INSPEC05861 - Laserfiche WebLink

Home Browse Search

~~ L MIfdE ID # OR PROSPECTING ID #: M-77-J51 INSPECTION DATE: ns-ni-nn (Page 4) INSPECTOR'S INITIALS: raM observed swimming in the pond. The water was a greenish color probably attributable to algal growth. The impoundment serves to lessen sedimentation to surrounding areas, however, the operator needs to check with the Office of the State Engineer to see if this impoundment is permitted. It may be possible to obtain a permit for acattle-watering impoundment. Within 60 days, the operator must provide the DMG with documentation demonstrating that the impoundment is permitted. See PB 1. Acid mine drainage (AMD) has indeed been observed issuing from the Hogback Mine just south of this property. It is believed that this drainage Flows from mine workings located in the Dakota formation clays. At the time the Lariat Mine permit amendment was considered and issued, this problem was not known. The present permit allows the underground mining of clays from the Dakota formation, The present permit requires the operator to leave a barrier of clay that is four times the thickness of the seam mined between mine workings and the surface to mitigate subsidence (see adequacy answer letter dated and received February 23, 1987). Also, Robco has committed to backfilling to the surface and reclaiming any caving due to post-law underground mining (see page 16-Reclamation Plan in the first adequacy response received February 10, 1987). DMG believes that these measures will help to mitigate and lessen the chance of AMD at this site. We have no evidence at the present time that AMD is flowing from this site. DMG will continue to monitor this situation. If AMD is observed at any time and it can be demonstrated that it is a result of post law mining activities then DMG will take action. 9. "...Robinson apparently does not have a decreed augmentation plan or approved substitute supply plan from the State Engineer's Office for replacement of the water detained at the existing Lariat mine." This matter will be referred to the Office of the State Engineer (see also number 8 above and PBl). 10. ...according to Amended Permit no. M-77-251, a maximum of 39 acres may be disturbed at any time under the permit. Mr. Stockwell requests an evaluation be made of the disturbed acreage to determine if Robinson is Complying with Amended Permit No. M-77-251." The permit document was investigated and it was found that "No more that (sic) 35 acres will be disturbed at any one time; 2 mining areas will be active in Stage 1 (13.4 acres + or -each); and 8.20 acres + or -will be in various phases of reclamation. Initial reclamation will begin in approximately 10 years. After Stage 1 is complete, no more than 21 acres will be disturbed at any one time. In either stage, once the maximum disturbance is met, no additional acreage will be disturbed until and (sic) equivalent acreage is released by the MLRB." The DMG paced the present area of disturbance and it was found that an area roughly 1410 feet long by 165 feet wide was disturbed in the actual mine area for a total of 5.3 acres of disturbance. This is well within the allowed disturbance under the permit. The access road is designated on the maps and was considered at the time of permit issuance as a pre-law road and that road has only been maintained up to this point. Therefore, Robco is not responsible for its reclamation. The follow-up letter of May 9, 2000 essentially asked the question of whether Robco could begin mining in Stage 2 at this time in light of a statement on page 9 of the permit. The statement quoted from the permit was, "Mining in Stage 2 will not begin until all of the surface mining operation in Stage I is complete." In view of this statement, the DMG believes that mining cannot take place in Stage 2 until all of the surface mining operation in Stage 1 is complete. However, this does not preclude Robco from exploration and testing of the resources in Stage Z. Nor does it preclude the operator from changing the permit document to allow mining to take place in Stage 2. Such a change could take the form of a technical revision to the permit so long as the affected land acreage was not increased and no significant change to the reclamation plan was proposed. As to the contention that Robco and Mr. Stockwell do not have any agreement as to surface damages nor have the parties entered into a surface lease, Ms. Beyer-Ulrich is referred to the DMG answer to item one of this inspection report.