xt7n5t3g095w https://exploreuk.uky.edu/dips/xt7n5t3g095w/data/mets.xml   Kentucky Agricultural Experiment Station. 1946 journals kaes_circulars_004_431 English Lexington : The Service, 1913-1958. Contact the Special Collections Research Center for information regarding rights and use of this collection. Kentucky Agricultural Experiment Station Circular (Kentucky Agricultural Experiment Station) n. 431 text Circular (Kentucky Agricultural Experiment Station) n. 431 1946 2014 true xt7n5t3g095w section xt7n5t3g095w   l { J   ·  l‘
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' |‘.4·.4J4‘°4·_t be the trap to the drain—tile line. This sewer line should be of 4-inch
year, PIDG with calked and cemented joints laid to a grade of 4 inches in `
sed· lOO feet.
SIS; Outside toilet. -An outside toilet should be constructed CIC-
cording to the plans and specifications of the Kentucky State Board
{ of Health, Louisville, Ky. Get your plans from your county health I ,
2et 0 _ officer. I
5 per g
rness A farmhouse with modern plumbing and running water should I
rectly have a septic tank. A septic tank is considered by health officers Ԥ
D ]Om Gnd $¤¤lt¤ry engineers to be the simplest safe method of disposing ,
_` OI $€WCIQ€ fFOm 0 rural or urbcm dwelling where G public S€W€I' is  

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not available. It is safest because the tank is watertight and the  
overflow is disposed of in the upper layers of soil where soil bac-  
teria, air, and sunlight can carry on the purifying process begun   li
in the tank. Contrary to general belief, however, the action in  
the septic tank and the disposal area cannot be depended upon to   =
remove all disease—producing bacteria from sewage; j
Frequently cesspools or dry wells are used for disposal of  
sewage from houses with running water. As a rule these are con-  
demned by sanitary engineers. The operation of a cesspool depends j .
on seepage of the liquefied sewage through the porous walls of l
the underground tank into the adjoining soil area. As the seepage ` A
is at a depth of several feet below ground (where there is little _
chance of purification by air, sunlight, or bacteria in the soil)
the sewage may enter and contaminate a water supply. This is the `
j greatest objection to a cesspool. lf the liquid does not seep through .
the walls, the cesspool soon fills to overflowing and becomes a .
nuisance. Cesspools should not be tolerated; ll
How the Septic Tonk and the ·`
Disposal Line Work j
A septic tank is a watertight tank in which the solids in the j _
sewage are held until they become liquefied by the action of l
anaerobic bacteria——that is, bacteria which live only where the ‘
air is entirely or mostly excluded. A scum composed of solids in (
the sewage forms on the liquid in the tank. This scum tends to j
. keep air out of the liquid, and thus provides ideal working con- ‘
ditions for the anaerobic bacteria. As a result of the bacterial
action in the tank, gas, liquid, and sludge (material not liquefied)
are formed. The sludge settles to the bottom of the tank. The -
liquid flows from the tank through a line of tight-jointed sewer j
tile to the disposal area. There it is distributed in the upper soil .
through common agricultural drain tile laid with open joints. The
agricultural drain tile forms the "disposal line."
The liquid as it comes from a septic tank may be clear but il
is far from pure and must be carried into the upper layers of soil
for final purification. The area that is to receive this liquid must .
be well drained, either naturally or artificially. lf the area is noi
properly drained the excess of moisture keeps out the air and the
aerobic bacteria (which live only in the presence of air) which
accomplish final oxidation of the sewage, cannot live and worl<
properly. If the soil is tight and not well drained, special pro-
vision must be made for distributing the sewage, as shown ifi
Fig. 6, page l6.
The sewage must come into and leave the tank without dis- T
turbing the scum which forms on top of the water. lf water laden
with any considerable amount of solid matter is permitted to entef

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4 g 2.-A Septic Tank Sewage Dipasal System
the The septic tank sewage disposal system consists of (l) a line of sewer tile .
ls in ‘ to carry sewage from the house to the `septic tank; (2) a grease trap to remove
[S to y excessive quantities of grease from the water draining from the kitchen sink; `
{ (3) the septic tank where solids in the sewage are liquefied; and (4) a disposal
CQn‘ System -which may consist of agricultural drain tile alone, or of a sewer line to ‘ _ l
gy-igl carry the liquefied sewage to the disposal area and the dis osal line com osed ‘
f- d) of agricultural drain tile p p
ie ·
The - ll
Ewa, 4 the tile line of the distribution system, the tile line will become
, SOM _ c ogged and will have to be cleaned.
The . T
Location (
Mt it ln planning the location of a septic tank and disposal bed it 4
F SON Should be kept in mind that unless the sewer line and septic tank
are absolutely tight there will be a possibilit of leaka e enterin
must , _ _ Y Q 9 i
s not G nearby well or cistern. The septic tank may be as close as 25
;l the feet to the house, but neither sewer line nor tank should be closer
mich Than 50 feet to a well or cistern. The disposal bed should be in i
work ground draining away from the house and water supply. lt may ,
pro- bs in ahlawn, but it is not considered safe to run the disposal line
. t roug a vegetable garden ·
in in · 1
Sewer Line
t dis- T The sewer line leading from the house to the se tic tank should V l
l d ri b f ‘ · · p (
a e e o 4-1nch or 6—inch bell-jointed sewer pipe, depending upon the .
enter amount of fall that can be given. A 4—inch sewer line should have a  

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qg   Fig. 4.—-A straightedge and c¤rpenter's level used·as suggested here will , "
  help in making an even grade. A 'l/4” block with a straightedge  
C6   6'3" long, gives a grade of 4" per l00 ft. · , ~ `
th   ` ·
he   tile line parallel to the disposal line at a depth of 30 to 36 inches. l "   _
or   (See Fig. 6, page l6.) T,
th YI The disposal line should consist of 4-inch agricultural tile ..
are if laid with open joints M4 to % inch apart. A strip of tarred paper ‘ V · ·
iill r. (6" x l2") should be placed over each joint between the tile to pre- _  
 ` vent earth from entering the joint and clogging the tile. The tile ` ·
jjs  Q should be laid at a depth of l6 to 24 inches and to a grade of 4 ”
ne   inches per lOO feet. Purification of the sewage becomes slower , l
Bd lY_-_ and less effective the deeper the tile is laid, because oir in the soil, ,·
jr.   required for the process, decreases as depth increases. The dis- T “
Jr. posal line should consist of one continuous line rather than a main ·
leg `  with lateral lines leading from it. lt is difficult to have an even _ Q
  distribution of the liquid throughout 0 disposal bed composed of a ‘ Y
24 number of short lines, because a very slight difference in levels at
EH Y a junction point in a line will determine the course the liquid will ` °
g follow. This is especially true when the volume is small. The T
  continuous disposal line may be laid on any slope by changing , °
  ‘ the direction of the line, as illustrated in Fig. 2.
  Where a continuous disposal line must be on a hillside, and ‘ ._ l
Tm 4 the direction of the line has to be reversed one or more times as A
my ” shown in Fig. 2, grades of the "U" curves will have to be greater ·i
the , · than 4 inches per lOO feet.
lj The number of feet of disposal line needed depends upon the
l number of persons using the tank, or the amount of sewage enter-
,SGj l' lng the line daily, and how readily the soil in which the tile is laid l ,
uell   T will absorb the liquid sewage. No septic tank for a dwelling should .
t c gs have less than lOO feet of 4—inch agricultural tile disposal line ‘
»s¤l   laid in a trench l8 inches wide. Lay the tile on top of 6 inches of
ing ; Crushed stone or coarse gravel and cover it with crushed Stone to G A
{ith   €l€Dlh of 2 inches (Fig, 5). A trench of l8 inches wide and lOO feet
iter   long will provide an absorption area of l5O square feet, which T ,
  Will be enough to core for 2 persons, in a fairly tight soil, and 5 ‘
l= Dersons, in a more porous