Riverchase(5)-CS 770101 DE-~IGN !~.NTJAL
}'OR.
WATER
m Ci?.' CF DALLAS ..
D.qL~ WAT--R UT!LITIZ$
J ~.I;~ 1977
Sewers in eas~ents through private property shall be encased in concrete
for protection against root infiltration and o:her possible
general, the minimum dep=h required for severs to serve a given proper:y
shall be 2 ft. plus a depth necessary :o provide a 2% grade for :he la:oral
(the lateral distance being :he dis:anco from the sever main :o :he center
of ~he house). Thus, for a house 135 ft. fxom the sever, the depth
2 ft. plus 2% X 135 ft.=2.0 + 2.7 - A.? fr. The depth of :he flo~ line of
:he scour shall then be at least &.7 ft. below the e!eva:ion of the ground
at the house.
&. Se~aage flow shall be co=puted in accordance with Char= &12A-2,
(A~pendix B), =i:h exceptions only as approved by :he Engineer of Design
cf the Wa-er U:illties Department. Pipes should be place6 on a gra~e such
that :he ve!oci:y within the pipe, when flovlng full, is at leas: 2 f~.
per second and not more :ham 10 ft. per second.
A~z sanitary sewer ~rades shaiI be Sho%~ :e :he me~ es' O.el foe:. Grades
shall be evenly divisible by 6, a~d if practical, :hey should be even, such
as: 0.20I; 0.&0%, 0.6'0%; and 1.00%, etc., ~ urger :o facilitate field
comDutatlons. . ~%~en ~he grade of a se~e~' . main changes be:~een manhcies cr
=unctions, vertical cur~es are often used :e s=oc:h the~iou. Vertlc~i
curves ~ill be required ~here :he grade change is groove- :kan q'' The length
cf :he curve shall be a minimum cf 100 ft. and :he PVi cf :he curves shall be
placed on an even or half station unless o:he~ise aTprcve~. If :he grade
difference is less than 1%, a grade break may be used.
6. i~he sizes and locations of manholes, ~%'es, Bends, tap connec:iens,
cleanou~-, etc. shall be as deslgna~e~ by the Engineer cf Design uf :he
Ua=er Uttli les Department. In general, manholes on ~--i=ary se ·~ mains
should be provide~ a: the follo~ing locations to facillta=e =ain=enance,
ci~anlng and inspect!on: !nter~ecticn cf ~ains; chat&es in TiDe sizes; at
each en~ cf a slphon,' o--~ horlzc~ral cr verricai ben~s in e>:ce£s