notify the operator upon arrival and provide pertinent
information such as name of hauler, origin of septage, and
certification, if applicable. The monitoring of septage quantity
and quality, as described in par 6.3, should take place at the
Screening Facility. The septage typically flows
by gravity from the dumping station to the screening facility.
The purpose of the screening facility is to remove the large
solids to protect the downstream treatment processes and
associated equipment. The screens, or "bar racks," can be
manually or mechanically cleaned. Provisions should be available
to efficiently dewater and dispose of the screened materials.
This will minimize the potential for odors.
Grit Removal System. The screened septage will
flow by gravity to the grit removal system. The purpose of the
grit removal facility is to separate the sand, gravel, cinders,
food particles, etc., from the septage while maintaining the
organic material in the main flow for downstream treatment.
Effective grit removal systems include aerated grit chambers and
vortex-type chambers. A grit removal facility may not be
necessary if sufficient grit removal is provided as part of the
liquid or solids process treatment units.
Grinder Pump Stations. Grinder pumps and other
types of wastewater grinders are sometimes used for primary
treatment in lieu of screening. Grinders screen and shred
material into smaller sizes without removing the particles from
the flow. Grinders reduce odors, flies, and unsightliness often
associated with screening and essentially eliminate the steps of
screening removal and handling, which may not be practical for
smaller treatment systems.
Unfortunately, solids from grinders cause problems
downstream, including deposits of plastics in sludge handling
facilities. Pulverized synthetic materials will not decompose in
the sludge digestion process and therefore may affect some sludge
disposal methods, especially land application. Using grinders
can also result in "ropes" or "balls" of material (particularly
rags) that can clog downstream equipment such as pipes,
diffusers, pumps, and aerators.
holding basins is to provide storage, equalization, and mixing
prior to further treatment. Storing the septage will help reduce
the peak loadings to the downstream processes and help maintain
the appropriate blending of septage with the raw sewage. The