The ETS, which became effective May 22, is only the fourth such act in 30 years. Its focus, intended to illustrate the hazards posed by seal failure, includes improvement of the design, construction, maintenance and repair of seals and new requisites for the sampling of air behind seals and keeping it at controlled levels.
MSHA pointed out the ETS’s authority as a regulation, as the publication of the ETS overrides the Public Information Bulletin (PIB) and Program Instruction Letter previously released for the topic – PIB 06-16 and PIL I06-V-09.
The compliance assistance tips, published in a question-and-answer format, also laid out specific items that are vital to all operations, including the fact that 20psi seals are no longer acceptable under federal rules for new construction.
“The ETS applies to all seals. If at any time a gob isolation stopping is used as a seal or becomes a seal, then it must meet the ETS requirements. Sampling and monitoring must be addressed in the protocol as specified in the ETS and in the spontaneous combustion control plan submitted as part of the ventilation plan,” it said, adding that all operators must submit their ventilation plan revisions to MSHA no later than June 21.
For seals that are already under construction, MSHA noted, work progression does not need to be discontinued: “This construction must be completed by June 21, 2007. However, the mine operator must comply with the new seal requirements for construction examination and certification under 75.337.”
Sampling was also a topic of discussion, with the agency clarifying its standing on sampling protocol. According to MHSA, those methods, techniques and equipment, while not regulated, should be “appropriate” and operators should use “generally accepted methods” for sampling at their own mines, as well as employ the use of detectors or analyses for gas concentration determinations.
Because federal requirements include a 14-day sampling period, the agency also noted that sealed atmospheres should be sampled in each seal through both sampling pipes.
“To determine which sampling pipe in which seal should be used for monitoring under the protocol, mine operators should use the results of the 14-day sampling period,” it said.
“For example, if the results of the samples taken during the 14-day sampling period through both sampling pipes are similar, then only one pipe may need to be used.
“Additionally, if sampling results for all seals in a set of seals are similar, then only one seal in that set of seals may need to be sampled.”
When both solid concrete block seals and 20psi alternative seals are employed, with the former outby, MSHA noted that two runs of sampling must be completed to remain in compliance.
“Both the area between the solid concrete block seals and the 20psi alternative seals and the area inby the old 20psi seals must be monitored and maintained inert as specified in 75.335(b),” the agency said.
However, it added, “the area inby the 20psi seals may be monitored through boreholes from the surface, from within the mine, or from another method that is approved by the district manager.”
The agency considered questions on training, another factor that is part of the new ETS. Workers who repair or construct seals, those who examine them during construction, and senior mine management who are responsible for post-construction approval must be trained prior to any work done. Certified samplers must have completed their training no later than June 21.
Also addressed with MSHA was a report released by the National Institute for Occupational Safety and Health (NIOSH), a draft document that examines a 120psi pressure-time curve and is noted in the ETS’s introduction. In response to the inquiry on whether that 120psi pressure-time curve for 120psi seals from the draft report could be used in a mine’s engineering design application, MSHA said that it would be permissible if the mine’s “atmospheric conditions within the sealed area are consistent with those assumed in the 2007 NIOSH Draft Report”.
It elaborated: “The pressure-time curve provided by NIOSH for the 120psi overpressure is based on an explosion occurring from an accumulation of methane located adjacent to the seal with an inert atmosphere in the rest of the sealed area.
“Therefore, if the 120psi pressure-time curve from the 2007 NIOSH Draft Report is used, it must be specified in the design application that the mine operator will determine that an explosive mixture may be present only for a short distance behind the seal, but the rest of the atmosphere in the sealed area will be inert.”
The agency added that operators must sample that sealed area to determine if the specifications of design were indeed followed.
To collect information on the ETS from the industry public, the agency said last month it will hold four meetings throughout the US where attendees are invited to speak and share opinions.
The first will be held July 10 in Morgantown, West Virginia at the Lakeview Golf Resort, while the others will be hosted by the Crowne Plaza Hotel in Lexington, Kentucky (July 12), the Embassy Suites Denver in Colorado (July 17) and the Sheraton Birmingham Hotel in Alabama (July 19).
The comment period will close on July 6. For the complete ETS or for information on the public hearings and process for submitting input, visit http://www.msha.gov/Seals/SealsSingleSource2007.asp.
