The Portland daily press., 1885-03-11
TEE TIDAL SEWER.
MIR. Jordan's Objections 40 the Proposed
Eniereeptins sewer on Back Ray,

posed mterceptlng sewer Tor our northwestern
slope and also examined the plans for the
details of construction which show the same
labor and thought 1t is a subject of no mean
proportions and importance to the city of
Portland.
| Thet there should be differences of opinion
as to the best method of achieving sanitary
improvem emit, or as to our financial capacity to
approach the best, is not to be wondered at
That have arrived at a different conclusion
| from that towards which the proposed sewer
| tends. is not the result of casual examina-
| ton but of years of thought and investigation.
| In the summer of 1876, when this subject
was under discussion, l advocated in several
articles printed in the Eastern Argus a rem
edy and relief from our Back Cove nuisance,
to consist of an intercepting sewer discha1g-
ing easterly of Tukey's bridge into the ebb
| tide only and as a relief from the mussel
bed and mud fat smells, / proposed a dam
| about feet high at Tukey's bridge which
| would impound water to cover the flats to the
| grass line about the shores. This last PROPOSE
| ton attracted the attention of the harbor
| commissioners, who protested through the
| published opinion of a specialist in hydro
| graphy, on account of anticipated injury to
| the harbor. l felt that the conditions of rny
| proposition had not been made clear to the
| specialists mind and / so learned by per-
sonal interview with him. The method of
| equating the new condition incident to the
| half dam was one that not only commended
| itself to him but enlisted the promise of his
| CO. operation. / have always felt that the
| scheme was impracticable only on account of
| its probable large cost The dam can wait,
because if considered advisable it can only be
| SO after an intercepting sewer is in operation.
| From my further research upon the subject.
| propose to give my conclusions as to what a
tidal sewer would effect in the same locality,
and its fitness OF unfitness for the work which
we want performed.
| In the first place, take it for granted that
there is to be growth in the development and
| value of the property around Back Cove,
within the proposed marginal way, and that
| it Is anticipated by the owners, and that
nothing should be done that would tend to
limit its uses and impair its prospective val lie.
If this is not true, certain measure of my
| objections to the tidal sewer are groundless.
| If true they are, think, valid.
| The object of a sewer is that it shall re
| move the sewage filth rapidly and before de-
i composition, to point where it shall cease to
| be nuisance, and that it shall be deep enough
| to give drainage to cellars and saturated Soils
| We know that Back Cove itself is not the
| place for the deposit of this filth. The sewer
now under construction passes through level
l area, 1ll6Q anu 10 De ul1eQ Only OF 4 lGeI
above average high water an area which is at
the foot of steep slope that sheds its water
| rapidly. Without overfows to prevent it. the
| main sewer would become choked at the time
| of high tide, or its concurrence with an orNi-
| nary storm, and the sewage would flow back
| in the street sewers to infict serious damage
| upon cellars which in the absence of such a
| sewer might be quite satisfactory. And with
| overfows sewage would be discharged into
| Back Cove practically in the same manner aus il
| is to- day.
To explain. The top of the proposed
| sewer at its outfall is 81 feet under water al
average high tide. At Franklin street the
overflow is 1853 feet under high water and il
would discharge sewage during the rise and
fall of that amount of tide which for one siay
would be hours and IS minutes or 20 pei
cent of the time Similar overhows to the
| north towards Tukey's bridge would discharge
| greater percentage of the time, and
those towards Green street less
| percentage. Pearl and Myrtle are submerged
l.25 feet and would discharge sewage 25 pei
cent of the time. Chestnut and Cedar are
about O.S3 feet submerged and would dis
charge 20 per cent of the time, and Pre,ble
| street about "A per cent of the time; and the
| millpond sewer overflow, which is at a point
| 40 feet below high tide, would discharge sew
age OU per CGub OI Tie LII IdcI, dIIer the
| food tide has reached the overflow to the mill
pond sewer, the sewage from alarge proportion
of the whole drainage area would for great
| percentage of the time, be discharged through
the millpond overflow into the mill pond it self
The overfows which discharge sewage into the
| cove are the safety valves against damage to
| property already improved. Even with them
it appears that the estimate of the back flood
| ing midway the sewer, at Franklin and Will
| mot streets, is II feet more than now exists
| at an average tide; and moreover it seems to
me that the serious difficulties that are to be
anticipated are those incident to the regular re-
curing full tides, which are feet and 5
| inches higher than average, and cannot be neg
| lected when the element of damage enters into
the calculation. High water may hold for a
| few minutes only but decided injury is sure to
occur before it subsidies
have not been able to find that such a
tidal sewer can furnish us the relief to the de-
gree that is anticipated or desired. and farther
we cannot afford an outlay of $9l 900 on a
system that does not bear the impress of a
| fuller return for the expenditure Tidal sewers
are acknowledged ohave grave faults in them
selves, and are only at their best for such q
| locality as ours. when they are placed on i
| Grade and at an elevation, that shall enable
| Them to do successfully their proper work. II
necessarily leaves a small fiat low area to take
care of itself until its own individual growth
is such as to demand its proper sewerage,
| which must then be done by pumping scheme
| such scheme J. Herbert Shedd found
adapted to the cities of Lynn and Brookline
| Al LYNN a part of Mr.. Shedd's plan of work
was doubted and DELAYED seven years. Rudolph
| Herring was recently EMPLOYED by LYNN and
| his plan was practically the same as Mr..
Shedds, with such improvements as the rapid
growth of certain localities suggested. Both
Of these sanitary engineers, while they found
the conditions such as demanded tidal sewer,
realized that they could provide sewerage for
| the filled land only by pumping, which they
| accordingly recommended.
J. Bailey Denton. a prominent sanitary en-
gineer, speaking of the inherent objections ia
tidal sewer says "that in Liverpool, which
has tidal sewersl notwithstanding extraordi-
| nary efforts for the extraction of sewer gases
| by specially arranged shafts and numerous
openings in streets to afford every facility for
the escape of the gases, the death rate yet
reaches 2715 in 1000 and the still greater un-
1