The Yakima herald. [volume] (North Yakima, W.T. [Wash.]) 1889-1914, 1906-08-15


which had been made, this change Of
grade being but .005 feet per 100 feet
of sewer. 1t would have caused ac-
emulation of deposits and serious in
terruption of the flow of this part Of
the sewer. The 1S-inch sewer at con-
nection of 16-inch sewer was therefore
raised to a sufficient height (210 by
my levels) to insure the continued SUP
mersion of the wood pipe with its
preservation from decay for an ndefi-
mite period.
Influence of Change of Grade-The
original grade of the 1S-inch tile sewer
was 0.25 per cent from point of con-
nection with 16-inch sewer westerly to
Sixth street, distance of about 100
feet At the lower end the grade was
raised 2.10 feet for the reason stated
and at Sixth street it runs out to the
original grade. In lessenng excava-
average saving of cutting of one foot
by 100 feet, and the width of the
trench For this lessened quantity OF
excavation the engineer in charge OBJ
tanned rebate for the city of $204
This payment was optional with the
contractor as the city was Obliged to
make the change of grade.
Is Change Detrimental?-Now comes
the most important question under con-
sideration. Does the change in grade
thus made in any manner depreciate
the working value of the sewer to the
citizens residing between Sixth and
Tenth streets and between Beech street
and Yakima avenue-the only section
which uses this portion of the sewer?
Let us take an illustration: The eff
feet on the blocks between Ninth and
Tenth streets from Beech street to
Yakima avenue; the lateral sewers
emptying into Beech street in these
blocks will run in the alleys at the
rear of lots.
The elevation of the surface of the
street is 104S The elevation of the
ground at Yakima avenue and Nintn
Beech street sewer invert, on new
grade. where the sewer for these
blocks would run into it is 1029.75
which makes the invert of the Beech
street sewer 1926 feet below the sur
face of the ground at Yakima avenue.
We could build a cellar ten feet IN
depth below the surface of ground at
Yakima avenue, and yet have a clear
S.25 feet of fall in the lateral sewer
before connecting with the Beech street
sewer.
Six feet of fall would provide a
grade of 02O per cent, which would be
ample, ana this iii the most unfavor-
able of the conditions presenting, as |
find the following:
At Eighth and Ninth streets a diff
ference of 1852 feet
At Seventh and Eighth streets a d.
ference of 2o.32 feet
And between Sixth and Seventh
streets a difference Of Else feet.
This is an effectual answer to the
question propounded. The raise of
grade in the sewer will not interfere
with the working value of the sewer to
the people who will have to use it.
In this connection l wish to call at
tention to this fact, that the outlet of
the sewer is only IA inches; that into
this l6-inch sewer empties, and into
the latter the lS-inch tile sewer. 81
that the capacity of this sewer really
is measured by the outlet. which IL
but IA inches. Furthermore the 1e-
inch pipe has no appreciate fail what,
ever.
The evident intent Of the origlnators
Of the plan was to utilize the old a.
inch sewer until it became imperativelv
necessary to enlarge the outlet. which
can be done at any time
As a physician and sanitary en-
gineer | could not help but observe the
admirable location Of the ground for
the construction of septic tanks near
the river. when it becomes necessary to
construct them.
Conclusion-First. The first change
IN plan. namely, that Of raising the IT,
inch sewer two feet was 4 wise one.
as it was being built AT a depth Of
about l6 feet, which was needlessly
deep for amy purpose at this point,
Second-The change of grade at the
junction Of the lG-inch and lS-inch tile
sewer became practically necessary
after the first had beer made, for the
reasons given in report.
Third-The change Of grade in Is
inch tile sewer of cos GIVE hundredths
of foop per 100 feet for 1900 feet.
with the conditions existing. will not
influence the workings of the sewer to
any appreciable extent
Fourth-The minor changes in the
sewer as constructed will not interfere
in any way with the proper working
of the sewer TO its full capacity as
planned.
Respectfully submitted,
GEORGE Il. FELL