther Bradford. chairman Of the Deering
board of selectmen, his report in regard to
the sewerage of the town of Deering. Mr..
Shedd's report In full is as follows, and will
be read with interest by the citizens of Deer
ing:
have carefully considered the problem of
sewerage in Deering.
First-As to what shall be discharged
through the system. The liquid household
wastes should certainly be so discharged.
am satisfied that the excess of ground water
should also be so discharged. in order that
the cellars and the grounds about dwellings
may be so dried as to be In healthful condi-
tion.
1t is very desirable, on many accounts, that
a certain amount of clean rain water should
be admitted to the sewers, and the only i'm
portant reason for excluding 1t is the in
creased cost arising from the increased size
required. This, however, need not be rela-
lively large item. AS practical matter it
has been found nearly, or quite, impossible
to keep out all the rain water from a sewer
age system, and think, in your case. 1t will
be much more judicious plan to provide for
a considerable amount of roof water and a
limited amount of rain water from other un-
Objectionable sources. In the suggestions Of
sizes, ETC., which l shall make to you have
assumed that you will admit such rain water
as above mentioned.
The ordinary storm water of the streets
and land surfaces may, in this case, think,
be properly excluded, and provision be 9TH
erwise made, Jas circumstances require, for
its disposal. have assumed, in the follow
ing suggestions that such will be your policy.
Second-As to the 0utfall.
For nearly all the present populated part
of Deering tbe deep water of the govern
ment ship channel seems to be the best place
for discharging the sewage, temporarily at
least, and all that now much needs drainage
can be discharged at single point. have
considered its discharge at behring's bridge.
If delivered at this point the sewage will
still have to run something ever 500 feet to
reach the ship channel. Its track would be
through the outlet Of a valley, which must
always have passage kept open for the dis
charge of its storm waters. Naturally. the
rainfall of about $50 acres finds vent here,
and a channel for the discharge Of excessive
storms would need to be about nine feet in
diameter, circular, II all Is to come this way,
Possibly some may be artifeially turned the
other way into Fore river, and thus the re-
quired channel may be smaller. but In any
event the discharge of the sewage of the
town into the outlet of this valley will be
much more Objectionable than its direct dis
charge into the deep water Of the ship chan
mel on account, largely, of the comparatively
small amount Of dry weather flow compared
with the size of the channel. At point on
Forest avenue, about 100 feet southerly from
Deering street, private lane runs easterly,
nearly in line with the middle Of the ship
channel. This furnishes what seems to me
the most desirable route for the discharge of
the sewage Of the town. From this point on
Forest avenue, the distance through the lane
to the ship channel Is about the same as the
distance on Forest avenue to behring's
bridge, and sewage which would have to
flow about 1860 feet to reach the same point
by the way of Deering's bridge. Unless
there is some controlling objection which
has not come to my knowledge. recon-
mend that the outfall be run from Forest av-
enue to the ship channel, about In the line of
this lane. i am informed that s0undlngs In
Forest avenue disclose the existence OF
auicksand, opposite Deering street. This
will, of course, somewhat increase the
cost of laying sewer, but 1t Is not an un-
| common thing to meet this sand in such
work, and If properly managed 1t Is not q
| very serious objection to any proposed loea-
| tion. 1t Is also said that similar sand has
been found while dredging in the ship chan
| mel, and it is not impossible that it exists
| generally about the neighborhood. Very
L har a fOr tho nuffal ah
would be feasible on other grounds, would
| be found to have quicksand on the line. This
| objection is not one which would deter me
| from selecting the route for the outfall which
/ have above suggested.
Third--As to the necessary depth for the
sewers.
If the sewers were to carry roof-water, or
| other clean rain-water,- only they could be
| very shallow so long as they were beyond in
jury by frost. To carry household refuse
commodate all buildings and give proper
| fall in the private drains, even if water
| closets, sinks and laundry tubs were exclud-
| ed from the Easements. of buildings. But
| such exclusion is not always practicable, and
| sometimes the value Of an increased depth to
the sewer is greater for single building
J than the cost of deepening long line OF
I street main. In your case still greater
depth is needed, think, to provide. for the
thorough drainage of ground water below all
/ c6lldIS dIlu lOuuudblOuS. ho WIG SlhuCo VI
your streets are, unfortunately, not general
ly established, it is little difficult to fix up
on proper grade for sewer In given
street. All figures defining grades for sew.
ers should be given to the inside crown oi
| the sewer, as that Is the limit of efficient
drainage and sewers of larger sizes should
have their crowns at proper grade to re-
| ceive the flow of the lateral sewers without
backing it above the crowns of those later
ais. The red lines on the profles l received
% rrfw
good grades for the inside crowns of the
proposed sewers and for Forest avenue
to Fessenden street. ana through
Fessenden street, l approve OF their adop
tion. From Deering street to the ship chan
mel the sewer may be laid on falling grade
shown on the profile Of Forest avenue
seems to me unnecessarily deep; il ma,
have been intended for an invertix grade.
As general guide suggest that the sew
ers be laid about eight feet deep to th
crown.
Fourth-As to material for construction.
For all sizes under and including IL inche
in diameter / recommend the use of salt
glazed, vitrifed. clay pipe. For sizes of Is /
Is inches in diameter the local character o
the earth and other conditions, like the nee,
Of keeping the street free for travel, etc
should determine between the use Of pip
and brick sewers. For sizes over IS inche
in diameter recommend the elliptical forr
Of section. of to II, and single ring brio
laid in hydraulic cement mortar.
Fifth-As to sizes.
The sizes will be mainly determined by th
quality of sewage to be discharged, accord
ing to the suggestions under the headin
First" and the grades at which the sewer
are laid. But 1t is well to establish a min
mum size for street sewers TO be f0llowe
except in rare cases. So far as simple ca
pacity Is concerned a pipe Of six inches, o
even four inches diameter would convey a.
the sewage 1t is intended to supply to theI
in many of the streets in the town, but sma