INSPEC35731 - Laserfiche WebLink

Home Browse Search

• (Page 2) • MINE ID # OR PROSPECTING ID # M-77-560 INSPECTION DATE 06/01/94 INSPECTOR'S INITIALS RCO OBSERVATIONS This inspection was conducted by the Division in part to monitor the operation of the existing pit, assess the site of the planned expansion before its operations begin, and to assess the adequacy of the existing bond amount for the existing pit. The operator was met at his office for an initial meeting, then the site was visited by this inspector accompanied by the operator. The proposed expansion area was given a complete inspection; the existing area was partially inspected. This report will cover topics relevant to both the existing and proposed operations. EXISTING PIT: The identification sign and markers adequately delineating the boundary were present. The operation has a stormwater permit (the amendment application file contains the stormwater permit number for the existing pit). There is a 52250 bond for this operation. This may be found to be an insufficient amount. When new figures are calculated by the Division, they will be forwarded to the operator for review. The main portion of the operation is a pond. It is being mined to the west, at a depth of about 25 feet below the grade of surrounding land, The water level is about 10 feet below what it would be naturally, because of a drainage structure on the northeast part of the banks. The operator states that the structure will be eliminated, when the mining ie finished or when the DOW (who has expressed interest in managing the pond) takes over the area. A 7.22-acre portion of the pond, on the southeast corner, is not included in the permit area. That portion is entirely contiguous with the permitted portion, and was apparently not included because it was existing in 1977 and was not to be disturbed. The banks are well vegetated. All topsoil is salvaged and stockpiled in the permit area, on the north side. All overburden is likewise stockpiled on the north side. All material from the pit is processed (mainly batching for use as concrete) or stockpiled in an area to the west of the pit. However, these piles, facilities, equipment areas and offices are outside of the permit area. No material from other pits is processed here. A review of the files shows that the Division noticed this in a 1985 inspection, stating that this area should be incorporated into the permit area. There is no response or action from Valco noted in the files. Inasmuch as this process and batch plant is a "captive" operation (using material from this pit only), and therefore could be regarded as part of the mining operation, operator should take this opportunity to either bring this area into the permit, or explain why it need not be. This ~ is noted as a problem in the records, and must be addressed as shown on the last page. If ~~ it is not resolved, this may become a possible violation for offsite damage. The margins of the existing pit are not completely stable. Though no material is leaving the sits, there appears to be ongoing slumping of unconsolidated material of the banks into the pond. The material most subject to said slumping is that part from just above the waterline ' down to that that part underwater. These saturated silts, sands, etc., are not graded to a stable slope, or topsoiled, or revegetated. There is ample evidence of stable banks at this pond. The operation was originally to be reclaimed in an ongoing fashion, and bond was set accordingly. The operator should either begin reclaiming all those areas that are not to be rediaturbed, or be willing to provide a more substantial bond for the larger amount of unreclaimed area. At the very least, and even though the water level may eventually be higher, the operator may wish to consider stabilizing the slopes by grading and planting willow or cottonwood stubs at the waterline, to begin catching the eroding material. PROPOSED PIT EXPANSION (AMENDMENT): The adequacy issues were discussed before and during the inspection of the expansion area. There are several items regarding the descriptions of the area, structures, and operations which need to be clarified. (These are covered in detail in an adequacy letter. ) The site is located to the east of the existing permit area, separated by a county road. It is an open, fairly level grassy field. The application referenced several easements for ditches, wells and utilities. These were seen on the site, and applicable setbacks were discussed. The grass is due to the revegetation efforts of the prior landowner, City of Aurora, who still has some court-decreed obligation over its revegetation. Aurora must be cleared of any future obligations before any mining may occur. There is apart of the proposed operation which will potentially impact the unpermitted (7.22 ~ acre) portion of the existing pit. The operation is to bring water from the west pit to the