Idaho County free press. [volume] (Grangeville, Idaho Territory) 1886-current, 1905-12-14
ESTIMATES FOR
SEWER SYSTEM
Engineer Roberts Thinks II Can be Built
For $4,000.
SUFFICIENT TO SERVE 5000 PEOPLE
Council Will Take UP Question
at Next Meeting.

The city council has received
detailed estimate from Engineer
Roberts of the cost of installing
sewerage system in this city and
will probably act on the matter at
their next meeting. The report is
as follows:
Pullman, Wash, Nov. %, 1905.
To the Hon. Mayor and City Coun-
Gil, Grangeville, Idaho.
Gcntlemen: l am sending by
express today to the mayor, the
map, profiles, specifications, in
structions to bidders, details of
materials required and estimates of
the cost of the system.
l will ask you to examine the
proposed lines Of sewers with ref
erence to the topography of
Grangeville, and l will be glad to
render every assistance in making
the plans complete in every respect.
l will ask that you will give me
time enough to have the duplicate
blueprints Of map and profiles
made in the east after you return
them to me. l had no frame, nor
was there one in Spokane, large
enough to print the profiles on one
sheet.
If I could only anticipate your
Questions l could explain the
'why" and wherefore for many
items in the details.
The red lines on the tracing of
map will show the extent of the
system, which l think covers pret-
ty much the whole town as built
up last July. Small laterals, OF
four or six-inch sizes can be run
out from the proposed lines when
ever the grad ents secured can be
as great as 2 per cent for 4-inch
and about l per cent for 6inch
pipes.
NY determination of the size 70,
the outlet line from near the mil
about half mile down the creek
was determined thus: The fattest
grade on this line (see profile) ii
l6 feet per thousand; with such 8
grade, a 12-inch line will discharge
2,76O,OOO gallons in "a hours,
while 1O-inch will discharge l.,
65O,OOO gallons. Assuming tn.
average sewage discharge per capits
to be 100 gallons per day, then thu
maximum hourly discharge will b.
about IA OF this-say 175 gallons
per capita. Thus the 1O-inch lin,
will care for !, $50, 900 divided by
175 equals 945O population: quite
ample you see for fourfold expan
sion. On all other lines s. and 6
inch sizes are quite ample, excep
on the one fiat grade on Ginning
ham street (see profle), where
have again used 1O-inch to secur
velocity sufficient to prevent de
posits. For house laterals Cline
from house to street) would rec
ommend 4inch pipes if the grade
are as much as 4-inch per foot
about 2 per cent grade. Fo
laundries, hotels, and stables, Q
where the lateral can not have
2 per cent grade, l would recon-
mend 6-inch pipe.
The Office of a man-hole, as tn
name implies, is to admit ma
for the purpose Of examination {
sewer, or for direct flushing. A
designed there are few lines on tn
system where the pipe is nc
straight from man-hole to mar
hole, or from lamp-hole to mar
hole, so that light lowered in or
opening can be see by man at tt
adjacent man-hole. For the sha
low man-holes, under four fee
there is hardly depth sufficient
turn the arch to support the ire
cover; hence for depth under for
feet, you can use wooden cove
with some saving in cost, but n,
so durable.
/ have inserted six automat
fush-tanks, either at the head
the lines having very fat grade
or at the ends of principal line
They can be set to discharge tw
three, or many times, in twent
four hours, according to the plea
ure of the one in cnarge.
The depths adopted for the d
! ferent lines may call for more e
/! plantations than I can give in
/; brief letter or report, but l we
! over the matter with some of Il
I council last summer and, rough
! speaking, ten to twelve feet
! about right for sewers to drain
/ Main street basement, while
! residence streets, 3.5 to 4. 8 is abo
! right. Where the sewer runs alo
+; a hillside street, as College sire
!; for example, it can only accol
I modate the upper side of t
!; street, unless at a greater expent