drawings. The Contractor is responsible for the design, fabrication, and
installation of the underground piping system within the system design
parameters established by the project designer.
Distribution Site Location.
Fluid distribution site locations
should be according to the following:
For location factors for each system, refer
to Table 4.
Subsurface Explorations. When a concrete trench or a buried steam
or hot water system is specified, make a thorough investigation of ground and
water conditions shall be made. Employ a soils engineer familiar with ground
water conditions at the site to establish the classification. In the absence
of existing definitive information on soil types and ground water conditions,
make a detailed site classification survey. Upon completion of the survey,
classify each exploration point as A, B, C, or D on the basis of the criteria
presented in Tables 5 and 6. The worst ground water condition encountered
between adjacent manholes determines the class of the system to be installed
between adjacent manholes. Conduct this survey within the guidelines
specified in paras. 220.127.116.11 through 18.104.22.168. When concrete shallow trench
systems are specified, use the criteria of NFGS-02693 for prefabricated piping
systems covered in this handbook.
Timing of Survey. Conduct the survey after the general layout of
the system has been determined.
Time of Year. Make the survey at a time of year when the highest
water table is expected to exist, if possible. If this is not possible,
correct water table measurements on the basis of professional judgment, to
indicate conditions likely to exist at the time of year when the water table
is at its highest point. Follow exploration methods indicated in the NAVFAC
criteria manual DM-7.01, Soil Mechanics.
Exploration Considerations. As a minimum, collect information on
ground water conditions, soil types, terrain, and precipitation rates and
irrigation practices in the area of the system. Information on terrain and
precipitation rates and irrigation practices may be obtained from available
records at the installation.
Test Explorations. Make test explorations (borings or test pits)
at least every 100 feet (30.5 m) along the line of a proposed system. If
changes in stratification are noted, decrease the boring spacings so an
accurate horizontal soil profile may be obtained.