Current through Register Vol. 35, No. 18, September 24, 2024
A. General operating requirements.
(1) The operator shall confine the landfill's
working face to the smallest practical area and compact the oil field waste to
the smallest practical volume. The operator shall not use equipment that may
damage the integrity of the liner system in direct contact with a geosynthetic
liner.
(2) The operator shall
prevent unauthorized access by the public and entry by large animals to the
landfill's active portion through the use of fences, gates, locks or other
means that attain equivalent protection.
(3) The operator shall prevent and extinguish
fires.
(4) The operator shall
control litter and odors.
(5) The
operator shall not excavate a closed cell or allow others to excavate a closed
cell except as approved by the division.
(6) The operator shall provide adequate cover
for the landfill's active face as needed to control dust, debris, odors or
other nuisances, or as otherwise required by the division.
(7) For areas of the landfill that will not
receive additional oil field waste for one month or more, but have not reached
the final waste elevation, the operator shall provide intermediate cover that
shall be:
(a) approved by the
division;
(b) stabilized with
vegetation; and
(c) inspected and
maintained to prevent erosion and manage infiltration or leachate during the
oil field waste deposition process.
(8) When the operator has filled a landfill
cell, the operator shall close it pursuant to the conditions contained in the
surface waste management facility permit and the requirements of Paragraph (2)
of Subsection C of
19.15.36.18
NMAC. The operator shall notify the division's environmental bureau at least
three working days prior to a landfill cell's closure.
B. Ground water monitoring program. If fresh
ground water exists at a site, the operator shall, unless otherwise approved by
the division, establish a ground water monitoring program, approved by the
division's environmental bureau, which shall include a ground water monitoring
work plan, a sampling and analysis plan, a ground water monitoring system and a
plan for reporting ground water monitoring results. The ground water monitoring
system shall consist of a sufficient number of wells, installed at appropriate
locations and depths, to yield ground water samples from the uppermost aquifer
that:
(1) represent the quality of background
ground water that leakage from a landfill has not affected; and
(2) represent the quality of ground water
passing beneath and down gradient of the surface waste management
facility.
C. Landfill
design specification. New landfill design systems shall include a base layer
and a lower geomembrane liner (e.g., composite liner), a leak
detection system, an upper geomembrane liner, a leachate collection and removal
system, a leachate collection and removal system protective layer, an oil field
waste zone and a top landfill cover.
(1) The
base layer shall, at a minimum, consist of two feet of clay soil compacted to a
minimum ninety percent standard proctor density (ASTM D-698)(Copyright ASTM
International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. This
document is available for public viewing at the New Mexico state records center
and archives and may not be reproduced, in full or in part. A copy of this
publication may be obtained from ASTM International,
www.astm.org.) with a hydraulic conductivity of 1 x
10-7 cm/sec or less. In areas where no ground water
is present, the operator may propose an alternative base layer design, subject
to division approval.
(2) The lower
geomembrane liner shall consist of a 30-mil flexible PVC or 60-mil HDPE liner,
or an equivalent liner approved by the division.
(3) The operator shall place the leak
detection system, which shall consist of two feet of compacted soil with a
saturated hydraulic conductivity of 1 x 10-5 cm/sec
or greater, between the lower and upper geomembrane liners. The leak detection
system shall consist of a drainage and collection system placed no more than
six inches above the lower geomembrane liner in depressions and sloped so as to
facilitate the earliest possible leak detection at designated collection
points. Drainage piping shall be designed to withstand chemical attack from oil
field waste and leachate and structural loading and other stresses and
disturbances from overlying oil field waste, cover materials, equipment
operation, expansion or contraction, and to facilitate clean-out maintenance.
The material placed between the pipes and laterals shall be sufficiently
permeable to allow the transport of fluids to the drainage pipe. The slope of
the landfill sub-grade and drainage pipes and laterals shall be at least two
percent grade; i.e., two feet of vertical drop per 100
horizontal feet. The piping collection network shall be comprised of solid and
perforated pipe having a minimum diameter of four inches and a minimum wall
thickness of schedule 80. The operator shall seal a solid drainage pipe to
convey collected liquids to a corrosion-proof sump or sumps located outside the
landfill's perimeter for observation, storage, treatment or disposal. The
operator may install alternative designs as approved by the division.
(4) The operator shall place the upper
geomembrane liner, which shall consist of a 30-mil flexible PVC or 60-mil HDPE
liner, or an equivalent liner approved by the division, over the leak detection
system.
(5) The operator shall
place the leachate collection and removal system, which shall consist of at
least two feet of compacted soil with a saturated hydraulic conductivity of 1 x
10-2 cm/sec or greater, over the upper geomembrane
liner to facilitate drainage. The leachate collection and removal system shall
consist of a drainage and collection and removal system placed no more than six
inches above the upper geomembrane liner in depressions and sloped so as to
facilitate the maximum leachate collection. Piping shall be designed to
withstand chemical attack from oil field waste or leachate and structural
loading and other stresses and disturbances from overlying oil field waste,
cover materials, equipment operation, expansion or contraction and to
facilitate clean-out maintenance. The material placed between the pipes and
laterals shall be sufficiently permeable to allow the transport of fluids to
the drainage pipe. The slope of the upper geomembrane liner and drainage lines
and laterals shall be at least two percent grade; i.e., two
feet of vertical drop per 100 horizontal feet. The piping collection network
shall be comprised of solid and perforated pipe having a minimum diameter of
four inches and a minimum wall thickness of schedule 80. The operator shall
seal a solid drainage pipe to convey collected fluids outside the landfill's
perimeter for storage, treatment and disposal. The operator may install
alternative designs as approved by the division.
(6) The operator shall place the leachate
collection and removal system protection layer, which shall consist of a soil
layer at least one foot thick with a saturated hydraulic conductivity of 1 x
10-2 cm/sec or greater, over the leachate collection
and removal system.
(7) The
operator shall place oil field waste over the leachate collection and removal
system protective layer.
(8) The
top landfill cover design shall consist of the following layers (top to
bottom): a soil erosion layer composed of at least 12 inches of fertile topsoil
re-vegetated in accordance with the post closure provisions of Subparagraph (b)
of Paragraph (2) of Subsection C of
19.15.36.18
NMAC; a protection or frost protection layer composed of 12 to 30 inches of
native soil; a drainage layer composed of at least 12 inches of sand or gravel
with a saturated hydraulic conductivity of 1 x 10-2
cm/sec or greater and a minimum bottom slope of four percent, a hydraulic
barrier-layer-geomembrane (minimum of a 30-mil flexible PVC or 60-mil HDPE
liner, or an equivalent liner approved by the division); and a gas vent or
foundation layer composed of at least 12 inches of sand or gravel above oil
field waste with soils compacted to the minimum eighty percent Standard Proctor
Density. The operator shall install the top landfill cover within one year of
achieving the final landfill cell waste elevation. The operator shall ensure
that the final landfill design elevation of the working face of the oil field
waste is achieved in a timely manner with the date recorded in a field
construction log. The operator shall also record the date of top landfill cover
installation to document the timely installation of top landfill covers. The
operator shall provide a minimum of three working days' notice to the division
in advance of the top landfill cover's installation to allow the division to
witness the top landfill cover's installation.
(9) Alternatively, the operator may propose a
performance-based landfill design system using geosynthetics or geocomposites,
including geogrids, geonets, geosynthetic clay liners, composite liner systems,
etc., when supported by EPA's "hydrologic evaluation of landfill performance"
(HELP) model or other division-approved model. The operator shall design the
landfill to prevent the "bathtub effect". The bathtub effect occurs when a more
permeable cover is placed over a less permeable bottom liner or natural
subsoil.
(10) External piping,
e.g., leachate collection, leak detection and sump removal
systems shall be designed for installation of a sidewall riser pipe. Pipes
shall not penetrate the liner with the exception of gas vent or collection
wells where the operator shall install a flexible clamped pipe riser through
the top landfill cover liner that will accommodate oil field waste settling and
will prevent tears.
D.
Liner specifications and requirements.
(1)
General requirements.
(a) Geomembrane liner
specifications. Geomembrane liners shall consist of a 30-mil flexible PVC or
60-mil HDPE liner, or an equivalent liner approved by the division. Geomembrane
liners shall have a hydraulic conductivity no greater than 1 x
10-9 cm/sec. Geomembrane liners shall be composed of
impervious, geosynthetic material that is resistant to petroleum hydrocarbons,
salts and acidic and alkaline solutions. Liners shall also be resistant to
ultraviolet light, or the operator shall make provisions to protect the
material from sunlight. Liner compatibility shall comply with EPA SW-846 method
9090A.
(b) Liners shall be able to
withstand projected loading stresses, settling and disturbances from overlying
oil field waste, cover materials and equipment operations.
(c) The operator shall construct liners with
a minimum of two percent slope to promote positive drainage and to facilitate
leachate collection and leak detection.
(2) Additional requirements for geomembranes.
(a) Geomembranes shall be compatible with the
oil field waste to be disposed. Geomembranes shall be resistant to chemical
attack from the oil field waste or leachate. The operator shall demonstrate
this by means of the manufacturer's test reports, laboratory analyses or other
division-approved method.
(b)
Geosynthetic material the operator installs on a slope greater than twenty-five
percent shall be designed to withstand the calculated tensile forces acting
upon the material. The design shall consider the maximum friction angle of the
geosynthetic with regard to a soil-geosynthetic or geosynthetic-geosynthetic
interface and shall ensure that overall slope stability is
maintained.
(c) The operator shall
thermally seal (hot wedge) field seams in geosynthetic material with a double
track weld to create an air pocket for non-destructive air channel testing. In
areas where double-track welding cannot be achieved, the operator may propose
alternative thermal seaming methods. A stabilized air pressure of 35psi, plus
or minus one percent, shall be maintained for at least five minutes. The
operator shall overlap liners four to six inches before seaming, and shall
orient seams parallel to the line of maximum slope; i.e.,
oriented along, not across, the slope. The operator shall minimize the number
of field seams in corners and irregularly shaped areas. The operator shall use
factory seams whenever possible. The operator shall not install horizontal
seams within five feet of the slope's toe. Qualified personnel shall perform
all field seaming.
E. Requirements for the soil component of
composite liners.
(1) The operator shall
place and compact the base layer to ninety percent standard proctor density on
a prepared sub-grade.
(2) The soil
surface upon which the operator installs a geosynthetic shall be free of stones
greater than one half inch in any dimension, organic matter, local
irregularities, protrusions, loose soil and abrupt changes in grade that could
damage the geosynthetic.
(3) The
operator shall compact a clay soil component of a composite liner to a minimum
of ninety percent standard proctor density, which shall have, unless otherwise
approved by the division, a plasticity index greater than ten percent, a liquid
limit between twenty-five and fifty percent, a portion of material passing the
no. 200 sieve (0.074 mm and less fraction) greater than forty percent by
weight; and a clay content greater than eighteen percent by weight.
F. The leachate collection and
removal system protective layer and the soil component of the leak detection
system shall consist of soil materials that shall be free of organic matter,
shall have a portion of material passing the no. 200 sieve no greater than five
percent by weight and shall have a uniformity coefficient (Cu) less than 6,
where Cu is defined as D60/D10. Geosynthetic materials or geocomposites
including geonets and geotextiles, if used as components of the leachate
collection and removal or leak detection system, shall have a hydraulic
conductivity, transmissivity and chemical and physical qualities that oil field
waste placement, equipment operation or leachate generation will not adversely
affect. These geosynthetics or geocomposites, if used in conjunction with the
soil protective cover for liners, shall have a hydraulic conductivity designed
to ensure that the liner's hydraulic head never exceeds one foot.
G. Landfill gas control systems. If the gas
safety management plan or requirements of other federal, state or local
agencies require the installation of a gas control system at a landfill, the
operator shall submit a plan for division approval, which shall include the
following:
(1) the system's design,
indicating the location and design of vents, barriers, collection piping and
manifolds and other control measures that the operator will install (gas vent
or collection wells shall incorporate a clamped and seamed pipe riser design
through the top cover liner);
(2)
if gas recovery is proposed, the design of the proposed gas recovery system and
the system's major on-site components, including storage, transportation,
processing, treatment or disposal measures required in the management of
generated gases, condensates or other residues;
(3) if gas processing is proposed, a
processing plan designed in a manner that does not interfere or conflict with
the activities on the site or required control measures or create or cause
danger to persons or property;
(4)
if gas disposal is proposed, a disposal plan designed:
(a) in a manner that does not interfere or
conflict with the activities on the site or with required control
measures;
(b) so as not to create
or cause danger to persons or property; and
(c) with active forced ventilation, using
vents located at least one foot above the landfill surface at each gas vent's
location;
(5) physical
and chemical characterization of condensates or residues that are generated and
a plan for their disposal;
(6)
means that the operator will implement to prevent gas' generation and lateral
migration such that:
(a) the concentration of
the gases the landfill generates does not exceed twenty-five percent of the
lower explosive limit for gases in surface waste management facility structures
(excluding gas control or recovery system components); and
(b) the concentration of gases does not
exceed the lower explosive limit for gases at the surface waste management
facility boundary; and
(7) a routine gas monitoring program
providing for monitoring at least quarterly; the specific type and frequency of
monitoring to be determined based on the following:
(a) soil conditions;
(b) the hydrogeologic and hydraulic
conditions surrounding the surface waste management facility; and
(c) the location of surface waste management
facility structures and property lines.
H. Landfill gas response. If gas levels
exceed the limits specified in Paragraph (6) of Subsection G of 19.15.36.14
NMAC, the operator shall:
(1) immediately
take all necessary steps to ensure protection of fresh water, public health and
the environment and notify the division;
(2) within seven days of detection, record
gas levels detected and a description of the steps taken to protect fresh
water, public health and the environment;
(3) within 30 days of detection, submit a
remediation plan for gas releases that describes the problem's nature and
extent and the proposed remedy; and
(4) within 60 days after division approval,
implement the remediation plan and notify the division that the plan has been
implemented.