Xylem IMCPFIBRGL R01 Fiberglass Basin - Manual (Page 4)

4
WARNING
the basins until they are needed for installation and if
windy conditions are possible, secure the basins with
non-marring restraints of a size and number adequate for
securing the basin.
PRE-INSTALLATION INSPECTION
Basins, vales, equipment, and piping materials should
be physically and visually inspected before installation.
Adherence to the project’s specifications should also be
confirmed before installation. If the basin or any of its
internal components are damaged, installation should be
suspended until a determination of the extent of damage
can be made by CentriPro or its agent. Any repairs must
be first authorized in writing by CentriPro and then be
done in accordance with CentriPro instructions.
5: EXCAVATING
EXCAVATING
The excavation should provide adequate space for
the basin, piping, and other buried equipment and for
the replacement and compaction of backfill materials
particularly around the basin walls. The size, shape and
wall slope of the excavation should be determined by soil
conditions, depth of excavation, shoring requirements,
and if workers are required to enter the excavation,
safety considerations and federal, sate, county, and
municipal regulations.
Locate all overhead and underground
utilities before excavating.
LOCATION OF EXCAVATING
Excavation for an underground basin should be made
with due care to avoid undermining foundations of
existing structures and contact with underground
utilities. In the absence of building codes or regulations,
maintain a minimum distance of five feet plus a slope or
45* from the bottom of the compacted sub-base to the
bottom of the adjacent structures, foundations, footings,
and property lines (as shown in the attached illustration).
Additional distances may be required to assure that
any loading carried or created by the foundations and
supports cannot be transferred to the basins.
MAXIMUM BURIAL DEPTH
If burial depth is greater than the basin height, contact
CentriPro to determine if additional wall reinforcement
is required and secure written authorization.
HANDLING OF EXCAVATED MATERIALS
Excavated materials, which cannot be removed from the
job site, should be carefully stored as far from the edge of
the basin excavation as possible. Unless approved for use
as backfill, excavation materials should be securely stored
separate from the approved backfill materials.
WORK AREA SAFETY
Safe installation procedures shall be the sole responsibil-
ity of the basin installer. Work safety requirements are
defined in U.S. Department of Labor 29 CFR part 1926,
subpart P, Excavations.
6: BACKFILLING
GENERAL
Careful selection, placement, and compaction of
approved backfill material is critical to a successful basin
installation. Among the common problems associated
with basin leaks and premature failures are:
• Use of incorrect backfill material
• Inadequate or improper placement or compaction
• Rocks, clods, or debris left in the excavation or basin
• Voids under or around the perimeter of the basin
• Failure to prevent the migration of backfill materials
PLACEMENT OF BASIN
The bottom of the basin excavation should be covered
with suitably with graded, leveled, and compacted
backfill material to a depth of at least 12 inches
(compacted sub-base). If a concrete hold-down/anti-
flotation pad is required, this bedding can be reduced
to a depth of at least 6 inches. The carefully lower the
basin into the excavation and centered on the compacted
backfill or concrete pad (see attached).
Placement of a basin on a concrete pad or
compacted sub-base smaller than the total
basin bottom area or on intermediate supports (saddles)
will cause uneven distribution of loads. This may
contribute to structural failure, and is never permitted.
BACKFILL MATERIAL
Back fill material should be clean, well granulated, free
flowing, non-corrosive, and inert. It should be free of ice,
snow, debris, rock, or organic material, all of which could
damage the tank and interfere with the compaction of
the backfill material. The largest particles should not be
larger than 3/4”. Not more than 3% (by weight) should
pass through a # 8 sieve, and the backfill material should
conform to ASTM C-33, Paragraph 9.1 requirements.
Approved backfill materials include:
• Pea Gravel, naturally rounded particles with a
minimum diameter of 1/8” and a maximum diameter
of 3/4”.
• Crushed rock, washed and free-flowing angular
particles between 1/8” and 1/2” in size.
6: BACKFILLING
WARNING
5: EXCAVATING