California Code of Regulations › Title 14 - Natural Resources › Division 2 - Department of Conservation › Chapter 8 - Mining and Geology › Subchapter 1 - State Mining and Geology Board › Article 9 - Reclamation Standards › Section 3704.1 - Performance Standards for Backfilling Excavations and Recontouring Lands Disturbed by Open Pit Surface Mining Operations for Metallic Minerals

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
Notwithstanding the provisions of Section
						3700(b) of this
						Article, no reclamation plan, including any reclamation plan in which the end
						use is for wildlife habitat, wildland conservation, or open space, or financial
						assurance for a surface mining operation subject to the provisions of this
						section, shall be approved by a lead agency unless the reclamation plan meets
						the provisions of this section. Financial assurances must be maintained in an
						amount sufficient to provide for the backfilling and contour grading of the
						mined lands as required in this section.
(a) An open pit excavation created by surface
					 mining activities for the production of metallic minerals shall be backfilled
					 to achieve not less than the original surface elevation, unless the
					 circumstances under subsection (h) are determined by the lead agency to
					 exist.
(b) Backfilling shall be
					 engineered, and backfilled materials shall be treated, if necessary, to meet
					 all of the provisions of Title 27, California Code of Regulations, Division 2,
					 Chapter 7, Subchapter 1, Mining Waste Management, commencing with Section
					 22470, and the applicable Regional
					 Water Quality Control Board's Water Quality Control Plan.
(c) Excavated materials remaining in
					 overburden piles, waste rock piles, and processed or leached ore piles not used
					 in the backfilling process and remaining on the mine site shall be graded and
					 contoured to create a final surface that is consistent with the original
					 topography of the area. Care shall be taken to avoid the creation of un-natural
					 topographic features, impediments to natural drainage, or conditions hazardous
					 to human life and wildlife.
(d)
					 Backfilling, recontouring, and revegetation activities shall be performed in
					 clearly defined phases to the engineering and geologic standards required for
					 the end use of the site as stipulated in the approved reclamation plan. All
					 fills and fill slopes shall be designed to protect groundwater quality, to
					 prevent surface water ponding, to facilitate revegetation, to convey runoff in
					 a non-erosive manner, and to account for long term settlement.
(e) The requirements of subsections (a), (b),
					 (c), and (d) notwithstanding, no final reclaimed fill slopes shall exceed 2:1
					 (horizontal:vertical), nor shall the resultant topography exceed in height the
					 pre-mining surface contour elevations by more than 25 feet. Final fill slopes
					 shall have static and dynamic factors of safety, as determined by an engineer
					 licensed in California, that are suitable for the proposed end use of the site
					 and meet or exceed the requirements of applicable building or grading codes,
					 ordinances, statutes, and regulations. Final slopes must be capable of being
					 revegetated, and shall blend visually with the local topography. Surface soil
					 shall be salvaged, stored, and reapplied to facilitate revegetation of
					 recontoured material in accordance with the requirements of Section
					 3711 of this Article.
(f) For the purposes of this section, a
					 metallic mine is defined as one where more than ten percent of the mining
					 operation's gross annual revenues as averaged over the last five years are
					 derived from the production of, or any combination of, the following metallic
					 minerals by the open pit extraction method: Precious metals (gold, silver,
					 platinum);
Iron;
Nickel;
Copper;
Lead;
Tin;
Ferro-alloy metals (tungsten, chromium,
						manganese);
Mercury;
Uranium and thorium;
Minor metals including rubidium, strontium, and
						cesium;
Niobium and tantalum;
(g) For the purposes of this regulation, an
					 open pit mine is the same as an open pit quarry, opencast mine, or opencut
					 mine, and is defined as a mine working or excavation that is open to the
					 surface and in which the opening is approximately the full size of the
					 excavation.
(h) The requirement to
					 backfill an open pit excavation to the surface pursuant to this section using
					 materials mined on site shall not apply if there remains on the mined lands at
					 the conclusion of mining activities, in the form of overburden piles, waste
					 rock piles, and processed or leached ore piles, an insufficient volume of
					 materials to completely backfill the open pit excavation to the surface, and
					 where, in addition, none of the mined materials has been removed from the mined
					 lands in violation of the approved reclamation plan. In such case, the open pit
					 excavation shall be backfilled in accordance with subsections (b) and (d) to an
					 elevation that utilizes all of the available material remaining as overburden,
					 waste rock, and processed or leached ore.
(i) This regulation does not apply to any
					 surface mining operation as defined in Public Resources Code Section
					 2735(a) and
					 (b) for which the lead agency has issued
					 final approval of a reclamation plan and a financial assurance prior to
					 December 18, 2002.
1. New
						section filed 12-18-2002 as an emergency; operative 12-18-2002 (Register 2002,
						No. 51). A Certificate of Compliance must be transmitted to OAL by 4-17-2003 or
						emergency language will be repealed by operation of law on the following
						day.
2. New section refiled 4-15-2003 as an emergency; operative
						4-15-2003 (Register 2003, No. 16). A Certificate of Compliance must be
						transmitted to OAL by 8-13-2003 or emergency language will be repealed by
						operation of law on the following day.
3. Certificate of Compliance
						as to 4-15-2003 order, including repealer and new section, transmitted to OAL
						4-18-2003 and filed 5-30-2003 (Register 2003, No.
						22).
Note: Authority cited: Sections
						  2755
						  and
						  2756,
						  Public Resources Code; Reference: Sections
						  2733,
						  2772
						  and
						  2773,
						  Public Resources Code.