[Federal Register Volume 64, Number 124 (Tuesday, June 29, 1999)]
[Notices]
[Pages 34770-34778]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-16470]
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DEPARTMENT OF AGRICULTURE
Natural Resources Conservation Service
Mining Specifications for Prime Farmland
AGENCY: Natural Resources Conservation Service, USDA.
ACTION: Final notice.
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SUMMARY: The Natural Resources Conservation Service (NRCS) of the
Department of Agriculture (USDA) is issuing specifications for soil
handling in relation to mining activities on prime farmland, as
provided for in the Surface Mining Control and Reclamation Act of 1977
(SMCRA). SMCRA requires the Secretary of Agriculture to establish
specifications for the removal, storage, replacement, and
reconstruction of prime farmland soils.
The Soil Conservation Service, now called the Natural Resources
Conservation Service, first proposed these specifications on February
19, 1988 (53 FR 4989). Beginning in 1997, NRCS and the Office of
Surface Mining (OSM) began reviewing and updating these specifications
to be published as a rule in the Federal Register. The process included
reviewing comments received from the 1988 Federal Register, knowledge
gained from field experiences since 1988, and field reviews conducted
with state regulatory authorities.
During the process of developing these specifications, we concluded
that these specifications should be published through a notice rather
than a rule because the specifications are not regulatory. These
specifications serve as guidelines to NRCS State Conservationists for
developing state-specific specifications and may assist the various
states in developing state standards. They will also help the mining
industry, state regulatory authority, and OSM develop reclamation
plans, which if implemented, will provide the best opportunity to meet
the post-reclamation crop production standards required by SMCRA.
General Background on Proposed Specifications
Section 515(b)(7) of the Surface Mining Control and Reclamation Act
of 1977 (SMCRA), Pub. L. 95-87, 30 U.S.C. 1265(b)(7), authorizes the
Secretary of Agriculture to establish specifications for soil removal,
storage, replacement, and reconstruction for all prime farmlands, as
identified in Section 507(b)(16) of the Act 30 U.S.C. 1257(b)(16), to
be mined and reclaimed. This authority is delegated to NRCS in 7 CFR
2.61(a)(22).
NRCS determined that national specifications for soil handling must
allow for consideration of the wide diversity of soils, geology,
climate, mining equipment, and crops in coal mining areas across the
nation. These differences are recognized in the permanent program
regulations published by the Office of Surface Mining Reclamation and
Enforcement, U.S. Department of the Interior, specifically in 30 CFR
823.4(a) which states that ``NRCS within each State shall establish
specifications for prime farmland soil removal, storage, replacement,
and reconstruction.''
Accordingly, NRCS developed the specifications set forth in this
notice to ensure that local and site-specific factors are considered.
Within the individual States, each NRCS State Conservationist will
maintain and make available a local version of these specifications
that incorporates the general criteria set forth in these
specifications and any modifications made for the respective State. To
the fullest extent possible, the basic specifications and the
applicable modifications for individual States reflect the latest
scientific information and experience regarding reclamation techniques.
During the development of these specifications, NRCS' national
office provided certain general guidelines to assist the NRCS State
staffs in developing specifications at the local level. These
guidelines were set out in the advance notice of the proposed rule
published on August 26, 1985 (50 FR 34490). The first version of these
proposed specifications was published on February 19, 1988 (53 FR
4989). The specifications set forth in this notice reflect comments
received as a result of the 1988 publication and include technical
revisions based on research results and improvements in
[[Page 34771]]
technology, which have occurred since the 1988 publication.
Discussion of These Specifications
The Soil Removal section provides guidance on the identification of
prime farmland soils where a published survey is not available and
outlines how a soil scientist should proceed with identifying and
sampling the soils to be removed for later replacement and
reconstruction. This section identifies needed documentation of field
conditions, including rooting zones; surface relief; pre-mining
drainage conditions (including subsurface); flood frequency; physical,
chemical, and morphological soil properties of the soils to be removed;
and the procedures to be used in soil removal. The soil removal
specifications address the handling of the various soil horizons
encountered on prime farmland and the procedures to be followed if
substitute materials are to be used. NRCS recognizes that compaction of
prime farmland soils during removal and reconstruction is a significant
factor in prime farmland reclamation and therefore, the specifications
include guidance to avoid compaction problems.
In the Soil Stockpiling section, NRCS recognizes that stockpiling
of soil horizons, while not the preferred procedure for reclamation, is
often necessary because of weather conditions, limitations or
availability of equipment, or the reclamation method utilized. These
specifications provide guidance to ensure that if stockpiling is
utilized, the soil resources will be protected until reconstruction
begins. This section provides criteria for stockpile site selection,
protection against contamination and loss, and temporary distribution
if long-term stockpiling is required.
In the Soil Reconstruction section, NRCS incorporates the principle
of SMCRA that the reclamation of prime farmland requires the re-
establishment of the pre-mining productivity of the disturbed soils.
The soil reconstruction specifications provide a framework which, if
followed and the required conditions are achieved, should maximize the
probability that the reconstructed soil will achieve the required
productivity.
Many factors contribute to the pre-mining productivity of prime
farmland, including the chemical and physical characteristics of the
soil horizons, the soil depth, the soil slope, and the drainage
conditions. Research has shown that when the post-mining soil
characteristics are similar to the pre-mining characteristics, pre-
mining productivity can be achieved. These specifications provide for
documentation of the characteristics of original soil, as required by
SMCRA, 30 U.S.C. 1257 and 1258, and provide that the reconstructed
soils should achieve these characteristics to the greatest extent
possible. These specifications provide guidance on how to utilize pre-
mining information in the development of a reconstruction plan for
successful reclamation. This guidance includes provisions regarding
rooting depths, chemical and physical characteristics of the soil
horizons, and site conditions. These specifications also include
erosion control measures to ensure that the reconstructed soils remain
in place after reclamation.
NRCS has attached appendices A and B for informational and
compliance assistance. These appendices do not establish an obligation
not otherwise imposed by other rules and regulations, nor do they
detract from obligations imposed by other rules and regulations.
Appendix A contains information describing the procedures for
determining the rooting zone of the pre-mined prime farmland soil.
Appendix B contains information describing the procedure and
quantitative specifications, which can be used to evaluate the rooting
zone of the reconstructed soil in relation to the pre-mined soil.
Response to Comments
We received 17 comments. A majority of the commentors had multiple
responses to the notice. Therefore, we have grouped the responses by
issue to address each of the comments received.
Comment: One commenter stated that NRCS should withdraw this
national guidance and proceed with state specific guidance. The
commenter apparently believes that these specifications were to be
implemented as national standards for removal, storage, replacement and
reconstruction of prime farmland soils. The commenter also believes
NRCS has no reason for proposing national guidance. Furthermore,
commentor states that national guidance is contradictory to NRCS long-
standing position that national specifications are not possible or
appropriate.
Response: We agree with the commenter that national specifications
are not appropriate. These specifications will not be published in 7
CFR 652 as national specifications. As stated in the preamble of the
Mining Specifications for Prime Farmland (63 FR 57651) this guidance is
advisory in nature, not regulatory. These specifications are intended
only to serve as guidance for development of state specific
specifications for the removal, storage, replacement and reconstruction
of prime farmland soils.
Comment: This same commenter also argued that NRCS is not obligated
to publish a national ``rule'' or guidance.
Response: We disagree. SMCRA at Sec. 515(b)(7) requires the
Secretary of Agriculture to publish specifications for removal,
storage, replacement and reconstruction of prime farmland soils. We see
these specifications as necessary guidance and an integral part of the
process that will result in state specific prime farmland
specifications. To reiterate, these specifications are not intended to
be implemented as they stand; they are to be used as a basis for
developing state specific prime farmland specifications.
Comment: Commenters suggested that the specifications should not
use binding language.
Response: We agree and the mandatory or binding language has been
changed in this final document to better indicate the advisory nature
of the specifications.
Comment: Commenters questioned whether specifications and
performance standards are both necessary.
Response: The specifications are required by the SMCRA to address
soil removal, storage, replacement and reconstruction. Both the
establishment of specifications and the achievement of performance
standards (crop production) are required by SMCRA and the OSM
regulations.
Comment: Commenters questioned why a soil scientist, as defined in
these guidelines, should locate and mark on the ground and on the plan
map the boundaries of prime farmland soils that will be removed during
mining.
Response: As used in this final notice, a soil scientist ``means a
technical specialist with the academic credentials or work experience,
which enables the specialist to use established procedures to collect
the required soil information.'' We believe this is a very liberal
definition of soil scientist, which allows anyone with the appropriate
knowledge to carry out the required operations. Several commenters
argued that only certified professional soil scientists should be
considered soil scientists for the purposes of these specifications.
These specifications are guidelines and individual states may set their
own standards for who qualifies as a soil scientist under their own
state specific specifications.
Comment: Commenters identified a potential conflict in the
discussion of removal of topsoils less than six inches thick.
[[Page 34772]]
Response: We agree with the comments and we have removed that
discussion from these specifications.
Comment: Commenters objected to the requirement under item (iii) in
section entitled ``Specifications for Soil Removal'' that says ``In no
case will prime farmland topsoil be mixed with topsoil containing rocks
larger than 2mm.''
Response: This section has been rewritten in the final guidance to
require that prime farmland topsoil not be mixed with topsoil, which
will result in an increase in the amount of rock fragments in the
resulting soil mix.
Comment: Commenters objected to the specification at part a (v) of
``Soil Removal Specifications'' that states ``soil removal should occur
only in water state classes that are slightly dry or dryer.'' The
commenters also contend that this specification contradicts the goal of
restoring prime farmland and is impossible to comply with.
Response: We disagree with this comment. We recognize that prime
farmland soils will be handled in other water state classes, however,
this results in a greater degradation in the quality of the replaced
prime farmland soil. Collectively these specifications are designed to
maximize the probability of reclamation success.
Comment: One respondent commented that the provision of ``Soil
Stockpiling,'' stating that stockpiling is permitted only if the soil
removal and reclamation cannot occur at the same time, is not
consistent with SMCRA.
Response: The sentence has been reworded to reflect the advisory
nature of these guidelines.
Comment: Commenters pointed out that there appeared to be language
missing from paragraph (b) of ``Soil Stockpiling.''
Response: The missing language has been replaced.
Comment: One commenter noted that paragraph (f) of ``Soil
Stockpiling'' is unclear.
Response: This paragraph has been revised to allow topsoil and
topsoil substitutes and subsoil and subsoil substitutes to be handled
together.
Comment: One commenter stated that the language of paragraph (b) of
``Soil Replacement and Reconstruction,'' which states that the depth
and quality of the replaced subsoil should be verified before
replacement of topsoil, may conflict with contemporaneous mining
operations where such activity would be impractical.
Response: We disagree. The specification is intended to prevent
topsoil from being placed over subsoil not meeting the reclamation plan
requirements. This could result in having to remove the topsoil. It
does not conflict with the direct haul back situation.
Comment: Several commenters stated that they were not able to
understand the meaning of the section on Root Permissive Structure in
Appendix B.
Response: This section describes a soil test that is applicable
only under semiarid conditions and may not be familiar to some persons
involved in coal mining and reclamation. However, it is a legitimate
test under some reclamation conditions. This section has been retained.
Comment: Several commenters pointed out conflict between the soil
strength discussions in the original Appendices A and B.
Response: We accept the comment and have removed the soil strength
discussion from Appendix A. The soil strength discussion in Appendix B
has been simplified.
Comment: Commenters requested that the references and sources of
values given in Appendices A and B be included.
Response: This has been done.
Comment: One commenter stated that we have not provided needed
references for data, research or other scientific information that was
relied on to establish these specifications. The commenter also states
that an agency must disclose this type of information to afford
interested parties a reasonable opportunity to comment on the agency's
proposal. They further stated that ``(i) interested persons, as well as
reviewing courts, have great difficulty analyzing agency decisions when
there is no indication in the rulemaking record as to how the agency
arrived at its decisions.''
Response: We have provided appropriate references in this final
notice.
Comment: One commenter states that there is no indication that the
agency has complied with the National Environmental Policy Act (NEPA),
the Regulatory Flexibility Act as amended by the Small Business
Regulatory Enforcement Fairness Act, the Paperwork Reduction Act, or
Executive Order 12866.
Response: NRCS reviewed the Environmental Impact Statement
developed by the Department of the Interior for the SMCRA regulatory
program and determined that this action is covered by that document.
Based on the amount of time since the SMCRA EIS, the agency, though it
is not necessary for publication of guidelines, developed an
Environmental Assessment (EA). This EA is on file at the agency's
headquarters. As with the NEPA requirements, the other requirements
identified by the commenter are not necessary for the publication of
these guidelines.
Comment: One commenter felt that the guidelines are written with
detailed specifications that undermine the stated purpose of providing
a national guideline to support state specific guidelines.
Response: We do not agree with this comment because the specific
parameter values and guidance are included to provide a basis for
developing state specific specifications, as stated in the preamble.
Some of the specific examples they identify in the comment letter
contain items that have been addressed in the response to other
commenters. The purpose of the appendices is given in the section
titled ``Discussion of the Proposed Specifications.''
Comment: Commenters questioned the use of 0.06 inches per inch of
available water capacity to determine the limit for fragipans or other
root inhibiting layers in Appendix A: Criteria for Determining Pre-
Mining Rooting Zone.
Response: We have not changed this value because it is generally
accepted by NRCS, and the guidance provided by this document may be
modified to accommodate state specific conditions.
Comment: Commenters felt that the listing of root inhibiting layers
and repetition of statements was not necessary.
Response: We agree with this comment and have removed the language.
Comment: Commenters felt that the lack of comparability of chemical
property values specified in Appendix A and Appendix B was
inappropriate.
Response: We disagree with this comment because the values in
Appendix A address root inhibiting horizons in undisturbed soils,
whereas values in Appendix B address desirable chemical properties of
reconstructed soils.
Comment: One commenter felt that the list of physical and chemical
properties in these guidelines should be expanded to include additional
soil properties.
Response: We have not made this change. These guidelines were not
developed to be all inclusive, but to serve as the basis for state
specific specifications.
Comment: One commenter requested that the guidelines include a
mechanism to resolve soil mapping differences when a soil survey is
done for
[[Page 34773]]
permitting and may be more detailed than the published soil survey.
Response: We feel that this issue is better addressed by the
regulatory authority consulting with the appropriate NRCS State
Conservationist.
Comment: Some commenters suggested that the SAR values in these
guidelines be changed, based on experience in their respective states.
Response: This was not done because the stated values provide a
greater chance of achieving performance standards.
Comment: One commenter suggested that inclusion of Bw and Bt
horizons in ``Specifications for Soil Removal'' should be conditioned
on the structure and texture being similar to the topsoil.
Response: We agree and the language has been changed.
Comment: One commenter noted the difficulty in interpreting Table 2
of Appendix B.
Response: We have simplified the table and accompanying
explanation.
Comment: One commenter expressed concern about the definition of
prime farmland.
Response: To address this concern, we have clarified the definition
of prime farmland as used in this document. The definition is
consistent with Office of Surface Mining regulations at 30 CFR, Part
700. Office of Surface Mining regulations protect prime farmland soils
(defined in 7 CFR 657) which have been historically used for crop
production. These definitions are found at 30 CFR 701.5, which can be
accessed on the OSM internet home page (www.osmre.gov).
Comment: One commenter stated that ``Section 507(b)(16) of the
Surface Mining Control and Reclamation Act of 1977 contemplate that the
Secretary of Agriculture will establish standards for the conducting of
soil surveys.
Response: With regard to the conducting of soil surveys, OSM
regulations require that soil surveys meet the standards of the
National Cooperative Soil Survey. Therefore, the standards for the soil
survey have been established by the Secretary of Agriculture.
Comment: This same commenter also stated that Sec. 515(b)(7)
mandates that specifications for soil removal, storage, replacement and
reconstruction shall be established. The commenter further states that
these standards are substantive rules under the Administrative
Procedure Act in that they require actions to be taken by regulated
entities, and effect the rights of third-party landowners by
establishing the standards for handling and replacement of the soil in
prime farmland mining situations. The commenter asserts that the
specifications are not merely interpretive in nature, but are intended
to bind the regulated entities through the vehicle of surface coal
mining permit and reclamation plan.
Response: We agree with the commenter that Section 515(b)(7) of
SMCRA, 30 U.S.C. 1265(b)(7), is the authority that requires the
Secretary of Agriculture to establish specifications for the removal,
storage, replacement, and reconstruction of prime farmland soils that
are disturbed by coal mining. This section also outlines certain
minimum requirements for soil handling and replacement. However, we
disagree with the next assertions of the commenter. These
specifications are not substantive rules and do not bind the RA to
issue permits under these specifications. Section 515(b)(7) does not,
nor does any section of SMCRA, establish these specifications as law or
regulation that is binding on OSM or any other RA. Section 510(d)(1) of
SMCRA, 30 U.S.C. 1260(d)(1), states that permits for mining of prime
farmland will be issued under regulations issued by the Secretary of
the Interior (OSM) after consultation with the Secretary of Agriculture
(NRCS). SMCRA and its regulations, found at 30 CFR Chapter 7,
consistently rely on the Secretary of Agriculture (NRCS) for
concurrence or advice, not regulation, on matters dealing with mining
and reclamation of prime farmland. In conclusion, the prime farmland
specifications published here are a useful tool for reclamation
planning in that they are all known components of a soil's capacity to
support crop yields and not the basis for measuring successful
restoration of capacity.
Implementation Issues
It is important that the implementation and administration of the
specifications be understood by everyone with an interest in the
successful reclamation of surface mined prime farmlands. Once these
specifications are finalized, NRCS will distribute these specifications
to each NRCS State Office for use in the development or revision of
State specifications. NRCS will send copies to each State Regulatory
Authority (RA) and each OSM office so that the specifications can be
used in carrying out their responsibilities for prime farmland
reclamation. The applicant for a mining permit on prime farmland will
prepare a reclamation plan, as required by sections 507 and 508 of
SMCRA, 30 U.S.C. 1257 and 1258, based upon the particular prime
farmland soils proposed to be mined, the equipment to be used, and the
physical characteristics of the site. Because these conditions vary
considerably among sites, the mining and reclamation plans will also
vary.
The RA must rely on its technical staff to assure the proposed
reclamation plan will likely yield the required results. The RA
technical staff will utilize NRCS specifications in making their
recommendations for approving, disapproving, or revising the proposed
reclamation plan. In addition to the plan review by the RA technical
staff, the RA will consult with the NRCS State Conservationist on the
plan prior to a final decision. The NRCS State Conservationist will
review and comment on the proposed reclamation plan and, if the plan
does not reflect NRCS specifications, the NRCS State Conservationist
will suggest appropriate plan revisions to the RA.
The RA will make a final decision on the reclamation plan based, in
part, on its review of NRCS specifications and consideration of
comments received from the NRCS State Conservationist. The decision
will be specific to the particular permit under review.
If a NRCS State Conservationist determines that a revision in the
State reconstruction specifications is desirable, then NRCS, in
consultation and cooperation with the RA, will utilize a public
outreach process to obtain comments on the proposed revision. Under no
circumstances will the State reconstruction specifications be less
effective than the National specifications. After a public comment
process, including publication in the Federal Register and internal
review by NRCS and RA, the NRCS State Conservationist will incorporate
the changes into the specifications and distribute them to the NRCS
local offices within the State and to the RA. The RA will make the
revised specifications available to mine operators and other interested
parties.
Questions and Answers
NRCS lists below questions related to implementation of NRCS
specifications, which have arisen during their development along with
answers to those questions.
Question 1: Are the RAs required to incorporate the NRCS
specifications into their approved state program through the formal
amendment process?
Answer: The RA will use the specifications in making their
determinations on prime farmland reclamation plans, but NRCS
specifications are not required to be a part of the approved state
program.
[[Page 34774]]
Question 2: What if the RA decides not to incorporate the State
Conservationist's recommendations into a reclamation plan?
Answer: The RA is required, under , 30 U.S.C.1260(d)(1), to consult
with the State Conservationist and to consider any suggested revisions.
It is not mandatory that NRCS recommendations be adopted on the permit
application and reclamation plan. Under the OSM regulations, 30 CFR
823.15, success of prime farmland reclamation is based on crop
production. NRCS specifications are provided to aid the permittee and
RA in reviewing and approving reclamation plans and in achieving
productivity standards. The specifications are not performance
standards. Section, 30 U.S.C. 1265(6)(7), sets forth the general
performance standards for mining and reclamation activities on prime
farmland. Under the OSM regulation, the ultimate standard, which must
be met, is the production standard. The specifications were not
developed to restrict prime farmland reclamation, but rather to provide
a basis upon which a prime farmland reclamation plan can be developed.
A reclamation plan that differs from the specification can be approved
if, in consultation with NRCS, the RA determines that a plan takes into
consideration the particular soil conditions, equipment, and mining
reclamation methods applicable to a site and will yield the desired
results.
Question 3: The proposed specifications would require permit
applicants to submit information which may not be required under the
current RA regulations or in the current permit application form. What
will be required of the RA's to address this issue?
Answer: The proposed specifications allow for a variety of options
in the area of needed information. This approach is consistent with the
variable site conditions, mining and reclamation equipment, and
procedures inherent in mining. Individual State RA's will determine
their informational needs using NRCS specifications. Some RA's, at
their discretion, may wish to change permit information requirements.
Question 4: How will the adoption of NRCS Soil Reconstruction
Specifications change the manner in which prime farmland plans are
currently being approved?
Answer: Adoption of these specifications will formalize the
knowledge and expertise that NRCS has brought to prime farmland
reclamation for over 20 years. State and Federal RA's and mine
operators have always relied upon NRCS for technical advice relating to
prime farmland reconstruction. State RA's have been required to consult
with NRCS on every acre of non-exempted prime farmland which has been
mined since enactment of SMCRA. Prior to the enactment of SMCRA, many
State RAs with a large amount of prime farmland being mined, such as
Illinois, have included NRCS in their mine plan review. Because of this
long relationship and prior history of consultation, we anticipate that
adoption of the specifications will not change the manner in which
plans are approved. Formalization of the specifications will provide a
written framework developed during many years of experience and
research, from which RA's and permittee can operate. The specifications
will be available to all that have an interest in prime farmland
restoration.
Applicability
The specifications apply to the removal, stockpiling, replacement,
and reconstruction of soil materials during surface coal mining and
reclamation operations on prime farmland, as defined and regulated by
the Surface Mining Control and Reclamation Act of 1977 (SMCRA), 30
U.S.C. 1201 et seq. These specifications are to be used in conjunction
with the permanent program performance standards of the Office of
Surface Mining Regulation and Enforcement, Department of the Interior,
which are set forth in 30 CFR 785.17, 816.22, and part 823. These
specifications apply to prime farmlands as defined by the Secretary of
Agriculture in 7 CFR part 657 and historically used for cropland.
Definitions
The following definitions apply to all documents issued in
accordance with these specifications, unless specified otherwise:
Prime farmland (as used in this document) means those lands which
are defined by the Secretary of Agriculture in 7 CFR part 657 and which
have historically been used for cropland.
Reclamation Plan means the part of a permit application that
details the actions a mine operator will take to restore the area to be
mined to an approved post-mining land use.
Rooting zone means the part of the soil that can be penetrated by
plant roots. The rooting zone of a soil can be obtained from a
published NRCS soil survey or determined in the field by a soil
scientist in accordance with procedures.
Soil characteristics mean properties of the soil, which can be
described or measured by field or laboratory observations, such as
color, temperature, water content, structure, pH, and exchangeable
cations.
Soil morphology means:
(a) The physical constitution of a soil profile as exhibited by the
kinds, thickness, and arrangement of the horizons in the profile, and
by the texture, structure, consistence, and porosity of each horizon;
or
(b) The visible characteristics of the soil or any of its parts.
State regulatory authority means the agency in each State, which
has the primary responsibility at the state level for administering the
initial or permanent state regulatory program relating to mining of
prime farmland.
Soil scientist means a technical specialist with the academic
credentials or work experience, which enables the specialist to use,
established procedures to collect the required information about soils.
Soil survey means field and other investigations which result in a
map showing the geographic distribution of different kinds of soils and
an accompanying report that describes, classifies, and interprets such
soils for use, and which meets the standards of the National
Cooperative Soil Survey as incorporated by reference in 30 CFR
785.17(c)(1).
Soil Removal
Specifications for designating prime farmland soils for removal.
(a) A soil scientist should locate and mark, on the ground and on
the plan map, the boundaries of prime farmland soils that will be
removed during mining. Prime farmland soils on the proposed mining site
will be identified from a published NRCS soil survey. If a soil survey
is not available or does not provide the physical, chemical, and
morphological soil properties described in 30 CFR 785.17(c)(1), a soil
scientist should sample and document those properties for the
identified prime farmland soils using the following procedures:
(i) Soil laboratory analysis for testing any sample will use the
procedures described in Soil Survey Investigations Report No. 42.
(ii) Identify the rooting zone of the undisturbed prime farmland
soils in the reclamation plan.
(iii) Identify the original topography of prime farmland soils to
be mined in the reclamation plan.
(iv) Identify the pre-mining surface and internal drainage
conditions, flooding frequency, and surface or subsurface drainage
systems of the prime farmland in the reclamation plan.
[[Page 34775]]
(v) Identify the equipment that will be used for soil removal in
the reclamation plan.
Specifications for Soil Removal
(a) Soil removal should be accomplished with adherence to the
following principles;
(i) Minimize pre-mining compaction and destruction of the soil
structure by using equipment that will have the least impact on the
natural soil.
(ii) Route soil removal equipment and adjust removal depth with
each cycle of that equipment to minimize the compaction and destruction
of soil structure in the natural soil.
(iii) Remove the topsoil layer (A, AP, AE, AB, E horizons and where
the structure and texture are similar to the A horizon, dark
noncalcareous Bw and Bt horizons). If there is not an area to use the
topsoil, place it in a designated stockpile. The topsoil of prime
farmlands may be mixed with other topsoils or substitute materials only
if the resulting topsoil will have greater productivity. In no case
should prime farmland topsoil be mixed with other material that will
result in an increase in the amount of rock fragments.
(iv) Remove the B horizon and/or C horizon, or an RA approved
substitute rooting media and, if there is not a currently or a recently
mined area to concurrently place the rooting media, place it in a
designated stockpile.
(v) Soil removal should occur only in water state classes that are
slightly dry or dryer, as defined in the Soil Survey Manual, United
States Department of Agriculture, Handbook No. 18, October 1993.
(b) Substitution of any material for naturally occurring prime
farmland topsoil should be approved by the RA, in consultation with the
NRCS, only when the substitute material will have a demonstrated
productivity that is higher than the original topsoil. Substitution of
any material, or mixing of the existing layers, for a naturally
occurring prime farmland subsoil should be approved by the RA, in
consultation with the NRCS, only when the substitute material will have
a demonstrated productivity that is equal to or higher than the
original subsoil.
Soil Stockpiling
Specifications For Stockpiling: Stockpiling should only occur only
if the soil removal and reconstruction operations cannot be carried out
concurrently.
(a) Stockpiled materials should:
(i) Be placed on a stable site within the permit area;
(ii) Be protected from contaminants and unnecessary compaction that
would interfere with revegetation;
(iii) Be protected from wind and water erosion through prompt
establishment and maintenance of an effective, quick growing vegetative
cover or through other measures approved by the regulatory authority;
and
(iv) Not be moved until required for redistribution.
(b) Where long-term surface disturbances will result from
facilities, such as support facilities and preparation plants, and
where stockpiling of soils would be detrimental to the quality or
quantity of those soils, the RA may approve the temporary distribution
of the removed soil materials to an approved site within the permit
area to enhance the current use of that site until needed for later
reclamation, provided that it does not diminish the capability of host
site and the soil material will be retained in a condition more
suitable for redistribution than if stockpiled.
(c) Sites subject to flooding or slippage are to be avoided for
stockpiling of soil. The soil survey map for the proposed stockpiling
site, as well as a field investigation, should be used to determine if
a proposed soil stockpile location will be subject to flooding or
slippage.
(d) Ponding of water should be avoided on all stockpiles.
(e) All woody vegetation and any other materials on the stockpile
site that may degrade the quality of stored material or interfere with
placement or removal of stockpiled soils should be removed.
(f) The topsoil, or approved substitute material, should be
stockpiled separately from the subsoil or approved substitute material.
(g) If possible, topsoil and subsoil stockpiles should not be
located on prime farmland soils. If prime farmland must be used as a
stockpile site, actions should be taken to avoid and mitigate any
adverse effects such as compaction.
Soil Replacement and Reconstruction
Specifications for soil replacement and reconstruction are as
follows:
(a) The minimum depth of soil and substitute soil material to be
reconstructed should be 48 inches; or (1) a lesser depth equal to the
depth of a sub-surface horizon in the natural soil that inhibits or
prevents root penetration; or (2) a greater depth if determined by the
RA, in consultation with the NRCS, to be necessary to restore the
original soil productive capacity.
(b) The rooting zone of the pre-mining soils will be used as a
basis for determining the replacement soil depth. Appendix A provides
guidance for establishing the pre-mining rooting zone depth. The depth
and quality of the rooting zone of the reconstructed prime farmland
soils should be equal to or greater than the pre-mined soil rooting
zone. The depth and quality of the replaced subsoil should be verified,
using characteristics in Appendix B, before replacement of the topsoil.
(c) Topsoil, or the approved substitute material, should be
returned to the mined area to a thickness not less than that of the
pre-mined topsoil.
(d) The reconstructed soil should have a hydraulic conductivity,
texture, porosity, consistency, penetration resistance, and other
physical properties which approximates the pre-mined soil or are more
favorable for plant growth as outlined in Appendix B.
(e) The reaction (pH) and other chemical properties of the major
horizon of the reconstructed soil must be within the ranges of the pre-
mined soil or be more favorable for plant growth. (Appendix B provides
additional guidance on desirable physical and chemical properties for
the reconstructed soils).
(f) Final grading of the reconstructed soil should provide for
adequate surface drainage and for slope gradients within the range of
the pre-mined prime farmland mapping units. In semi-arid and arid
regions, surface drainage patterns and slope gradients must be
reestablished to ensure that reconstructed prime farmland soils receive
approximately the same amount of surface water run-on from adjacent
areas as they did in their pre-mined condition.
(g) Soon after topsoil replacement, the soil should be tilled at
sufficient depth to encourage root and water penetration into the
subsoil to reduce runoff and erosion.
(h) Erosion control measures contained in the approved reclamation
plan should be implemented immediately after replacement of the
topsoil. These erosion control measures should meet, at a minimum, the
specifications found in Section IV of the local NRCS Field Office
Technical Guide for seeding, mulching, and other appropriate erosion
control methods.
All field observation and testing should be performed by a soil
scientist or persons under the direction of a soil scientist.
[[Page 34776]]
Appendices
An Introduction to Appendices A and B
Appendices A and B illustrates the importance of soil chemical and
physical properties during the reconstruction of prime farmland in the
restoration of productivity. These appendices do not establish an
obligation not otherwise imposed by other rules and regulations, nor do
they detract from obligations imposed by other rules and regulations.
Appendix A contains information describing the procedures for
determining the rooting zone of the pre-mined farmland soil. Appendix B
contains information describing the procedure and quantitative
specifications, which can be used to evaluate the rooting zone of the
reconstructed soil in relation to the pre-mined soil.
Appendix A: Criteria for Determining Pre-Mining Rooting Zone
Soil horizons are considered as preventing root penetration if
their physical or chemical properties or water holding capacity
cause them to prevent penetration by roots of plants common to the
area. Soil features, e.g. tillage pan, formed during mechanical
disturbance are not to be considered as root inhibiting for purposes
of determining pre-mining rooting zone.
Most prime farmland soils have a favorable rooting depth of at
least 48 inches and, for such soils, proper soil reconstruction to
this depth will help in the restoration of productivity. However,
there may be some prime farmland soils for which reconstruction to a
greater depth is needed. Where bedrock or approved root inhibiting
horizons are at a depth of less than 48 inches, reconstruction is
thus required to a lesser depth. Fragipans or other root inhibiting
layers, in order to qualify for exclusion from reconstruction, must
contribute little or nothing to the productive capacity of the soil.
This contribution must be less than 0.06 inches per inch of
available water capacity to qualify for such exclusion.
The rooting zone of the prime farmland soils before mining will
be determined and documented in the reclamation plan. The rooting
zone can be obtained from published soil surveys or field
determination.
If a soil survey or field determination (observation of rooting
depth in an excavation) is not used to determine the rooting zone,
the following guidelines will be used to determine depth (below 20
inches) to a root inhibiting soil layer for each of the following
factors.
Sodium Adsorption Ratio (SAR): This is a measure of the amount
of sodium (Na+) relative to calcium (Ca++) and
magnesium (Mg++) in the water extract from saturated soil
paste. SAR is calculated from the following equation:
[GRAPHIC] [TIFF OMITTED] TN29JN99.024
Soils having the SAR values listed below will have increased
dispersion of organic matter and clay particles, reduced
permeability and aeration, and a degradation of soil structure.
SAR Values
A value of greater than 30 is a root inhibiting soil layer.
Electrical Conductivity: This is a measure of the concentration
of water soluble salts in a soil (from an extract of saturated soil
paste) and is used to indicate saline soils. High concentrations of
neutral salts interfere with the absorption of water by plants
because the osmotic pressure in the soil solution is higher than
that in the plant cells.
Salts in a soil layer can interfere with the exchange capacity
of nutrient ions, thereby resulting in nutritional deficiencies in
plants. Soils having the following value will be root inhibiting: A
value of greater than 8 mmho/cm.
Aluminum Saturation: Excess aluminum restricts plant root
penetration and proliferation in acid subsoils by decreasing water
uptake in plants. Aluminum toxicity damage roots to the extent that
they cannot absorb adequate water. High concentrations of aluminum
are linked to adverse interaction with other elements, e.g., iron
and calcium. The relationship of aluminum and calcium is the most
important factor affecting calcium uptake by plants. Aluminum
toxicity is linked to phosphorus deficiency, and conversely,
aluminum tolerance is related to the efficient use of phosphorus. A
value of equal to or more than 55 percent aluminum saturation for
cotton, peanuts, soybeans, and other similar crops and equal to or
more than 60 percent aluminum saturation for corn, wheat, sorghum,
and other similar crops is a root inhibiting soil layer using the
following equation
[GRAPHIC] [TIFF OMITTED] TN29JN99.025
Root Inhibiting Structures: Any structural unit that prevents
root penetration is considered root inhibiting. Structural units
that have an average spacing of more than 4 inches on the horizontal
dimension may be considered root inhibiting structures even though
roots penetrate between the structural units. The determination of
structures must occur at a consistency of firm or firmer. The kind
and size of structure and consistency are always evaluated under
moderately moist or very moist conditions.
Moist Bulk Density: Bulk density is an indicator of the soil's
ability for root development, both vertically and horizontally. A
soil having moist bulk density equal to or more than values shown in
table 1 is considered having a soil root inhibiting layer:
Table 1.--Root-Limiting Bulk Densities for Each Family Texture Class
------------------------------------------------------------------------
Rooting-
limiting
Family texture class bulk
density
(g/cm\3\)
------------------------------------------------------------------------
Sandy........................................................ 1.85
Coarse loamy................................................. 1.80
Fine loamy................................................... 1.78
Coarse silty................................................. 1.79
Fine silty................................................... 1.65
Clayey: 35-45% clay.......................................... 1.58
>45% clay.................................................... 1.47
------------------------------------------------------------------------
Appendix B: Desirable Characteristics for Physical and Chemical
Properties of Reconstructed Soils
The reconstructed soils should have the following
characteristics. These characteristics will help ensure the success
of meeting the performance standards. Terms used in this Appendix
are explained in Appendix A. All rooting media must meet the
following chemical and physical properties to have the minimal
favorable environment for root growth:
Sodium Adsorption Ratio
[GRAPHIC] [TIFF OMITTED] TN29JN99.026
SAR: A value of less than 4.
Electrical Conductivity: A value of less than 4 mmho/cm.
Aluminum Saturation: Aluminum saturation value of less than 20
percent for cotton, peanuts, soybeans, and other similar crops and
less than 35 percent aluminum saturation for corn, wheat sorghum,
and other similar crops using the following equation--
[GRAPHIC] [TIFF OMITTED] TN29JN99.027
[[Page 34777]]
Root Permissive Structure: The reconstructed soil must have a
root permissive structure after the soil material has been subject
to the passage of at least 1.5 pore volumes of water in excess of
the retention at 15 bar bringing all parts through the depth of
consideration at least one time to very moist or wet. The pore
volume is obtained by multiplying the depth zones by the water
holding capacity volume fractions to follow: stratified by family
particle-size class excluding the effect of those larger than 2 mm:
------------------------------------------------------------------------
Volume
Family particle size a fraction
------------------------------------------------------------------------
Sandy........................................................ 0.10
Coarse-loamy................................................. 0.18
Fine-loamy................................................... 0.20
Coarse-silty................................................. 0.25
Fine-Silty................................................... 0.23
Clayey....................................................... 0.15
------------------------------------------------------------------------
a Family particle size classes defined in Soil Taxonomy Agriculture
Handbook 436.
Alternative volume fractions may be substituted if documented.
The volume of water for the family particle-size class is multiplied
by the thickness of the zone and the amounts of zones are added
through to 48 inches. Under raid fed conditions, the water addition
is taken as the aggregate of successive monthly positive differences
between precipitation and the evapotranspiration as computed by an
acceptable method. Figure 1 is a method for determination of soluble
salts and percent sodium for extract for identifying dispersive
soils. Irrigation should be considered when precipitation is
insufficient to subject the reclaimed soil to the passage of at
least one pore volume of water while all parts of the soil are very
moist or wet. The water added must not change the soil solution
chemistry from indicative of dispersion (zone A in figure 1) to non-
dispersive (zone B).
Figure 1. The field of percent sodium and total dissolved
solids, both for the saturation extract, divided into a non-
dispersive part (zone A), a dispersive part (zone B), and a
transitional part (zone C). From Flanagan, C.P. and G.G.S. Holmgren.
1977. Field methods for determination of soluble salts and percent
sodium from extract for identifying dispersive soils. Am. Soc. Test
Mat. STP 623. Reference Address: American Society of Testing and
Materials (ASTM), 100 Barr Harbor Drive, West Conshohcken, PA 19428-
2959
[GRAPHIC] [TIFF OMITTED] TN29JN99.028
Moist Bulk density is an indicator of the soil's ability to
allow root development, both vertically and horizontally. Table 2
has values for bulk densities, by family soil texture class, that
are non-limiting to root development. Soil handling methods can
result in reclaimed soils that do not have continuity of pores or
interpedal voids: therefore, values in table 2 are an important
consideration during the reconstruction and reclamation of mined
soils. A bulk density value above those shown may be associated with
reduced crop yields.
Table 2.--Non-Limiting Bulk Density for Each Family Texture Class
------------------------------------------------------------------------
Nonlimiting
Family texture class bulk
density
------------------------------------------------------------------------
Sandy...................................................... 1.60
Coarse loamy............................................... 1.50
Fine loamy................................................. 1.46
Coarse silty............................................... 1.43
Fine silty................................................. 1.34
Clayey: 35-45% clay........................................ 1.40
45% clay........................................ 1.30
------------------------------------------------------------------------
Caution--Because of the diversity of soil texture, rock
fragments, climate, mining equipment, and other variables during
reclamation, moist bulk density values are only a guide. In spite of
overall high bulk density, there are cases where good root
deployment and targeted crop yields have been achieved, mainly
because the pattern of pore spaces was favorable. On the other hand,
there are cases in which the overall bulk density is not high and
good root deployment was expected, but a very thin highly compacted
layer that could not be detected in a standard test method
prohibited the entry of plant roots.
Soil Strength: Soil strength is highly correlated to crop yields
on reclaimed and reconstructed mined soils. The response is
curvilinear with crop yield decreasing as soil strength increases.
There appears to be a threshold where soil strength has an effect on
crop yield. A soil strength value above 100 PSI may be associated
with reduced crop yields. The PSI values are determined by inserting
into the soil profile a 3/4 inch rod with a 300 right circular cone
point on the end of the rod.
Even when soil strength is not the limiting factor (<100 PSI),
the quality of rooting
[[Page 34778]]
material and the practices used during reconstruction and
reclamation can have a significant impact on crop yields.
References
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1992. Physical Root Restriction Prediction in Mine Spoil Reclamation
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Natl. Symp. on Prime Farmland Reclamation. Dep. Of Agron., Univ. of
IL, Urbana, IL.
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Penetration and Development of Some Farm Crops as Related to Soil
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classification for making and interpreting soil surveys. USDA-SCS
Agric. Handb. 436. U.S. Gov. Print. Office, Washington, DC.
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Handbook 436. U.S. Gov. Print Office, Washington, DC.
Soil Survey Staff. 1996. National Soil Survey Handbook, title
430-VI. USDA-NRCS. U.S. Gov. Print. Office, Washington, DC.
Soil Survey Staff. 1998. Keys to Soil Taxonomy. Eighth Edition.
USDA-NRCS. Washington, DC.
Vance, S.L., R.E. Dunker, C.L. Hooks, and R.G. Darmondy. 1992.
Relationship of Soil Strength and Rowcrop Yields on Reconstructed
Surface Mine Soils. P. 35-42. In R.E. Dunker, et al. (ed.) Proc. of
the 1992 Natl. Symp. On Prime Farmland Reclamation. Dep. of Agron.,
Univ. Of IL, Urbana, IL.
Signed at Washington, DC on June 23, 1999.
Danny D. Sells,
Associate Chief, Natural Resources Conservation Service.
[FR Doc. 99-16470 Filed 6-28-99; 8:45 am]
BILLING CODE 3410-16-P