North Dakota Administrative Code › Title 33.1 - Department of Environmental Quality › Article 33.1-20 - SOLID WASTE MANAGEMENT AND LAND PROTECTION › Chapter 33.1-20-08 - DISPOSAL OF COAL COMBUSTION RESIDUALS IN LANDFILLS AND SURFACE IMPOUNDMENTS › Section 33.1-20-08-04 - Design criteria

Current through Supplement No. 393, July, 2024
1. New CCR
				landfills and any lateral expansion of a CCR landfill must be designed,
				constructed, operated, and maintained with the appropriate hydraulic barrier
				and leachate management system capable of collecting and removing leachate and
				contaminated surface water within the disposal unit during the operating period
				and postclosure period.
a. Prior to
				construction of an overfill, the underlying CCR surface impoundment must meet
				the requirements of subdivision d of subsection 3 of section
				33.1-20-08-07.
b. Prior to
				construction of the CCR landfill or any lateral expansion of the CCR landfill,
				the owner or operator shall obtain a certification from a qualified
				professional engineer and approval by the department that the design of the
				composite liner (or, if applicable, alternative composite liner) and the
				leachate collection and removal system meets the requirements of this
				subsection.
c. Upon completion of
				construction of the CCR landfill or any lateral expansion of the CCR landfill,
				the owner or operator shall obtain a certification from a qualified
				professional engineer and approval by the department that the composite liner
				(or, if applicable, alternative composite liner) and the leachate collection
				and removal system has been constructed in accordance with the requirements of
				this subsection.
d. A composite
				liner is required. The liner must consist of at least two feet [60.9
				centimeters] of recompacted clay with a hydraulic conductivity not to exceed 1
				x 10-7 centimeters per second overlain with at least a sixty mil flexible
				membrane liner. The composite liner must be:
(1) Constructed of materials that have
				appropriate chemical properties and sufficient strength and thickness to
				prevent failure due to pressure gradients, including static head and external
				hydrogeologic forces, physical contact with the CCR or leachate to which they
				are exposed, climatic conditions, the stress of installation, and the stress of
				daily operation;
(2) Constructed of
				materials that provide appropriate shear resistance of the upper and lower
				component interface to prevent sliding of the upper component including on
				slopes;
(3) Placed upon a
				foundation or base capable of providing support to the liner and resistance to
				pressure gradients above and below the liner to prevent failure of the liner
				due to settlement, compression, or uplift; and
(4) Installed to cover all surrounding earth
				likely to be in contact with the CCR or leachate.
e. The department may consider an alternative
				composite liner if all of the requirements of this subdivision are met. A
				certification must be obtained from a qualified professional engineer stating
				that:
(1) The alternative composite liner
				consists of two components; the upper component consisting of, at a minimum, a
				sixty-mil flexible membrane liner, and a lower component, that is not a
				flexible membrane liner. If the lower component of the alternative liner is
				compacted soil, the flexible membrane liner must be installed in direct and
				uniform contact with the compacted soil.
(2) The transmissivity through the lower
				component of the alternative composite liner is no greater than the
				transmissivity through two feet [60.9 centimeters] of compacted soil with a
				hydraulic conductivity of 1 x 10 
				-7 centimeters per second.
(3) The hydraulic conductivity for the two
				feet [60.9 centimeters] of compacted soil used in the comparison shall be no
				greater than 1 x 10 
				-7 centimeters per second.
(4) The hydraulic conductivity of any
				alternative to the two feet [60.9 centimeters] of compacted soil must be
				determined using recognized and generally accepted good engineering
				practices.
(5) The transmissivity
				comparison must be made using this equation, which is derived from Darcy's Law
				for gravity flow through porous media:
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Where:
Q = flow rate (cubic centimeters/second);
A = surface area of the liner (squared centimeters);
q = flow rate per unit area (cubic centimeters/second/squared
				  centimeter);
k = hydraulic conductivity of the liner
				  (centimeters/second);
h = hydraulic head above the liner (centimeters); and
t = thickness of the liner (centimeters).
(6) The alternative composite liner must meet
				the requirements specified in paragraphs 1 through 4 of subdivision
				d.
f. The drainage layer
				must be designed and operated to minimize clogging during the active life and
				post-closure care period and have a hydraulic conductivity of 1 x 10 
				-3 centimeters per second or greater
				throughout. The drainage layer must have a sufficient thickness to provide a
				transmissivity of 3 x 10 
				-2 centimeters squared per second or
				greater.
g. The liner and leachate
				removal system must be compatible with the waste and leachate.
h. The liner and leachate removal system must
				maintain its integrity during the operating period and through postclosure
				period.
i. The system must have a
				collection efficiency of ninety percent or better and must be capable of
				maintaining a hydraulic head of less than twelve inches [30.5 centimeters]"
				above the liner.
j. The liner and
				leachate removal system in combination with the final cover must achieve a site
				efficiency of at least ninety-eight and one-half percent or better for
				collection or rejection of the precipitation that falls on the site.