CERTIFIED SOLIDE WASTE EXAM: SOLID WASTE
DISPOSAL FACILITY OPERATOR STUDY GUIDE FOR SITE
OPERATOR CERTIFICATION
In composite-lined landfills, leachate is pumped from the landfill's leachate collection
system inside a _______________, a large-diameter pipe that extends from a sump at
the base of the landfill to the top of the berm.
Sideslope riser
Municipal solid waste combustor residue is most likely to be identified as what type of
waste based on toxicity characteristic leaching procedure (TCLP) testing.
Hazardous
Municipal solid waste combustor residue is disposed of in either a single lined or double
lined composite landfill depending on what?
Depending on whether or not the residue exceeds allowable concentration limits of certain
chemicals.
What type of soil is used for clay liner construction?
Fine-grained soil as defined by the Unified Soil Classification System (USCS).
According to USCS a soil is classified as fine grained if a minimum of what percentage
of a given sample by weight passes through the #200 sieve.
50 percent
The saturated hydraulic conductivity of the clay used in liners must how great after
compaction?
1x10-7 cm/sec or less.
,The clay used in liners must have an average liquid limit of _______________, with no
values less than _______________?
25, 20
The clay used in liners must have an average plasticity index of _______________ or
greater with no values less than _______________?
12, 10
Why are both the base liner and the lower 10 feet of the inside slopes are required to be
protected from freeze - thaw damage?
Because freezing and thawing increases the permeability of clay, newly constructed liners
must be protected from freeze - thaw damage using 4 feet of solid waste or other frost
protection material during winter months.
While constructing clay liners, clods larger than _______________ inches should be
broken up and the lift heights must not be greater than _______________ inches after
compaction.
4, 6
Clay must be compacted to which specifications while constructing clay liners?
The clay must be compacted to 90% modified or 95% standard Proctor density at or wet of
optimum moisture content using a sheep's foot roller with a minimum weight of 30,000
pounds.
State codes require which tests to demonstrate the constructed quality of landfill clay
liners and final cover clay layers:
Dry density and as-placed moisture content, grain size analysis up to .002 millimeter particle
size, Atterberg limits, and hydraulic conductivity of field samples.
True or False? The geomembrane in composite liners must be placed on a properly
rolled and smoothly graded clay liner surface.
, True!
Geomembranes made of polyethylene resins must be welded using what?
Double track fusion welding machines.
True or False? Seams on the geomembranes placed on inside slopes must run parallel to
the slope baseline as far as practicable.
False! Seams on the geomembranes placed on inside slopes must run perpendicular to the
slope baseline as far as practicable.
True or False? Wrinkles that are wider than they are high must be smoothed or cut out
and repaired.
False, Wrinkles that are higher than they are wide must be smoothed or cut out and repaired.
The geomembrane product in composite liners and final covers must be tested for which
physical characteristics?
It must be tested for thickness, tensile properties, density, melt index of the polymer, and
environmental stress.
What are the two primary types of landfills?
Natural attenuation and engineered or containment
Which of the two primary types of landfills rely on natural soils to filter, dilute, or
otherwise prevent leachate from the landfill from contaminating groundwater?
Natural attenuation landfills
DISPOSAL FACILITY OPERATOR STUDY GUIDE FOR SITE
OPERATOR CERTIFICATION
In composite-lined landfills, leachate is pumped from the landfill's leachate collection
system inside a _______________, a large-diameter pipe that extends from a sump at
the base of the landfill to the top of the berm.
Sideslope riser
Municipal solid waste combustor residue is most likely to be identified as what type of
waste based on toxicity characteristic leaching procedure (TCLP) testing.
Hazardous
Municipal solid waste combustor residue is disposed of in either a single lined or double
lined composite landfill depending on what?
Depending on whether or not the residue exceeds allowable concentration limits of certain
chemicals.
What type of soil is used for clay liner construction?
Fine-grained soil as defined by the Unified Soil Classification System (USCS).
According to USCS a soil is classified as fine grained if a minimum of what percentage
of a given sample by weight passes through the #200 sieve.
50 percent
The saturated hydraulic conductivity of the clay used in liners must how great after
compaction?
1x10-7 cm/sec or less.
,The clay used in liners must have an average liquid limit of _______________, with no
values less than _______________?
25, 20
The clay used in liners must have an average plasticity index of _______________ or
greater with no values less than _______________?
12, 10
Why are both the base liner and the lower 10 feet of the inside slopes are required to be
protected from freeze - thaw damage?
Because freezing and thawing increases the permeability of clay, newly constructed liners
must be protected from freeze - thaw damage using 4 feet of solid waste or other frost
protection material during winter months.
While constructing clay liners, clods larger than _______________ inches should be
broken up and the lift heights must not be greater than _______________ inches after
compaction.
4, 6
Clay must be compacted to which specifications while constructing clay liners?
The clay must be compacted to 90% modified or 95% standard Proctor density at or wet of
optimum moisture content using a sheep's foot roller with a minimum weight of 30,000
pounds.
State codes require which tests to demonstrate the constructed quality of landfill clay
liners and final cover clay layers:
Dry density and as-placed moisture content, grain size analysis up to .002 millimeter particle
size, Atterberg limits, and hydraulic conductivity of field samples.
True or False? The geomembrane in composite liners must be placed on a properly
rolled and smoothly graded clay liner surface.
, True!
Geomembranes made of polyethylene resins must be welded using what?
Double track fusion welding machines.
True or False? Seams on the geomembranes placed on inside slopes must run parallel to
the slope baseline as far as practicable.
False! Seams on the geomembranes placed on inside slopes must run perpendicular to the
slope baseline as far as practicable.
True or False? Wrinkles that are wider than they are high must be smoothed or cut out
and repaired.
False, Wrinkles that are higher than they are wide must be smoothed or cut out and repaired.
The geomembrane product in composite liners and final covers must be tested for which
physical characteristics?
It must be tested for thickness, tensile properties, density, melt index of the polymer, and
environmental stress.
What are the two primary types of landfills?
Natural attenuation and engineered or containment
Which of the two primary types of landfills rely on natural soils to filter, dilute, or
otherwise prevent leachate from the landfill from contaminating groundwater?
Natural attenuation landfills
