(a) Each operator shall take representative samples of the concentration of respirable dust in the active workings of the mine as required by this part only with an approved CMDPSU. On February 1, 2016, the operator may use an approved CPDM if the operator notifies the District Manager in writing that only an approved CPDM will be used for all DWP sampling at the mine. The notification must be received at least 90 days before the beginning of the quarter in which CPDMs will be used to collect the DWP samples.

(b) Sampling devices shall be worn or carried directly to and from the DWP to be sampled. Sampling devices shall remain with the DWP and shall be operational during the entire shift, which includes the total time spent in the DWP and while traveling to and from the DWP being sampled. If the work shift to be sampled is longer than 12 hours and the sampling device is:

(1) A CMDPSU, the operator shall switch-out the unit's sampling pump prior to the 13th-hour of operation.

(2) A CPDM, the operator shall switch-out the CPDM with a fully charged device prior to the 13th-hour of operation.

(c) If using a CMDPSU, one control filter shall be used for each shift of sampling. Each control filter shall:

(1) Have the same pre-weight data (noted on the dust data card) as the filters used for sampling;

(2) Remain plugged at all times;

(3) Be used for the same amount of time, and exposed to the same temperature and handling conditions as the filters used for sampling; and

(4) Be kept with the exposed samples after sampling and in the same mailing container when transmitted to MSHA.

(d) Records showing the length of each normal work shift for each DWP shall be made and retained for at least six months and shall be made available for inspection by authorized representatives of the Secretary and the representative of miners, and submitted to the District Manager when requested in writing.

(e) Upon request from the District Manager, the operator shall submit the date and time any respirable dust sampling required by this part will begin. This information shall be submitted at least 48 hours prior to scheduled sampling.

(f) Upon written request by the operator, the District Manager may waive the rain restriction for a normal work shift as defined in §71.2 for a period not to exceed two months, if the District Manager determines that:

(1) The operator will not have reasonable opportunity to complete the respirable dust sampling required by this part without the waiver because of the frequency of rain; and

(2) The operator did not have reasonable opportunity to complete the respirable dust sampling required by this part prior to requesting the waiver.

(g) Operators using CPDMs shall provide training to all miners expected to wear the CPDM. The training shall be completed prior to a miner wearing the CPDM and then every 12 months thereafter. The training shall include:

(1) The importance of monitoring dust concentrations and properly wearing the CPDM;

(2) Explaining the basic features and capabilities of the CPDM;

(3) Discussing the various types of information displayed by the CPDM and how to access that information; and

(4) How to start and stop a short-term sample run during compliance sampling.

(h) An operator shall keep a record of the CPDM training at the mine site for 24 months after completion of the training. An operator may keep the record elsewhere if the record is immediately accessible from the mine site by electronic transmission. Upon request from an authorized representative of the Secretary, Secretary of HHS, or representative of miners, the operator shall promptly provide access to any such training records. The record shall include:

(1) The date of training;

(2) The names of miners trained; and

(3) The subjects included in the training.