FEDERAL REGISTER: 43 FR 20793 (May 5, 1978) DEPARTMENT OF THE INTERIOR AGENCY: Office of Surface Mining Reclamation and Enforcement (OSM) 30 CFR Part 837 Abandoned Mine Reclamation Fund; Fee Collection and Coal Production Reporting; Establishment of an interest Rate for Delinquent Reclamation Fee Payments and Method of Interest Computation ACTION: Final rulemaking. SUMMARY: These rules revise the reclamation fee payment regulations to establish an interest rate to be assessed against delinquent fee payments and to provide a method for computing interest on late payments. EFFECTIVE DATE: June 14, 1978. ADDRESSES: Office of Surface Mining Reclamation and Enforcement, United States Department of the Interior, 18th and C Streets NW., Washington, D.C. 20240. FOR FURTHER INFORMATION CONTACT: M. Richard Nalbandian, Chief, Division of Reclamation Planning and Standards, Abandoned Mine Land Reclamation, 202-343-4057. SUPPLEMENTARY INFORMATION: Proposed rules establishing an interest rate for delinquent fee payments and providing a method of computation were published in the FEDERAL REGISTER on February 21, 1978. (43 FR 7305). At the close of the comment period on March 23, 1978, comments had been received from four commenters. The purpose of these rules is to provide a financial inducement for operators to comply with the statutory requirement in section 402(b) of the Surface Mining Control and Reclamation Act of 1977 (30 U.S.C. 1232(b)) that reclamation fees must be paid no later than 30 days after the end of the calendar quarter for which they were due. The rules are issued under the Secretary's authority to promulgate rules and regulations that may be necessary or expedient to implement and administer the provisions of Title IV (section 412(a), 30 U.S.C. 1242(a)). The rule is deemed necessary to provide an administratively effective method for encouraging operators to make accurate and timely reclamation fee payments on coal produced each calendar quarter. The rate is established at a sufficiently high level to discourage operators from withholding payments in order to realize financial gains by using money due and payable for other purposes. Under this rule, interest assessed on delinquent payments will become part of the debt owed the federal government in the event legal action is necessary to compel payment. {20794} The Office of Surface Mining Reclamation and Enforcement (OSM) has made a few changes of a non- substantive editorial nature. A change also has been made in response to one of the public comments. EDITORIAL CHANGES 1. In Sec. 837.15(d), the phrase "Except as provided in paragraph (e)," has been inserted at the beginning of the third sentence to clarify the time when interest shall first begin to accrue on delinquent payments. Paragraph (e) establishes the date when payments due on first and second calendar quarter coal production must be received to avoid being delinquent and the date when interest shall begin to accrue on those payments once they become delinquent. 2. The dates in Sec. 837.15(e) establishing the times when interest shall begin to accrue, and when payments due on coal produced from October 1, 1977 through March 31, 1978 must be received to avoid an interest charge, have been changed to produce a result consistent with the effective date of this final rule. 3. In Sec. 837.15(e), the word "on" before the date "April 1, 1978" has been deleted because it is unnecessary. SUMMARY OF COMMENTS RECEIVED ON PROPOSED RULEMAKING 1. One commenter stated that OSM does not have any statutory authority to impose, by rule, an interest charge of one percent per month on delinquent fee payments. This comment was not accepted. Section 412(a) of the Act authorizes the Secretary of the Interior to do all things necessary or expedient, including promulgation of rules and regulations, to implement and administer the provisions of the Act relating to Abandoned Mine Reclamation (Title IV). Section 402(b) of the Act requires payment of reclamation fees on produced coal no later than thirty days after the end of each calendar quarter in which the coal was produced. Therefore, this rule is promulgated under the authority of Section 412(a) of the Act to provide the Secretary, through OSM, with an administratively effective method of assuring timely compliance with Section 402(b) of the Act. 2. One commenter suggested that the proposed amendments did not distinguish between an operator who had attempted, in good faith, to submit the appropriate fee and an operator who simply did not meet the payment deadline. The commenter argued that failure to distinguish between those two groups of operators would be inequitable. The commenter therefore proposed amending Sec. 837.14(b) to provide that interest charged on fees subsequently redetermined by the Director should be at the prevailing prime interest rate and that the interest should not begin to accrue until the end of the calendar quarter in which the determination of a higher fee was made. To complete the distinction, the commenter also suggested amending Sec. 837.15(d) by substituting "delinquent" for "late" in the last sentence of the paragraph, and amending Sec. 837.15(e) by adding the word "delinquent" to modify the phrase "reclamation fee payments" found in the first sentence. The latter comment was partially accepted by substituting "delinquent" for "late" in the last sentence of paragraph (d) of Sec. 837.15. That change provides consistency of word usage throughout the paragraph. However, for effective administration of Section 402(b) of the Act, it is necessary to provide a uniform rule applicable to all operators. It would be virtually impossible to distinguish between those operators who in good faith attempted to pay the appropriate fee and those who might use this commenter's proposed changes to avoid accurate reporting and timely payments required by the Act and the rules. Furthermore, a charge based on the prevailing prime interest rate would not provide sufficient incentive for operators to submit accurate production figures, although such a rule would allow operators to avoid a higher rate if they did report something on time. The Act and the rules requires both accurate reporting of production figures and timely payments. 3. Two commenters argued that the interest charge was unduly burdensome or punitive and that an interest charge greater than that paid by the Federal government on its general obligations and bonds would be unconscionable. This comment was not accepted. A sufficient financial inducement to encourage compliance within the time specified by Congress is necessary. OSM's goal is to collect the reclamation fee in an orderly and timely manner and, of course, the burden imposed by an interest charge will only fall on those operators who neglect their legal responsibility to pay on time. 4. Another commenter suggested that, with respect to coal mined during reclamation of previously abandoned areas, interest on delinquent fees should be eliminated entirely or should not begin to accrue until after reclamation is completed or until after an extended grace period of 90 days from the end of the applicable calendar quarter. No change was made because section 402(b) of the Act requires payment of reclamation fees "no later than thirty days after the end of each calendar quarter." Moreover, section 402(a) of the Act requires that "all operators of coal mining operations * * * " must pay a reclamation fee on coal produced, whether or not coal is produced during reclamation activities. 5. One commenter argued that he found no consideration given for the usury laws of various States and that the proposed interest charge would, in many cases, exceed statutory limits. To constitute usury, there must be a loan of money or an agreement by the lender to refrain during a given period of time from requiring the borrower to repay a loan or debt which is due and payable. Here, the annual percentage charged, although possibly in excess of some statutory rates of interest, cannot be regarded as usury, since the essential borrowing and lending are not present. The Act establishes an obligation to pay a reclamation fee by a certain date and interest is charged only if the payment is not received on time. The interest charge is not a condition of such an agreement between the operators liable for the fee and OSM, but, rather it is an inducement for operators to meet their financial obligations under the Act. 6. A comment was received suggesting that OSM had not carefully reviewed the economic consequences of this proposal. OSM did consider the economic impact of the proposed rule, as noted in the FEDERAL REGISTER notice of proposed rulemaking (43 FR 7305), and determined in accordance with Departmental regulations that the anticipated consequences would not be of the magnitude required for the preparation of an Economic Impact Statement. EFFECTIVE DATE Consistent with Department of the Interior policy, this final rulemaking will be effective June 14, 1978. DRAFTING INFORMATION The principal authors of this rulemaking are Paul Reeves, Office of Surface Mining Reclamation and Enforcement, and John Beattie, Office of the Solicitor, Department of the Interior. In consideration of the comments received and pursuant to the authority of sections 201(c) and 412(a) of the Surface Mining Control and Reclamation Act of 1977, 30 CFR Part 837 is amended as follows: 1. Paragraph (b) of Sec. 837.14 is revised to read as follows: Sec. 837.14 Determination of percentage based fees. (b) If the Director determines that a higher fee shall be paid, the operator shall submit the additional fee together with interest computed under Sec. 837.15(d). 2. In Sec. 837.15 paragraph (d) is revised, paragraph (e) is redesignated as paragraph (f) and a new paragraph (e) is added. Revised paragraph (d) and new paragraph (e) read as follows: Sec. 837.15 Reclamation fee payment. (d) The reclamation fee payment for each calendar quarter shall be paid no later than 30 calendar days after the end of the calendar quarter. Delinquent payments are subject to interest at the rate of 1 percent per month, or any part thereof, on any amounts due. Except as provided in paragraph (e), interest shall begin to accrue on the 31st day following the end of the calendar quarter and will run until the date of payment, or until judgment is rendered by a court of competent jurisdiction in an action to compel payment of debts. The Office of Surface Mining Reclamation and Enforcement will then compute the interest on delinquent payments and bill the operator in accordance with procedures followed by the Department of the Interior for the collection of debts. (e) Interest shall begin to accrue (31 days after publication) on reclamation fee payments due on coal produced from October 1, 1977 through March 31, 1978 for which payments have not been received by (30 day after publication). For reclamation fee payments due on coal produced during succeeding calendar quarters, beginning with the quarter commencing April 1, 1978, interest, at the prescribed rate, shall accrue in accordance with paragraph (d) of this section. {20795} (Secs. 201 and 412(a), Pub.L. 95-87, 91 Stat. 445 (30 U.S.C. 1201, 1242(a)).) NOTE. - The Department of the Interior has determined that this document does not contain a major proposal requiring preparation of an Economic Impact Statement under Executive Order 11821 and OMB Circular A-107. Dated: May 9, 1978. JOAN M. DAVENPORT, Assistant Secretary, Energy and Minerals. [FR Doc. 78-13072 Filed 5-12-78; 8:45 am] FEDERAL REGISTER: 43 FR 8090 (FEBRUARY 27, 1978) DEPARTMENT OF THE INTERIOR AGENCY: Office of Surface Mining Reclamation and Enforcement (OSM) 30 CFR Parts 710, 715, 717 Interim Final Rules and Notice of Public Hearing ACTION: Interim Final Rules and announcement of hearing. SUMMARY: These interim final rules amend the design criteria for sedimentation ponds and temporary diversion structures for surface coal-mining operations and extend the filing deadlines for submission of schedules for the reconstruction of existing sedimentation ponds, and related pre-existing, non-conforming structures to May 3, 1978. In addition, the construction on such pre-existing, non-conforming structures must begin by June 3, 1978. Construction on all pre-existing, non-conforming structures must still be completed by November 4, 1978. These interim final rules are applicable to all surface coal mining operations during the public hearing and comment period contemplated on these rules. DATES: Interim Final Regulations are effective February 27, 1978. Comments on the interim final regulations must be received by March 29, 1978. The hearing will be held on March 15, 1978 at 9:30 am. ADDRESSES: Director, Office of Surface Mining Reclamation and Enforcement, Department of the Interior, Washington, D.C. 20240, 202-343-4237. The hearing will be at the Department of the Interior Auditorium, 18th and C Streets NW., Washington, D.C. 20240. FOR FURTHER INFORMATION CONTACT: Walter N. Heine, 202-343-4237. SUPPLEMENTARY INFORMATION: The Surface Mining Control and Reclamation Act of 1977 (hereinafter the Act), Pub.L. 95-87, requires the Secretary of the Interior to publish initial environmental protection regulations that are applicable to all coal-mining operations on lands that are regulated by the States until a State has an approved regulatory program. Proposed rules implementing the Act were published in the FEDERAL REGISTER on September 7, 1977 (42 FR 44920). Public hearings on the proposed rules were held on September 20-22, 1977, in Washington, D.C., Charlestown, W.Va., St. Louis, Mo., and Denver, Colo. At the close of the comment period on October 7, 1977, over 300 commenters had submitted written comments, many of which were very lengthy. On December 13, 1977, the Department promulgated final regulations as required by the Act for the initial regulatory program (42 FR 62639). Both in the proposed regulations and the final regulations, the Department detailed requirements for sedimentation ponds to prevent, to the extent possible using the best technology currently available, additional contributions of suspended solids to streamflow, or runoff outside the permit area. As a result of extensive comments from States and industry after publication of the final design criteria for sedimentation ponds, the Department reconsidered the design criteria for sedimentation ponds. Many States and industry commenters suggested that the final standard required unnecessarily large sedimentation ponds which could pose a hazard to the surrounding community. Commenters also felt that good management which is presently utilized in some States would preclude the need for large basins. In light of these and other comments, the Director of the Office of Surface Mining Reclamation and Enforcement, other representatives of the Department and representatives of the Environmental Protection Agency viewed a number of mining operations in West Virginia on January 31, 1978, to determine if this standard needed modification. As a result of these visits to mining sites and extensive discussions with State and industry and public interest representatives, the Department has modified the design criteria for sedimentation ponds to allow greater flexibility and accommodate diversity in terrain and other physical conditions. In large measure the modifications are supported by the transcripts of the public hearings on the proposed regulations, written comments received prior and subsequent to the final regulations, technical studies, manuals, and generally accepted engineering practice. Primary technical literature relied upon in developing these new regulations included, Curtis, "Sediment Yield From Strip-Mined Watersheds in Eastern Kentucky," Second Research and Applied Technology Symposium on Mined Land Reclamation, 1974; Kathuria, "Effectiveness of Surface Mine Sedimentation Ponds," EPA Report EPA- 660/2-76-117, August 1976; Simpson, "Interagency Evaluation Tour of West Virginia - Water Quality Committee Report," September 1977; "Erosion and Sediment Control-Surfacing Mining in the Eastern United States," Volumes 1 and 2, EPA Technology Transfer Seminar Publication, October 1976; Hill, "Sedimentation Ponds - A Criterial Review" NCA/BCR Coal Conference, October 1976; Janiak, "Purifications of Waters From Strip Lignite Mines," proceeding of the Polish-U.S. Symposium, May 1975. The December 13, 1977, regulations (42 FR 62686) specified three principal criteria which controlled the size and design of sedimentation ponds: Pond surface area, sediment storage volume and water detention time. The Department has modified these criteria as follows: At many mining locations, the controlling design criterion was to size sedimentation ponds to provide a surface area of at least 1 square foot of pond surface area for each 50 gallons per day of runoff entering the ponds resulting from a 10-year 24-hour precipitation event. The modifications delete the requirement that sedimentation ponds must provide at least 1 square foot for each 50 gallons per day of inflow. In lieu thereof, the new regulations require coal operators to consider sedimentation pond surface area in the design of ponds in order to achieve the effluent limitations (sec. 715.17(a)). The effect of this change is to remove a constraint on the design and size of sedimentation ponds and substitute in its place greater design flexibility, which if properly exercised, will permit the construction of smaller ponds. The new regulations clarify the sediment storage volume requirement for sedimentation ponds. A sediment storage volume must be provided equal to 0.2-acre feet of disturbed area within the upstream drainage area, unless the operator utilizes on-site or point-of-origin activities which may be considered as credits to reduce the required 0.2- acre feet storage volume. The new regulations specify a list of on-site activities including prompt and progressive backfilling, revegetation, mulching, and check dams. These credits, if approved by the regulatory authority, can have a significant impact on reducing the size of ponds. Section 715.17(e)(1) of the December 13, 1977, regulations required a 24-hour detention time for the design inflow or runoff entering sedimentation ponds. The new regulations require that the pond be designed to provide a 24-hour detention time for the design inflow or runoff unless a lower detention time is approved by the regulatory authority. In addition, in determining the design runoff volume, the operator can consider the characteristics of the mine site, reclamation control procedures and on-site sediment control practices. The 24-hour theoretical detention time can be reduced to 10 hours if the operator implements sediment control measures approved by the regulatory authority. The Office of Surface Mining will allow credits for sediment control measures such as pond configuration, inflow and outflow facilities and onsite measures to reduce detention time. Detention time can be reduced even below 10 hours by utilizing chemical treatment or flocculation or demonstrating to the regulatory authority that particle size, or specific gravity could warrant even a lower detention time. {8091} The new regulations ease to a considerable degree the burden upon coal operators to bring existing sedimentation ponds into compliance. The deadline for starting reconstruction has been extended and the reconstruction burden has been significantly lessened. Therefore, the Department has decided to maintain the November 4, 1978, compliance date for existing sedimentation ponds which cannot be in compliance by May 3, 1978. To allow adequate time for coal operators to submit schedules and statements of impossibility to regulatory authorities, the Department has extended the filing deadline for sedimentation ponds from March 1, 1978, to May 3, 1978. In addition, the filing deadline has been extended to May 3, 1978, for other pre-existing, non-conforming structures which are related to the redesign of sedimentation ponds. Related structures or facilities are those which an engineer must necessarily redesign as a result of the new sedimentation pond standard. Reconstruction must be initiated on such existing structures on or before June 3, 1978. Additional approval responsibilities have been added to assure that no schedules extend beyond November 4, 1978. The Department has decided to make these rules effective upon publication to provide immediate guidance to State regulatory agencies and coal operators. In this way, State regulatory agencies can issue new permits incorporating these requirements and immediately approve applications to reconstruct existing sedimentation ponds. In addition, the Department believes that it is essential to assure timely compliance with section 502 of the Act. It is emphasized, however, that the Department intends to hold at least one public hearing on the interim final rules, obtain necessary concurrences and consider public comments before making the rule final. This interim final rulemaking also includes a modification to the regulation governing temporary diversion structures. Additional State and industry comments received after promulgation of the final rules on December 13, 1977, have demonstrated that under the prior rules, construction of temporary diversions to safely pass a peak runoff from a precipitation event with a 10-year recurrence interval could result in disturbing an area in excess of the effective control provided by such structures. Therefore, the Department has reduced the design criteria to require the structure to safely pass the peak runoff from a precipitation event with a one-year recurrence interval. The Department has added an additional design criterion to adequately protect the public and the environment during the existence of temporary diversion structures. In addition, in response to comments requesting clarification, the Department emphasizes that small depressions allowed by Sec. 715.14(d) are not considered as temporary or permanent diversions under Sec. 715.17(c)(1) and (2). Temporary or permanent diversions are those structures which divert water away from disturbed areas. Thus, upon approval of the regulatory authority, coal operators may leave small depressions, small ditches and swales which act to diffuse water or reduce water velocity as part of erosion control practices. Statutory authority for interim final rules is contained in Sections 201(c)(2), 501 and 502 of the Act and 5 U.S.C. Sec. 553. The Department intends to entertain comments for a thirty-day period following publication of these interim final rules in the FEDERAL REGISTER. In addition, it will shortly announce the place and time of public hearings on these interim final rules. The Department of the Interior has determined that this document does not contain a major proposal requiring preparation of an Economic Impact Statement under Executive Order 11821 and OMB Circular A-107. In accordance with the Surface Mining Control and Reclamation Act of 1977, Pub.L. 95-87 and 5 U.S.C. Sec. 553, a public hearing will be held at the Department of the Interior Auditorium, 18th and C Streets NW., Washington, D.C. 20240 on March 15, 1978 at 9:30 a.m. The purpose of the hearing is to allow full public participation in the rulemaking process. Individuals making oral statements or submitting written comments should limit their statements to these interim final rules. Individuals are encouraged to submit statements in writing. Individuals making oral statements are limited to 10 minutes. Further information and reservation of time for oral statements may be obtained by contacting Walter N. Heine, Director, Office of Surface Mining Reclamation and Enforcement, Department of the Interior, Washington, D.C. 20240, 202-343-4237. DRAFTING INFORMATION Principal authors of these regulations are Ronald D. Hill, Environmental Protection Agency, Cincinnati, Ohio; Walter N. Heine, Director, Office of Surface Mining Reclamation and Enforcement; and Donald Crane, Consultant to the Office of Surface Mining Reclamation and Enforcement, Denver, Colo. Dated: February 22, 1978. JOAN M. DAVENPORT, Assistant Secretary Energy and Minerals. Energy and Minerals. Chapter VII of Title 30 of the Code of Federal Regulations is amended as follows: Parts 710, 715, 717 [Amended]. PART 710 - INITIAL REGULATORY PROGRAM In 30 CFR Sec. 710.11, paragraph (d) is revised to read as follows: Sec. 710.11 Applicability. (d) * * * (3) Notwithstanding paragraph (d)(2) of this section, any sedimentation pond, or related pre-existing, nonconforming structure or facility which is used in connection with or to facilitate mining after the effective date of these regulations shall comply with the requirements of the regulations unless - (i) The permittee submits to the regulatory authority and to the Director by May 3, 1978, a statement in writing demonstrating that it is physically impossible to bring the structure or facility into compliance by May 3, 1978. The statement shall include the steps to be taken to reconstruct the structure or facility in conformance with applicable performance standards and a schedule for reconstruction including the estimated date of completion; (ii) The regulatory authority finds in writing that it is physically impossible to bring the structure or facility into compliance by May 3, 1978; (iii) The construction work is to be performed in accordance with plans designed by a professional engineer; (iv) The construction work is to be started and completed as soon as possible and in no event is to be started later than June 3, 1978 and completed later than November 4, 1978; and (v) The Director approves of any schedules which contain an estimated date of completion beyond October 3, 1978. (4) The Director shall be deemed to have approved such schedules referred to in paragraph (d)(3)(v) of this section, unless written disapproval is received by the operator on or before June 3, 1978. PART 715 - GENERAL PERFORMANCE STANDARDS In 30 CFR Sec. 715.17, paragraph (c)(1) is revised to read as follows: Sec. 715.17 [Amended] (c) * * * (1) Temporary diversion structures shall be constructed to safely pass the peak runoff from a precipitation event with a one year recurrence interval, or a larger event as specified by the regulatory authority. The design criteria must assure adequate protection of the environment and public during the existence of the temporary diversion structure. {8092} Section 715.17 is further amended as follows: 1. Paragraphs (e), (e)(1), and (e)(2) are revised. 2. Paragraphs (e)(3)-(e)(9) are redesignated as (e)(4)-(e)(10) and a new paragraph (e)(3) is added. (e) Sediment control measures. Appropriate sediment control measures shall be designed, constructed, and maintained to prevent additional contributions of sediment to streamflow or to runoff outside the permit area to the extent possible, using the best technology currently available. (1) Sediment control measures include practices carried out within and adjacent to the disturbed area. The scale of downstream practices shall reflect the degree to which successful techniques are applied at the sources of the sediment. Sediment control measures consist of the utilization of proper mining, reclamation methods, and sediment control practices (singly or in combination) including but not limited to: (i) Disturbing the smallest practicable area at any one time during the mining operation through progressive backfilling, grading and timely revegetation; (ii) Consistent with the requirements of Sec. 715.14 and Sec. 715.15 shaping the backfill material to promote a reduction of the rate and volume of runoff; (iii) Retention of sediment within the pit and disturbed area; (iv) Diversion of overland and channelized flow from undisturbed areas around or in protected crossings through the disturbed area; (v) Utilization of straw dikes, riprap, check dams, mulches, vegetative sediment filters, dugout ponds, and other measures that reduce overland flow velocity, reduce runoff volume or entrap sediment; (vi) Sedimentation ponds. (2) Sedimentation ponds may be used individually or in series, should be located as near as possible to the disturbed area and where possible out of major stream courses, and shall (either individually or in series) meet the following criteria: (i) Sedimentation ponds must provide 24-hour theoretical detention time for the inflow or runoff entering the ponds from a 10-year, 24-hour precipitation event. Runoff diverted, in accordance with paragraphs (c) and (d) of this section, away from the disturbed drainage areas need not be considered in sedimentation pond design. In determining the runoff volume the characteristics of the mine site, reclamation procedures, and on-site sediment control practices shall be considered. (ii) Upon approval of the regulatory authority theoretical detention time may be reduced to not less than 10 hours, as demonstrated by the permittee, equal to the improvement in sedimentation removal efficiency as a result of pond design including but not limited to pond configuration, inflow outflow facilities and their relative location, baffles to decrease inflow velocity and short circuiting, a surface area sufficient to achieve the sediment trap efficiency necessary to meet effluent limitations (Sec. 715.17(a)), and sediment control measures provided in Sec. 715.17(e)(1). (iii) The regulatory authority may approve a detention time less than the time required by paragraph (e)(2)(i) or (ii) of this section, when the permittee has demonstrated that the size distribution or the specific gravity of the suspended matter or the utilization of chemical treatment or flocculation are such that the effluent limitations can be met. The detention time shall be stipulated. (3) An additional sediment storage volume must be provided equal to 0.2 acre-feet for each acre of disturbed area within the upstream drainage area. Upon approval of the regulatory authority, the sediment storage volume may be reduced in an amount, as demonstrated by the permittee, equal to the sediment removed by other appropriate sediment control measures such as those identified in paragraph (e)(1) of this section, or by lesser sediment yields as evidenced by empirical data for runoff characteristics. Redesignated paragraph (e)(6) is revised to read as follows: (e) * * * (6) Sediment shall be removed from sedimentation ponds so as to assure maximum sediment removal efficiency and attainment and maintenance of effluent limitations. Sediment removal shall be done in a manner that minimizes adverse effects on surface waters due to its chemical and physical characteristics, on infiltration, on vegetation, and on surface and ground water quality. Sediment that has been removed from sedimentation ponds and that meets the requirements for topsoil may be redistributed over graded areas in accordance with Sec. 715.16. PART 717 - UNDERGROUND MINING GENERAL PERFORMANCE STANDARDS Sec. 717.17 [Amended] In 30 CFR Sec. 717.17, paragraph (c)(1) is revised to read as follows: (c) * * * (1) Temporary diversion structures shall be constructed to safely pass the peak runoff from a precipitation event with a one year recurrence interval, or a larger event as specified by the regulatory authority. The design criteria must assure adequate protection of the environment and public during the existence of the temporary diversion structure. Paragraph (e) of Sec. 717.7 is amended as follows: 1.Subparagraphs (1) and (2) are revised. 2. Subparagraphs (e)(3)-(e)(9) are redesignated as (e)(4)-(e)(10), and a new paragraph (e)(3) is added. (e) Sediment control measures. Appropriate sediment control measures shall be designed, constructed, and maintained to prevent additional contributions of sediment to streamflow or to runoff outside the permit area to the extent possible, using the best technology currently available. (1) Sediment control measures include practices carried out within and adjacent to the disturbed area. The scale of downstream practices shall reflect the degree to which successful techniques are applied at the sources of the sediment. Sediment control measures consist of the utilization of proper mining, reclamation methods, and sediment control practices (singly or in combination) including but not limited to: (i) Disturbing the smallest practicable area at any one time during the mining operation through progressive backfilling, grading and timely revegetation; (ii) Consistent with the requirements of Sec. 715.14 and Sec. 715.15 of this chapter shaping the backfill material to promote a reduction of the rate and volume of runoff; (iii) Retention of sediment within the pit and disturbed area; (iv) Diversion of overland and channelized flow from undisturbed areas around or in protected crossings through the disturbed area; (v) Utilization of straw dikes, riprap, check dams, mulches, vegetative sediment filters, dugout ponds, and other measures that reduce overland flow velocity, reduce runoff volume or entrap sediment; {8093} (vi) Sedimentation ponds. (2) Sedimentation ponds may be used individually or in series, should be located as near as possible to the disturbed area and where possible out of major stream courses, and shall (either individually or in series) meet the following criteria: (i) Sedimentation ponds must provide 24 hour theoretical detention time for the inflow or runoff entering the (ponds) from a 10 year, 24-hour precipitation event. Runoff diverted, in accordance with paragraphs (c) and (d) of this section, away from the disturbed drainage areas need not be considered in sedimentation pond design. In determining the runoff volume the characteristics of the mine site, reclamation procedures, and on-site sediment control practices shall be considered. (ii) Upon approval of the regulatory authority theoretical detention time may be reduced to not less than 10 hours, as demonstrated by the permittee, equal to the improvement in sedimentation removal efficiency as a result of pond design including but not limited to pond configuration, inflow outflow facilities and their relative location, baffles to decrease inflow velocity and short circuiting, a surface area sufficient to achieve the sediment trap efficiency necessary to meet effluent limitations (Sec. 715.17(a)), and sediment control measures provided in Sec. 715.17(e)(1). (iii) The regulatory authority may approve a detention time less than the time required by paragraph (e)(2)(i) or (ii) of this section, when the permittee has demonstrated that the size distribution or the specific gravity of the suspended matter or the utilization of chemical treatment or flocculation are such that the effluent limitations can be met. The detention time shall be stipulated. (3) An additional sediment storage volume must be provided equal to 0.2 acre-feet for each acre of disturbed area within the upstream drainage area. Upon approval of the regulatory authority, the sediment storage volume may be reduced in an amount, as demonstrated by the permittee, equal to the sediment removed by other appropriate sediment control measures such as those identified in paragraph (e)(1) of this section, or by lesser sediment yields as evidenced by empirical data for runoff characteristics. In 30 CFR 717.17(e), redesignated subparagraph (6) is revised to read as follows: (6) Sediment shall be removed from sedimentation ponds so as to assure maximum sediment removal efficiency and attainment and maintenance of effluent limitations. Sediment shall be disposed of in a manner that minimizes adverse effects on surface waters due to its chemical and physical characteristics, on infiltration, or surface or ground water quality. [FR Doc. 78-5309 Filed 2-24-78; 11:34 am]