FEDERAL REGISTER: 48 FR 9788 (March 8, 1983)

DEPARTMENT OF THE INTERIOR

AGENCY: Office of Surface Mining Reclamation and Enforcement (OSM)

30 CFR Parts 715, 780, 816, and 817

Surface Coal Mining and Reclamation Operations; Initial and Permanent Regulatory Programs; Use of Explosives

ACTION: Final rule. 

SUMMARY: The Office of Surface Mining Reclamation and Enforcement (OSM) is amending its rules governing the 

use of explosives. The rules revise the requirements relating to blasting standards, preblasting surveys, airblast, ground 

vibration and flyrock, monitoring of blasts, and blast design. Final rules are adopted for the initial regulatory program, 

and the permanent regulatory program. The rules govern the blasts associated with surface and underground mines. The 

effect of the rule is to provide increased flexibility to design professionals to meet the regulatory performance standards 

contained in this rule. 

EFFECTIVE DATE: April 7, 1983. 

FOR FURTHER INFORMATION CONTACT: Arthur Anderson, Office of Surface Mining, U.S. Department of the 

Interior, 1951 Constitution Ave., NW., Washington, DC 20240; 202-343-5954. 

SUPPLEMENTARY INFORMATION: 

I. Background. 

II. Discussion of Rules Adopted and Responses to Comments. 

III. Procedural Matters. 

 

I. BACKGROUND. 

 The Surface Mining Control and Reclamation Act of 1977, 30 U.S.C. 1201 et seq. (the Act), sets forth initial 

regulatory procedures, permit requirements, and performance standards in Sections 502(c), 507(g), and 515(b)(15), 

respectively, governing the use of explosives in surface coal mining operations. Section 516 provides performance 

standards governing the surface effects of underground mining. Rules implementing those sections were published by 

OSM at 42 FR 62639 (December 13, 1977) under the initial regulatory program (30 CFR 715.19) and at 44 FR 14901

(March 13, 1979) under the permanent regulatory program (30 CFR 780.13, 816.11, 816.61-816.68, 817.11, and 

817.61-817.68). 

 In litigation over the initial program rules, the U.S. Court of Appeals for the District of Columbia issued a decision on 

May 2, 1980. In re: Surface Mining Regulation Litigation, 627 F. 2d 1346 (D.C. Cir. 1980). That decision addressed 

two blasting issues: (1) The 1,000-foot limitation on blasting near houses, schools, and other buildings in Section

715.19(e)(1)(vii), and (2) the 1.0-inch-per-second limitation on particle velocity produced by blasting in Section

715.19(e)(2)(ii). The court ruled that the 1,000-foot limit was not authorized by Sections 522(e) (4) and (5) of the Act 

and that the 1.0-inch-per-second vibration limit was arbitrary and capricious because it lacked technical support. 

 On May 16, 1980, in litigation over the permanent program rules, the U.S. District Court for the District of Columbia 

remanded the 1,000-foot limitation on blasting in Section 816.65(f). In re: Permanent Surface Mining Regulation 

Litigation, No. 79-1144 (D.D.C. May 16. 1980). The court did not invalidate the 1.0-inch-per-second vibration 

limitation, but at footnote 19 in its opinion the court recognized that the court of appeals had invalidated a similar 

provision in Section 715.19(e)(2)(ii) in the initial program rules. To implement the court's decision, Sections 816.65(f) 

and 817.65(f) were suspended by notice at 45 FR 51549 (August 4, 1980). 

 In response to these decisions, amendments to the blasting rules were proposed at 46 FR 6982 (January 22, 1981). 

These proposed rules were later withdrawn, by notice at 46 FR 32455 (June 23, 1981) to allow OSM to undertake a 

more general review of all the blasting rules under the permanent regulatory program. On March 24, 1982, OSM 

proposed to amend many of the rules governing the use of explosives under the initial and permanent regulatory 

programs (47 FR 12760). 
 OSM today adopts many of the rules proposed on March 24, 1982. Final rules are adopted with regard to the use of 

explosives under the initial regulatory program ( Section 715.19). Final rules are also adopted under the permanent 

regulatory program for surface ( Sections 816.11 and 816.61-816.68) and underground ( Sections 817.11 and 

817.61-817.68) mines and with regard to blasting plans ( Section 780.13) for surface mines. 

 

II. DISCUSSION OF RULES ADOPTED AND RESPONSES TO COMMENTS 

 OSM received numerous comments on the proposed rules. Although public hearings were scheduled to be held in 

Washington, D.C.; Pittsburgh, Pa.; and Denver, Colo., no one requested the opportunity to speak at any of these 

hearings; therefore they were not held. Two requests for public meetings were filed. Meetings were held on June 9, 1982, 

in Washington, D.C., and on May 4, 1982, in Indianapolis, Ind. 

 Summaries of each of those meetings have been included in the Administrative Record. 

 The rules adopted today place increased responsibility on design professionals, such as certified blasters and blast 

vibration experts, in establishing the design standards to meet the regulatory performance standards contained herein. 

Those operators staying within the approved limits, complying with approved performance standards, and maintaining a 

responsible relationship with surrounding residents will be able to operate without additional constraint. 

 Technical References. In promulgating the previous permanent program rules governing blasting, OSM analyzed the 

technical references which were available through the fall of 1978. Those materials are listed at 44 FR 15179. OSM 

relied upon those references, as well as the following additional and, in some cases, more recent technical documents in 

the development of these revised rules: 

 Bollinger, G. A., 1971, Blast vibration analysis: Southern Illinois University Press, Carbondale and Edwardsville, 132 

pp. 

 Braile, L. W., Sexton, J. L., Martindale, K. W., and Chiang, C. S., 1982, Seismic wave generation and preparation 

from coal mine blasts at the Wright mine, Warrick County, Indiana: Prepared by Department of Geosciences and Center 

for Earthquake Engineering and Ground Motion Studies, Purdue University, for U.S. Office of Surface Mining under 

contract J6211205, 344 pp. 

 Hemphill, Gary B., 1981, Blasting operations: McGraw-Hill Book Co., New York City, 258 pp. 

 Medearis, Kenneth, 1976, The development of rational damage criteria for low-rise structures subjected to blasting 

vibrations: National Crushed Stone Association, Washington, D.C., 94 pp. 

 Roth, Julius, Britton, K. C., Campbell, R. W., Ketler, W. R., 1977, Evaluation of surface Mining blasting procedures: 

Prepared by Management Science Associates for U.S. Bureau of Mines under contract J0366017, 152 pp. 

 Siskind, D. E., Stachura, V. J., Stagg, M. S., and Kopp, J. W., 1980, Structure response and damage produced by 

airblast from surface mining: U.S. Bureau of Mines Report of Investigations RI8485, 11 pp. 

 Siskind, D. E., Stagg, M. S., Stachura, V. J., 1979, Safe ground vibration and airblast criteria: 51st Annual Meeting, 

Eastern Section Seismological Society of America, October 1979, Blacksburg, Va. 

 Siskind, D. E., Stagg, M. S., Kopp, J. W., Dowding, C. H., 1980, Structure response and damage produced by 

ground vibration from surface mine blasting: U.S. Bureau of Mines Report of Investigations RI8507, 74 pp. 

 Stachura, V. J., Siskind, D. E., and Engler, A. J., 1981, Airblast instrumentation and measurement techniques for 

surface mine blasting: U.S. Bureau of Mines Report of Investigations RI8508, 53 pp. 

 Stagg, M. S., and Engler, A. J., 1980, Measurement of blast-induced ground vibration and seismograph calibration: 

U.S. Bureau of Mines Report of Investigations RI8506, 62 pp. 

 Swedish Detonic Research Foundation, 1978, Annual Report 1978: 14 pp. 
 U.S. Bureau of Mines, 1971, Blasting vibrations and their effects on structures: Bulletin 656, 105 pp. 

 

SECTION 715.19 

 OSM proposed three options for amending 30 CFR 715.19(e)(2), which contains those parts of the initial regulatory 

program governing ground vibration. OSM is adopting a hybrid of the three options. 

 Comments on these three options and the ground vibration rule adopted today are discussed later in this rulemaking in 

conjunction with the rules adopted at Section 816.67(d). 

 In its proposed rule OSM neglected to propose a rule comparable to previous Section 715.19(e)(2)(iii), which made 

the maximum peak-particle-velocity standard inapplicable to property inside the permit area owned or leased by the 

permittee. In order to correct this oversight, OSM is adopting a new rule at Section 715.19(e)(2)(iii), which provides the 

same exemption as found in the new permanent program rules under Section 816.67(e). Previous Section 715.19(e)(3)

has also been removed and incorporated into Section 715.19(e)(2), and previous paragraph (e)(4) has been redesignated 

as paragraph (e)(3). 

 One commenter suggested that the rules governing flyrock proposed on March 24, 1982, at Sections 816.67(c) and 

817.67(c) should be adopted under the initial regulatory program at Part 715 as well. The commenter pointed out that 

flyrock should be regulated under the initial regulatory program as well as under the permanent regulatory program. 

OSM declines to adopt such a change for several reasons. First, OSM believes that flyrock is already regulated by 

Section 715.19(e)(2)(i). Second, the initial regulatory program is of such limited applicability at this time that OSM 

expects that such a rule would be of limited value. If a compelling reason for such a rule becomes evident, OSM may, at 

a later date, determine that it would be useful to propose an initial regulatory program flyrock rule. 

 

SECTION 780.13 

 Blasting plans outline the procedures the operator intends to follow in conducting blasting operations. Section 780.13 

of 30 CFR requires each application for a permit for a surface coal mine to have a blasting plan, sets standards for 

blasting plans, and details the information which is to be submitted along with the permit application. 

 Section 780.13(a) requires the operator to demonstrate in the blasting plan that the operator will achieve the 

applicable performance standards. In the blasting plan the operator will explain how the performance standards set out in 

Sections 816.61-816.68 will be achieved. The plan will include information setting the applicable ground vibration and 

airblast limits and justifying the use of these limits. These limits are discussed more fully in the preamble in relation to 

Section 816.67. The plan must also discuss steps to be taken to control the adverse effects of blasting operations. 

 Some commenters believed that the blasting plan requires excessive detail in descriptions of limits to be met in 

protecting structures and the public from damage. Section 507(g) of the Act mandates that an applicant outline in the 

application the procedures and standards to be used to meet the environmental protection performance standards of 

Section 515(b)(15) of the Act. Therefore OSM believes the requirement for explanations of the applicable ground 

vibration and airblast levels is justified. 

 A commenter requested clarification of the information and explanations required in a blasting plan and suggested that 

OSM should require identification of sensitive areas, and "worst case scenarios." The intent of these rules is to provide 

nationwide requirements for blasting plans as required by the Act. OSM does not believe that it is necessary specifically 

to require identification of sensitive areas and worst case scenarios in the blasting plan. The blasting plan must be 

sufficient in any case to demonstrate compliance with the applicable performance standards and the blasting plan may 

include such information as appropriate. Additionally, this information may be required under a State program in every 

case if deemed appropriate by the State regulatory authority. The commenter also felt that an explanation of how the 

applicant will meet the performance standards should be required. Such an explanation is required by the last sentence of 

Section 780.13(a). 

 A commenter objected to the fact that no blasting plan is required for underground operations. Because of the 

generally limited extent of surface blasting associated with the underground mining, OSM does not believe it is necessary 
to require a blasting plan for underground operations. OSM's existing rules do not require blasting plans for underground 

mines nor has OSM proposed to require such plans. Accordingly, no requirement for an underground mining blasting 

plan is adopted today. However, the rules adopted today do require the submission of some information (specifically 

blast designs) prior to certain surface blasts incidental to underground mining. See the discussion accompanying Section

817.61(d). 

 A commenter recommended that OSM require the inclusion in the blasting plan of details such as: (1) The names of 

certified blasters who will be supervising blasting, (2) lists of structures near blast sites, and (3) a copy of the blasting

schedule in the blasting plan. OSM acknowledges that this information could be useful in some instances, but believes 

that this information is not always necessary to decide whether to issue a permit. In any event, this information will 

become available prior to blasting. (See Sections 816.61, 817.61, 816.68 and 817.68 for information on certified blasters 

and lists of structures; Sections 816.64 and 817.64, on blasting schedules; and Section 779.24(d), on location of buildings 

and identification of their current use.) Moreover, regulatory authorities who desire additional information incidental to 

permitting may require it. 

 Commenters indicated concern about the lack of a requirement in Section 780.13(a) for a certified blast design in all 

blasting plans and the identification of a certified blaster who is in charge of all blast plans. As to the latter comment, a 

certified blaster is required for all blasting operations. Identification of a specific certified blaster in the blasting plan 

would not influence the regulatory authority's decision to issue a permit and would unnecessarily reduce operator 

flexibility. 

 OSM rejects the suggestion that a certified blast design be required in all blasting plans. Such detail is unnecessary to 

assure safe blasting and is unnecessary for the regulatory authority to determine that the blasting will be conducted in 

accordance with the performance standards. It would be difficult or impossible to require and review blast design for 

every blast which will occur. Some conditions are unknown at the time of permitting, and operators need flexibility to 

design blasts for conditions as they are encountered. Absence of a certified blast design in the blasting plan will not allow

unrestricted blasting. The blasting plan must show the general approach to all blasts and how all performance standards 

set out in Sections 816.67 and 817.67 will be met. In addition, for some sensitive areas more complete analyses, 

including blast designs, must be submitted as required by new Section 816.61(d). 

 Comments were received regarding OSM's proposed change to allow for blasting plan submissions at a time other 

than permit application. Commenters were concerned that this would limit the opportunity to comment on blasting plans. 

No such result is intended. As discussed below, OSM intends to allow later submission of certain blast designs, but these 

will not be considered to be part of the blasting plan. Although regulatory authorities could receive comments on blast 

designs, the purpose of having blast designs is largely served by their advance preparation and submission to the 

regulatory authority. Such submissions increase operator accountability and demonstrate compliance with performance 

standards. As indicated above, OSM does not believe that submission of detailed designs is necessary in the permit 

application to assure safe blasting in accordance with the performance standards. 

 Section 780.13(b), which has been adopted as proposed, provides that each application must contain a description of

any system to be used to monitor compliance with the standards of Section 816.67, including the type, capability, and 

sensitivity of any blast monitoring equipment and proposed procedures and locations of monitoring. 

 One commenter objected to listing capability and sensitivity of blast monitoring equipment in the description of the 

monitoring system to be used. OSM believes that this is important in assessing control of adverse effects, since the 

degree of sophistication and complexity of instruments may result in additional data by which to evaluate the damage 

potential. Seismographs can vary in type, capabilities, complexity of data records, and analytical ability. Therefore, the 

monitoring system used, including capabilities and sensitivities, may assist the regulatory authority in setting allowable 

limits for each blasting plan. For instance, operators using instruments with sensitivity to low frequency airblast 

(concussion) could be given different airblast limits than operators using less sensitive equipment. This could occur 

because one instrument's range will include more sound levels, whereas a less sensitive instrument might ignore some low 

frequency noise. It is also important for the regulatory authority to know the type and sensitivity of equipment in order to 

evaluate the information it receives. 

 Commenters objected to the proposed deletion (from OSM's previous rules) of the requirement that an operator 

specify the procedures by which an operator will meet recordkeeping requirements. OSM proposed to delete the list of 
data from Section 780.13(b) because that data is required by Section 816.68. OSM believes that the recordkeeping 

procedures set out in Sections 816.68 and 817.68 are sufficient to ensure that the records are complete and adequately 

kept. A further requirement that the operator indicate how the operator intends to keep such records would be 

unnecessarily repetitive. The rule adopted today, at Section 780.13(a), continues to require an explanation of how the 

operator intends to comply with Section 816.68. All that has been removed is the specific list of information the blasting 

plan must include. Therefore, Section 507(g) is satisfied without regulatory redundancy. False or inaccurate recording of 

information will be handled through enforcement of Section 816.68 or Section 817.68. Commenters raised questions 

about the ability of blasters to keep records without an adequate knowledge of terms. Knowledge of terms and the ability 

to keep records would be evaluated in the context of training, examination, and certification of blasters. (This is governed 

by 30 CFR Chapter VII, Subchapter M.) For permitting purposes, it should be sufficient to show that blasts will be 

conducted under the direction of certified blasters. Accordingly, OSM adopts no rule in Part 780 requiring operators to 

demonstrate a knowledge of blasting terminology prior to permitting. However, such a demonstration can be included as 

a facet of the certification program. 

 Commenters objected to deletion of previous Section 780.13(f) requiring that the operator define what specific 

conditions might require deviations from blasting schedules. Control of all blasts should be under the cognizance of 

certified blasters who will be trained in recognizing and handling hazardous conditions. Trying to anticipate all potentially 

hazardous situations is nearly impossible since many may not occur or be discovered until after mining commences. 

Furthermore, variation of potentially dangerous conditions may warrant alternative action to that specified in a permit 

application. 

 Other commenters suggested that the description of the monitoring system required by proposed Section 780.13(b) be 

optional or be submitted only if required by the regulatory authority. In proposing that portion of the rule OSM intended 

to leave discretion available to the regulatory authority under Sections 816.67(d) (1), (2), and (4) as to whether 

monitoring systems will be used or if an equation could be used instead. OSM did not intend to require monitoring of all 

blasts nor monitoring where none would be needed. 

 OSM has slightly reworded the final rule in Sections 816.67(d) and 817.67(d), adopting the suggestion offered by one 

of the commenters so as to avoid the appearance that monitoring is mandatory in all cases. (No seismic monitoring is 

required if ground vibration limits are set using the scale-distance equation of Section 816.67(d)(3) and 817.67(d)(3).) 

However, if a monitoring system will be used, the permit application must contain its description. 

 OSM's proposed language at Section 780.13(c) required additional information on blasts to be conducted within 1,000 

feet of certain structures or 500 feet of underground mines. Several commenters objected to inclusion of regulatory 

provisions which limit blasting within 1,000 feet of certain structures and 500 feet of underground mines. OSM believes 

that such provisions are necessary and that ensuring proper blast design is important in these sensitive areas. If properly 

implemented, blast design will prevent damage to structures or underground mines. In addition, requiring blasting 

operations within 500 feet of active underground mines to be approved by both the regulatory authorities concerned with 

surface mining regulations and with the health and safety of underground miners will help guard against potential hazards 

of such blasting to underground miners. 

 A commenter recommended limiting the applicability of the 500-foot provision from underground mines to active 

mines, excluding abandoned workings. OSM has accepted this comment with respect to the joint approval requirements 

included in revised Section 780.13(c). The language of the proposed rule has been revised to require the approval of the 

State and Federal regulatory authorities for health and safety of mines. Other mine safety and health agencies as well as 

MSHA may be involved since many States have counterpart agencies with responsibility for health and safety of mines. 

The language adopted tracks the requirement set forth in Section 515(b)(12)(A) of the Act. There are no specific 

underground mining activities associated with abandoned underground mines that must be coordinated with surface 

mining activities. If an abandoned underground mine becomes active, the requirement for joint approval of the blasting 

would immediately become effective. This change does not preclude MSHA involvement, but provides for joint 

approvals by all agencies involved. OSM does not agree with the commenter with respect to limiting the submission of 

blast designs to active underground operations. This comment is further discussed below under Section 816.61(d). 

 Blast design need not be part of the permitting requirements; therefore the requirement of blast designs has been 

moved into the performance standards section. These designs require a great deal of factual information which may not 

be developed until mining approaches these critical areas. Accordingly, while OSM has decided to adopt these blast 
design requirements, they will be included in the performance standards for blasting, rather than permitting. These rules 

and comments thereto are discussed below at Sections 816.61 and 817.61. OSM also hopes that this restructuring of the 

rule will eliminate any concern with respect to the performance standards and the unsuitability criteria of Section 522 of 

the Act. The provision for blast designs when blasting close to certain structures or underground mines is not a 

prohibition of mining, as previously found invalid by In re: Permanent Surface Mining Regulation Litigation, supra.

Rather it is a requirement imposing additional standards where the greatest potential hazards exist. The requirement for 

additional compliance data when blasting within these limits is based on Sections 515(b)(12), 515(b)(15) and 516 of the 

Act (See also Roth and others, 1977). 

 Also in the above case, industry challenged OSM's authority to issue regulations governing blasting. OSM believes 

that it has such authority based upon the reasoning set forth in its brief to the U.S. Court of Appeals for the District of 

Columbia in the above case. 

SECTION 816.11 - SIGNS AND MARKERS. 

 OSM proposed to delete the requirements of Section 816.11(f) relating to blasting signs because its provisions would 

be duplicative of those in proposed Sections 816.66 and 817.66 or duplicative of rules of the Mine Safety and Health 

Administration. OSM is adopting these changes as proposed. 

 Commenters objected to the deletion of Section 816.11(f) because, according to them, it was necessary to meet the 

requirements of Section 515(b)(15). OSM believes that the provision for flagging charged holes is chiefly designed to 

protect mine workers and it would be duplicative to require a second flagging provision in OSM's rules. The Mine Safety 

and Health Administration rules are adequate to protect mine workers and will also provide protection of other persons 

who may enter the property. Section 816.61(a) requires compliance with all applicable State and Federal rules, which 

include those set by MSHA at 30 CFR 77.1303(g). 

SECTION 816.61 - USE OF EXPLOSIVES: GENERAL REQUIREMENTS. 

 OSM proposed to change the phrase "person who conducts surface mining activities" to "operator" in this section 

and throughout the blasting rules. OSM received no negative comments on this change. Accordingly, the change has 

been adopted as proposed. 

 

SECTION 816.61(a) 

 Section 816.61(a) requires operators to comply with all State and Federal laws governing the use of explosives. One 

commenter indicated that proposed Section 816.61(a) gave the regulatory authority power to enforce laws and 

regulations beyond those authorized by the Act. Section 515(b)(15) requires that general performance standards ensure 

that explosives are used in compliance with existing State and Federal law. In addition, provisions of Section 

515(b)(15)(A) through (E) authorize requirements that are supplemental to existing law. Thus, OSM has the authority 

under the Act to require compliance with other State or Federal laws regarding the use of explosives in conjunction with 

any applicable regulations implementing those laws. This is not a change from OSM's existing rule or its existing 

authority. 

 

SECTION 816.61(b) 

 OSM proposed no change to Section 816.61(b). That section, which requires a schedule for blasts that use more than 

5 pounds of explosives, is adopted without change. The blasting schedule requirements are discussed below at Section

816.64. 

 

SECTION 816.61(c) 

 OSM proposed in Section 816.61(c) to retain the requirement that a blaster certified under Subchapter M of 30 CFR 

Chapter VII be responsible for all blasting operations. Among those activities cited both in existing Section 816.61(c) and 

in the proposed rule were transportation, storage, and destruction of explosives within the permit area. Commenters 

suggested deleting transportation, storage, and destruction of explosives from the identified activities. Section 515(b)(15) 

of the Act requires that explosives be used in accordance with existing State and Federal laws; OMS believes that this 
includes the transportation, storage, and destruction of explosives. This section was revised in the blaster certification 

rule which was issued together with this final rule. (See 48 FR 9486, March 4, 1983.) 

 

SECTION 816.61(d) 

 OSM proposed in Section 780.13(c) to require designs for blasts to be conducted within 1,000 feet of buildings used 

as public buildings, dwellings, schools, community or institutional buildings or within 500 feet of an underground mine, 

to be included in the permit application. As discussed above, OSM has determined that this information is more properly 

obtained in conjunction with the performance at individual blasting operations and is therefore adopted as part of the 

performance standards for blasting in new Section 816.61(d). Operators may continue to submit blast designs as part of 

the permit application, but may also do so at a later time prior to the blast as approved by the regulatory authority. 

 This new Section 816.61(d) requires that additional design information must be provided when blasting will be 

conducted within 1,000 feet of any building used as a dwelling, public building, school, or community or institutional 

building or within 500 feet of an underground mine. Some commenters felt that the requirement that operators submit 

typical blast designs within 1,000 feet of buildings or 500 feet of underground mines was prohibited according to Judge 

Flannery's decision. In re: Permanent Surface Mining Regulation Litigation, supra. These commenters also felt that a 

typical design requirement would be unnecessary and is irrelevant. 

 OSM disagrees. As described above, Judge Flannery's decision struck down OSM's attempt to prohibit blasting within 

these areas. The rule adopted today does not prohibit blasting within 1,000 feet of buildings or 500 feet of underground 

mines. Rather it requires the operator to take extra steps in these areas to help ensure the prevention of damage. In this 

context, blast designs can be a useful tool. They assure adequate planning and, together with the required direction by a 

certified blaster, ensure proper implementation. They allow regulatory authority involvement if necessary and provide a 

record if problems should occur. 

 The rule requires that the operator submit information outlining specific precautions to be taken and criteria to be 

implemented. Sketches of drill patterns, delay periods, and decking and the type and amount of explosives to be used, 

critical dimensions, and the location and general description of structures to be protected will be submitted. Thus, where 

the damage potential is highest, the regulatory authority will have the greatest information to ensure adequate protection. 

 The 1,000-foot distance has been selected so that the operator is alerted that special precautions are necessary to 

prevent property damage and personal injury when conducting blasting operations within this distance. The blast design 

required when blasting within this area: (1) Provides a preblasting record of the blast design, (2) provides notification to 

the regulatory authority so that monitoring may be scheduled if appropriate, and (3) ensures that a certified blaster has 

developed a specific blast design for such blasting. The requirement that a certified blaster prepare and sign the design 

imposes on the blaster the responsibility for designing the blast in a responsible manner. It also assures that a competent 

professional has designed the blast. 

 A commenter recommended limiting the 500-foot provision from underground mines to active mines, excluding 

abandoned and collapsed workings. The blast design requirement provides for extra protection when blasting near 

underground mines and recognizes the sensitivity of all these structures in accordance with Section 515(b)(12) of the 

Act. 

 Other commenters suggested changing the proposed requirement for "specific" blast designs to "standard" or "typical" 

designs to indicate the acceptability of a typical engineering design solution rather than submitting a series of specific 

designs and later amending these based on site-specific conditions encountered. Although the words "standard" or 

"typical" are insufficient to tie the design to the specific blast, OSM believes that the intent of this section will be 

preserved by using the term "anticipated" rather than "specific." Using the term "anticipated" will allow operators the 

flexibility to change the designs based on unexpected conditions encountered at particular sites without having to 

resubmit the designs to the regulatory authority. To the extent a single design is intended to be used on more than one 

occasion, it need not be submitted more than once, although each blast for which it is used should be identified. 

 Some commenters believed that the blast design requirement would be duplicative of the record required by Section

816.68. OSM, however, believes that both are important; one is necessary for implementing the blast properly, and the 

other for postblast analysis. As in other professions, the use of a detailed design better ensures its completion. OSM 
recognizes that formal submission of written blast design is more stringent than other operating practices, but believes 

that appropriate additional protection will be afforded by such submissions, particularly when mining operations are 

conducted in residential or inhabited areas. 

 One commenter objected to the provision in proposed Section 780.13(c)(2), that a blast design may be submitted at 

some time after the initial permit application, because the public may not be afforded adequate participation. OSM 

believes that the blast design is best submitted at the time when an area is ready to be mined. The rule, adopted in Section

816.61(d)(2), allows the regulatory authority to specify a particular time for design submittal. The intent of the design is 

not primarily for public or regulatory review; rather it serves as a tool for the operator, blaster, and the blasting crew to

understand the blast layout and implementation and for the regulatory authority to be advised of the blast parameters and 

timing, to initiate monitoring, if appropriate, and to ensure compliance with performance standards. 

 Proposed Section 780.13(c)(5) would have allowed the regulatory authority to require a change in the blast design. 

This has been adopted in Section 816.61(d)(5). Some commenters stated that no benefit would result from regulatory 

authority revision of blast design. OSM recognizes that the certified blaster must retain primary design responsibility. 

However, the regulatory authority should have the authority to require changes in the design if it believes that required 

performance standards will not be met. 

 Commenters felt that proposed Section 780.13(c)(6), which required 30-day notice to property owners whose 

structures are within 1,000 feet of the blasting site, would conflict with Section 816.64(b) which requires similar notice 

via blasting schedules. OSM agrees and has chosen not to adopt the requirement proposed at Section 780.13(c)(6). 

SECTION 816.62 - USE OF EXPLOSIVES: PREBLASTING SURVEY. 

 

SECTION 816.62(a) 

 A number of commenters requested specific time frames for requesting and conducting preblasting surveys. OSM had 

originally proposed to have notification of the availability of preblasting surveys distributed with the blasting schedule. In 

response to the comments, a provision has been added as Section 816.62(a) which requires an operator, at least 30 days 

prior to the initiation of the blasting, to notify in writing residents within one-half mile of the permit area of the 

procedures for requesting a preblasting survey. This notice may be accompanied by a copy of the blasting schedule. The 

30-day notice requirement is set to give a resident sufficient time to request a survey and an operator adequate time 

within which to complete the survey. This change has been made because OSM agrees with those commenters who 

believed that it is feasible for preblasting surveys to begin earlier than blasting schedules are set. Preblasting surveys may 

be conducted independently of the actual blasting schedules. Furthermore, the earlier such surveys are requested and 

completed, the more flexibility the operator will have in scheduling blasts. 

 Several commenters requested that time limits be placed on preparation of preblasting surveys and for the filing of 

disagreements. The rules as adopted require operators to provide property owners or residents at least 30 days of notice 

for requesting blasting surveys, and to promptly complete the survey upon request. Section 816.62(e) has been added to 

clarify that for those surveys that have been requested at least 10 days prior to the scheduled initiation of blasting, 

completion of the survey is required prior to the initiation of blasting. If a survey is requested less than 10 days prior to 

the scheduled initiation of blasting, the operator should take all reasonable measures to complete the survey in a timely 

manner. Individual regulatory authorities may impose additional time limits if appropriate for the region or locale. OSM 

has declined to attach a time limit within which to file disagreements. Such a time limit would not necessarily serve the 

regulatory process. However, it should be recognized that disagreements which are filed promptly or prior to the start of 

blasting will be more likely to be satisfactorily resolved between the operator and resident than those filed long after the 

report has been completed and blasting has begun. 

 

SECTION 816.62(b) 

 Section 816.62(b) of the final rule allows the owner or resident of a manmade structure within one-half mile of the 

permit area to request the operator to provide a preblasting survey by writing directly to the operator or to the regulatory 

authority, who then will request the operator to conduct the survey. Although one commenter objected to this proposal, 

OSM believes it provides needed flexibility and could expedite the preblasting survey process. An operator is required to 

conduct the survey promptly and to promptly prepare the report. 
 Another commenter objected to the requirement for requesting surveys in writing, citing previous preambles as 

allowing verbal requests. Although the Act does not mandate written requests for a survey, it is the best method to 

provide control over the request and survey production process, without placing undue burdens on the regulatory 

authority manpower or on persons requesting surveys. Moreover, the written request will serve as a verification of the 

request and trigger action by the operator in timely conduct of the survey. 

 Updated surveys may be requested by the owner or resident at any time. If a structure is enlarged, renovated or 

modified after a survey is completed, an update to the preblasting survey must be performed if requested. 

 Other commenters believed that the second sentence of Paragraph (b) should be rewritten to clarify the roles of the 

requester, the operator, and the regulatory authority in requesting, initiating, and conducting preblasting surveys. OSM 

has accepted these comments and has edited the sentence slightly to help clarify its intent. 

 A commenter indicated the need to include owners of property such as pipelines, water wells, and utility towers in the 

list of those notified for preblasting surveys. OSM does not consider the language of the Act or the rules to limit the 

preblasting survey to residences or buildings. Section 515(b)(15)(E) of the Act refers to manmade structures and 

therefore includes any structure such as dams, utility stations, pipelines, etc. 

 Commenters suggested that the proposed system of preblasting surveys would not protect operators from false 

damage claims. As a solution they suggested operators should have the right to request preblasting surveys. The 

preblasting survey provisions of the Act only provide the owner or resident the opportunity to request preblasting 

surveys. If the operator wishes to conduct a survey, a specific request could be made to the owner of the particular 

structure. If concern of false claims persists where a property owner does not request or refuses to allow a preblasting 

survey to be conducted, the operator should ensure that the blasting is carefully monitored. 

 Commenters objected to the requirement of a preblasting survey within one-half mile of a "permit area" while other 

requirements, such as notification in proposed Section 816.64(b)(2), were keyed to the "blasting site." All blasting sites 

are contained within a permit area. Section 515(b)(15)(E) of the Act offers every resident or owner within one-half mile 

of any portion of the permit area the opportunity for a preblasting survey. Therefore, OSM has adopted the regulatory 

provisions which gives all owners and residents within one-half mile of the permit area the opportunity to receive a 

preblasting survey before blasting begins on any portion of the permit area. OSM believes that any other regulation 

would conflict with the language of the Act. 

 

SECTION 816.62(c) 

 Under Section 816.62(c) as adopted, preblasting surveys will address the condition of the structure and document any 

preblasting damage or structural defects. Assessments of structures such as pipelines, cables, transmission lines, and 

wells, cisterns, and other water systems will be required, but such assessments may be limited to surface conditions and 

other readily available data. The person conducting the survey must give special attention to such water systems and 

should document all available data and determine whether such additional analysis is appropriate, based upon the 

significance of the water system, its vulnerability, and the availability of data. 

 Commenters objected to OSM's proposal to require that special attention be given to water wells because recent 

studies have proven that blast vibrations have little effect on water quantity and quality. Other commenters believed that 

assessment of quality and quantity of water is essential in surveys involving wells. Such information is believed important 

for both the user and the operator, since hydrologic impacts can be caused both by mining and blasting. The degree of 

detail may be determined for each case by the regulatory authority, depending on the nature and amount of water or 

structures involved. Based on these comments the last sentences of Section 816.62(c) have been rewritten to clarify 

OSM's intent. 

 

SECTION 816.62(d) 

 Section 816.62(d), which was proposed as Section 816.62(c), requires the person completing the survey to sign it and 

provide a copy of the report to the regulatory authority and the person requesting the survey. This section also allows the 
person who requested the survey to note disagreement with the contents by submitting a written detailed description of 

the disagreement. 

 A commenter requested that the owner or resident sign the preblasting survey indicating concurrence. OSM declines 

to adopt such a requirement which it believes is unnecessary. OSM believes that allowing residents or property owners to 

file their disagreements is adequate. 

 OSM's proposed rules had specified that the original of the survey be provided to the regulatory authority. 

Commenters suggested that either a copy or the original be provided to the regulatory authority. OSM accepts this 

suggestion and has adopted appropriate regulatory language. 

 A commenter objected to the omission in the proposed rule of a mechanism to resolve disagreements in survey data. 

OSM declines to adopt this suggestion. OSM believes that the regulatory authority is responsible to insure that blasting 

surveys are complete and accurate. Further, the regulatory authority could direct that inadequate surveys be redone. 

However, OSM does not believe it necessary to require that any disputes be resolved by the regulatory authority, but 

only that the survey, including the description of disputed results, should serve as a record of the condition. It should be 

noted that the regulatory authority could take appropriate action to ensure that surveys are complete and if a serious 

potential danger exists could incorporate restrictions into the blasting plan and performance standards. 

SECTION 816.64 - USE OF EXPLOSIVES: BLASTING SCHEDULES. 

 The title of new Section 816.64 has been shortened to "Use of explosives: Blasting schedules" as was proposed. 

 

SECTION 816.64(a) 

 OSM has revised Section 816.64(a)(1) to clarify the fact that the regulatory authority may limit the timing of blasts, 

the area covered by a blasting schedule, and the sequence of blasting. The proposal only mentioned limitations pertaining 

to hours per day, times per day, or number of blasts per day. As adopted Section 816.64(a)(1) will allow blasting only at 

times approved by the regulatory authority and announced in the blasting schedule. The regulatory authority's decision 

restricting blasts must be justified on the basis of public health and safety or welfare. OSM has not adopted the proposed 

requirement that limitations on blasting be based on written submissions only. However, every determination must have 

an adequate basis. 

 OSM believes that prevention of excessive noise, especially in populated and residential areas, is within the ambit of 

"health and safety or welfare." Thus if noise from blasting will disrupt nearby residents, blasting may be limited to times 

which create the least discomfort. OSM believes that certain site-specific conditions, such as residential surroundings, 

may require prohibition of nighttime blasting. The final rule has been revised to require such prohibitions, if conditions 

warrant. 

 Several commenters objected to the proposed removal of regulations absolutely limiting the times of blasting 

(previous Sections 816.64(b)(2)(ii) and 816.65(a)) or the blasting area (previous Section 816.64(b)(2)(i)). The old rules 

set absolute limits on the number of hours per day, nighttime blasting, and the size of an area covered under one blasting 

schedule. OSM recognizes that such limits may be useful under some conditions. For this reason OSM has decided to 

retain the requirement that blasting be conducted between sunrise and sunset. That requirement is contained in Section

816.64(a)(2). The final rule provides flexibility to the regulatory authority to impose more restrictive time periods or to 

allow nighttime blasting based upon a showing by the operator that the public will be protected from adverse noise and 

other impacts. 

 OSM does not believe, however, that national limits on the size of the blasting area or number of hours of blasting per 

day are necessary. The final rule deletes the prior absolute constraints of 4-hour aggregate amount of blasting per day, 

and 300-acre maximum blasting areas. These standards presented limits which in some cases were arbitrary or too 

stringent for an operator to develop an effective schedule. Individual regulatory authorities may impose such restrictions 

or other more stringent limitations on a site-specific or statewide basis as appropriate. Restraints on the total time of 

blasting is more a function of planning. The blasting schedule is required, and adherence to the schedule is expected. The 

regulatory authority must review and approve the times for blasting in the blasting schedule. To make the schedule work, 

the operator must control production, loading, delivery, and other physical factors to meet his schedule. Where the 
regulatory authority determines that blasting should be limited, it should impose such limits. In the absence of such a 

determination, the operator must conform to the approved blasting schedule. 

 OSM had proposed to relax some restrictions governing unscheduled blasts. Commenters objected that the specific 

restrictions on unscheduled blasting were omitted. In some instances, such as unusual weather conditions or unavoidable 

delays, public or operator safety may dictate unscheduled detonations. Obviously, where public or operator safety so 

require, unscheduled blasting is appropriate. However, OSM has declined to adopt the portion of the proposal which 

would have allowed unscheduled blasts in nonemergency situations. Thus, while OSM recognizes that some blasting 

activities such as the construction of roads or the creation of faceups are nonperiodic, these nonemergency blasts should 

be planned, scheduled, and announced in advance in the blasting schedule. Thus, Section 816.64(a)(3) allows 

unscheduled blasts only in emergency situations. However, schedule changes for nonemergency blasts may be made 

between 10 and 30 days before blasting begins under Section 816.64(b)(3). 

 Because unscheduled blasts will only be conducted in emergency situations, OSM has adopted the requirement of 

notification of all residents within one-half mile of the blasting site when unscheduled blasts will occur by requiring that 

audible notification take place. This allows for more efficient notification of everyone within one-half mile, and such 

notification can be provided more quickly. Commenters expressed concern that in emergencies such as adverse 

unexpected weather conditions it might be impossible to notify all residents orally. Accordingly, in these situations, 

audible signals may be used. 

 Some commenters suggested adding a provision for the resolution of disputes with regulatory authorities regarding 

blasting schedules. 

 Apparently, the commenter was concerned with possible problems caused by disapproval of proposed blasting 

schedules. OSM believes that no such provision is necessary. In making the determination to restrict blasting, the 

regulatory authority must determine that such limits are reasonable and necessary in order to protect the public health and 

safety and welfare. OSM believes that standard is sufficiently objective to minimize disputes. 

 

SECTION 816.64(b) 

 OSM is adopting paragraph (b)(1) of Section 816.64 and most of paragraph (b)(2) as proposed. These require 

newspaper publication of the blasting schedule between 10 and 30 days before blasting is to begin and set the 

requirements for distribution of the blasting schedule to local governments, public utilities, and residences within one-half 

mile of the blasting site. The term "blasting site" here is the area formed by the perimeter of the blast holes. 

 One commenter felt that publication of a blasting schedule 10-30 days in advance would be too difficult. He suggested 

that production schedules could not be set that far in advance. OSM believes it is important for operators to undertake 

sufficient planning and preparation so that they know their schedule with sufficient certainty to allow publication of 

schedules well in advance. Accordingly, OSM has adopted the requirements as proposed. 

 OSM had proposed that information on how to obtain preblasting surveys should be provided when copies of the 

blasting schedule were distributed. OSM received comments that 10-30 days were insufficient to conduct preblasting 

surveys. Both operator and regulatory authority commenters felt that additional notification of the availability of preblast 

surveys should be provided. Accordingly, OSM has provided that notice of availability of preblasting surveys may be 

distributed separately from and earlier than the blasting schedule. As discussed earlier, preblasting survey information is 

required to be distributed according to Section 816.62(a). 

 Notification of blasting as required by Section 515(b)(15)(A) of the Act and by the regulations is provided by three 

methods: (1) Schedules published in newspapers, (2) schedules delivered to persons living within one-half mile of the 

blasting site, and (3) daily notification of blasts through audible signals to locations within at least one-half mile of the 

blasting site (required by Section 816.66(b)). 

 

SECTION 816.64(c) 

 Section 816.64(c), setting forth the blasting schedule contents, is adopted as proposed. As indicated above, the final 

rule removes the constraints of 4-hour aggregate per day, daylight-only blasting (upon approval of the regulatory 
authority), and 300-acre blasting areas. Such restrictions may be imposed by individual regulatory authorities under 

Section 816.64(a), as appropriate. 

 

SECTION 816.65 

 As proposed, OSM has deleted previous Section 816.65 and recodified its requirements as follows: 

 The requirements contained in previous Section 816.65 (a) and (b), which set forth limitations on the hours and times 

of blasting, are adopted in amended form in Section 816.64(a), which is discussed above. The requirements contained in 

previous Section 816.65(c), pertaining to audible signals, are adopted in an amended form in Section 816.66. OSM has 

deleted the requirement of periodic notification of meanings of warnings and all-clear signals. Those notifications are 

adequately provided through blasting signs and the blasting schedule. 

 Previous Section 816.65(d), limiting access to blasting areas, has been rewritten and renumbered as new Section

816.66(c), which is discussed below. 

 Previous Section 816.65(e), governing airblast, has been adopted in amended form as Section 816.67(b). 

 Previous Section 816.65(f), pertaining to blasting within 1,000 feet of certain buildings and 500 feet of other facilities, 

was proposed to be incorporated in amended form in Section 780.13(c). Instead it has been adopted in amended form as 

Section 816.61(d), which is discussed above. 

 Previous Section 816.65(g), governing flyrock, has been adopted as Section 816.67(c), which is discussed below. 

 Previous Section 816.65(h), containing a general performance standard requiring blasting to be conducted to prevent 

injury or damage, has been adopted as Section 816.67(a), which is discussed below. 

 Requirements similar to those in previous Section 816.65(i), which contained maximum peak-particle-velocities for 

blasting, have been adopted in amended form in Section 816.67(d). 

 The requirements of previous Section 816.65(j), identifying the circumstances where less stringent performance 

standards apply, have been adopted as Section 816.67(e). 

 Previous Section 816.65 (k) and (l), containing alternative means to determine peak-particle-velocities, have been 

modified and adopted as part of Section 816.67(d). 

SECTION 816.66 - USE OF EXPLOSIVES: BLASTING SIGNS, WARNINGS, AND ACCESS CONTROL. 

 Section 816.66 contains provisions for blasting signs and warning procedures throughout the permit area. It also 

contains the physical access and control requirements to fulfill the notification provisions of Section 515(b)(15)(A) and 

the public protection provisions of Section 515(b)(15)(C) of the Act. 

 

SECTION 816.66(a) 

 New Section 816.66(a)(1) includes provisions from previous Section 816.11(f)(1) and the proposed rule, and requires 

that the operator conspicuously place signs reading "Blasting Area" along the edge of any blasting area that comes within 

100 feet of any public road right-of-way and at the point where any other road provides access to the blasting area. 

Notice along any road that provides access to a blasting area will ensure that anyone entering the blasting area is aware 

that blasting is taking place. 

 New Section 816.66(a)(2) includes provisions from previous Section 816.11(f)(2), and, at all entrances to the permit 

area from public roads or highways, requires signs which state "Warning! Explosives in Use." These signs must clearly 

list and describe the meaning of the audible blast warning and all-clear signals and explain the marking of blasting areas 

and charged holes. 
 In addition, all signs used to mark blasting areas must conform to the specification for signs and markers set out in 

Section 816.11. 

 A State regulatory authority commenting on the proposal recommended that signs required under proposed Section

816.66(a)(1) contain the warnings and explanations required for signs under proposed Section 816.66(a)(2), because in 

some instances the signs referenced in Section 816.66(a)(1) may be closer to the blasting site than those at entry points 

(referenced in Section 816.66(a)(2)). OSM has not accepted this recommendation. The "Blasting Area" signs are 

intended to warn people of the limits of and to stay out of the area where blasting will take place. The more complete 

description of paragraph (a)(2) is intended to provide guidance to persons who may need to enter the permit area of 

precautions to follow when within the permit area. 

 Commenters objected to the 100-foot requirement and suggested that signs be required only when a public road 

right-of-way occurs within 50 feet of the blasting area, citing that more signs would be required than under the previous 

rules. OSM disagrees since the previous rules required signs on roads within 100 feet of the permit area but required 

signs at 50 feet when roads were actually within the permit area. OSM has adopted a consistent 100-foot distance in 

order to simplify the requirements. 

 A commenter suggested adding to Section 816.66(a)(2) the phrase "awaiting firing" after "charged holes." OSM has 

accepted this suggestion, recognizing the need to clearly advise personnel entering the mine site of the precautions to be 

taken to prevent injury. 

 

SECTION 816.66(b) 

 New Section 816.66(b) requires the use of audible warning and all-clear signals of different pattern. It also requires 

notification of the meaning of the signals to those who work within the permit area and those who reside or regularly 

work within one-half mile of the permit area. 

 Several commenters objected to the term "different character" in proposed Section 816.66(b) regarding the 

application of audible signals, assuming this meant different sounds, sounds with different tonal qualities. OSM 

recognizes this concern and has replaced "character" with "character or pattern" to allow use of the same instrument to 

make the sound in a different pattern to differentiate between "warning" and "all-clear." 

 

SECTION 816.66(c) 

 New Section 816.66(c) requires the controlled restriction of access to the blast area until hazards no longer exist and 

access can be safely resumed. Both livestock and persons are protected. Also it requires that no unusual hazards such as 

imminent slides or undetonated charges exist. 

 A commenter objected to the deletion of the first sentence of Section 816.65(d) restricting access to areas subject to 

flyrock, when it was redesignated Section 816.66(c). By including the phrase "within the blasting area" in Section

816.66(c), OSM intends to encompass all areas where the hazards of flyrock are present. Therefore Section 816.66(c) 

controls the same area where access was previously controlled under Section 816.65(d). 

SECTION 816.67 - USE OF EXPLOSIVES: CONTROL OF ADVERSE EFFECTS. 

 

SECTION 816.67(a) 

 OSM is adopting Section 816.67(a) as proposed. The rule requires that blasting be conducted to prevent injury to 

persons, damage to public or private property outside the permit area, adverse impacts on any underground mine, and 

change in the course, channel, or availability of ground or surface waters outside the permit area. This provision, which is 

the successor to previous Section 816.65(h), implements Section 515(b)(15)(C) of the Act. 

 Commenters objected to the requirement in proposed Section 816.67(a) which requires blasting to be conducted in 

such a way as to prevent the "change in the course, channel, or availability of ground or surface waters outside the permit 

area." The commenters felt that it would be impossible to distinguish between changes resulting from blasting and those 

resulting from other mine-related operations. The requirements of Section 816.67(a) are adopted from Section 
515(b)(15) of the Act which specifically requires that blasting be conducted in that manner. Furthermore, since OSM's 

permitting regulations at Section 786.19(c) require the finding that damage will be prevented with respect to hydrology 

outside of the permit area resulting from mining, no blasting could be permitted which would result in material offsite 

hydrologic damage. 

 

SECTION 816.67(b) 

 AIRBLAST LIMITS. OSM is adopting a slightly modified version of the airblast rule from that proposed in Section

816.67(b). Airblast limits must be met at any dwelling, public building, school, church, or community or institutional 

building outside the permit area, with the exception of certain structures owned by the operator and covered by Section

816.67(e). OSM has lowered the allowable airblast limit from that proposed for measuring systems with lower frequency 

limits below 6 Hz (hertz) from 130 to 129 dB (decibels). This has been done at the request of a commenter who indicated 

that the higher airblast limit was inconsistent with data published by the Bureau of Mines in RI8485 (Siskind and others, 

1980). 

 In addition, OSM has retained separate airblast limits from previous Section 816.65(e)(1) for c-weighted, slow 

response measuring systems and flat response measuring systems with a lower frequency limit of .1 Hz or lower. These 

peak limits are 105 dBC and 134 dB, respectively, and are consistent with BOM data. The c-weighted, slow response 

limit is the same as the previous rule and the .1 Hz or lower system limit than the previous rule. The use of both of these 

measuring systems must be approved by the regulatory authority. 

 Several commenters suggested that airblast limits should not apply at locations where a structure is owned by an 

operator. It appears that there was some confusion as to the applicability of Section 816.67(e). In its proposal OSM 

intended that Paragraph (e) apply to such structures for both airblast and ground vibration. In order to clarify the 

applicability of the exception in Section 816.47(e), the phrase "except as provided in Paragraph (e) of this section" has 

been added to the end of the airblast standard in Section 816.67(b)(1)(i). 

 A commenter suggested inclusion in Section 816.67(b)(1)(ii) of specific rulemaking and public hearing procedures for 

reduction of the airblast standard. In its proposal OSM intended that the maximum allowable airblast standard applicable 

to a specific mine may be modified by the regulatory authority if OSM's permanent program limits appear to create 

excessive levels which may cause damage. To clarify its intent, OSM has revised Section 816.67(b)(1)(ii) and inserted the 

phrase "for use in the vicinity of the specific blasting operation." Rulemaking procedures are not required for changes to 

the standards that are not of general applicability. 

 Another commenter believed that OSM's proposed language which included the word "may" and also the requirement 

"if necessary" gave the regulatory authority too much discretion to decline to reduce the maximum airblast limit, if it 

determined that a lower value is necessary to prevent damage. OSM believes that imposition of a lower value is properly 

within the discretion of the regulatory authority. However, should the regulatory authority determine a lower value to be 

necessary it must set a lower value. For this reason the final rule contains the language under which the regulatory 

authority determines whether or not imposition of a lower limit is necessary, and, if so, must reduce the limit. 

 Commenters objected to proposed Section 816.67(b)(1)(iii) because it placed a burden on operators to evaluate 

"adverse atmospheric conditions." OSM agrees that there is no need to have such a specific requirement. Accordingly, 

proposed Section 816.67(b)(1)(iii) has not been adopted. However, the requirement to meet applicable airblast standards 

is general and applies regardless of atmospheric conditions. 

 AIRBLAST MONITORING. A commenter on proposed Section 816.67(b)(2)(i) suggested that airblast 

measurements should be required at the location and occurrence of every seismographic reading. In considering this 

provision, OSM recognizes the need for ensuring that airblast levels are met, but also believes that the location of 

seismographic monitoring, for instance, may not be the critical or appropriate location for airblast monitoring. Wind, 

temperature, and overcast weather can affect the maximum airblast location. Therefore, the final rule includes a general 

provision for periodic airblast monitoring by the operator in which the locations and the periods of such monitoring are 

left to the discretion of operators and the regulatory authority. A sentence has been added to the Section 816.97(b)(2)(i) 

to emphasize that the regulatory authority may specify monitoring locations and determine which blasts have to be 

monitored. 
 A commenter was dissatisfied with the explanation in the preamble to Section 816.67(b)(2) (47 FR 12766) concerning 

airblast monitoring "at or near the nearest structure." The issues raised are: (1) When is a notice of violation issued for 

exceeding airblast standards? and (2) where should monitoring be located? In response, OSM notes that airblast limits 

apply at any location where damage may occur (i.e., the location of any structure, not necessarily the nearest). Therefore, 

a monitor located at any structure which records a value exceeding the maximum value for that frequency would record a 

violation. The location may not be the nearest structure because wind conditions may focus airblast away from near 

structures to those at greater distances from the blast. Although OSM is not requiring specific locations to be monitored, 

the operator is responsible to insure that such airblast monitoring does take place to assure compliance with airblast limits

at all locations. 

 Section 816.67(b)(2)(ii) specifies the sensitivity of airblast monitoring equipment, requiring the upper end of the 

response range of the measuring system to have a flat frequency response of at least 200 Hz. A commenter objected to 

the provision in proposed Section 816.67(b)(2)(iii) which would have allowed the regulatory authority to approve 

alternative measuring systems for airblast. As discussed in the preamble to the proposed rules (47 FR 12766), some 

suitable alternative monitoring systems exist, such as a 0.1 Hz- or a C-weighted instrument. As described above, OSM 

has inserted limits for these particular alternatives in the final that will provide equivalent levels of protection. Therefore 

proposed Section 816.67(b)(2)(iii) is unnecessary and has not been adopted. 

 SECTION 816.67(c) -- Flyrock. OSM has adopted Section 816.67(c) approximately as proposed. The final rule is 

essentially the same as previous Section 816.65(g). Flyrock includes material either travelling along the ground or in the 

air. It may not be cast more than one-half the distance to the nearest dwelling or other occupied structure nor beyond the 

area of regulated access. It may not be cast off the permit area. 

 Comments varied on the items to be included as flyrock. OSM, in review of these comments intends to include rock, 

mud, and debris as flyrock. It should be noted that flyrock is considered to be cast, projected, or thrown, not drifting 

smoke or dust particles of fragmented rock. Several commenters disagreed with the provision limiting flyrock range to 

one-half the distance to the nearest inhabited structure. These commenters cited this restriction as contrary to other 

departmental requirements for maximum coal recovery. Others cited this provision as providing a degree of safety in 

excess of that required by the Act. OSM has opted to retain the provision for one-half the distance, but has limited its 

applicability to dwellings or other occupied structures. This places the burden on operators to provide appropriate design 

restraints when mining close to such dwellings or structures, such as additional stemming, burden, or mats to prevent 

flyrock. Section 522(e)(5) of the Act limits mining within 300 feet of occupied dwellings, subject to valid existing rights 

or unless a waiver is obtained from the owner. Such a waiver does not, however, waive the protection of Section

816.67(c)(1) from flyrock or other adverse effects of blasting. 

 OSM has also chosen to retain the prohibition against casting flyrock beyond the permit boundary limit, rather than 

allowing operators to cast it on the land owned or leased by the operator. 

 Unless such land is permitted, access control is not provided, and public protection might be jeopardized. 

 A commenter suggested including public road rights-of-way in Section 816.67(c)(1). OSM considered this addition, 

but rejected it because such areas will be protected according to either Section 816.66(c)(2) or Section 816.67(c)(3) 

which prevents flyrock from being cast outside the permit boundary or the area of control under Section 816.66(c). 

 A commenter raised the question of defining the blasting site as the location from which flyrock distances are 

measured. OSM agrees with explosives industry terminology which generally refers to the limits of a blasting site as 

encompassing an area contained within the perimeter formed by the exterior charged holes. This differs from the area of 

regulated access (blasting area) referred to in Section 816.66(a)(1) and Section 816.66(c). The blasting area reflects the 

area where danger from flyrock exists for mine workers and persons potentially entering the mine site. 

 Commenters requested the phrase: "from the blasting site" be changed to "from its point of origin" in Section

816.67(c) referring to the precise location of the flyrock. Determining the exact point of origin of flyrock is generally 

impossible after blasting has occurred, and therefore the language "from the blasting site" has been adopted as proposed. 

 SECTION 816.67(d) -- Ground vibration. Section 515(b)(15)(C) of the Act requires the regulatory authority to 

establish limits on the use of explosives based on physical conditions of the site so as to prevent injury to persons and 
damage to public and private property outside the permit area. Ground vibration is among the most relevant factors 

which must be considered. 

 OSM has proposed three options for the control of ground vibration. The final rule governing ground vibration 

incorporates aspects of each of the three options proposed. The three options were: (1) A peak-particle-velocity for each 

permit based on site-specific data, (2) A variable ground-vibration limit based on distance to the nearest structure; and 

(3) A constant particle-velocity criterion of 1.0 inch per second at any structure outside the permit area. The discussion 

which follows first describes the rule that is adopted and then responds to specific comments on the various alternatives. 

 The rule adopted today sets limits on the allowable ground vibration (i.e., peak-particle-velocity) at certain types of 

protected structures to ensure the prevention of damage. These include dwellings, public buildings, schools, churches, or 

community of institutional buildings outside the permit area. 

 Peak-particle-velocities have been selected which reasonably assure that structures will be protected from damage. 

Blasts conducted close to structures where the frequency of ground vibration is generally highest will be allowed to have 

higher peak-particle-velocities. Further away, where potentially damage-causing lower frequencies would predominate, a 

lower peak-particle-velocity is mandated. For structures which are not buildings, the operator must submit a value for 

regulatory authority approval. 

 Three methods for ground-vibration limitation are provided in Sections 816.67(d) (2), (3) and (4) for the use of 

operators. These methods vary in their complexity and expense in application. 

 First, peak-particle-velocities are set for use with seismic monitoring. Section 816.67(d)(2)(i) provides specific 

numeric limits for ground vibration for use with general seismic monitoring and equivalent scaled-distance factors. These 

limits provide the protection to structures including residences, based on an analysis of the damage recorded by the 

RI8507 study (Siskind and others, 1980). The specific limits are described below, together with OSM's justification 

therefor. 

 Second, as an alternative provided under Section 816.67(d)(3)(i), an operator may use a scaled-distance equation 

which determines charge-weights (the weight of explosives) based on the distance of the blast to the nearest structure. 

The equation is used to determine the allowable charge-weight per delay without mandatory seismic monitoring. Under 

Section 816.67(d)(3)(ii) operators may, with regulatory authority approval, develop and use a modified scaled-distance 

equation. 

 Third, under Section 816.67(d)(4) the operator is allowed to conform to maximum peak-particle-velocities that vary 

by frequency. In those situations an operator must use sophisticated seismic monitoring which records the frequency 

content of the ground vibrations. A detailed discussion of this paragraph is included below. 

 Under Section 816.67(d)(5), the regulatory authority may reduce ground vibration levels on a site-specific basis if 

necessary to provide sufficient damage protection. Generally seismic monitoring is at the option of the operator; 

however, under Section 816.67(d)(6) the regulatory authority may require it and specify locations for such monitoring. 

 Under Section 816.67(e) the operator may exceed the prescribed ground-vibration levels at structures owned by the 

operator with the written waiver of any lessees. 

 In selecting particle-velocity limits, OSM has considered the differences between performance criteria, design 

standards, and the range of potential damage based on these parameters. 

 In controlling ground vibration, information such as geology, hydrology, seismic characteristics, distances to 

structures, and the amount of explosives must be evaluated. These factors, plus the level of fragmentation necessary, 

must be considered in setting the pattern of drill holes, selecting of explosives, and determining charge-weight. Design 

standards for ground vibration, such as burden, spacing, stemming, and subdrilling were not mandated by the previous 

rules and are not found in the final rule. Such design considerations are more appropriately applied by the certified 

blaster. The performance criteria to be met for ground vibration must be based on the ground-vibration levels predicted 

to cause damage. To stay within these levels, design parameters which are intended to keep ground vibration at or below 

the maximum allowable level must be used. Ground-vibration limits which protect homes and buildings from damage 
have been predicted from research studies. One Bureau of Mines study, RI8507 by Siskind and others (1980), provides a 

consolidation of such studies for the purpose of developing safe limits. The study recommended a 0.75 inch-per-second 

standard for dwellings with gypsum-board interiors and 0.50 for plaster-on-lath interiors. These recommended limits have 

been highly criticized by operators, explosives users, explosives engineers, explosives manufacturers, and others as overly 

stringent. Some claim that these limits result from misinterpretation of the data. Also, portions of the RI8507 study have 

been cited for inaccurate data and damage findings, placing some question on the conclusions and recommendations of 

the study. A number of comments contained such criticism. 

 OSM considers RI8507 as the most up-to-date consolidation of research data for evaluation of blast-induced damage, 

but agrees that the interpretation of the data raises some questions. OSM utilizes the study's data base to support the 

regulatory limits on blasting, but does not accept the study's recommended standards. From the data on page 16 of 

RI8507, OSM concludes that design indicators, relating design to performance levels such as the weight of explosives per 

delay, do not consistently produce absolutely predictable uniform levels of performance. Thus a blast using a specific 

charge-weight of explosives may result in a range of particle-velocities, and repeated blasts at that charge-weight may 

result in somewhat different ranges. Use of scaled-distance factors as design guides produces ranges of results as 

depicted on Figure 11 of RI8507. (For example, the range of expected particle-velocities for different mining blasts for a 

scaled-distance of 100 is from 0.015 to 0.20 inch per second, a factor of 1,333 percent.) Therefore, an operator 

attempting to meet a 1.0-inch-per-second standard would not design for a blast with a peak particle velocity of 1.0 inch 

per second, but rather would design for a blast with an expected range of peak particle velocities not to exceed 1.0 inch 

per second. The design range for a 1.0-inch-per-second limit from Figure 11 is 0.15 to 1.0 inch per second with a 

scaled-distance of 30. A scaled-distance of 55 results in a range of lower values. When monitored with seismographs, this 

approach will require careful application of design criteria to fall within the maximum limit. Without seismic monitoring, 

conservative safety factors must be applied to assure compatible performance for regulatory compliance. 

 Because OSM believes operators must design to achieve lower levels than the maximum permissible, setting a 

1.0-inch-per-second performance level is believed by OSM to result in actual readings in the range 0.30 to 0.70 inch per 

second. This range is consistent with the recommendations in RI8507 (Siskind and others, 1980). OSM believes that a

1.0-inch-per-second peak-particle-velocity will prevent the occurrence of threshold damage and has set such a standard in 

Section 816.67(d)(2)(i) for distances of 301 to 5,000 feet from the blasting site to the nearest building. 

 Several commenters objected to the use of the RI8507 study. The report incorporates and consolidates field data and 

laboratory experiments conducted in the definition of damage produced by blast vibrations. In addition to the conclusions 

reached, which have been the subject of much dispute, it has several chapters dealing with the fundamentals of ground 

vibration and airblast, including ground-vibration propagation with scaled-distance, response-spectra analysis 

applications, interior considerations such as amplification, and a chapter on failure characteristics of materials which 

relates damage potential to the inability of materials to undergo deformation and withstand stress or strain. 

 Commenters' concerns focused on the adequacy of the new structures and data observed, the relevance of the old 

study data, and the definition of the terms "threshold," "minor," and "major" damage. In developing these rules, OSM 

has relied upon the new data in RI8507 which was collected on actual structures in a controlled manner using highly 

complex and sensitive monitoring equipment. OSM followed the suggestion of commenters and used such data as a basis 

for its regulatory actions. 

 In review of damage data in the RI8507 study in Figure 46 on page 51, as related to the readings in Table 1 on page 

10 of that report, OSM finds that threshold damage did not occur until considerably higher levels than the report's 

conclusions indicate. For instance, "structure 51" incurred damage from all recorded blasts except one at 0.5 inch per 

second. Threshold damage ranged from levels of 1.04 to 7.25 inches per second, but the damage which was observed at 

1.04 inches per second immediately followed six higher recordings in the following order: 1.16, 1.22, 2.84, 1.24, 1.86, 

and 10.21 inches per second. OSM believes that if the structure had not been weakened by the six successive stronger 

blasts, a vibration of 1.04 inches per second may not have damaged it. "Structure 27" recorded damage at the lowest 

reading of the new data in RI8507 (0.72 inch per second). This value followed blasts at the following levels: 1.38, 1.89, 

1.91, 2.33, 3.73, 5.31, 2.34, and 1.22 inches per second. Of these, only blasts with ground vibrations recorded at 1.91 

and 5.31 inches per second were attributed with threshold damage. Numerous blasts with considerably higher values did 

not result in damage. 
 The data below taken from Report RI8507 demonstrate that the range of threshold damage occurred at 0.75 to 2.0 

inches per second, with the majority of damage points concentrated between 1.0 and 2.5 inches per second, whereas, no 

nondamage points were observed above 2.0 inches per second. Of the structures presented as new damage points on 

Figure 46 of RI8507, the following data are evaluated: 

____________________________________________________________________________________________

Structure No. Material type Number of observations Number of damage points

<1.0 n1 >1.0 n1 <1.0 n1 >1.0 n1

19 Plaster/lath 29 16 1 5

20 Gypsum board 13 2 2 1

27 Plaster/lath 1 9 1 2

51 Plaster/lath/brick 1 11 0 n2 13

58 Gypsum board/brick 1 5 0 5

61 Gypsum board/plaster 1 1 1 1

Total 46 44 4 27

____________________________________________________________________________________________

 n1 Inch per second. 

 n2 Questionable data plotting. 

 Based on the above table, 91 percent of blasts observed below 1.0 inch per second did not cause damage. Of the 4 

blasts observed below 1.0 inch per second that caused damage, one at 0.72 inch per second followed two blast 

observations greater than 1.0 inch per second (2.34 and 1.22) which did not result in damage. Therefore, the 0.72 value 

is questionable as the actual damage-producing blast. Another damage value of 0.79 followed a nondamage value of 1.10 

inches per second. 

 Therefore, OSM considers the 1.0-inch-per-second standard adopted in Section 816.67(d)(2)(i) for the range of 300 

to 5,000 feet to provide a degree of protection consistent with the Act, because (1) The range of threshold damage 

appears to occur at levels above 1.0 inch per second; (2) the range of recordings in field blasts designed to meet a 

maximum limit of 1.0 inch per second will infrequently reach 1.0 inch per second with expected results in the range from 

0.30 to 0.90 inch per second; and (3) the ground-vibration criteria coupled with other limitations on adverse effects from 

blasting will tend to require design considerations which lead to cumulative protection (i.e., separate constraints on 

flyrock and airblast will limit charge-weight, dimensions, and explosive characteristics). 

 Several commenters compared the recommended levels in the RI8507 study (Siskind and others, 1980) to the values 

OSM proposed in Option I for structure type and frequency. 

 As can be seen from the following comparison, the recommended peak-particle-velocities of the study are lower than 

those in OSM's proposal. 

____________________________________________________________________________________________

Structure type RI8507 recommended at 40 Hz (in/sec) OSM rule at 10 Hz (in/sec)

2 0.50 0.75

3 0.75 1.00

____________________________________________________________________________________________

 2. Older homes more than 20 years old with construction elements such as plaster-on-lath interiors and deteriorated or 

rigid, easily fractured construction materials. 

 3. Modern homes less than 20 years old with gypsum-board interiors, reinforced concrete or concrete masonry unit 

foundations, and other wood-frame and wood-clad structure. 

 In response to these commenters, OSM recognizes the need for blasting levels which prevent damage. However, in 

review of the data contained in Figure 46 of RI8507, OSM observes that the lowest damage value associated with blasts 

affecting plaster-on-lath interiors was 0.72 inch per second on "structure 27," and the lowest value affecting 
gypsum-board interiors was about 0.79 inch per second on "structure 20." Structures such as "51" (plaster/lath/brick), 

"19" (plaster/lath), and "58" (gypsum board/brick) showed the occurrence of threshold damage at blasts ranging from 

0.85 to 5.75 inch per second with the majority of points between 1.0 and 3.0 inches per second. 

 Imposing a ground-vibration level of 0.5 inch per second for such structures would protect these structures, but OSM 

believes this level is overly conservative. A value of 0.75 inch per second would also have provided protection. OSM 

believes that if a blast is designed to avoid exceeding the limit, the design level will have to be far less than the maximum, 

because predictability of the maximum particle velocity is difficult unless a conservative scaled-distance equation is 

applied. OSM expects that blast designers would have to use design criteria of 0.3 to 0.5 inch per second to meet a 

0.75-inch-per-second performance standard. Under a 1.0-inch-per-second standard, only rarely are values expected 

actually to reach the maximum levels. Actual recorded vibration levels are expected to range from 0.30 to 0.90 inch per 

second. The setting of particle velocity limits, rather than specifying design parameters for different types of structures 

ensures protection and allows the blaster reasonable latitude in conducting the shot. Such practices ensure protection 

consistent with the parameters of the RI8507 study (Siskind and others, 1980) without penalizing the operator by 

restrictive performance levels. The possibility of every blast reaching a constant 1.0-inch-per-second level is small. 

Furthermore, an occasional blast which reaches that level does not present a high degree of damage potential. 

Additionally, if blasting levels do consistently reach the prescribed standard and the regulatory authority considers this a 

potentially damaging level, it is authorized in Section 816.67(d)(3)(ii) to reduce the allowable maximum standard to a 

lower value. 

 One commenter agreed that the concepts applied by OSM were valid, but disagreed with the specific values proposed 

and the claimed oversimplification of the ground-vibration issue. The commenter recommended a constant 

1.0-inch-per-second standard be mandated in the final rule. OSM, in developing the final rule, has incorporated 

suggestions from various commenters and under Section 816.67(d)(2)(i) has applied a constant 1.0-inch-per-second 

value over a normal operating range of 300 to 5,000 feet, recognizing the occurrence of high frequency close to 

structures and low frequencies which would exist if the vibration intensity carried beyond 5,000 feet. This does not 

preclude low frequency from occurring in close-in blasts or high frequency from occurring at distances greater than 5,000 

feet. However, based on the data found in RI8507, a constant 1.0-inch-per-second standard would have prevented at 

least 85 percent of the damage points, and it is noted that 15 observations produced no damage above the 

1.0-inch-per-second particle-velocity level. 

 In Section 816.67(d)(20)(i), ground-vibration limits within 300 feet and beyond 5,000 feet are different from the 

1.0-inch-per-second standard. Based on the predominant occurrence of high frequency vibration near the blasting site, 

OSM allows a 25-percent higher particle-velocity limit within 300 feet of a blasting site. The higher level would only be 

allowed for residences within 300 feet after owner approval and when prior blast designs must also be submitted to the 

regulatory authority. The additional constraints when blasting within 300 feet, as well as the probability of higher

frequencies, justify the increase to 1.25 inches per second. 

 Conversely, at distances beyond 5,000 feet, levels at 0.75 inch per second must be observed with due regard to the 

potential for potentially damaging low frequency vibrations. 

 Commenters called OSM's attention to the study conducted at the Wright Mine in Warrick County, Ind., by Braile and 

others (1982). This study only dealt with the propagation of ground-vibration waves: data was observed for the 

site-specific geology and geologic type but no analysis of damage was conducted. The conclusions support the limits on 

blasting which produces low frequency ground vibrations and long duration surface waves, because such occurrences 

raise damage potential as well as result in annoyance to residents. The study concludes that vibrations at 5,000 feet could 

be perceptible and disturbing to persons inside a structure. However, the study does not indicate a damage threshold for 

these low frequency waves. Other studies suggest that the results achieved by the peak-particle-velocity standards 

prescribed today will prevent damage from low frequency blasts. Because OSM is statutorily charged only to prevent 

damage to structures and injury to persons, OSM has based blast limits on avoidance of physical injury or damage rather 

than annoyance. 

 Many commenters suggested that OSM consolidate proposed Options 1 and 3, while others supported variable peak 

particle velocity as a function both of frequency and distance from the blasting site. Several commenters recommended 

proposed Option 1 because it (1) Considered levels of protection by structure type as well as frequency and (2) allowed a 

2.0-inch-per-second maximum peak particle velocity under some site-specific conditions, whereas Options 2 and 3 apply 
generally conservative limits and equations. Based on these comments, OSM has adopted a variant of Option 1 in the 

form of Figure 1 as an alternative method of determining peak particle velocity. This provision, Section 816.67(d)(4), 

provides a site-specific approach to blasting restrictions based on carefully monitored frequency of the blast and provides 

adequate flexibility for State program adaption. The derivation of the values used in this alternative is described below. 

 An operator-commenter preferred proposed Option 1 because it allowed limits to be set based on site-specific 

conditions. Other commenters objected to Option 1 because it contained values believed to be too permissive and would 

be difficult to implement due to the variety of structure types, frequency verification, and monitoring constraints. The 

commenters also felt that levels for Type 4 structures would be too restrictive. OSM believes that the final rule reflects 

the positive aspects of Option 1, flexibility and site-specific levels, but only places the requirement of stringent monitoring 

and data development on those choosing to undertake such a sophisticated approach. OSM has decided not to adopt 

different standards for different types of structures because such a rule would be unnecessarily complex, would require an 

extensive analysis of structures surrounding the blasting site and would be difficult to enforce. 

 Some commenters expressed support for the Option 1 standards, because it appeared to be the only limit restricting 

ground vibration at the location of utilities (buried pipes, etc.). OSM did not intend that Option 1 be the only protection 

for pipelines, underground mines, water towers, impoundments, and tunnels, but recognizes that these structures are less 

susceptible to damage than buildings and residences. Therefore, OSM has included a provision under Section

816.67(d)(1) to limit ground vibration at such structures as determined by the regulatory authority. Currently, the Mine 

Safety and Health Administration requires levels less than or equal to 2.0 inches per second for underground mines. 

 Some commenters preferred Option 3, but suggested a modification to allow values greater than 1.0 inch per second 

in areas specifically approved by the regulatory authority. In the new rule being adopted, OSM has incorporated two 

provisions allowing such values. First, at distances less than 300 feet an upper limit of 1.25 inches per second has been 

established in Section 816.67(d)(2)(i) because of the frequency considerations; however, as noted throughout the 

comments, lack of substantiating data precludes incorporating limits in excess of 1.0 inch per second as proposed in 

Option 2 for distances between 300 and 3000 feet. Second, the use of alternative blasting criteria under Section

816.67(d)(4), the limits of which are specified in Figure 1, will allow values up to 2.0 inches per second if site conditions

warrant for blast frequencies in excess of 30Hz. 

 A commenter suggested that the only acceptable safe blasting criteria would be a variable limit with frequency similar 

to proposed Figure 1, or the use of response-spectra analysis requiring investigation of the natural frequency of the 

structure to be protected and relating this information to the blast vibration frequencies. OSM acknowledges that 

response-spectra analysis as used in the RI8507 study (Siskind and others, 1980) and by vibration consultants provides 

a unique solution because it sets allowable limits accurately by predicting the range of potential damage. However, OSM 

believes that a much more general standard must be authorized for application at coal mines where 200 to 1,000 houses 

may be involved. OSM does not want to discourage the use of response-spectra analysis, especially where a regulatory 

authority determines that a lower standard should apply. This technique if applied on a case-by-case basis might prove to 

be the best substantiation of the actual damage range. In order to allow such technique and to provide operators the 

option to increase particle velocities above the maximum limits set for general compliance, OSM has included in Section

816.67(d)(4) an alternative method using Figure 1. Using this option requires monitoring of particle velocity at the 

frequency levels, which may be augmented by response spectra for confirmation of the structure's interaction with the 

monitored wave forms. In using this alternative, the seismographic record will provide evidence of regulatory 

compliance, as well as evidence of damage potential for information of nearby homeowners. 

 A commenter, objecting to all options presented in the proposed rules, cited difficulty in the application of proposed 

Option 1, disputed the assumption that frequency decreases linearly with distance from the blasting site as found in 

proposed Option 2, and did not like the inclusion of the alternative blasting criteria under proposed Option 3. 

 Commenters also believed that proposed Option 3 ignored structural response, claiming that single value limits are an 

oversimplification of blasting effects and misleading to further study. 

 As described above, the new rule combined the three options; it allows the application of three levels of 

ground-vibration control: (1) Seismic monitoring of peak particle velocity, (2) use of a scaled-distance equation without 

monitoring, and (3) complex monitoring of velocity at associated frequencies. Each allows a somewhat different 

approach to control of blasts, but each provides equivalent levels of damage prevention. 
 Several commenters suggested adding the use of vector-sum seismographs to the peak-particle-velocity component 

concept of Section 816.67(d)(1)(i). OSM recognizes that some monitoring equipment records vector sum and that 

requiring component seismographs may be expensive for the operator. To avoid this unnecessary burden, OSM has 

allowed, but does not require, the use of vector-sum units. The Bureau of Mines has concluded that component velocity 

is the best indicator of damage potential and thus recommends limits and readings be in component format. The values 

listed for acceptable vector sum limits are identical for component limits, ensuring conservative results when using a 

vector-sum instrument. OSM recognizes that this will produce conservative monitoring standards, but a general 

conversion of component to vector-sum equivalent is not available. 

 Commenters were concerned that OSM's 1.0-inch-per-second standard would not provide adequate protection of 

sensitive structures. OSM believes that the limit of 1.0-inch per second over the range from 300 to 5,000 feet does set a 

limit which considers structural response. Setting a universally applied limit assumes that structures to be protected have 

natural frequencies in the range of 10-20 Hz (hertz). At frequencies between 10 and 20 Hz the safe vibration level 

recommended in RI8507 ranges between 0.75 and 1.40 inches per second. As indicated in OSM's evaluation of data from 

RI8507, the range of threshold damage appears to begin at levels greater than 1.0 inch per second. Therefore, a 

1.0-inch-per-second standard provides protection within this range over the broad range of distances. 

 A commenter objected to the prohibition placed on mining within 300 feet of a dwelling without owner approval and 

within 300 feet of public buildings. The commenter felt that such limitations were inappropriate and could interfere with 

maximum coal recovery. Section 522 of the Act prohibits any mining operations within 300 feet of public buildings or 

dwellings (without owner consent) subject to valid existing rights. Rules governing these areas are set forth at 30 CFR 

Parts 761 and 769. It would be duplicative to restate them in conjunction with the blasting rules. Accordingly, the 

proposed language in Section 816.67(d) has not been adopted. 

 Section 816.67(d)(1) sets levels for structures other than buildings. This new rule places the burden of setting 

particle-velocity limits for these structures on the operator and the regulatory authority. Operators would propose 

standards for structures, and the regulatory authority would approve or modify them. 

 Various commenters made recommendations regarding scaled-distance equations, a variant of which was proposed for 

all three options. Some commenters agreed with the correlation values proposed (e.g., Ds =55 correlating to 1.0 inch per 

second) while others believed that Ds =60 should be used to correspond to 1.0 inch per second, stating that it would 

better meet the requirements of the Act. Another commenter objected to the use of scaled distance as a safe blasting 

criterion. That commenter presented information attempting to refute the accuracy of scaled distance as a predictor at 

any specific value. OSM based the correlation values proposed (47 FR 12768) on the blast data contained on pages 

10-17 of the RI8507 study and believes use of scaled distance will prevent damage in more than 99 percent of blasts as 

described below. 

 The use of the scaled-distance equations of Section 816.67(d)(3) provides an operator with the option of not 

monitoring every blast to ensure compliance with the specified maximum ground-vibration level. Siskind and others 

(1980) in the RI8507 study collected and consolidated blast vibration data from blasting at various distances and blasting 

parameters. When displayed and analyzed, these data provide a line representing the mean occurrence of a specific 

particle velocity for a specified scaled-distance level. The equation adopted in Section 816.67(d)(3) divides distance from 

the blast to the structure to be protected by a scaled-distance factor to yield the square root of the total charge weight of 

explosives which may be detonated in any 8-millisecond period: (D /Ds )=/W , where D =the distance from the blast to 

the structure to be protected, Ds =the scaled-distance factor, and W =the charge weight of explosives. 

 The values of ground vibration measured at location D from the blast reflect the actual measured ground vibration. 

Mean curves were developed as part of the RI 8507 study based on the actual ground vibrations measured. (See p. 14 of 

the RI 8507 study.) The mean portrayed thereon reflects an averaging of values above and below the curve at any 

scaled-distance factor. The curve representing a 95-percent-confidence level for specific vibration levels is obtained 

statistically, resulting in a similar curve two standard deviations above the mean. This results in a level providing 

95-percent confidence that actual monitoring will fall at or below the predicted ground vibration. OSM has selected 

scaled-distance factors taken from the standard deviation curve. Coupled with the remote possibility of damage at the 

predicted level, these factors will afford a degree of protection in excess of 99 percent for the structure to be protected. 
 Some commenters felt that the proposed scaled distance of 70 in Option 1 was too conservative. Under the final rule, 

the maximum scaled-distance factor will be 65. Under the tables in new Sections 816.67(d)(2)(i) and 817.67(d)(2)(i), the 

scaled distance of 65 is applied only when the distance to the nearest building is greater than 5,000 feet. This will allow 

the use of a maximum of 5,900 pounds of explosives per 6-millisecond delay period at a distance of 5,000 feet. OSM 

does not believe this limit will constrain an operator unduly since explosive technology has developed delay blasting 

techniques available to conduct large blasts using this amount per delay. The scaled-distance denominator of 65 

corresponds to a 0.75-inch-per-second peak particle velocity. In setting this peak particle velocity, OSM recognizes the 

need for lower ground vibration at locations of lower frequency. After traveling 5,000 feet, the intensity of a seismic 

wave should dissipate below the 0.75 peak-particle-velocity level; thus the standard should rarely be exceeded. 

 Some commenters contended that the proposed equation W=D <1>.5 /90 in Option 2 was too conservative for the 

large areas blasted in the West. OSM has not adopted that optional equation because it was too stringent at long 

distances and not stringent enough when structures were within 500 feet. Therefore, its applicability would have been 

limited to the distances between 1,000 and 3,000 feet, whereas the scaled-distance equation adopted in this new rule, 

using Ds =55, can be applied at distances between 300 and 5,000 feet. 

 OSM believes that the 55 level for Ds over the 300 to 5,000 foot range provides sufficient protection; as described 

earlier, a 1.0 inch-per-second level reflects an appropriate standard to provide damage protection. 

 Section 816.67(d)(3)(ii) allows the operator flexibility in modifying the scaled-distance factor Ds to allow for higher 

or lower scaling factors. The provision requires that after the operator correlates the mean occurrence of particle velocity 

with scaled distance, the modified value for the scaled-distance factor Ds must reflect a point that is two standard 

deviations above the mean regression curve. This correlation value provides a 95-percent-confidence level that the 

maximum allowable particle velocity will not be exceeded. A technical guidance document will be made available by 

OSM demonstrating the application of the modified equation and its derivation. 

 One commenter suggested that a lower limit be established on modified scaled-distance below which the regulatory 

authority would not set a standard. OSM has not accepted the suggestion. OSM believes that a 1.0-inch-per-second 

standard over the normal working distances provides adequate protection in general blasting practice, but recognizes that 

structure condition, geology, and vibration frequency affect damage potential and are site specific. The Act requires 

site-specific limits for use of explosives, and values as low as 0.5 inch per second may be necessary. The setting of a 

lower value is more appropriately left to the discretion of the regulatory authority at the time of evaluating the 

site-specific conditions. 

 Certain site-specific conditions warrant higher bore hole loadings per delay, but protection of people and property 

must be assured. Other site-specific conditions may warrant reduction of allowable peak particle velocity and the 

lowering of the weight of explosives per delay (i.e., higher scaled-distance factors). The provisions of Section

816.67(d)(5)(ii) require the regulatory authority to take action if necessary to provide damage protection. Critical factors 

in assessing damage probability include distance to the nearest structure and charge weight. 

 A commenter objected to the proposed term "in the vicinity of the mine" with respect to proposed Section

816.67(d)(3)(iii) which would have required regulatory authorities, upon requests from owners and residents, to evaluate 

the maximum allowable ground-vibration standard. The same commenter felt that "vicinity" could mean 100 feet or 100 

miles. The commenter suggested that such requests be limited to structures within one-half mile of the permit area. OSM 

believes that the proposed provision is unnecessary. Upon request from a resident, or for any other reason, the regulatory 

authority may require seismic monitoring of blasts and may reduce ground vibration limits if conditions warrant. Thus, 

the regulatory authority has ample authority to protect those in the vicinity of the blasting. 

 As mentioned above, Section 816.67(d)(4) presents a third optional ground-vibration standard. This is based on the 

standard proposed as Figure 1 in Option 3 in the proposed rule. It requires more stringent monitoring than the normal 

peak particle velocity and allows more flexibility to operators to use greater charge weights. The limits are set forth in a 

graphic distribution of maximum allowable particle velocity versus blast vibration frequency. These are shown in a new 

Figure 1 to be included as part of the rule. Commenters requested that the limits of proposed Figure 1 be revised. Several 

commenters wanted this criterion to be the only one to apply to regulation of ground vibration. Others objected to the 

use of the criterion altogether and suggested its deletion. OSM has included the criterion as an alternative to allow 

flexibility by operators and regulatory authorities if they wish to conduct the more extensive monitoring required. The 
alternative blasting criterion (new Figure 1) differs slightly from that proposed. One commenter suggested retention of 

the proposed curve above 20 Hz, but a limit of 1.0 inch per second for the portion of the curve below 20 Hz. Another 

commenter provided a rationale for adjusting the cutoff point for the 2.0-inch-per-second standard from 40 Hz to 30 Hz, 

since the interaction with an amplification of natural frequencies of residential structures primarily occurs in the 5 to 20 

Hz range. The suggestion to rely on a constant 1.0-inch-per-second limit up to 20 Hz has been rejected because it fails to 

acknowledge the impact of predominant low-level blast vibration frequency within the range of 5 to 10 Hz. 

 In determining the values in Figure 1, OSM has adopted the Bureau of Mines proposal cited in Appendix B of RI8507 

(Siskind and others, 1980). For frequencies up to 4 Hz, a constant maximum amplitude of 0.030 inch will be allowed. 

(Under this standard, amplitude is related to particle velocity through the use of the equation V =2para. fA, where V 

is the particle velocity, f is the frequency, and A is the amplitude.) Over this frequency range the maximum allowable 

particle velocity increases from 0.19 inch per second to 0.75 inch per second. At frequencies of 4 through 11 Hz a 

constant allowable particle velocity of 0.75 inch per second is set. 

 The level over the range 4 to 11 Hz was set at 0.75 inch per second rather than 1.0 inch per second to acknowledge 

the need to reduce particle velocity at low frequencies. Over the frequency range of 11 through 30 Hz, a constant 

amplitude of 0.0107 inch is allowed. This correlates to maximum particle velocities of 0.75 inch per second to 2.0 inch 

per second. Above 30 Hz, a constant peak particle velocity of 200 inches per second will be allowed. 

 A commenter cited concern with varying threshold levels on the basis of structure type and vibration frequency and 

allowing a maximum level of 2.0 inches per second. These commenters felt that proposed Option 1 would be the most 

beneficial in regulating the industry. OSM does not believe that a general limit of 2.0 inches per second provides 

adequate protection. In the previous rules, a peak particle velocity of 2.0 inches per second was allowed in some 

instances only when applying stringent monitoring techniques. In the final rule, the particle-velocity standard sought by 

the commenter is allowed under Section 816.67(d)(4) at frequencies above 30 Hz, but only under well-monitored and 

controlled conditions that require seismic monitoring using equipment recording both particle-velocity data and vibration 

frequency levels to assure continuous compliance. 

 A commenter raised the problem of determining predominant frequency in applying proposed Option 1 dealing with 

the structure tables. This problem also exists in implementing the alternative blasting criteria of Figure 1. Therefore, a 

provision has been added to Section 816.67(d)(4) to require approval of the method to be used in evaluating and 

ultimately establishing the predominant frequency at which vibration levels occur. 

 A commenter felt that the proposed alternative blasting criterion of Figure 1 was overly stringent and too expensive 

for most operators. They also were concerned about the possibility of rendering existing monitoring equipment obsolete 

by this rule. OSM has included new Figure 1 in the final rule for optional application. Some operators may find the 

economic outlay beneficial to production and the protection of nearby structures; those who do not need not use this 

alternative method of determining maximum ground vibration. Other provisions of the rules allow conventional 

monitoring and use of equations without monitoring. 

 Commenters requested clarification as to what was required to evaluate blast vibration frequency. They wanted to 

know whether visual inspection of seismographic records was adequate or whether electronic anlaysis of frequency 

would be required. Under Section 816.67(d)(4), which requires regulatory authority approval of the method of analysis 

of the predominant frequency contained in the blasting records, visual inspection may be adequate if traces are distinct 

and only a few frequencies are contained in the wave-form. However, seismographic consultants have found that various 

waves with multiple frequencies typically are contained in the blasting record. In those cases, electronic analysis is 

necessary to separate the wave traces and analyze each intensity and frequency. OSM does not intend to mandate 

electronic analysis; rather the determination of what type of analysis is appropriate should be made by the regulatory 

authority. 

 Commenters did not believe that frequency analysis, which requires sophisticated equipment, should be required in all 

cases. Except when the criteria of Section 816.67(d)(4) are used, the final rule leaves frequency analysis to the discretion 

of the regulatory authority. OSM recognizes its value as an indicator of vibration damage probability, but also 

recognizes the complexity and expense in its application, as well as the uncertainties in determining specific frequency 

levels. 
 Commenters referred to human annoyance from blast vibrations. Human response has been addressed by the RI8507 

study (Siskind and others, 1980) and other researchers in the ground-vibration field. OSM concludes that the limits on 

airblast provide the most appropriate basis for minimizing disturbance to nearby residents. In addition, there does not 

appear to be a standardized correlation between ground vibration levels and degrees of annoyance, apart from injury and 

damage. OSM believes that through an effective public relations program and communication with nearby residents much 

anxiety over annoyance can be mitigated. 

 A commenter complained that OSM had not satisfied its obligations under the Administrative Procedure Act (APA) 

by indicating a preferred course of action. The APA requires that an agency publish an explanation of its proposed action 

sufficient to allow for meaningful comments. Due to the complexity of these issues OSM devised several regulatory 

approaches and has explained each of them with sufficient specificity to attract the numerous comments it has received. A 

decision on which option to adopt was not made until after evaluation of all the comments received. This new rule 

adopted by OSM falls well within the range of the alternatives proposed. 

 

SECTION 816.67(e) 

 New Section 816.67(e) excludes from ground vibration and airblast limits structures owned by the operator and those 

owned by the operator and leased to others if waivers are obtained from the lessees. Commenters requested that the 

exclusion for structures owned by the operator and leased to others apply to all options. This was the intent of the 

proposed rule, but was misinterpreted as applying only to Option 3. This section has been retained in the final rule as 

Section 816.67(e). 

SECTION 816.68 - USE OF EXPLOSIVES: RECORDS OF BLASTING OPERATIONS. 

 As proposed, the new Section 816.68 requires the operator to maintain blasting records for at least 3 years and to 

make them available for inspection by the regulatory authority or the public on request. This is required in Section 

515(b)(15)(B) of the Act. Among the information which must be included is the name of the operator; the location, date, 

and time of the blast; the name signature, and certification number of the blaster conducting the blast; identification, 

direction, and distance from the nearest blast hole to the nearest dwelling or other structure outside the permit area; 

weather conditions described in more detail below; the type of material blasted; sketches of blast pattern including 

number of holes and the burden, spacing, decks, and delay pattern; the diameter and depth of holes, the type of 

explosives used; the total weight of explosives used per hole; the maximum weight of explosives detonated within any 

8-millisecond period; the initiation system; type and length of stemming; and mats or other protection used. 

 Section 816.68(o) includes the requirement that if seismographic and airblast records are required, they should include 

a record of the instrument type, its sensitivity and calibration signal or the certification of annual calibration; location, 

date, time, and distance the instrument is from the blast; the person's name and firm who obtained the readings, and the 

person's name and firms analyzing the seismographic record; and vibration and/or airblast levels recorded. In addition 

Section 816.68(p) provides that information stating the reasons and conditions for each unscheduled blast shall be 

contained within the record. 

 Commenters objected to deletion of specific weather characteristics listed in the previous rules. These commenters 

reasoned that these conditions may assist in determining adverse effects due to blasting focused by weather such as: 

clouds, wind, and temperature inversions. OSM believes the commenter is correct, but a blaster in the field may not know 

if an inversion exists or what the specific wind velocity is. The requirement of this data could result in inaccurate entries

leading to false interpretation of impacts of weather. OSM acknowledges the potential impacts on blasting of temperature 

inversions, wind direction, and velocity and has inserted a provision for the blaster to estimate any adverse weather 

conditions which might exist. 

 A commenter objected to the deletion of previous Section 816.68(1) establishing the number of holes to be detonated 

in any 8-millisecond-delay period because providing this information places no great burden on the operator. OSM 

believes this information summarizes data which are insignificant in the total blast record and are not necessary for 

assuring compliance with the rules. Another commenter believed that physical separation can provide the same effect as 

an 8-millisecond delay. OSM agrees. The 8-millisecond separation was determined by the Bureau of Mines as the 

minimum delay period to separate charges to reflect nonadditive ground-vibration levels when measured at some distance 

from the blast. However, this concept assumes that delay holes are at the same distance from the seismograph. In 
situations where holes are varying distances from the recorder, physical distance separation will delay arrival times of the 

ground vibration at a structure. This is variable, dependent on the velocity that the seismic wave travels in the specific 

geologic material. 

 A commenter objected to OSM's proposed deletion of the requirement that operators keep a record of the number of 

persons in the blasting crew. OSM believes that a specific number of persons should not be regulated on a national basis. 

The entry in OSM's old rules served the requirement governing crew size found in 30 CFR Part 850 which has been 

proposed for change. If a crew size is imposed by a State program, an appropriate entry could be required by the State. 

Accordingly, OSM has adopted no change to reinstate this entry. 

 A commenter suggested amending the entry under Section 816.68(o)(3) to include the name of the person and firm 

conducting seismographic tests. OSM believes this to be an acceptable inclusion. Accordingly, OSM has adopted this 

requirement. 

 A commenter suggested including the frequency of recorded blast vibration in the seismic record. Not all records 

produced by seismographs in use in the industry today produce frequency spectra. Most recordings must be analyzed on 

complex systems to identify trace frequencies as expressed in the RI8507 report (Siskind and others, 1980). As discussed 

above, the use of a vibration criterion based on frequency monitoring is required in Section 816.67(d)(4) in those 

situations where such sophistication is necessary. However, imposing this condition on all monitored blasts would be 

overly stringent and unnecessary. 

 A commenter objected to inclusion of the amount of information required by proposed Section 816.68(g) stating that 

sketches should only be required if blasts are conducted within 1,000 feet from a dwelling or other structure. OSM 

believes the record is important for reference purposes to ensure the mitigation of damage. Moreover, OSM's regulation 

of aspects of the blast such as burden, spacing, decking, and delays is mandated by the Act. Other information proves 

valuable if a complaint arises. Also, an operator who maintains this type of record may revise future blast design if 

problems occur. OSM believes this degree of information is within that envisioned by the Act, and the final rule adopts 

the requirement. Commenters also felt that too much information was required for a single sketch. OSM accepts the 

comment that a single sketch may be cluttered and allows multiple sketches to reflect this information if a single sketch 

cannot be made. 

 A commenter believed that all blasts should be certified as designed by a certified blaster in the record. OSM does not 

require every blast to be designed by a certified blaster. Rather, they must be carried out by certified blasters. Since blast 

patterns and delays may be designed by someone other than the blaster carrying out the blast, the name of the designer 

may not be available. Furthermore, OSM requires certifications of blast designs when blasting is conducted within 1,000 

feet of structures. OSM therefore has not added such a provision to its recordkeeping rules. 

 A commenter suggested limiting the data kept in records required by Section 816.68(j) on explosives to total 

explosives used per blast rather than explosives per hole. OSM believes this information is necessary to evaluate the 

amount of explosives per delay. Furthermore, the per-hole information requirement is taken from the Section 

515(b)(15)(B) of the Act. OSM agrees that total charge weight information is important, but recognizes that it is 

available by totalling all holes. Therefore, it is not considered to be necessary as additional data to be entered. 

Accordingly, OSM has not adopted such a provision. 

 A commenter requested that a provision be made in Section 816.68(o) to allow "annual calibration" to relieve 

operators from showing calibration signals on each record. The commenter argued that some seismographs do not have 

calibration signals integral with the records. OSM has adopted this provision in the final rule. 

 A commenter suggested deletion of the requirement in proposed Section 816.68(o)(2) for location of the instrument 

and the date and time of the blast. OSM believes that this information is necessary to ensure that the operator is utilizing 

the monitoring system agreed to in the permit, and that the data recorded can be traced to a specific blast. 

 A commenter requested deletion of the requirement in proposed Section 816.68(p) of the names of persons notified 

when unscheduled blasts are conducted. As discussed above in conjunction with Section 816.64(a)(2), OSM is deleting 

the requirement of verbal notification of area residents of unscheduled blasts. Instead, audible signals will be used. 
Weather and other site-specific conditions which necessitate unscheduled blasts may not allow notification to individual 

residences. Accordingly, OSM does not require records of individuals notified. 

 A commenter requested confirmation of the availability of blasting records to the public. Both Section 816.68 and the 

Act require the operator to provide access to the blasting records for public inspection upon request. A commenter 

objected to the degree of detail made available to the public in the records required by Section 816.68, stating that it 

exceeds the requirements of the Act. OSM recognizes that the information required in Section 816.68 exceeds that 

specifically listed in Section 515(b)(15)(B) of the act. OSM requires additional information to evaluate the performance 

levels of rules implemented pursuant to Sections 515(b)(15)(C), (D), and (E) and 719 of the Act. The additional 

information relates to performance standard found in Sections 816.61 through 816.67. Such information is necessary to 

determine whether performance levels were attained. Segregating in the record the items listed in the Act to be available 

for public inspection is impractical and unnecessary. The commenter failed to demonstrate any harm that would occur 

through the public disclosure of the additional information. OSM therefore, has chosen to require the entire blasting 

record to be made available for public inspection. 

RULES GOVERNING USE OF EXPLOSIVES ASSOCIATED WITH UNDERGROUND MINING. 

 The performance standards adopted in this rule governing the use of explosives associated with underground mining 

are identical to those governing surface mining except as noted below. Most offsite impacts, such as airblast and ground 

vibration, for surface blasting incident to underground mines are not substantially different from those for blasting at 

surface mines. OSM only regulates the surface impacts of blasting from underground mines, which are derived almost 

exclusively from surface blasting associated with such mines. This is not a change from the previous rules which also only 

regulated surface blasting activities incident to underground mining. 

 Only one difference exists between the two sets of rules in Parts 816 and 817. This relates to the use of blasting 

schedules. Rather than requiring a blasting schedule, Section 817.64 will require weekly notice prior to any surface 

blasting in support of underground coal mining. Because of the occasional, sporadic nature of surface blasting in support 

of underground coal mining, the public will be sufficiently served by receiving notification weekly, but not less than 24 

hours before any blasting occurs. The mine operator also will be relieved of the task of publishing and republishing a 

blasting schedule. 

 BLAST DESIGN. OSM had proposed to place blast designs among the permitting requirements of Section 780.13 for 

surface mines. No similar planning requirement was included for underground mines because blasting plans are not 

required for underground mines. 

 As described above, in adopting the final rules governing surface mines, OSM has shifted the requirement for blast 

design from the blasting plan section to the general performance standards requirement. This has been done for several 

reasons: (1) To emphasize the fact that the requirement for special information when blasting within sensitive areas is not 

a prohibition of mining within these areas, but a protection of structures more likely to suffer damage; (2) To ensure that 

blast designs are prepared in advance for blasting in areas where the possibility of damage is greatest; (3) To provide the 

regulatory authority with the greatest information when blasting will be conducted in sensitive areas to allow for 

monitoring or review of blast designs. 

 A number of commenters urged that blast designs also be required for underground mines. Because surface blasts may 

be equally damaging when associated with underground mines, OSM has adopted a requirement in Section 817.61(d) 

identical to the blast design requirement of Section 816.61(d). 

 BLASTING SCHEDULES. Several commenters objected to the proposed retention of the previous 24-hour notice 

requirement for notification of local residents within one-half mile of the blasting site in proposed Section 817.64(a). 

Since underground mines have a reasonably constant area of surface disturbance and the time period in which surface 

blasting would be performed is limited, OSM has rewritten the notification provisions for underground mines to require 

notification of residents within the 1/2 mile of the blasting site and local governments. The rule also allows weekly 

schedules to be distributed. This concept is envisioned to provide the advanced written notice required by statute, while 

recognizing the infrequent and limited blasting operations used in surface operations of underground mine development. 

The rule allows daily notification as in the previous rule, but also allows an operator to publish a schedule of weekly 
blasting events to avoid daily notification. This final rule is envisioned to allow flexibility in use of notification 

procedures. 

 SIGNS AND MARKERS. It was mentioned by several commenters that the introductory language to proposed 

Section 817.66(a) used the wrong wording for the underground section. This has been corrected by removing the 

introductory language and restructuring the provision to parallel Section 816.66. New Section 817.61(a) limits the 

applicability of Section 817.66 to surface blasting activities incidental to underground coal mining. 

 Addition of Figure 1. The addition of Figure 1 to Sections 715.19(e)(2)(ix), 816.67(d), and 817.69(d) is discussed in 

the preamble under the "Ground Vibration" section. 

 

III. PROCEDURAL MATTERS 

 

Federal Paperwork Reduction Act 

 The information collection requirements in existing 30 CFR Parts 715, 780, 816, and 817 were approved by the Office 

of Management and Budget (OMB) under 44 U.S.C. 3507 and assigned new clearance numbers 1029-0007, 1029-0036, 

1029-0047, and 1029-0048 on April 1, 1981. This approval was identified in "Notes" at the introduction to 30 CFR Parts 

715, 780, 816, and 817 under the old numbers R0494, R0606, R0618, and R0619 (all under No. B-190462). OSM has 

codified the OMB approvals under the new Sections 715.10, 780.10, 816.10, and 817.10 (47 FR 33683, August 4, 1982) 

and has received new OMB approval of these information collection requirements. 

 The information required by 30 CFR Part 715 will be used by the regulatory authority in monitoring blasting 

operations. This information required by 30 CFR Part 715 is mandatory. 

 The information required by 30 CFR Part 780 will be used by the regulatory authority to determine whether the 

applicant can meet the environmental protection performance standards of the regulatory program. This information 

required by 30 CFR Part 780 is mandatory. 

 The information required by 30 CFR Parts 816 and 817 will be used by the regulatory authority to monitor surface 

and underground mining activities to ensure that they are conducted in a manner which preserves and enhances 

environmental and other values of the Act. This information required by 30 CFR Parts 816 and 817 is mandatory. 

 

Executive Order 12291 

 The DOI has determined that this document is not a major rule and does not require a regulatory impact analysis 

under Executive Order 12291. 

 

Regulatory Flexibility Act 

 The DOI certifies that this document will not have a significant economic effect on a substantial number of small 

entities and therefore does not require a regulatory flexibility analysis under Pub. L. 96-354. 

 

National Environmental Policy Act 

 Revision of Section 715.19 of the initial program regulations is deemed not to be a major Federal action within the 

meaning of the National Environmental Policy Act of 1969 (NEPA), 42 U.S.C. 4332, as stated in Section 501(a) of the 

Surface Mining Control and Reclamation Act of 1977 (the Act), 30 U.S.C. 1251, and a detailed statement on the analysis 

of the environmental impacts of its revision is not required. 

 Amendments relating to use of explosives in 30 CFR Parts 780, 816 and 817, have been considered in relation to 

revisions of certain other rules in OSM's Final Environmental Statement OSM-EIS-1: Supplement. The final supplement 

is available in OSM's Administrative Record in Room 5315, 1100 L Street, NW., Washington, D.C., or may be obtained 

by mail from Mark Boster, Chief, Branch of Environmental Analysis, Room 134, Interior South Building, U.S. 

Department of the Interior, Washington, D.C. 20240. This preamble serves as the record of decision under NEPA. These 

final rules are the same as the preferred alternatives published in Volume III of the final EIS and analyzed in the EIS. 

 
LIST OF SUBJECTS 

 

30 CFR Part 715 

 Coal mining, Environmental protection, Surface mining, Underground mining. 

 

30 CFR Part 780 

 Coal mining, Reporting requirement, Surface mining. 

 

30 CFR Part 816 

 Coal mining, Environmental protection, Reporting requirements, Surface mining. 

 

30 CFR Part 817 

 Coal mining, Environmental protection, Reporting requirements, Underground mining. 

 Agency Approval. Section 516(a) requires that, with regard to rules directed toward the surface effects of 

underground mining, OSM must obtain written concurrence from the head of the department which administers the 

Federal Coal Mine Health and Safety Act of 1969. OSM has obtained the written concurrence of the Assistant Secretary 

for Mine Safety and Health, U.S. Department of Labor. 

 Accordingly, 30 CFR Parts 715, 780, 816, and 817 are amended as set forth herein. 

Dated: February 28, 1983. 

William P. Pendley, Acting Assistant Secretary, Energy and Minerals. 

PART 715 -- GENERAL PERFORMANCE STANDARDS 

 1. Section 715.19 is amended by revising Paragraphs (e)(2)(ii) and (e)(2)(iii) and removing Paragraphs 

(e)(2)(iv)-(e)(2)(vi) to read as follows: 

SECTION 715.19 - USE OF EXPLOSIVES. 

 

* * * * * 

(e) * * * 

(2) Blasting standards. (i) * * * 

(ii) Ground vibration. -- (A) General. In all blasting operations, except as otherwise authorized in 

Paragraph (e)(2)(iii) of this section, the maximum ground vibration shall not exceed a value approved by the regulatory 

authority. It shall be established in accordance with the maximum peak-particle-velocity limit of Paragraph (e)(2)(ii)(B), 

the scaled-distance equation of Paragraph (e)(2)(ii)(C), or the blasting-level chart of Paragraph (e)(2)(ii)(D), or such 

other standard established under Paragraph (e)(2)(ii)(E), of this section. All structures in the vicinity of the blasting area, 

not listed in Paragraph (e)(2)(ii)(B), of this section, such as water towers, pipelines and other utilities, tunnels, dams, 

impoundments, and underground mines, shall be protected from damage by establishment of a maximum allowable limit 

on the ground vibration, submitted by the operator and approved by the regulatory authority before the initiation of 

blasting. 
(b) Maximum peak-particle velocity. 

(1 ) The maximum ground vibration shall not exceed the following limits at the location of any dwelling, public 

building, school, church, or community or institutional building outside the permit area. 

____________________________________________________________________________________________

Distance (D) Maximum allowable peak particle Scaled-distance factor to be 

from blasting site velocity (Vmax) for ground applied without seismic 

in feet vibration, in inches/second n1 monitoring n2

0 to 300 1.25 50

301 to 5,000 1.00 55

5,001 and beyond 0.75 65

____________________________________________________________________________________________

 n1 Ground vibration shall be measured as particle velocity. Particle velocity shall be recorded in three mutually 

perpendicular directions. The maximum allowable peak particle velocity shall apply to each of the three measurements. 

 n2 Applicable to the scaled-distance equation of Paragraph (e)(2)(ii)(C)(1 ) of this section. 

(2 ) A seismographic record shall be provided for each blast. 

(C) Scaled-distance equation. 

(1 ) The operator may use the scaled-distance equation, W =(D /Ds ) 2 , to determine the allowable charge 

weight of explosives to be detonated in any 8-millisecond period without seismic monitoring; where W =the maximum 

weight of explosives, in pounds; D =the distance, in feet, from the blasting site to the nearest protected structure; and Ds 

=the scaled-distance factor, which may initially be approved by the regulatory authority using the values for 

scaled-distance factor listed in Paragraph (e)(2)(ii)(B)(1 ), of this section. 

(2 ) The development of a modified scaled-distance factor may be authorized by the regulatory authority on 

receipt of a written request by the operator, supported by seismographic records of blasting at the minesite. The modified 

scaled-distance factor shall be determined such that the particle velocity of the predicted ground vibration will not exceed 

the prescribed maximum allowable peak particle velocity of Paragraph (e)(2)(B)(1 ) of this section at a 95-percent 

confidence level. 

(D) Blasting-level chart. 

(1 ) An operator may use the ground-vibration limits in Figure 1 to determine the maximum allowable ground 

vibration. 

 [See Illustration in Original] 

(2 ) If the Figure 1 limits are used, a seismographic record including both particle-velocity and 

vibration-frequency levels shall be provided for each blast. The method for the analysis of the predominant frequency 

contained in the blasting records shall be approved by the regulatory authority before application of this alternative 

blasting criterion. 

(E) The maximum allowable ground vibration shall be reduced by the regulatory authority beyond the limits otherwise 

provided by this section, if determined necessary to provide damage protection. 

(F) The regulatory authority may require an operator to conduct seismic monitoring of any or all blasts and may specify 

the location at which the measurements are taken and the degree of detail necessary in the measurement. 

(iii) If blasting is conducted in accordance with Paragraph (e)(2)(i) of this section, the maximum ground-vibration and 

airblast standards shall not apply at the following locations: 

(A) At structures owned by the permittee and not leased to another person. 
(B) At structures owned by the permittee and leased to another person, if a written waiver by the lessee is 

submitted to the regulatory authority before blasting. 

 

* * * * * 

SECTION 715.19 [Amended] 

 2. Section 715.19 is amended by removing Paragraph (e)(3) and redesignating Paragraph (e)(4) as Paragraph (e)(3). 

PART 780 -- SURFACE MINING PERMIT APPLICATIONS -- MINIMUM REQUIREMENTS FOR 

RECLAMATION AND OPERATION PLAN 

 3. Part 780 is amended by revising Section 780.13 to read as follows: 

SECTION 780.13 - OPERATION PLAN: BLASTING. 

(a) Blasting plan. Each application shall contain a blasting plan for the proposed permit area, explaining how the applicant 

will comply with the requirements of Sections 816.61-816.68 of this chapter. This plan shall include, at a minimum, 

information setting forth the limitations the operator will meet with regard to ground vibration and airblast, the bases for 

those limitations, and the methods to be applied in controlling the adverse effects of blasting operations. 

(b) Monitoring system. Each application shall contain a description of any system to be used to monitor compliance with 

the standards of Section 816.67 including the type, capability, and sensitivity of any blast-monitoring equipment and 

proposed procedures and locations of monitoring. 

(c) Blasting near underground mines. Blasting operations within 500 feet of active underground mines require approval 

of the State and Federal regulatory authorities concerned with the health and safety of underground miners. 

PART 816 -- PERMANENT PROGRAM PERFORMANCE STANDARDS -- SURFACE MINING 

ACTIVITIES 

SECTION 816.11 [Amended] 

 4. Section 816.11 is amended by removing paragraph (f) and redesignating paragraph (g) as paragraph (f). 

 5. Section 816.61 is amended by revising paragraphs (a) and (b) and adding paragraph (d) to read as follows: 

SECTION 816.61 - USE OF EXPLOSIVES: GENERAL REQUIREMENTS. 

(a) Each operator shall comply with all applicable State and Federal laws and regulations in the use of explosives. 

(b) Blasts that use more than 5 pounds of explosive or blasting agent shall be conducted according to the schedule 

required under Section 816.64. 

 

* * * * * 

(d) Blast design. 

(1) An anticipated blast design shall be submitted if blasting operations will be conducted within -- 

(i) 1,000 feet of any building used as a dwelling, public building, school, church, or community or 

institutional building outside the permit area; or 

(ii) 500 feet of an active or abandoned underground mine. 
(2) The blast design may be presented as part of a permit application or at a time, before the blast, approved by 

the regulatory authority. 

(3) The blast design shall contain sketches of the drill patterns, delay periods, and decking and shall indicate the 

type and amount of explosives to be used, critical dimensions, and the location and general description of structures to be 

protected, as well as a discussion of design factors to be used, which protect the pubic and meet the applicable airblast, 

flyrock, and ground-vibration standards in Section 816.67. 

(4) The blast design shall be prepared and signed by a certified blaster. 

(5) The regulatory authority may require changes to the design submitted. 

 6. Section 816.62 is revised to read as follows: 

SECTION 816.62 - USE OF EXPLOSIVES: PREBLASTING SURVEY. 

(a) At least 30 days before initiation of blasting, the operator shall notify, in writing, all residents or owners of dwellings 

or other structures located within 1/2 mile of the permit area how to request a preblasting survey. 

(b) A resident or owner of a dwelling or structure within 1/2 mile of any part of the permit area may request a preblasting 

survey. This request shall be made, in writing, directly to the operator or to the regulatory authority, who shall promptly 

notify the operator. The operator shall promptly conduct a preblasting survey of the dwelling or structure and promptly 

prepare a written report of the survey. An updated survey of any additions, modifications, or renovations shall be 

performed by the operator if requested by the resident or owner. 

(c) The operator shall determine the condition of the dwelling or structure and shall document any preblasting damage 

and other physical factors that could reasonably be affected by the blasting. Structures such as pipelines, cables, 

transmission lines, and cisterns, wells, and other water systems warrant special attention; however, the assessment of 

these structures may be limited to surface conditions and other readily available data. 

(d) The written report of the survey shall be signed by the person who conducted the survey. Copies of the report shall be 

promptly provided to the regulatory authority and to the person requesting the survey. If the person requesting the 

survey disagrees with the contents and/or recommendations contained therein, he or she may submit to both the operator 

and the regulatory authority a detailed description of the specific areas of disagreement. 

(e) Any surveys requested more than 10 days before the planned initiation of blasting shall be completed by the operator 

before the initiation of blasting. 

 7. Section 816.64 is revised to read as follows: 

SECTION 816.64 - USE OF EXPLOSIVES: BLASTING SCHEDULE. 

(a) General requirements. 

(1) The operator shall conduct blasting operations at times approved by the regulatory authority and announced 

in the blasting schedule. The regulatory authority may limit the area covered, timing, and sequence of blasting as listed in 

the schedule, if such limitations are necessary and reasonable in order to protect the public health and safety or welfare. 

(2) All blasting shall be conducted between sunrise and sunset, unless nighttime blasting is approved by the 

regulatory authority based upon a showing by the operator that the public will be protected from adverse noise and other 

impacts. The regulatory authority may specify more restrictive time periods for blasting. 

(3) Unscheduled blasts may be conducted only where public or operator health and safety so require and for 

emergency blasting actions. When an operator conducts an unscheduled blast, the operator, using audible signals, shall 

notify residents within 1/2 mile of the blasting site and document the reason for the unscheduled blast in accordance with 

Section 816.68(p). 

(b) Blasting schedule publication and distribution. 

(1) The operator shall publish the blasting schedule in a newspaper of general circulation in the locality of the 

blasting site at least 10 days, but not more than 30 days, before beginning a blasting program. 
(2) The operator shall distribute copies of the schedule to local governments and public utilities and to each 

local residence within 1/2 mile of the proposed blasting site described in the schedule. 

(3) The operator shall republish and redistribute the schedule at least every 12 months and revise and republish 

the schedule at least 10 days, but not more than 30 days, before blasting whenever the area covered by the schedule 

changes or actual time periods for blasting significantly differ from the prior announcement. 

(c) Blasting schedule contents. The blasting schedule shall contain, at a minimum -- 

(1) Name, address, and telephone number of operator; 

(2) Identification of the specific areas in which blasting will take place; 

(3) Dates and time periods when explosives are to be detonated; 

(4) Methods to be used to control access to the blasting area; and 

(5) Type and patterns of audible warning and all-clear signals to be used before and after blasting. 

SECTION 816.65 [Removed] 

 8. Section 816.65 is removed. 

 9. Section 816.66 is added to read as follows: 

SECTION 816.66 - USE OF EXPLOSIVES: BLASTING SIGNS, WARNINGS, AND ACCESS CONTROL. 

(a) Blasting signs. Blasting signs shall meet the specifications of Section 816.11. The operator shall -- 

(1) Conspicuously place signs reading "Blasting Area" along the edge of any blasting area that comes within 100 

feet of any public road right-of-way, and at the point where any other road provides access to the blasting area; and 

(2) At all entrances to the permit area from public roads or highways, place conspicuous signs which state 

"Warning! Explosives in Use," which clearly list and describe the meaning of the audible blast warning and all-clear 

signals that are in use, and which explain the marking of blasting areas and charged holes awaiting firing within the permit 

area. 

(b) Warnings. Warning and all-clear signals of different character or pattern that are audible within a range of 1/2 mile 

from the point of the blast shall be given. Each person within the permit area and each person who resides or regularly 

works within 1/2 mile of the permit area shall be notified of the meaning of the signals in the blasting schedule. 

(c) Access control. Access within the blasting area shall be controlled to prevent presence of livestock or unauthorized 

persons during blasting and until an authorized representative of the operator has reasonably determined that -- 

(1) No unusual hazards, such as imminent slides or undetonated charges, exist; and 

(2) Access to and travel within the blasting area can be safely resumed. 

 10. Section 816.67 is revised to read as follows: 

SECTION 816.67 - USE OF EXPLOSIVES: CONTROL OF ADVERSE EFFECTS. 

(a) General requirements. Blasting shall be conducted to prevent injury to persons, damage to public or private property 

outside the permit area, adverse impacts on any underground mine, and change in the course, channel, or availability of 

surface or ground water outside the permit area. 
(b) Airblast. -- 

(1) Limits. 

(i) Airblast shall not exceed the maximum limits listed below at the location of any dwelling, public 

building, school, church, or community or institutional building outside the permit area, except as provided in Paragraph 

(e) of this section. 

____________________________________________________________________________________________

Lower frequency limit of measuring system, in Hz (+/- 3 dB) Maximum level, in dB

0.1 Hz or lower -- flat response n1 134 peak.

2 Hz or lower -- flat response 133 peak.

6 Hz or lower -- flat response 129 peak.

C-weighted -- slow response n1 105 peak dBC.

____________________________________________________________________________________________

 n1 Only when approved by the regulatory authority. 

(ii) If necessary to prevent damage, the regulatory authority shall specify lower maximum allowable 

airblast levels than those of Paragraph (b)(1)(i) of this section for use in the vicinity of a specific blasting operation. 

(2) Monitoring. 

(i) The operator shall conduct periodic monitoring to ensure compliance with the airblast standards. 

The regulatory authority may require airblast measurement of any or all blasts and may specify the locations at which 

such measurements are taken. 

(ii) The measuring systems shall have an upper-end flat-frequency response of at least 200 Hz. 

(c) Flyrock. Flyrock travelling in the air or along the ground shall not be cast from the blasting site -- 

(1) More than one-half the distance to the nearest dwelling or other occupied structure; 

(2) Beyond the area of control required under Section 816.66(c); or 

(3) Beyond the permit boundary. 

(d) Ground vibration -- 

(1) General. In all blasting operations, except as otherwise authorized in Paragraph (e) of this section, the 

maximum ground vibration shall not exceed the values approved in the blasting plan required under Section 780.13 of 

this chapter. The maximum ground vibration for protected structures listed in Paragraph (d)(2)(i) of this section shall be 

established in accordance with either the maximum peak-particle-velocity limits of Paragraph (d)(2), the scaled-distance 

equation of Paragraph (d)(3), the blasting-level chart of Paragraph (d)(4) of this section, or by the regulatory authority 

under Paragraph (d)(5) of this section. All structures in the vicinity of the blasting area, not listed in Paragraph (d)(2)(i) 

of this section, such as water towers, pipelines and other utilities, tunnels, dams, impoundments, and underground mines, 

shall be protected from damage by establishment of a maximum allowable limit on the ground vibration, submitted by the 

operator in the blasting plan and approved by the regulatory authority. 

(2) Maximum peak particle velocity. 

(i) The maximum ground vibration shall not exceed the following limits at the location of any dwelling, 

public building, school, church, or community or institutional building outside the permit area: 

____________________________________________________________________________________________

Distance (D) Maximum allowable peak particle Scaled-distance factor to be 

from blasting site velocity (Vmax) for ground applied without seismic 

in feet vibration, in inches/second n1 monitoring n2

0 to 300 1.25 50

301 to 5,000 1.00 55

5,001 and beyond 0.75 65

____________________________________________________________________________________________
 n1 Ground vibration shall be measured as the particle velocity. Particle velocity shall be recorded in three mutually 

perpendicular directions. The maximum allowable peak particle velocity shall apply to each of the three measurements. 

 n2 Applicable to the scaled-distance equation of Paragraph (d)(3)(i) of this section. 

(ii) A seismographic record shall be provided for each blast. 

(3) Scale-distance equation. 

(i) An operator may use the scaled-distance equation, W =(D/D ) 2 , to determine the allowable charge 

weight of explosives to be detonated in any 8-millisecond period, without seismic monitoring; where W =the maximum 

weight of explosives, in pounds; D =the distance, in feet, from the blasting site to the nearest protected structure; and Ds 

=the scaled-distance factor, which may initially be approved by the regulatory authority using the values for 

scaled-distance factor listed in Paragraph (d)(2)(i) of this section. 

(ii) The development of a modified scaled-distance factor may be authorized by the regulatory 

authority on receipt of a written request by the operator, supported by seismographic records of blasting at the minesite. 

The modified scale-distance factor shall be determined such that the particle velocity of the predicted ground vibration 

will not exceed the prescribed maximum allowable peak particle velocity of Paragraph (d)(2)(i) of this section, at a 

95-percent confidence level. 

(4) Blasting-level chart. 

(i) An operator may use the ground-vibration limits in Figure 1 to determine the maximum allowable 

ground vibration. 

 [See Illustration in Original] 

(ii) If the Figure 1 limits are used, a seismographic record including both particle velocity and 

vibration-frequency levels shall be provided for each blast. The method for the analysis of the predominant frequency 

contained in the blasting records shall be approved by the regulatory authority before application of this alternative 

blasting criterion. 

(5) The maximum allowable ground vibration shall be reduced by the regulatory authority beyond the limits 

otherwise provided by this section, if determined necessary to provide damage protection. 

(6) The regulatory authority may require an operator to conduct seismic monitoring of any or all blasts or may 

specify the location at which the measurements are taken and the degree of detail necessary in the measurement. 

(e) The maximum airblast and ground-vibration standards of paragraphs (b) and (d) of this section shall not apply at the 

following locations: 

(1) At structures owned by the permittee and not leased to another person. 

(2) At structures owned by the permittee and leased to another person, if a written waiver by the lessee is 

submitted to the regulatory authority before blasting. 

 11. Section 816.68 is revised to read as follows: 

SECTION 816.68 - USE OF EXPLOSIVES: RECORDS OF BLASTING OPERATIONS. 

 The operator shall retain a record of all blasts for at least 3 years. Upon request, copies of these records shall be made 

available to the regulatory authority and to the public for inspection. Such records shall contain the following data: 

(a) Name of the operator conducting the blast. 

(b) Location, date, and time of the blast. 

(c) Name, signature, and certification number of the blaster conducting the blast. 

(d) Identification, direction, and distance, in feet, from the nearest blast hole to the nearest dwelling, public building, 

school, church, community or institutional building outside the permit area, except those described in Section 816.67(e). 

(e) Whether conditions, including those which may cause possible adverse blasting effects. 
(f) Type of material blasted. 

(g) Sketches of the blast pattern including number of holes, burden, spacing, decks, and delay pattern. 

(h) Diameter and depth of holes. 

(i) Types of explosives used. 

(j) Total weight of explosives used per hole. 

(k) The maximum weight of explosives detonated in an 8-millisecond period. 

(l) Initiation system. 

(m) Type and length of stemming. 

(n) Mats or other protections used. 

(o) Seismographic and airblast records, if required, which shall include -- 

(1) Type of instrument, sensitivity, and calibration signal or certification of annual calibration; 

(2) Exact location of instrument and the date, time, and distance from the blast; 

(3) Name of the person and firm taking the reading; 

(4) Name of the person and firm analyzing the seismographic record; and 

(5) The vibration and/or airblast level recorded. 

(p) Reasons and conditions for each unscheduled blast. 

PART 817 -- PERMANENT PROGRAM PERFORMANCE STANDARDS -- UNDERGROUND MINING 

ACTIVITIES 

SECTION 817.11 [Amended] 

 12. Section 817.11 is amended by removing paragraph (f) and redesignating paragraph (g) as paragraph (f). 

 13. Section 817.61 is amended by revising paragraphs (a) and (b) and adding paragraph (d) to read as follows: 

SECTION 817.61 - USE OF EXPLOSIVES: GENERAL REQUIREMENTS. 

(a) Sections 817.61 -- 817.68 apply to surface blasting activities incident to underground coal mining, including, but not 

limited to, initial rounds of slopes and shafts. 

(b) Each operator shall comply with all applicable State and Federal laws and regulations in the use of explosives. 

 

* * * * * 

(d) Blast design. 

(1) An anticipated blast design shall be submitted if blasting operations will be conducted within -- 

(i) 1,000 feet of any building used as a dwelling, public building, school, church or community or 

institutional building; or 

(ii) 500 feet of active or abandoned underground mines. 

(2) The blast design may be presented as part of a permit application or at a time, before the blast, approved by 

the regulatory authority. 
(3) The blast design shall contain sketches of the drill patterns, delay periods, and decking and shall indicate the 

type and amount of explosives to be used, critical dimensions, and the location and general description of structures to be 

protected, as well as a discussion of design factors to be used, which protect the public and meet the applicable airblast, 

flyrock, and ground-vibration standards in Section 817.67. 

(4) The blast design shall be prepared and signed by a certified blaster. 

(5) The regulatory authority may require changes to the design submitted. 

 14. Section 817.62 is revised to read as follows: 

SECTION 817.62 - USE OF EXPLOSIVES: PREBLASTING SURVEY. 

(a) At least 30 days before initiation of blasting, the operator shall notify, in writing, all residents or owners of dwellings 

or other structures located within 1/2 mile of the permit area how to request a preblasting survey. 

(b) A resident or owner of a dwelling or structure within 1/2 mile of any part of the permit area may request a preblasting 

survey. This request shall be made, in writing, directly to the operator or to the regulatory authority, who shall promptly 

notify the operator. The operator shall promptly conduct a preblasting survey of the dwelling or structure and promptly 

prepare a written report of the survey. An updated survey of any additions, modifications, or renovations shall be 

performed by the operator if requested by the resident or owner. 

(c) The operator shall determine the condition of the dwelling or structure and shall document any preblasting damage 

and other physical factors that could reasonably be affected by the blasting. Structures such as pipelines, cables, 

transmission lines, and cisterns, wells, and other water systems warrant special attention; however, the assessment of 

these structures may be limited to surface conditions and other readily available data. 

(d) The written report of the survey shall be signed by the person who conducted the survey. Copies of the report shall be 

promptly provided to the regulatory authority and to the person requesting the survey. If the person requesting the 

survey disagrees with the contents and/or recommendations contained therein, he or she may submit to both the operator 

and the regulatory authority a detailed description of the specific areas of disagreement. 

(e) Any surveys requested more than 10 days before the planned initiation of blasting shall be completed by the operator 

before the initiation of blasting. 

 15. Section 817.64 is revised to read as follows: 

SECTION 817.64 - USE OF EXPLOSIVES: GENERAL PERFORMANCE STANDARDS. 

(a) The operator shall notify, in writing, residents within 1/2 mile of the blasting site and local governments of the 

proposed times and locations of blasting operations. Such notice of times that blasting is to be conducted may be 

announced weekly, but in no case less than 24 hours before blasting will occur. 

(b) Unscheduled blasts may be conducted only where public or operator health and safety so requires and for emergency 

blasting actions. When an operator conducts an unscheduled surface blast incidental to underground coal mining 

operations, the operator, using audible signals, shall notify residents within 1/2 mile of the blasting site and document the

reason in accordance with Section 817.68(p). 

(c) All blasting shall be conducted between sunrise and sunset unless nighttime blasting is approved by the regulatory 

authority based upon a showing by the operator that the public will be protected from adverse noise and other impacts. 

The regulatory authority may specify more restrictive time periods for blasting. 
SECTION 817.65 [Removed] 

 16. Section 817.65 is removed. 

 17. Section 817.66 is added to read as follows: 

SECTION 817.66 - USE OF EXPLOSIVES: BLASTING SIGNS, WARNINGS, AND ACCESS CONTROL. 

(a) Blasting signs. Blasting signs shall meet the specifications of Section 817.11. The operator shall -- 

(1) Conspicuously place signs reading "Blasting Area" along the edge of any blasting area that comes within 100 

feet of any public-road right-of-way, and at the point where any other road provides access to the blasting area; and 

(2) At all entrances to the permit area from public roads or highways, place conspicuous signs which state 

"Warning! Explosives in Use," which clearly list and describe the meaning of the audible blast warning and all-clear 

signals that are in use, and which explain the marking of blasting areas and charged holes awaiting firing within the permit 

area. 

(b) Warnings. Warning and all-clear signals of different character or pattern that are audible within a range of 1/2 mile 

from the point of the blast shall be given. Each person within the permit area and each person who resides or regularly 

works within 1/2 mile of the permit area shall be notified of the meaning of the signals in the blasting notification 

required in Section 817.64(a). 

(c) Access control. Access within the blasting areas shall be controlled to prevent presence of livestock or unauthorized 

persons during blasting and until an authorized representative of the operator has reasonably determined that --

(1) No unusual hazards, such as imminent slides or undetonated charges, exist; and 

(2) Access to and travel within the blasting area can be safely resumed. 

 18. Section 817.67 is revised to read as follows: 

SECTION 817.67 - USE OF EXPLOSIVES: CONTROL OF ADVERSE EFFECTS. 

(a) General requirements. Blasting shall be conducted to prevent injury to persons, damage to public or private property 

outside the permit area, adverse impacts on any underground mine, and change in the course, channel, or availability of 

surface or ground water outside the permit area. 

(b) Airblast. --

(1) Limits. 

(i) Airblast shall not exceed the maximum limits listed below at the location of any dwelling, public 

building, school, church, or community or institutional building outside the permit area, except as provided in Paragraph 

(e) of this section. 

___________________________________________________________________________________________

Lower frequency limit of measuring system, in Hz (+/- 3 dB) Maximum level, in dB

0.1 Hz or lower -- flat response n1 134 peak.

2 Hz or lower -- flat response 133 peak.

6 Hz or lower -- flat response 129 peak.

C-weighted -- slow response n1 105 peak dBC.

____________________________________________________________________________________________

 n1 Only when approved by the regulatory authority. 

(ii) If necessary to prevent damage, the regulatory authority may specify lower maximum allowable 

airblast levels than those of Paragraph (b)(1)(i) of this section for use in the vicinity of a specific blasting operation. 
(2) Monitoring. 

(i) The operator shall conduct periodic monitoring to ensure compliance with the airblast standards. 

The regulatory authority may require airblast measurement of any or all blasts and may specify the locations at which 

such measurements are taken. 

(ii) The measuring systems used shall have an upper-end flat-frequency response of at least 200 Hz. 

(c) Flyrock. Flyrock travelling in the air or along the ground shall not be cast from the blasting site -- 

(1) More than one-half the distance to the nearest dwelling or other occupied structure; 

(2) Beyond the area of control required under Section 817.66(c); or 

(3) Beyond the permit boundary. 

(d) Ground vibration. --

(1) General. In all blasting operations, except as otherwise authorized in paragraph (e) of this section, the 

maximum ground vibration shall not exceed the values approved by the regulatory authority. The maximum ground 

vibration for protected structures listed in paragraph (d)(2)(i) of this section shall be established in accordance with either 

the maximum peak-particle-velocity limits of paragraph (d)(2), the scaled-distance equation of paragraph (d)(3), the 

blasting-level chart of paragraph (d)(4) of this section, or by the regulatory authority under paragraph (d)(5) of this 

section. All structures in the vicinity of the blasting area, not listed in paragraph (d)(2)(i) of this section, such as water 

towers, pipelines and other utilities, tunnels, dams, impoundments, and underground mines shall be protected from 

damage by establishment of a maximum allowable limit on the ground vibration, submitted by the operator and approved 

by the regulatory authority before the initiation of blasting. 

(2) Maximum peak-particle velocity. 

(i) The maximum ground vibration shall not exceed the following limits at the location of any dwelling, 

public building, school, church, or community or institutional building outside the permit area: 

____________________________________________________________________________________________

Distance (D) Maximum allowable peak particle Scaled-distance factor to be 

from blasting site velocity (Vmax) for ground applied without seismic 

in feet vibration, in inches/second n1 monitoring n2

0 to 300 1.25 50

301 to 5,000 1.00 55

5,001 and beyond 0.75 65

___________________________________________________________________________________________

 n1 Ground vibration shall be measured as the particle velocity. Particle velocity shall be recorded in three mutually 

perpendicular directions. The maximum allowable peak particle velocity shall apply to each of the three measurements. 

 n2 Applicable to the scaled-distance equation of Paragraph (d)(3)(i) of this section. 

(ii) A seismographic record shall be provided for each blast. 

(3) Scaled-distance equation. 

(i) An operator may use the scaled-distance equation, W =(D/Ds ) 2 , to determine the allowable 

charge weight of explosives to be detonated in any 8-millisecond period, without seismic monitoring; where W =the 

maximum weight of explosives, in pounds; D =the distance, in feet, from the blasting site to the nearest protected 

structure; and Ds =the scaled-distance factor, which may initially be approved by the regulatory authority using the 

values for scaled-distance factor listed in Paragraph (d)(2)(i) of this section. 

(ii) The development of a modified scaled-distance factor may be authorized by the regulatory 

authority on receipt of a written request by the operator, supported by seismographic records of blasting at the minesite. 

The modified scaled-distance factor shall be determined such that the particle velocity of the predicted ground vibration 

will not exceed the prescribed maximum allowable peak particle velocity of paragraph (d)(2)(i) of this section, at a 

95-percent confidence level. 

(4) Blasting-level chart. 

(i) An operator may use the ground-vibration limits in Figure 1 to determine the maximum allowable 

ground vibration. 
 [See Illustration in Original] 

(ii) If the Figure 1 limits are used, a seismographic record including both particle velocity and 

vibration-frequency levels shall be provided for each blast. The method for the analysis of the predominant frequency 

contained in the blasting records shall be approved by the regulatory authority before application of this alternative 

blasting criterion. 

(5) The maximum allowable ground vibration shall be reduced by the regulatory authority beyond the limits 

otherwise provided by this section, if determined necessary to provide damage protection. 

(6) The regulatory authority may require an operator to conduct seismic monitoring of any or all blasts and may 

specify the location at which the measurements are taken and the degree of detail necessary in the measurement. 

(e) The maximum airblast and ground-vibration standards of paragraphs (b) and (d) of this section shall not apply at the 

following locations: 

(1) At structures owned by the permittee and not leased to another person, 

(2) At structures owned by the permittee and leased to another person, if a written waiver by the lessee is 

submitted to the regulatory authority before blasting. 

 19. Section 817.68 is revised to read as follows: 

SECTION 817.68 - USE OF EXPLOSIVES: RECORDS OF BLASTING OPERATIONS. 

 The operator shall retain a record of all blasts for at least 3 years. Upon request, copies of these records shall be made 

available to the regulatory authority and to the public for inspection. Such records shall contain the following data: 

(a) Name of the operator conducting the blast. 

(b) Location, date, and time of the blast. 

(c) Name, signature, and certification number of the blaster conducting the blast. 

(d) Identification, direction, and distance, in feet, from the nearest blast hole to the nearest dwelling, public building, 

school, church, community or institutional building outside the permit area, except those described in Section 817.67 (e). 

(e) Weather conditions, including those which may cause possible adverse blasting effects. 

(f) Type of material blasted. 

(g) Sketches of the blast pattern including number of holes, burden, spacing, decks, and delay pattern. 

(h) Diameter and depth of holes. 

(i) Types of explosives used. 

(j) Total weight of explosives used per hole. 

(k) The maximum weight of explosives detonated in an 8-millisecond period. 

(l) Initiation system. 

(m) Type and length of stemming. 

(n) Mats or other protections used. 
(o) Seismographic and airblast records, if required, which shall include -- 

(1) Type of instrument, sensitivity, and calibration signal or certification of annual calibration; 

(2) Exact location of instrument and the date, time, and distance from the blast; 

(3) Name of the person and firm taking the reading; 

(4) Name of the person and firm analyzing the seismographic record; and 

(5) The vibration and/or airblast level recorded. 

(p) Reasons and conditions for each unscheduled blast. 

 Authority: Pub. L. 95-87, 30 U.S.C. 1201 et seq. 

[FR Doc. 83-5565 Filed 3-7-83; 8:45 am] 

BILLING CODE 4310-05-M