City of Frisco Engineering Standards

Engineering Standards
G. All mains installed for future developable areas shall include wastewater service laterals; the use
of boots will not be permitted.
H. All wastewater service laterals crossing water mains shall conform to the requirements of the
TCEQ Chapter 217, Subchapter C, Rule 217.53(d), latest revision, or Section 5.2.3 of this
standard.
5.2.8 Manholes and Cleanouts
A. Manholes shall be installed at all changes in grade and direction, and have a maximum spacing of
500’.
B. Spacing between a manhole and an upstream cleanout shall be a maximum of 250’. A cleanout
or manhole shall be located at the end of a wastewater main.
C. Manholes on curved wastewater mains shall be located at the P.C. or P.T. of the curve and have a
maximum spacing of 300’ along the curve.
D. Manholes shall be constructed of monolithic, cast-in-place concrete, precast concrete or
fiberglass.
E. Manholes shall be concentric type unless otherwise approved by the Director of Engineering
Services.
F. Drop manholes shall be required when the inlet pipe flow line elevation is more than 24” above
the outlet pipe flow line elevation. Drops shall be outside the manhole unless otherwise approved
by the Director of Engineering Services.
G. Manholes shall be sized as follows:
1. 4’ in diameter for 8”, 10”, and 12” pipe.
2. 5’ in diameter for 15”, 18”, 21”, 24” and 27” pipe.
3. 6’ in diameter for 30” and 36” pipe.
4. 5’ in diameter minimum for manholes deeper than 15’.
H. Where more than three manholes in sequence are to be bolted and sealed, every third manhole
shall be vented 2’ above the 100-year floodplain elevation or 10’ above the adjacent ground line,
whichever is higher. The Engineer shall provide the elevation of the 100-year floodplain on the
profile.
I.
Construct manholes within 30’ of each end of wastewater mains that are installed by other than
open cut and within 30’ of each end of aerial crossings.
J. Manholes shall not be located in parking spaces.
K. A manhole with pipes of different sizes must have the tops of the pipes at the same elevation and
flow channels in the invert sloped on an even slope from pipe to pipe.
Section 5 – Water & Wastewater Design Requirements May 2012 Page 5-13