[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

    Grossman, R.B., E.C. Benham, D.S. Harms, and H.R. Sinclair, Jr. 
1992. Physical Root Restriction Prediction in Mine Spoil Reclamation 
Protocol. P. 191-196. In R.E. Ducker et al. (ed.) Proc. of the 1992 
Natl. Symp. on Prime Farmland Reclamation. Dep. Of Agron., Univ. of 
IL, Urbana, IL.
    Pierce, F.J., W.E. Larson, R.H. Dowdy, and W.A.P. Graham, 1983. 
Productivity of Soils: Assessing Long-term Changes Due to Erosion. 
J. Soil Water Conserv. 38: 39-44.
    Fehrenbacher, J.B. and H.J. Snider. 1954. Corn Root Penetration 
in Muscatine, Elliott, and Cisne Soils. Soil Sci. 77:281-291.
    Feherenbacher, J.B. and R.H. Rust. 1956. Corn Root Penetration 
in Soils Derived from Various Textures of Wisconsin Age Glacial 
Till. Soil Sci. 82:369-378.
    IL Agric. Exp. Stn. Spring 1967. Root Development of Corn, 
Soybeans, Wheat, and Meadow in Some Illinois Soils. Illinois 
Research, Univ. Of IL, Urbana, IL.
    McSweeney, K.M. and I.J. Jansen. 1984. Soil Structure and 
Associated Rooting Behavior. Soil Sci. Soc. Am. J. 48:607-612.
    Trans. Int. Congr. of Soil Sci., 7th, Madison, WI. 1960. J.B. 
Fehrenbacher, P.R. Johnson, R.T. Odell, and P.E. Johnson. Root 
Penetration and Development of Some Farm Crops as Related to Soil 
Physical and Chemical Properties. Volume III:248-252.ISSS.
    Soil Survey Staff. 1975. Soil Taxonomy: A basic system of soil 
classification for making and interpreting soil surveys. USDA-SCS 
Agric. Handb. 436. U.S. Gov. Print. Office, Washington, DC.
    Soil Survey Staff. 1993. Soil Survey Manual. USDA-SCS Agric. 
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