Fla. Admin. Code Ann. R. 62-701.400 - Landfill Construction Requirements
(1)
Minimum design standards. The requirements of this rule are the minimum
standards for constructing a landfill. Nothing in this rule shall be construed
to prevent the Department from imposing more stringent standards as necessary
to protect the environment and the public health and safety due to site
specific conditions and types of wastes to be disposed of in the landfill or
solid waste disposal unit. An applicant whose landfill design meets the design
standards of this rule will be presumed to provide reasonable assurance that
the performance standards of subsection
62-701.340(1),
F.A.C., will be met.
(2) Planned
construction and closure. All landfills shall be designed so that solid waste
disposal units will be constructed and subsequently closed at planned intervals
throughout the design period of the landfill. Designs to prevent failures of
side slopes, and designs to prevent deep-seated failures through the waste,
along liner systems, and through foundation soils, shall achieve a minimum
factor of safety of 1.5 using peak strength values.
(3) Landfill liner requirements. Class I
Landfills shall be constructed with composite or double liners, and a leachate
collection and removal system. Liners and leachate collection systems for Class
III landfills are addressed in paragraph
62-701.400(3)(g),
F.A.C.
(a) Liners shall be:
1. Constructed of materials that have
appropriate physical, chemical, and mechanical properties to prevent failure
due to physical contact with the waste or leachate to which they are exposed,
climatic conditions, the stress of installation, and other applied stresses and
hydraulic pressures which are anticipated during the operational and closure
period of the solid waste disposal unit. The supplier of materials for the
liner components shall provide test information accepted by the engineer of
record, that supports the capabilities of the materials to meet these needs,
2. Installed upon a base and in a
geologic setting capable of providing structural support to prevent
overstressing of the liner due to settlements and applied stresses,
3. Constructed so that the bottom of the
liner system is not subject to fluctuations of the ground water so as to
adversely impact the integrity of the liner system,
4. Designed to resist hydrostatic uplift if
the liner is located below the seasonal high ground water table; and,
5. Installed to cover all
surrounding earth which could come into contact with the waste or
leachate.
(b) Composite
liners.
1. The upper component of the
composite liner shall be a 60-mil minimum average thickness HDPE geomembrane. A
primary leachate collection and removal system and a drainage layer shall be
installed above the geomembrane liner. Except in sumps and leachate collection
trenches, the system shall be designed to limit leachate head above the liner
during routine landfill operation after placement of initial cover, as
specified in Table A below, depending upon the thickness and hydraulic
conductivity of the lower component of the composite liner. Leachate head
calculations shall consider leachate recirculation if the leachate is
recirculated.
2. The lower
component of the composite liner shall be constructed in six-inch lifts. The
thickness of the lower component may be varied in relation to the hydraulic
conductivity of the lower component and the design leachate head above the
liner, in accordance with Table A.
|
TABLE A: Minimum Thickness of Lower Component of Composite Liner (feet) |
|||
|
Maximum Design Hydraulic Head (inches) |
Maximum Hydraulic Conductivity (cm/sec) |
||
|
1x10-7 |
5x10-8 |
1x10-8 |
|
|
1 |
2.0 |
1.0 |
1.0 |
|
6 |
2.5 |
1.5 |
1.0 |
|
12 |
3.0 |
2.0 |
1.0 |
(c) Double liners.
1. Double liner systems shall consist of
upper and lower 60-mil minimum average thickness HDPE geomembranes, with a
primary leachate collection and removal system lying above the upper
geomembrane designed to limit the leachate head to one foot above the liner
during routine landfill operations after placement of initial cover, except in
sumps and leachate collection trenches; and a leak detection and secondary
leachate collection system between the upper and lower liners. The lower
geomembrane shall be placed directly on a sub-base which is a minimum six
inches thick, is free of sharp materials or any materials larger than one-half
inch, and has a saturated hydraulic conductivity of less than or equal to 1 x
10-5 cm/sec. A geosynthetic clay liner (GCL) with a
hydraulic conductivity not greater than 1x10-7
cm/sec may be used in place of the six-inch thick sub-base layer provided it is
placed on a prepared subgrade which will not damage the GCL.
2. The leak detection and secondary leachate
collection system shall have a minimum hydraulic conductivity of ten cm/sec,
shall be designed to limit the maximum hydraulic head on the lower liner to one
inch, and shall not allow leachate head to exceed the thickness of the drainage
layer. The hydraulic conductivity of the leak detection and secondary
collection system material shall be derived from transmissivity and thickness
measurements.
(d)
Standards for geosynthetic components.
1. HDPE
geomembranes and LLDPE geomembranes shall have factory and field seams whose
shear and peel strengths during testing are in conformance with the seam
strengths specified in method GRI GM19. PVC geomembranes shall have factory and
field seams whose shear and peel strengths during testing are in conformance
with the seam strengths specified in method PGI 1104. For all geomembranes, the
failure shall occur in the lining material outside the seam area. All field
seams must also be visually inspected and pressure or vacuum tested for seam
continuity using suitable non-destructive techniques.
2. Geomembranes shall not be used at
landfills unless they are subjected to continuous spark testing by the
manufacturer at the factory and no defects have been found.
3. Geomembranes shall be protected from
physical damage by placing a minimum 24-inch-thick protective layer above the
upper liner. All materials in direct contact with the liner shall be free of
sharp materials or any materials larger than one-half inch. The upper 12 inches
of the protective layer shall be composed of soil, tire chips four square
inches or smaller with no protruding wires that could pose a threat to the
integrity of the liner, or other materials approved by the Department which are
permeable, non-reactive, stable, and which offer protection for the liner from
punctures.
4. The first layer of
waste placed on the protective layer above the liner and leachate collection
system shall be a minimum of four feet in compacted thickness, and consist of
selected wastes containing no large, rigid objects that may damage the liner or
leachate collection system. Materials that could damage the liner shall be
removed from this layer.
5. HDPE
geomembranes shall meet the specification contained in method GRI GM13. LLDPE
geomembranes shall meet the specification contained in method GRI
GM17.
6. PVC geomembranes shall
meet the specification contained in method PGI 1104.
7. Interface shear strength of the actual
components which will be used in the liner system shall be tested with method
ASTM D5321, hereby adopted and incorporated by reference, or an equivalent test
method. To obtain this standard see subsection
62-701.210(14),
F.A.C. However, when testing GCLs, method ASTM D6243, hereby adopted and
incorporated by reference, or an equivalent test method, shall be used. To
obtain this standard see subsection
62-701.210(17),
F.A.C. Unless it can be justified otherwise, the interface shall be tested in a
water-saturated state. For the purposes of this test, clays compacted in the
test apparatus during setup which have a water content wet of optimum shall be
considered water saturated.
8. The
transmissivity of geonets shall be tested with method ASTM D4716, hereby
adopted and incorporated by reference, or an equivalent test method, to
demonstrate that the design transmissivity will be maintained for the design
period of the facility. To obtain this standard see subsection
62-701.210(15),
F.A.C. The testing for the geonet in the liner system shall be conducted using
actual boundary materials intended for the geonet at the maximum design normal
load for the landfill, and at the design load expected from one lift of waste.
At the maximum design normal load, testing shall be conducted for a minimum
period of 100 hours unless data equivalent to the 100-hour period is provided
in which case the test shall be conducted for a minimum period of one hour. In
the case of the design load from one lift of waste, the minimum period shall be
one hour. For geonets used in final covers, only one test shall be conducted
for a minimum period of one hour using the expected maximum design normal load
from the cover soils and the actual boundary materials intended for the
geonet.
9. The hydraulic
conductivity of GCLs shall be tested with method ASTM D5887, hereby adopted and
incorporated by reference, or ASTM D6766, hereby adopted and incorporated by
reference, or an equivalent test method. To obtain these standards see
subsections 62-701.210(16)
and 62-701.210(20),
F.A.C., respectively. First, the GCL test specimen shall be hydrated with the
fluid which is expected to cause hydration in the field, or a similar fluid,
for a minimum of 48 hours using sufficient backpressure to achieve a minimum B
coefficient of 0.9 and using a confined effective consolidation stress not
exceeding five pounds per square inch. Then, the hydraulic conductivity test on
the GCL specimen shall be conducted, using the appropriate permeant fluid, at a
confined effective consolidation stress not exceeding five pounds per square
inch. The hydraulic conductivity test shall continue until steady state
conditions are reached or a minimum of two pore volumes of permeant fluid have
passed through the test specimen. The permeant fluid shall be either leachate
from the landfill (or a similar landfill) if the GCL is used in a liner system,
or water if the GCL is used as a barrier layer in a final cover.
10. If not submitted as part of the permit
application to the Department, then the testing required in subparagraphs
(3)(d)7., 8. and 9. of this paragraph, for the materials used in the liner
construction shall be conducted as part of the construction quality assurance
activities, and the results of these tests shall be included in the completion
of construction documents required in subsection (7), of this rule.
11. The testing required in subparagraphs
(3)(d)7., 8. and 9. of this paragraph, are single-point tests required either
as part of the permit application phase of a landfill project or prior to liner
construction. The purpose of these tests is to confirm that the components
selected for the liner construction meet the design criteria used in the permit
application.
(e) The
following specifications shall be provided for geosynthetic components:
1. Definition and qualifications of the
designer, manufacturer, installer, geosynthetic quality assurance consultant,
geosynthetic quality assurance laboratory, and quality assurance
program,
2. Material specifications
for geomembranes, geotextiles, geogrids, geocomposites, and geonets, including
general requirements, specified geomembrane properties, and labeling,
3. Manufacturing and fabrication
specifications including:
a. Geomembrane
manufacturing, including raw material and roll quality control,
b. Geomembrane fabrication, including
requirements of personnel, seaming equipment and products, seam preparation,
weather conditions for factory seaming, overlapping and temporary bonding,
trail seams, and nondestructive seam continuity testing,
c. Destructive seam strength testing
including location and frequency, sampling procedure, size of samples, testing
at the fabrication factory, laboratory testing, fabricator's laboratory
testing, and procedures for destructive test failure; and,
d. Repairs.
4. Geomembrane installation specifications
including:
a. Earthwork,
b. Conformance testing,
c. Geomembrane placement, which shall address
layout drawings, panel identification, and field panel placement,
d. Field seaming, which shall address seam
layout, requirements of personnel, overlapping and temporary bonding, seam
preparation, seaming equipment and products, weather conditions for seaming,
trial seams, general seaming procedures, nondestructive seam continuity
testing, destructive testing, and defects and repairs including identification,
evaluation, and repair procedures,
e. Materials in contact with the geomembrane,
including granular materials, concrete, and sumps and appurtenances; and,
f. Lining system
acceptance.
5. Geotextile
and geogrid specifications including handling and placement, conformance
testing, seams and overlaps, repair, and placement of soil materials and any
overlying materials.
6. Geonet and
geocomposite specifications including handling and placement, conformance
testing, stacking and joining, repair, and placement of soil materials and any
overlying materials.
7. GCL
specifications including handling and placement, conformance testing, seams and
overlaps, repair, and placement of soil materials and any overlying
materials.
(f) Standards
for soil liner components.
1. Soil components
of liners shall be constructed to preclude, to the greatest extent practicable,
lenses, cracks, channels, root holes, pipes, or other structural
inconsistencies that can increase the saturated hydraulic conductivity of the
soil component. The design shall illustrate and describe those instances in
which overexcavation of permeable areas and backfilling may be necessary to
seal the permeable area. The soil component shall be placed and compacted in
layers to achieve the design performance.
2. The permeability of soil liner components
shall not be increased above the values specified for the component, as a
result of contact with leachate from the solid waste disposal unit.
Compatibility of the soil component and leachate shall be demonstrated by
testing the soil component with actual or simulated leachate in accordance with
EPA Test Method 9100 or an equivalent test method.
3. The soil component of the liner may
consist of in-situ soils, provided they meet the specifications for soil
liners. Testing of in-situ soil shall be performed in accordance with the site
specific Construction Quality Assurance Plan in accordance with subsections
62-701.400(7) and
(8), F.A.C.
4. Specifications for the soil component of
the liner shall be provided to and approved by the Department, and shall
contain at a minimum:
a. Allowable range of
particle size distribution and Atterberg limits, to include shrinkage
limit,
b. Placement moisture
criteria and dry density criteria,
c. Maximum laboratory-determined saturated
hydraulic conductivity, using simulated leachate as the saturating and testing
liquid,
d. Minimum thickness of the
soil liner,
e. Lift
thickness,
f. Surface preparation
(scarification) for tying lifts together; and,
g. Type and percentage of clay mineral within
the soil component.
5.
The soil liner shall be placed using construction equipment and procedures that
achieve the required saturated hydraulic conductivity and thickness. A field
test section shall be constructed using the proposed construction equipment and
tested to document that the desired saturated hydraulic conductivity and
thickness is achieved in the field. Test results shall be submitted to the
Department along with the completion of construction
documents.
(g) Class III
landfills. A Class III landfill shall be constructed with a bottom liner
consisting of a single 60-mil minimum average thickness HDPE geomembrane. In
the sumps located inside the landfill footprint and in the leachate collection
trenches, the geomembrane shall be placed on a GCL with a hydraulic
conductivity of less than or equal to 1 x 10-7
cm/sec, or on a compacted clay liner which is a minimum six inches thick with a
saturated hydraulic conductivity of less than or equal to 1 x
10-7 cm/sec. The liner shall be placed on a prepared
subgrade that will not damage the geomembrane liner or the GCL. A primary
leachate collection and removal system and a drainage layer shall be installed
above the geomembrane liner. Except in sumps and leachate collection trenches,
the system shall be designed to limit leachate head above the liner during
routine landfill operation after placement of initial cover to no greater than
12 inches. An applicant may request exemption from the requirements of this
paragraph in accordance with paragraph
62-701.340(2)(b),
F.A.C.
(4) Leachate
collection and removal system. Landfills shall have a leachate collection and
removal system that is designed, constructed, maintained, and operated to
collect leachate and convey it to collection points for removal.
(a) The primary and secondary leachate
collection and removal systems shall:
1. Be
constructed of materials that are chemically resistant to the waste disposed of
in the landfill and the leachate expected to be generated,
2. Have sufficient mechanical properties to
prevent collapse under pressures exerted by overlying wastes, cover materials,
and by any equipment used at the landfill,
3. Have granular material or synthetic
geotextile filter overlying or surrounding the leachate collection and removal
system to prevent clogging of the collection system by infiltration of fine
particles; and,
4. Have a method to
test that the pipes in the system are not clogged, and a method for cleaning
the pipes in the system if they become clogged. If any part of the system
cannot be tested for clogging, the design shall assure that leachate can be
rerouted from that part to a leachate sump in the event of
collapse.
(b) The primary
leachate collection and removal system shall have a granular drainage layer
above the top geomembrane liner, at least 12 inches thick, with a hydraulic
conductivity of not less than 1 x 10-3 cm/sec,
overlain with an additional 12 inches of protective material as specified in
subparagraph 62-701.400(3)(d)
3., F.A.C., that is chemically resistant to the waste and leachate. Leachate
collection systems incorporating synthetic drainage materials may be used if it
can be demonstrated that they are equivalent to or more effective than the
granular design, including chemical compatibility, flow under load, and
protection of the geomembrane liner.
(c) The leachate collection and removal
system shall be designed with a bottom slope to achieve the required leachate
head after the predicted settlement determined by the foundation analysis. The
minimum slope for the leachate collection system, in areas which drain to
lateral collection pipes and header pipes, shall be 1.0 percent after predicted
settlement. The minimum slopes for the collection pipes of the leachate
collection system, i.e., lateral and header pipes, shall be 0.3 percent after
predicted settlement. Minimum slopes shall be measured from the peak grade to
the lowest grade along the design flow path. Slopes shall be surveyed after
completion using a 50-foot grid in areas which drain to lateral collection
pipes and header pipes and at 50-foot intervals where pipes of the leachate
collection system are to be installed. These surveyed slopes must demonstrate
that positive drainage is shown in the direction of flow between any two grid
or interval points.
(d) A schedule
for routine maintenance of the leachate collection and removal system shall be
established to ensure operation of the system. The maintenance schedule shall
be a part of the facility operation plan.
(5) Leachate recirculation. Leachate shall be
recirculated only at solid waste disposal units which have a leachate
recirculation system included in their operation plan, and which have been
constructed and operated in a manner consistent with that system. If leachate
is recirculated after closure, the operation plan shall be included as part of
the approved closure plan. The leachate recirculation system shall include
estimated impacts on the head of leachate over the liner, subsidence of the
waste, and gas production, and shall meet the following requirements unless
otherwise approved in the operation plan.
(a)
The landfill shall be lined and have a leachate collection and removal
system.
(b) Ditches, berms, or
other devices shall be installed to control any leachate runoff. Initial and
intermediate cover receiving recirculated leachate shall be graded to shed
runoff into the leachate collection system and to minimize mixing of leachate
runoff and storm water.
(c) Initial
and intermediate cover shall be permeable to the extent necessary to prevent
perched water conditions and gas buildup.
(d) Leachate shall not be recirculated during
weather conditions or in quantities that may cause runoff outside the solid
waste disposal unit, surface seeps, wind-blown spray, or exceedance of the
limits of the leachate head on the liner. Ponding is prohibited unless it is an
integral part of the design plan.
(e) Landfill gas shall be managed in
accordance with rule 62-701.530, F.A.C.
(f) Recirculation of leachate is prohibited
on top of areas where a barrier layer which is part of the final cover has been
installed. Irrigation of the final vegetative cover may be done with treated
leachate which meets the water quality standards of the receiving water body,
if such irrigation does not contribute significantly to leachate
generation.
(6) Leachate
storage tanks and leachate surface impoundments.
(a) The requirements of this subsection apply
to all leachate storage tanks and leachate surface impoundments constructed
after January 6, 1993. Leachate storage tanks in use on January 6, 1993, are
not required to retrofit to comply with this subsection unless leakage,
corrosion or other defects are found. Leachate surface impoundments in use on
January 6, 1993, shall be replaced or modified to conform to this subsection by
January 6, 1995.
(b) Surface
impoundments for leachate treatment or storage that are located at landfills
are subject to the following requirements:
1.
Surface impoundments shall be constructed so that the bottom of the liner
system is not subject to fluctuations of the ground water so as to adversely
impact the integrity of the liner system. The applicant shall demonstrate that
the surface impoundment design will minimize infiltration of leachate into the
environment so that ground water and surface water quality standards and
criteria are not violated.
2. The
surface impoundment shall be designed in segments such that any one segment may
be taken out of service for inspection and repair with no interruption of
service.
3. The impoundment shall
have a double liner system consisting of an upper and lower 60-mil minimum
average thickness HDPE geomembrane, and a leak detection and collection system
between the geomembranes with a minimum hydraulic conductivity of one cm/sec.
The lower geomembrane shall be placed directly on a subbase which is at least
six inches thick and has a saturated hydraulic conductivity of less than or
equal to 1 x 10-5 cm/sec. A GCL with a hydraulic
conductivity not greater than 1x10-7 cm/sec may be
used in place of the six-inch thick sub-base layer provided it is placed on a
prepared subgrade which will not damage the GCL. The leak detection and
collection system shall be checked daily. The design of the upper liner shall
include calculations to predict the potential leakage through the upper liner.
If the daily checks indicate the upper liner is leaking at a rate greater than
predicted by the design calculations, the Department shall be notified. If the
leakage rate will result in the flooding of the leak detection and collection
system, the impoundment shall be emptied and the liner repaired.
4. To preserve the liner integrity and
prevent uplift, ballast material such as rounded gravel or sand, that will not
cause damage to the geomembrane liner, shall be placed on top of any liner
which is located below the water table.
5. A minimum of two feet of freeboard above
the depth which would occur in the event of a 25-year, 24-hour storm shall be
maintained in leachate surface impoundments.
6. Vectors and off-site odors shall be
controlled.
(c) Above
ground leachate storage tanks that are located at solid waste management
facilities are subject to the following requirements:
1. Tanks shall be constructed of concrete,
steel, reinforced plastic, polyethylene, or fiberglass. Tanks shall be
supported on a well drained, stable foundation.
2. Bottoms of steel tanks that rest on
earthen material shall be cathodically protected with either sacrificial anodes
or an impressed current system which is designed, fabricated, and installed in
accordance with the engineering plan submitted to the Department.
3. The exterior surfaces of all steel storage
tanks shall be protected by a primer coat, a bond coat, and two or more final
coats of paint or other surface coating system designed to prevent corrosion
and deterioration.
4. The interior
of all tanks shall consist of a material or must be lined with a material,
resistant to the liquid being stored.
5. All aboveground tanks shall have a
secondary containment system which may consist of dikes, liners, pads, ponds,
impoundments, curbs, ditches, sumps, or other systems capable of containing the
stored leachate. The design volume for the secondary containment system shall
be 110 percent of the volume of either the largest tank within the containment
system or the total volume of all interconnected tanks, whichever is
greater.
6. The secondary
containment system shall be constructed of materials compatible with the liquid
stored. The containment system shall be constructed of either:
a. A minimum three-foot layer of compacted
soil with a maximum saturated hydraulic conductivity of 1 x
10-7 cm/sec or one foot of compacted soil with a
maximum saturated hydraulic conductivity of 1 x 10-8
cm/sec with two feet of protective cover, or
b. A concrete pad that will maintain its
integrity for the lifetime of the tank, provided that the tank, if made of
steel, has a corrosion resistant coating, or
c. A HDPE geomembrane of a minimum average
thickness of 60 mils.
7.
A system shall be designed to contain and remove storm water from the secondary
containment area. Provisions shall be included for the removal of any
accumulated precipitation and be initiated within 24 hours or when 10 percent
of the storage capacity is reached; whichever occurs first. Disposal of this
stormwater shall be in accordance with the requirements of subsection
62-701.400(9),
F.A.C.
8. All aboveground tanks
shall be equipped with an overfill prevention system which includes level
sensors and gauges, high level alarms, or automatic shutoff controls. The
overfill control equipment shall be inspected weekly by the facility operator
to ensure it is in good working order.
9. The exposed exterior of all aboveground
tanks shall be inspected weekly by the facility operator for adequacy of the
cathodic protection system, leaks, corrosion, and maintenance deficiencies.
Interior inspection of tanks shall be performed whenever the tank is drained or
at a minimum of every three years. If the inspection reveals a tank or
equipment deficiency, leak, or any other deficiency which could result in
failure of the tank to contain the leachate, remedial measures shall be taken
immediately to eliminate the leak or correct the deficiency. Inspection reports
shall be maintained and made available to the Department upon request for the
lifetime of the liquid storage system.
(d) Underground leachate storage tanks that
are located at solid waste management facilities are subject to the following
requirements:
1. Tanks shall be constructed of
concrete, fiberglass, reinforced plastic, steel that is cathodically protected,
or steel that is clad with fiberglass.
2. A secondary containment and a continuous
leak detection system shall be installed in the form of a double-walled tank,
designed as an integral structure so that any release from the inner tank is
completely contained by the outer shell.
a.
The interstitial space shall be monitored at least once per week by the
facility operator for tightness using pressure monitoring, vacuum monitoring,
or electronic monitoring.
b. The
tank system shall be protected from both corrosion of the primary tank interior
and the external surface of the outer shell.
c. All resistant coatings applied to the
primary tank interior shall be compatible with the stored leachate.
d. Cathodic protection systems, where
installed, shall be inspected at least weekly by the facility operator. Any
deficiency in the cathodic protection system shall be corrected when
discovered.
3. All
underground tanks shall be equipped with an overfill prevention system which
includes level sensors and gauges, high level alarms, or automatic shutoff
controls. The overfill control equipment shall be inspected weekly by the
facility operator to ensure it is in good working order.
4. Inspection and leak detection monitoring
reports shall be maintained at the facility and made available to the
Department upon request for the lifetime of the liquid storage
system.
(7)
Liner systems construction quality assurance.
(a) Liner systems shall have a construction
quality assurance plan to provide personnel with adequate information to
achieve continuous compliance with the liner construction requirements. The
plan shall include or refer to specifications and construction methods which
use established engineering practices to construct a liner system and provide
for quality control testing procedures and sampling frequencies. Sampling and
testing shall be conducted in the field by trained personnel during
construction and after construction completion. Such personnel will be under
the direction of the construction quality assurance professional engineer, to
assure the liner system will comply with the standards. The construction
quality assurance professional engineer or his designee shall be on-site at all
times during construction to monitor construction activities and shall be
on-site to monitor off-loading of the geosynthetics to be used in the liner
system. Construction activities include the time during which the protective
layer is installed over the geomembrane, to ensure that the placement
techniques do not cause damage to the liner system materials.
(b) Liner systems shall be installed in
accordance with a Department-approved construction quality assurance plan.
Plans that comply with EPA Document EPA/600/R-93/182 shall be presumed to be in
compliance with this section. The following minimum specific elements shall be
included in the plan:
1. Responsibility and
authority of all organizations and key personnel involved in permitting,
designing, constructing, and providing construction quality assurance of the
waste disposal facility shall be described fully,
2. Minimum qualifications of the construction
assurance quality professional engineer and supporting personnel shall be in
the plan to demonstrate that they possess the training and experience necessary
to fulfill their identified responsibilities,
3. Procedures and tests that will be used to
monitor the installation of the liner system components shall be described in
detail,
4. The sampling activities,
sample size, sample locations, frequency of testing, acceptance and rejection
criteria, and plans for implementing corrective measures that may be necessary
shall be described; and,
5.
Reporting requirements for construction quality assurance activities shall be
described, including daily summary reports, observation data sheets, problem
identification and corrective measures, and final documentation. All such
documents shall be included in the final report which shall be forwarded to the
Department.
(c) Unless
otherwise approved by the Department, one destructive test sample shall be
collected every 500 feet along the total length of the seams. If an electrical
leak location survey method, or other equivalent non-destructive test method,
is used to locate and repair leaks in the installed liner system, then one
destructive test sample shall be collected every 1000 feet along the total
length of the seams in the areas where this method is used.
(d) If an electrical leak location survey
method, or other equivalent method is used to test the geomembrane(s) in the
liner system, testing shall be conducted after placement of the soil drainage
layer. The geomembrane liner leak location survey shall be performed using
standard industry methods, and any leaks located shall be repaired and tested
by methods approved by the Department. The results of the geomembrane liner
leak location survey, including a description of the locations of any leaks
detected and the repairs that were conducted on these leaks, shall be
documented in a final report included with the completion of construction
documents required in this subsection.
(e) A laboratory experienced in the testing
of geosynthetics, independent of the liner manufacturer and installer, shall
perform the required testing which must include, at a minimum, conformance
testing for all geosynthetics and geocomposites, and testing of seam shear and
peel strength for geomembranes.
(f)
The professional engineer in charge of construction quality assurance shall
provide a signed, sealed final report and record drawings to the Department
stating that the liner system has been installed in substantial conformance
with the plans and specifications for the liner system. The report and drawings
shall be submitted along with a certification of construction completion on
Form 62-701.900(2).
(8) Soil liner construction quality
assurance. In addition to the requirements of subsection (7), above, the
following requirements apply to construction of the soil component of liner
systems. All required testing and analysis shall be performed in accordance
with generally accepted engineering procedures, such as those promulgated by
the American Society for Testing and Materials (ASTM). Parenthetic references
to ASTM methods are intended as guidance only.
(a) A construction quality assurance/quality
control plan shall be prepared for each soil liner project to outline project
specifications and construction requirements. The plan shall specify
performance criteria for the soil liner, and provide quality control testing
procedures and minimum sampling frequencies. In addition, the plan shall define
the responsibilities of the parties that will be involved in soil liner
construction, and shall present minimum qualifications of each party to fulfill
their identified responsibilities.
(b) Field and laboratory testing during liner
construction shall be conducted by a qualified soil testing laboratory
representing the owner. A qualified field technician representing the owner
shall provide full time, on-site inspection during liner construction. The
field technician shall work under the supervision of a professional engineer
with experience in soil liner construction.
(c) Prior to soil liner installation, an
appropriate borrow source shall be located. Suitability of the liner
construction materials from that source shall be determined in accordance with
the following:
1. If demonstrated field
experience is available from at least three prior successful projects of five
or more acres each to document that a given borrow source can meet the
requirements of the project specifications, then extensive laboratory testing
of the borrow source will not be required. However, the source of material
shall be geologically similar to and the methods of excavating and stockpiling
the material shall be consistent with those used on the prior projects.
Furthermore, a minimum of three representative samples from the appropriate
thickness of the in-situ stratum or from stockpiles of the borrow material
proposed for liner construction shall be submitted to an independent soil
testing laboratory to document through index testing that the proposed material
is consistent with the material used on prior successful projects. At a
minimum, index testing shall consist of percent fines, Atterberg limits and
moisture content determinations.
2.
If demonstrated field experience as defined above is not available or cannot be
documented, then the following requirements shall be met.
a. A field exploration and laboratory testing
program shall be conducted by an independent soil testing laboratory to
document the horizontal and vertical extent and the homogeneity of the soil
strata proposed for use as liner material. A sufficient number of index tests
from each potential borrow stratum shall be performed to quantify the
variability of the borrow materials and to document that the proposed borrow
material complies with specifications. At a minimum, the index tests shall
consist of percent fines, Atterberg limits and moisture content
determinations.
b. Sufficient
laboratory hydraulic conductivity tests shall be conducted on samples
representative of the range invariability of the proposed borrow source (ASTM
D-5084). For each such sample, test specimens shall be prepared and tested to
cover the range of molding conditions (moisture content and dry density)
required by project specifications. The hydraulic conductivity tests shall be
conducted in triaxial type permeameters. The test specimens shall be
consolidated under an isotropic consolidation stress no greater than 10 pounds
per square inch and permeated with water under an adequate backpressure to
achieve saturation of the test specimens. The inflow to and outflow from the
specimens shall be monitored with time and the hydraulic conductivity
calculated for each recorded flow increment. The test shall continue until
steady state flow is achieved and relatively constant values of hydraulic
conductivity are measured (ASTM D-5084). The borrow source will only be
considered suitable if the hydraulic conductivity of the material, as
documented on laboratory test specimens, can be shown to meet the requirements
of the project specifications at the 98 percent confidence
level.
(d)
Prior to full-scale liner installation, a field test section or test strip
shall be constructed at the site above a prepared subbase. The test strip shall
be considered acceptable if the measured hydraulic conductivities of
undisturbed samples from the test strip meet the requirements of the project
specifications at the 98 percent confidence level. If the test section fails to
achieve the desired results, additional test sections shall be constructed in
accordance with the following requirements:
1.
The test section shall be of sufficient size such that full-scale liner
installation procedures can be duplicated within the test section,
2. The test section shall be constructed
using the same equipment for spreading, kneading and compaction and the same
construction procedures (e.g., number of passes, moisture addition and
homogenization, if needed) that are anticipated for use during full-scale liner
installation,
3. At a minimum, the
liner test section shall be subject to the following field and laboratory
testing requirements:
a. A minimum of five
random samples of the liner construction material delivered to the site during
test section installation shall be tested for moisture content (ASTM D-2216),
percent fines (ASTM D-1140) and Atterberg limits (ASTM D-4318),
b. At least five field density and moisture
determinations shall be performed on each lift of the compacted liner test
section,
c. Upon completion of the
test section lift, the thickness of the lift shall be measured at a minimum of
five random locations to check for thickness adequacy; and,
d. A minimum of five Shelby tube or drive
cylinder (ASTM D-2937) samples shall be obtained from each lift of the test
section for laboratory hydraulic conductivity testing. Laboratory hydraulic
conductivity testing shall be conducted in triaxial type permeameters (ASTM
D-5084). The test specimens shall be consolidated under an isotropic
consolidation stress no greater than 10 pounds per square inch and permeated
with water under an adequate backpressure to achieve saturation of the test
specimens. The inflow to and outflow from the specimens shall be monitored with
time and the hydraulic conductivity calculated for each recorded flow
increment. The test shall continue until steady state flow is achieved and
relatively constant values of hydraulic conductivity are measured (ASTM
D-5084).
(e)
Full scale liner installation may begin only after completion of a successful
liner test section. During liner construction, quality control testing shall be
provided to document that the installed liner conforms to project
specifications. The testing frequencies for quality control testing are
specified below; however, during construction of the first five acres of the
liner, these frequencies shall be doubled. Samples shall be obtained from
random locations selected by an independent soil testing laboratory. If there
are indications of a change in product quality or construction procedures
during liner construction, additional tests shall be performed to determine
compliance.
1. Field testing during liner
installation. The following field tests shall be performed:
a. Prior to the laying of the liner
materials, the liner subbase shall be compacted to the specified density.
Density tests shall be conducted at a minimum rate of two tests per acre,
b. A minimum of two moisture
content and field density determinations shall be conducted per acre per lift
of the compacted liner. The degree of compaction shall be checked using the
one-point field Proctor test or other appropriate test procedures; and,
c. A minimum of four thickness
measurements shall be conducted per acre per lift of the compacted
liner.
2. Laboratory
testing during liner installation. The following laboratory tests shall be
performed:
a. Percent fines (ASTM D-1140) of
the liner construction material shall be determined at a minimum frequency of
two tests per ace per lift of installed liner,
b. Atterberg Limits determinations shall be
performed on one sample per acre per lift of installed liner; and,
c. Hydraulic conductivity testing of Shelby
tube or drive cylinder (ASTM D-2937) samples of the compacted liner shall be
performed at a minimum frequency of one test per acre per lift. Laboratory
hydraulic conductivity tests shall be conducted in triaxial type permeameters
(ASTM D-5084). The test specimens shall be consolidated under an isotropic
consolidation stress no greater than 10 pounds per square inch and permeated
with water under an adequate backpressure to achieve saturation of the test
specimens. The inflow to and outflow from the specimens shall be monitored with
time and the hydraulic conductivity calculated for each recorded flow
increment. The test shall continue until steady state flow is achieved and
relatively constant values of hydraulic conductivity are
measured.
(f)
If the test data from a liner section does not meet the requirements of the
project specifications, additional random samples may be tested from that liner
section. If such additional testing demonstrates that the thickness and
hydraulic conductivity meet the requirements of the project specifications at
the 95 percent confidence level, that liner section will be considered
acceptable. If not, that liner section shall be reworked or reconstructed so
that it does meet these requirements.
(9) Surface water management systems.
(a) For aboveground disposal units, the
design of any features intended to convey stormwater to a permitted or exempted
treatment system shall be included in the solid waste construction
permit.
(b) Stormwater or other
surface water which comes into contact with the landfilled solid waste or mixes
with leachate shall be considered leachate and is subject to the requirements
of subsection 62-701.500(8),
F.A.C.
(10) Gas control
systems. Landfills that receive degradable wastes shall be designed and
constructed with a gas management system that complies with the requirements of
rule 62-701.530, F.A.C.
(11) Landfills in ground water. A landfill
constructed so that the bottom liner is constantly in contact with ground water
is not prohibited by this rule. However, an applicant proposing such a design
shall include special design features that demonstrate that the landfill will
provide an equivalent degree of protection for the environment as would a
similar landfill whose bottom liner is not in contact with ground water. Such a
design is not entitled to the presumption of compliance with performance
standards that is set forth in subsection (1), of this rule. In addition to any
other financial assurance responsibilities for closure, an applicant shall
provide financial assurance in accordance with rule
62-701.630, F.A.C., sufficient
to ensure long-term maintenance and operation of the leachate collection
system.
Notes
Rulemaking Authority 403.061, 403.704 FS. Law Implemented 403.0877, 403.702, 403.704, 403.707 FS.
New 1-6-93, Amended 1-2-94, 5-19-94, Formerly 17-701.400, Amended 5-27-01, 1-6-10, 8-12-12, 2-15-15.
State regulations are updated quarterly; we currently have two versions available. Below is a comparison between our most recent version and the prior quarterly release. More comparison features will be added as we have more versions to compare.
(1) Minimum design standards. The requirements of this rule are the minimum standards for constructing a landfill. Nothing in this rule shall be construed to prevent the Department from imposing more stringent standards as necessary to protect the environment and the public health and safety due to site specific conditions and types of wastes to be disposed of in the landfill or solid waste disposal unit. An applicant whose landfill design meets the design standards of this rule will be presumed to provide reasonable assurance that the performance standards of subsection 62-701.340(1), F.A.C., will be met.
(2) Planned construction and closure. All landfills shall be designed so that solid waste disposal units will be constructed and subsequently closed at planned intervals throughout the design period of the landfill. Designs to prevent failures of side slopes, and designs to prevent deep-seated failures through the waste, along liner systems, and through foundation soils, shall achieve a minimum factor of safety of 1.5 using peak strength values.
(3) Landfill liner requirements. Class I Landfills shall be constructed with composite or double liners, and a leachate collection and removal system. Liners and leachate collection systems for Class III landfills are addressed in paragraph 62-701.400(3)(g), F.A.C.
(a) Liners shall be:
1. Constructed of materials that have appropriate physical, chemical, and mechanical properties to prevent failure due to physical contact with the waste or leachate to which they are exposed, climatic conditions, the stress of installation, and other applied stresses and hydraulic pressures which are anticipated during the operational and closure period of the solid waste disposal unit. The supplier of materials for the liner components shall provide test information accepted by the engineer of record, that supports the capabilities of the materials to meet these needs,
2. Installed upon a base and in a geologic setting capable of providing structural support to prevent overstressing of the liner due to settlements and applied stresses,
3. Constructed so that the bottom of the liner system is not subject to fluctuations of the ground water so as to adversely impact the integrity of the liner system,
4. Designed to resist hydrostatic uplift if the liner is located below the seasonal high ground water table; and,
5. Installed to cover all surrounding earth which could come into contact with the waste or leachate.
(b) Composite liners.
1. The upper component of the composite liner shall be a 60-mil minimum average thickness HDPE geomembrane. A primary leachate collection and removal system and a drainage layer shall be installed above the geomembrane liner. Except in sumps and leachate collection trenches, the system shall be designed to limit leachate head above the liner during routine landfill operation after placement of initial cover, as specified in Table A below, depending upon the thickness and hydraulic conductivity of the lower component of the composite liner. Leachate head calculations shall consider leachate recirculation if the leachate is recirculated.
2. The lower component of the composite liner shall be constructed in six-inch lifts. The thickness of the lower component may be varied in relation to the hydraulic conductivity of the lower component and the design leachate head above the liner, in accordance with Table A.
| TABLE A: Minimum Thickness of Lower Component of Composite Liner (feet) | |||
| Maximum Design Hydraulic Head (inches) | Maximum Hydraulic Conductivity (cm/sec) | ||
| 1x10-7 | 5x10-8 | 1x10-8 | |
| 1 | 2.0 | 1.0 | 1.0 |
| 6 | 2.5 | 1.5 | 1.0 |
| 12 | 3.0 | 2.0 | 1.0 |
(c) Double liners.
1. Double liner systems shall consist of upper and lower 60-mil minimum average thickness HDPE geomembranes, with a primary leachate collection and removal system lying above the upper geomembrane designed to limit the leachate head to one foot above the liner during routine landfill operations after placement of initial cover, except in sumps and leachate collection trenches; and a leak detection and secondary leachate collection system between the upper and lower liners. The lower geomembrane shall be placed directly on a sub-base which is a minimum six inches thick, is free of sharp materials or any materials larger than one-half inch, and has a saturated hydraulic conductivity of less than or equal to 1 x 10-5 cm/sec. A geosynthetic clay liner (GCL) with a hydraulic conductivity not greater than 1x10-7 cm/sec may be used in place of the six-inch thick sub-base layer provided it is placed on a prepared subgrade which will not damage the GCL.
2. The leak detection and secondary leachate collection system shall have a minimum hydraulic conductivity of ten cm/sec, shall be designed to limit the maximum hydraulic head on the lower liner to one inch, and shall not allow leachate head to exceed the thickness of the drainage layer. The hydraulic conductivity of the leak detection and secondary collection system material shall be derived from transmissivity and thickness measurements.
(d) Standards for geosynthetic components.
1. HDPE geomembranes and LLDPE geomembranes shall have factory and field seams whose shear and peel strengths during testing are in conformance with the seam strengths specified in method GRI GM19. PVC geomembranes shall have factory and field seams whose shear and peel strengths during testing are in conformance with the seam strengths specified in method PGI 1104. For all geomembranes, the failure shall occur in the lining material outside the seam area. All field seams must also be visually inspected and pressure or vacuum tested for seam continuity using suitable non-destructive techniques.
2. Geomembranes shall not be used at landfills unless they are subjected to continuous spark testing by the manufacturer at the factory and no defects have been found.
3. Geomembranes shall be protected from physical damage by placing a minimum 24-inch-thick protective layer above the upper liner. All materials in direct contact with the liner shall be free of sharp materials or any materials larger than one-half inch. The upper 12 inches of the protective layer shall be composed of soil, tire chips four square inches or smaller with no protruding wires that could pose a threat to the integrity of the liner, or other materials approved by the Department which are permeable, non-reactive, stable, and which offer protection for the liner from punctures.
4. The first layer of waste placed on the protective layer above the liner and leachate collection system shall be a minimum of four feet in compacted thickness, and consist of selected wastes containing no large, rigid objects that may damage the liner or leachate collection system. Materials that could damage the liner shall be removed from this layer.
5. HDPE geomembranes shall meet the specification contained in method GRI GM13. LLDPE geomembranes shall meet the specification contained in method GRI GM17.
6. PVC geomembranes shall meet the specification contained in method PGI 1104.
7. Interface shear strength of the actual components which will be used in the liner system shall be tested with method ASTM D5321, hereby adopted and incorporated by reference, or an equivalent test method. To obtain this standard see subsection 62-701.210(14), F.A.C. However, when testing GCLs, method ASTM D6243, hereby adopted and incorporated by reference, or an equivalent test method, shall be used. To obtain this standard see subsection 62-701.210(17), F.A.C. Unless it can be justified otherwise, the interface shall be tested in a water-saturated state. For the purposes of this test, clays compacted in the test apparatus during setup which have a water content wet of optimum shall be considered water saturated.
8. The transmissivity of geonets shall be tested with method ASTM D4716, hereby adopted and incorporated by reference, or an equivalent test method, to demonstrate that the design transmissivity will be maintained for the design period of the facility. To obtain this standard see subsection 62-701.210(15), F.A.C. The testing for the geonet in the liner system shall be conducted using actual boundary materials intended for the geonet at the maximum design normal load for the landfill, and at the design load expected from one lift of waste. At the maximum design normal load, testing shall be conducted for a minimum period of 100 hours unless data equivalent to the 100-hour period is provided in which case the test shall be conducted for a minimum period of one hour. In the case of the design load from one lift of waste, the minimum period shall be one hour. For geonets used in final covers, only one test shall be conducted for a minimum period of one hour using the expected maximum design normal load from the cover soils and the actual boundary materials intended for the geonet.
9. The hydraulic conductivity of GCLs shall be tested with method ASTM D5887, hereby adopted and incorporated by reference, or ASTM D6766, hereby adopted and incorporated by reference, or an equivalent test method. To obtain these standards see subsections 62-701.210(16) and 62-701.210(20), F.A.C., respectively. First, the GCL test specimen shall be hydrated with the fluid which is expected to cause hydration in the field, or a similar fluid, for a minimum of 48 hours using sufficient backpressure to achieve a minimum B coefficient of 0.9 and using a confined effective consolidation stress not exceeding five pounds per square inch. Then, the hydraulic conductivity test on the GCL specimen shall be conducted, using the appropriate permeant fluid, at a confined effective consolidation stress not exceeding five pounds per square inch. The hydraulic conductivity test shall continue until steady state conditions are reached or a minimum of two pore volumes of permeant fluid have passed through the test specimen. The permeant fluid shall be either leachate from the landfill (or a similar landfill) if the GCL is used in a liner system, or water if the GCL is used as a barrier layer in a final cover.
10. If not submitted as part of the permit application to the Department, then the testing required in subparagraphs (3)(d)7., 8. and 9. of this paragraph, for the materials used in the liner construction shall be conducted as part of the construction quality assurance activities, and the results of these tests shall be included in the completion of construction documents required in subsection (7), of this rule.
11. The testing required in subparagraphs (3)(d)7., 8. and 9. of this paragraph, are single-point tests required either as part of the permit application phase of a landfill project or prior to liner construction. The purpose of these tests is to confirm that the components selected for the liner construction meet the design criteria used in the permit application.
(e) The following specifications shall be provided for geosynthetic components:
1. Definition and qualifications of the designer, manufacturer, installer, geosynthetic quality assurance consultant, geosynthetic quality assurance laboratory, and quality assurance program,
2. Material specifications for geomembranes, geotextiles, geogrids, geocomposites, and geonets, including general requirements, specified geomembrane properties, and labeling,
3. Manufacturing and fabrication specifications including:
a. Geomembrane manufacturing, including raw material and roll quality control,
b. Geomembrane fabrication, including requirements of personnel, seaming equipment and products, seam preparation, weather conditions for factory seaming, overlapping and temporary bonding, trail seams, and nondestructive seam continuity testing,
c. Destructive seam strength testing including location and frequency, sampling procedure, size of samples, testing at the fabrication factory, laboratory testing, fabricator's laboratory testing, and procedures for destructive test failure; and,
d. Repairs.
4. Geomembrane installation specifications including:
a. Earthwork,
b. Conformance testing,
c. Geomembrane placement, which shall address layout drawings, panel identification, and field panel placement,
d. Field seaming, which shall address seam layout, requirements of personnel, overlapping and temporary bonding, seam preparation, seaming equipment and products, weather conditions for seaming, trial seams, general seaming procedures, nondestructive seam continuity testing, destructive testing, and defects and repairs including identification, evaluation, and repair procedures,
e. Materials in contact with the geomembrane, including granular materials, concrete, and sumps and appurtenances; and,
f. Lining system acceptance.
5. Geotextile and geogrid specifications including handling and placement, conformance testing, seams and overlaps, repair, and placement of soil materials and any overlying materials.
6. Geonet and geocomposite specifications including handling and placement, conformance testing, stacking and joining, repair, and placement of soil materials and any overlying materials.
7. GCL specifications including handling and placement, conformance testing, seams and overlaps, repair, and placement of soil materials and any overlying materials.
(f) Standards for soil liner components.
1. Soil components of liners shall be constructed to preclude, to the greatest extent practicable, lenses, cracks, channels, root holes, pipes, or other structural inconsistencies that can increase the saturated hydraulic conductivity of the soil component. The design shall illustrate and describe those instances in which overexcavation of permeable areas and backfilling may be necessary to seal the permeable area. The soil component shall be placed and compacted in layers to achieve the design performance.
2. The permeability of soil liner components shall not be increased above the values specified for the component, as a result of contact with leachate from the solid waste disposal unit. Compatibility of the soil component and leachate shall be demonstrated by testing the soil component with actual or simulated leachate in accordance with EPA Test Method 9100 or an equivalent test method.
3. The soil component of the liner may consist of in-situ soils, provided they meet the specifications for soil liners. Testing of in-situ soil shall be performed in accordance with the site specific Construction Quality Assurance Plan in accordance with subsections 62-701.400(7) and (8), F.A.C.
4. Specifications for the soil component of the liner shall be provided to and approved by the Department, and shall contain at a minimum:
a. Allowable range of particle size distribution and Atterberg limits, to include shrinkage limit,
b. Placement moisture criteria and dry density criteria,
c. Maximum laboratory-determined saturated hydraulic conductivity, using simulated leachate as the saturating and testing liquid,
d. Minimum thickness of the soil liner,
e. Lift thickness,
f. Surface preparation (scarification) for tying lifts together; and,
g. Type and percentage of clay mineral within the soil component.
5. The soil liner shall be placed using construction equipment and procedures that achieve the required saturated hydraulic conductivity and thickness. A field test section shall be constructed using the proposed construction equipment and tested to document that the desired saturated hydraulic conductivity and thickness is achieved in the field. Test results shall be submitted to the Department along with the completion of construction documents.
(g) Class III landfills. A Class III landfill shall be constructed with a bottom liner consisting of a single 60-mil minimum average thickness HDPE geomembrane. In the sumps located inside the landfill footprint and in the leachate collection trenches, the geomembrane shall be placed on a GCL with a hydraulic conductivity of less than or equal to 1 x 10-7 cm/sec, or on a compacted clay liner which is a minimum six inches thick with a saturated hydraulic conductivity of less than or equal to 1 x 10-7 cm/sec. The liner shall be placed on a prepared subgrade that will not damage the geomembrane liner or the GCL. A primary leachate collection and removal system and a drainage layer shall be installed above the geomembrane liner. Except in sumps and leachate collection trenches, the system shall be designed to limit leachate head above the liner during routine landfill operation after placement of initial cover to no greater than 12 inches. An applicant may request exemption from the requirements of this paragraph in accordance with paragraph 62-701.340(2)(b), F.A.C.
(4) Leachate collection and removal system. Landfills shall have a leachate collection and removal system that is designed, constructed, maintained, and operated to collect leachate and convey it to collection points for removal.
(a) The primary and secondary leachate collection and removal systems shall:
1. Be constructed of materials that are chemically resistant to the waste disposed of in the landfill and the leachate expected to be generated,
2. Have sufficient mechanical properties to prevent collapse under pressures exerted by overlying wastes, cover materials, and by any equipment used at the landfill,
3. Have granular material or synthetic geotextile filter overlying or surrounding the leachate collection and removal system to prevent clogging of the collection system by infiltration of fine particles; and,
4. Have a method to test that the pipes in the system are not clogged, and a method for cleaning the pipes in the system if they become clogged. If any part of the system cannot be tested for clogging, the design shall assure that leachate can be rerouted from that part to a leachate sump in the event of collapse.
(b) The primary leachate collection and removal system shall have a granular drainage layer above the top geomembrane liner, at least 12 inches thick, with a hydraulic conductivity of not less than 1 x 10-3 cm/sec, overlain with an additional 12 inches of protective material as specified in subparagraph 62-701.400(3)(d) 3., F.A.C., that is chemically resistant to the waste and leachate. Leachate collection systems incorporating synthetic drainage materials may be used if it can be demonstrated that they are equivalent to or more effective than the granular design, including chemical compatibility, flow under load, and protection of the geomembrane liner.
(c) The leachate collection and removal system shall be designed with a bottom slope to achieve the required leachate head after the predicted settlement determined by the foundation analysis. The minimum slope for the leachate collection system, in areas which drain to lateral collection pipes and header pipes, shall be 1.0 percent after predicted settlement. The minimum slopes for the collection pipes of the leachate collection system, i.e., lateral and header pipes, shall be 0.3 percent after predicted settlement. Minimum slopes shall be measured from the peak grade to the lowest grade along the design flow path. Slopes shall be surveyed after completion using a 50-foot grid in areas which drain to lateral collection pipes and header pipes and at 50-foot intervals where pipes of the leachate collection system are to be installed. These surveyed slopes must demonstrate that positive drainage is shown in the direction of flow between any two grid or interval points.
(d) A schedule for routine maintenance of the leachate collection and removal system shall be established to ensure operation of the system. The maintenance schedule shall be a part of the facility operation plan.
(5) Leachate recirculation. Leachate shall be recirculated only at solid waste disposal units which have a leachate recirculation system included in their operation plan, and which have been constructed and operated in a manner consistent with that system. If leachate is recirculated after closure, the operation plan shall be included as part of the approved closure plan. The leachate recirculation system shall include estimated impacts on the head of leachate over the liner, subsidence of the waste, and gas production, and shall meet the following requirements unless otherwise approved in the operation plan.
(a) The landfill shall be lined and have a leachate collection and removal system.
(b) Ditches, berms, or other devices shall be installed to control any leachate runoff. Initial and intermediate cover receiving recirculated leachate shall be graded to shed runoff into the leachate collection system and to minimize mixing of leachate runoff and storm water.
(c) Initial and intermediate cover shall be permeable to the extent necessary to prevent perched water conditions and gas buildup.
(d) Leachate shall not be recirculated during weather conditions or in quantities that may cause runoff outside the solid waste disposal unit, surface seeps, wind-blown spray, or exceedance of the limits of the leachate head on the liner. Ponding is prohibited unless it is an integral part of the design plan.
(e) Landfill gas shall be managed in accordance with rule 62-701.530, F.A.C.
(f) Recirculation of leachate is prohibited on top of areas where a barrier layer which is part of the final cover has been installed. Irrigation of the final vegetative cover may be done with treated leachate which meets the water quality standards of the receiving water body, if such irrigation does not contribute significantly to leachate generation.
(6) Leachate storage tanks and leachate surface impoundments.
(a) The requirements of this subsection apply to all leachate storage tanks and leachate surface impoundments constructed after January 6, 1993. Leachate storage tanks in use on January 6, 1993, are not required to retrofit to comply with this subsection unless leakage, corrosion or other defects are found. Leachate surface impoundments in use on January 6, 1993, shall be replaced or modified to conform to this subsection by January 6, 1995.
(b) Surface impoundments for leachate treatment or storage that are located at landfills are subject to the following requirements:
1. Surface impoundments shall be constructed so that the bottom of the liner system is not subject to fluctuations of the ground water so as to adversely impact the integrity of the liner system. The applicant shall demonstrate that the surface impoundment design will minimize infiltration of leachate into the environment so that ground water and surface water quality standards and criteria are not violated.
2. The surface impoundment shall be designed in segments such that any one segment may be taken out of service for inspection and repair with no interruption of service.
3. The impoundment shall have a double liner system consisting of an upper and lower 60-mil minimum average thickness HDPE geomembrane, and a leak detection and collection system between the geomembranes with a minimum hydraulic conductivity of one cm/sec. The lower geomembrane shall be placed directly on a subbase which is at least six inches thick and has a saturated hydraulic conductivity of less than or equal to 1 x 10-5 cm/sec. A GCL with a hydraulic conductivity not greater than 1x10-7 cm/sec may be used in place of the six-inch thick sub-base layer provided it is placed on a prepared subgrade which will not damage the GCL. The leak detection and collection system shall be checked daily. The design of the upper liner shall include calculations to predict the potential leakage through the upper liner. If the daily checks indicate the upper liner is leaking at a rate greater than predicted by the design calculations, the Department shall be notified. If the leakage rate will result in the flooding of the leak detection and collection system, the impoundment shall be emptied and the liner repaired.
4. To preserve the liner integrity and prevent uplift, ballast material such as rounded gravel or sand, that will not cause damage to the geomembrane liner, shall be placed on top of any liner which is located below the water table.
5. A minimum of two feet of freeboard above the depth which would occur in the event of a 25-year, 24-hour storm shall be maintained in leachate surface impoundments.
6. Vectors and off-site odors shall be controlled.
(c) Above ground leachate storage tanks that are located at solid waste management facilities are subject to the following requirements:
1. Tanks shall be constructed of concrete, steel, reinforced plastic, polyethylene, or fiberglass. Tanks shall be supported on a well drained, stable foundation.
2. Bottoms of steel tanks that rest on earthen material shall be cathodically protected with either sacrificial anodes or an impressed current system which is designed, fabricated, and installed in accordance with the engineering plan submitted to the Department.
3. The exterior surfaces of all steel storage tanks shall be protected by a primer coat, a bond coat, and two or more final coats of paint or other surface coating system designed to prevent corrosion and deterioration.
4. The interior of all tanks shall consist of a material or must be lined with a material, resistant to the liquid being stored.
5. All aboveground tanks shall have a secondary containment system which may consist of dikes, liners, pads, ponds, impoundments, curbs, ditches, sumps, or other systems capable of containing the stored leachate. The design volume for the secondary containment system shall be 110 percent of the volume of either the largest tank within the containment system or the total volume of all interconnected tanks, whichever is greater.
6. The secondary containment system shall be constructed of materials compatible with the liquid stored. The containment system shall be constructed of either:
a. A minimum three-foot layer of compacted soil with a maximum saturated hydraulic conductivity of 1 x 10-7 cm/sec or one foot of compacted soil with a maximum saturated hydraulic conductivity of 1 x 10-8 cm/sec with two feet of protective cover, or
b. A concrete pad that will maintain its integrity for the lifetime of the tank, provided that the tank, if made of steel, has a corrosion resistant coating, or
c. A HDPE geomembrane of a minimum average thickness of 60 mils.
7. A system shall be designed to contain and remove storm water from the secondary containment area. Provisions shall be included for the removal of any accumulated precipitation and be initiated within 24 hours or when 10 percent of the storage capacity is reached; whichever occurs first. Disposal of this stormwater shall be in accordance with the requirements of subsection 62-701.400(9), F.A.C.
8. All aboveground tanks shall be equipped with an overfill prevention system which includes level sensors and gauges, high level alarms, or automatic shutoff controls. The overfill control equipment shall be inspected weekly by the facility operator to ensure it is in good working order.
9. The exposed exterior of all aboveground tanks shall be inspected weekly by the facility operator for adequacy of the cathodic protection system, leaks, corrosion, and maintenance deficiencies. Interior inspection of tanks shall be performed whenever the tank is drained or at a minimum of every three years. If the inspection reveals a tank or equipment deficiency, leak, or any other deficiency which could result in failure of the tank to contain the leachate, remedial measures shall be taken immediately to eliminate the leak or correct the deficiency. Inspection reports shall be maintained and made available to the Department upon request for the lifetime of the liquid storage system.
(d) Underground leachate storage tanks that are located at solid waste management facilities are subject to the following requirements:
1. Tanks shall be constructed of concrete, fiberglass, reinforced plastic, steel that is cathodically protected, or steel that is clad with fiberglass.
2. A secondary containment and a continuous leak detection system shall be installed in the form of a double-walled tank, designed as an integral structure so that any release from the inner tank is completely contained by the outer shell.
a. The interstitial space shall be monitored at least once per week by the facility operator for tightness using pressure monitoring, vacuum monitoring, or electronic monitoring.
b. The tank system shall be protected from both corrosion of the primary tank interior and the external surface of the outer shell.
c. All resistant coatings applied to the primary tank interior shall be compatible with the stored leachate.
d. Cathodic protection systems, where installed, shall be inspected at least weekly by the facility operator. Any deficiency in the cathodic protection system shall be corrected when discovered.
3. All underground tanks shall be equipped with an overfill prevention system which includes level sensors and gauges, high level alarms, or automatic shutoff controls. The overfill control equipment shall be inspected weekly by the facility operator to ensure it is in good working order.
4. Inspection and leak detection monitoring reports shall be maintained at the facility and made available to the Department upon request for the lifetime of the liquid storage system.
(7) Liner systems construction quality assurance.
(a) Liner systems shall have a construction quality assurance plan to provide personnel with adequate information to achieve continuous compliance with the liner construction requirements. The plan shall include or refer to specifications and construction methods which use established engineering practices to construct a liner system and provide for quality control testing procedures and sampling frequencies. Sampling and testing shall be conducted in the field by trained personnel during construction and after construction completion. Such personnel will be under the direction of the construction quality assurance professional engineer, to assure the liner system will comply with the standards. The construction quality assurance professional engineer or his designee shall be on-site at all times during construction to monitor construction activities and shall be on-site to monitor off-loading of the geosynthetics to be used in the liner system. Construction activities include the time during which the protective layer is installed over the geomembrane, to ensure that the placement techniques do not cause damage to the liner system materials.
(b) Liner systems shall be installed in accordance with a Department-approved construction quality assurance plan. Plans that comply with EPA Document EPA/600/R-93/182 shall be presumed to be in compliance with this section. The following minimum specific elements shall be included in the plan:
1. Responsibility and authority of all organizations and key personnel involved in permitting, designing, constructing, and providing construction quality assurance of the waste disposal facility shall be described fully,
2. Minimum qualifications of the construction assurance quality professional engineer and supporting personnel shall be in the plan to demonstrate that they possess the training and experience necessary to fulfill their identified responsibilities,
3. Procedures and tests that will be used to monitor the installation of the liner system components shall be described in detail,
4. The sampling activities, sample size, sample locations, frequency of testing, acceptance and rejection criteria, and plans for implementing corrective measures that may be necessary shall be described; and,
5. Reporting requirements for construction quality assurance activities shall be described, including daily summary reports, observation data sheets, problem identification and corrective measures, and final documentation. All such documents shall be included in the final report which shall be forwarded to the Department.
(c) Unless otherwise approved by the Department, one destructive test sample shall be collected every 500 feet along the total length of the seams. If an electrical leak location survey method, or other equivalent non-destructive test method, is used to locate and repair leaks in the installed liner system, then one destructive test sample shall be collected every 1000 feet along the total length of the seams in the areas where this method is used.
(d) If an electrical leak location survey method, or other equivalent method is used to test the geomembrane(s) in the liner system, testing shall be conducted after placement of the soil drainage layer. The geomembrane liner leak location survey shall be performed using standard industry methods, and any leaks located shall be repaired and tested by methods approved by the Department. The results of the geomembrane liner leak location survey, including a description of the locations of any leaks detected and the repairs that were conducted on these leaks, shall be documented in a final report included with the completion of construction documents required in this subsection.
(e) A laboratory experienced in the testing of geosynthetics, independent of the liner manufacturer and installer, shall perform the required testing which must include, at a minimum, conformance testing for all geosynthetics and geocomposites, and testing of seam shear and peel strength for geomembranes.
(f) The professional engineer in charge of construction quality assurance shall provide a signed, sealed final report and record drawings to the Department stating that the liner system has been installed in substantial conformance with the plans and specifications for the liner system. The report and drawings shall be submitted along with a certification of construction completion on Form 62-701.900(2).
(8) Soil liner construction quality assurance. In addition to the requirements of subsection (7), above, the following requirements apply to construction of the soil component of liner systems. All required testing and analysis shall be performed in accordance with generally accepted engineering procedures, such as those promulgated by the American Society for Testing and Materials (ASTM). Parenthetic references to ASTM methods are intended as guidance only.
(a) A construction quality assurance/quality control plan shall be prepared for each soil liner project to outline project specifications and construction requirements. The plan shall specify performance criteria for the soil liner, and provide quality control testing procedures and minimum sampling frequencies. In addition, the plan shall define the responsibilities of the parties that will be involved in soil liner construction, and shall present minimum qualifications of each party to fulfill their identified responsibilities.
(b) Field and laboratory testing during liner construction shall be conducted by a qualified soil testing laboratory representing the owner. A qualified field technician representing the owner shall provide full time, on-site inspection during liner construction. The field technician shall work under the supervision of a professional engineer with experience in soil liner construction.
(c) Prior to soil liner installation, an appropriate borrow source shall be located. Suitability of the liner construction materials from that source shall be determined in accordance with the following:
1. If demonstrated field experience is available from at least three prior successful projects of five or more acres each to document that a given borrow source can meet the requirements of the project specifications, then extensive laboratory testing of the borrow source will not be required. However, the source of material shall be geologically similar to and the methods of excavating and stockpiling the material shall be consistent with those used on the prior projects. Furthermore, a minimum of three representative samples from the appropriate thickness of the in-situ stratum or from stockpiles of the borrow material proposed for liner construction shall be submitted to an independent soil testing laboratory to document through index testing that the proposed material is consistent with the material used on prior successful projects. At a minimum, index testing shall consist of percent fines, Atterberg limits and moisture content determinations.
2. If demonstrated field experience as defined above is not available or cannot be documented, then the following requirements shall be met.
a. A field exploration and laboratory testing program shall be conducted by an independent soil testing laboratory to document the horizontal and vertical extent and the homogeneity of the soil strata proposed for use as liner material. A sufficient number of index tests from each potential borrow stratum shall be performed to quantify the variability of the borrow materials and to document that the proposed borrow material complies with specifications. At a minimum, the index tests shall consist of percent fines, Atterberg limits and moisture content determinations.
b. Sufficient laboratory hydraulic conductivity tests shall be conducted on samples representative of the range invariability of the proposed borrow source (ASTM D-5084). For each such sample, test specimens shall be prepared and tested to cover the range of molding conditions (moisture content and dry density) required by project specifications. The hydraulic conductivity tests shall be conducted in triaxial type permeameters. The test specimens shall be consolidated under an isotropic consolidation stress no greater than 10 pounds per square inch and permeated with water under an adequate backpressure to achieve saturation of the test specimens. The inflow to and outflow from the specimens shall be monitored with time and the hydraulic conductivity calculated for each recorded flow increment. The test shall continue until steady state flow is achieved and relatively constant values of hydraulic conductivity are measured (ASTM D-5084). The borrow source will only be considered suitable if the hydraulic conductivity of the material, as documented on laboratory test specimens, can be shown to meet the requirements of the project specifications at the 98 percent confidence level.
(d) Prior to full-scale liner installation, a field test section or test strip shall be constructed at the site above a prepared subbase. The test strip shall be considered acceptable if the measured hydraulic conductivities of undisturbed samples from the test strip meet the requirements of the project specifications at the 98 percent confidence level. If the test section fails to achieve the desired results, additional test sections shall be constructed in accordance with the following requirements:
1. The test section shall be of sufficient size such that full-scale liner installation procedures can be duplicated within the test section,
2. The test section shall be constructed using the same equipment for spreading, kneading and compaction and the same construction procedures (e.g., number of passes, moisture addition and homogenization, if needed) that are anticipated for use during full-scale liner installation,
3. At a minimum, the liner test section shall be subject to the following field and laboratory testing requirements:
a. A minimum of five random samples of the liner construction material delivered to the site during test section installation shall be tested for moisture content (ASTM D-2216), percent fines (ASTM D-1140) and Atterberg limits (ASTM D-4318),
b. At least five field density and moisture determinations shall be performed on each lift of the compacted liner test section,
c. Upon completion of the test section lift, the thickness of the lift shall be measured at a minimum of five random locations to check for thickness adequacy; and,
d. A minimum of five Shelby tube or drive cylinder (ASTM D-2937) samples shall be obtained from each lift of the test section for laboratory hydraulic conductivity testing. Laboratory hydraulic conductivity testing shall be conducted in triaxial type permeameters (ASTM D-5084). The test specimens shall be consolidated under an isotropic consolidation stress no greater than 10 pounds per square inch and permeated with water under an adequate backpressure to achieve saturation of the test specimens. The inflow to and outflow from the specimens shall be monitored with time and the hydraulic conductivity calculated for each recorded flow increment. The test shall continue until steady state flow is achieved and relatively constant values of hydraulic conductivity are measured (ASTM D-5084).
(e) Full scale liner installation may begin only after completion of a successful liner test section. During liner construction, quality control testing shall be provided to document that the installed liner conforms to project specifications. The testing frequencies for quality control testing are specified below; however, during construction of the first five acres of the liner, these frequencies shall be doubled. Samples shall be obtained from random locations selected by an independent soil testing laboratory. If there are indications of a change in product quality or construction procedures during liner construction, additional tests shall be performed to determine compliance.
1. Field testing during liner installation. The following field tests shall be performed:
a. Prior to the laying of the liner materials, the liner subbase shall be compacted to the specified density. Density tests shall be conducted at a minimum rate of two tests per acre,
b. A minimum of two moisture content and field density determinations shall be conducted per acre per lift of the compacted liner. The degree of compaction shall be checked using the one-point field Proctor test or other appropriate test procedures; and,
c. A minimum of four thickness measurements shall be conducted per acre per lift of the compacted liner.
2. Laboratory testing during liner installation. The following laboratory tests shall be performed:
a. Percent fines (ASTM D-1140) of the liner construction material shall be determined at a minimum frequency of two tests per ace per lift of installed liner,
b. Atterberg Limits determinations shall be performed on one sample per acre per lift of installed liner; and,
c. Hydraulic conductivity testing of Shelby tube or drive cylinder (ASTM D-2937) samples of the compacted liner shall be performed at a minimum frequency of one test per acre per lift. Laboratory hydraulic conductivity tests shall be conducted in triaxial type permeameters (ASTM D-5084). The test specimens shall be consolidated under an isotropic consolidation stress no greater than 10 pounds per square inch and permeated with water under an adequate backpressure to achieve saturation of the test specimens. The inflow to and outflow from the specimens shall be monitored with time and the hydraulic conductivity calculated for each recorded flow increment. The test shall continue until steady state flow is achieved and relatively constant values of hydraulic conductivity are measured.
(f) If the test data from a liner section does not meet the requirements of the project specifications, additional random samples may be tested from that liner section. If such additional testing demonstrates that the thickness and hydraulic conductivity meet the requirements of the project specifications at the 95 percent confidence level, that liner section will be considered acceptable. If not, that liner section shall be reworked or reconstructed so that it does meet these requirements.
(9) Surface water management systems.
(a) For aboveground disposal units, the design of any features intended to convey stormwater to a permitted or exempted treatment system shall be included in the solid waste construction permit.
(b) Stormwater or other surface water which comes into contact with the landfilled solid waste or mixes with leachate shall be considered leachate and is subject to the requirements of subsection 62-701.500(8), F.A.C.
(10) Gas control systems. Landfills that receive degradable wastes shall be designed and constructed with a gas management system that complies with the requirements of rule 62-701.530, F.A.C.
(11) Landfills in ground water. A landfill constructed so that the bottom liner is constantly in contact with ground water is not prohibited by this rule. However, an applicant proposing such a design shall include special design features that demonstrate that the landfill will provide an equivalent degree of protection for the environment as would a similar landfill whose bottom liner is not in contact with ground water. Such a design is not entitled to the presumption of compliance with performance standards that is set forth in subsection (1), of this rule. In addition to any other financial assurance responsibilities for closure, an applicant shall provide financial assurance in accordance with rule 62-701.630, F.A.C., sufficient to ensure long-term maintenance and operation of the leachate collection system.
Notes
Rulemaking Authority 403.061, 403.704 FS. Law Implemented 403.0877, 403.702, 403.704, 403.707 FS.
New 1-6-93, Amended 1-2-94, 5-19-94, Formerly 17-701.400, Amended 5-27-01, 1-6-10, 8-12-12, 2-15-15.