Louisiana Administrative Code › Title 43 - NATURAL RESOURCES › Part XV - Office of Conservation-Surface Mining › Subpart 5 - Permanent Program Performance Standards › Chapter 53 - Permanent Program Performance Standards: Surface Mining Activities › Section XV-5367 - Disposal of Excess Spoil: Valley Fills

Current through Register Vol. 50, No. 6, June 20, 2024
A. Valley fills shall meet all of the
				  requirements of
				  §5365 and the
				  additional requirements of this Section.
1.
				  The fill shall be designed to attain a long-term static safety factor of 1.5
				  based upon data obtained from subsurface exploration, geotechnical testing,
				  foundation design and accepted engineering analyses.
2. A subdrainage system for the fill shall be
				  constructed in accordance with the following:
a. a system of underdrains constructed of
				  durable rock shall meet the requirements of §5367. A.2 d; and
i. be installed along the natural drainage
				  system;
ii. extend from the toe to
				  the head of the fill; and
iii.
				  contain lateral drains to each area of potential drainage or seepage;
b. a filter system to insure the
				  proper functioning of the rock underdrain system shall be designed and
				  constructed using standard geotechnical engineering methods;
c. in constructing the underdrains, no more
				  than 10 percent of the rock may be less than 12 inches in size and no single
				  rock may be larger than 25 percent of the width of the drain. Rock used in
				  underdrains shall meet the requirements of §5367. A.2.d The minimum size
				  of the main underdrain shall be:
Total Amount of Fill Material
Predominant Type of Fill Materials
Minimum Size of Drain, in Feet
Width
Height
Less than
1,000,000 yd3
Sandstone
10
4
Do
Shale
16
8
More than
1,000,000 yd3
Sandstone
16
8
Do
Shale
16
16
d.
				  underdrains shall consist of nondegradable, non-acid or non-toxic-forming rock
				  such as natural sand and gravel, sandstone, limestone or other durable rock
				  that will not slake in water and will be free of coal, clay or shale.
3. Spoil shall be hauled or
				  conveyed and placed in a controlled manner and concurrently compacted as
				  specified by the office, in lifts no greater than 4 feet or less if required by
				  the office to:
a. achieve the densities
				  designed to ensure mass stability;
b. prevent mass movement;
c. avoid contamination of the rock underdrain
				  or rock core; and
d. prevent
				  formation of voids.
4.
				  Surface water runoff from the area above the fill shall be diverted away from
				  the fill and into stabilized diversion channels designed to pass safely the
				  runoff from a 100-year, 6-hour precipitation event or larger event specified by
				  the office. Surface runoff from the fill surface shall be diverted to
				  stabilized channels off the fill which will safely pass the runoff from a
				  100-year, 6-hour precipitation event. Diversion design shall comply with the
				  requirements of §5323
5. The
				  tops of the fill and any terrace constructed to stabilize the face shall be
				  graded no steeper than 1v:20h (5 percent). The vertical distance between
				  terraces shall not exceed 50 feet.
6. Drainage shall not be directed over the
				  outslope of the fill.
7. The
				  outslope of the fill shall not exceed 1v:2h (50 percent). The office may
				  require a flatter slope.