INSPEC10317 - Laserfiche WebLink

Home Browse Search

(Page 2) MINE ID # OR PROSPECTING ID ;# M-83-090 INSPECTION DATE 05/14/99 INSPECTOR'S INITIALS ESC OBSERVATIONS The La Poudre S & G site is located in Weld County south of State Highway 392. The mine was transferred from La Poudre Saud & Gravel Inc. to Hall-Irwin Construction Company in 1994. An inspection was conducted by :3rica Crosby and Carl Mount of the Division in response to a complaint letter from Don Neuwerth of Sinclair Pipeline Company. The letter was received by the Division by fax on May 11, 1999 and an inspection of the site was conducted on May 14, 1999. The letter from Sinclair states that recent flooding on the Poudre River has created a potentially dangerous situation on the Sinclair, Wyoming to Denver 6" refined petroleum products pipeline where it crosses Hall-Irwin's LaPOUdre gravel mining operation. During high water conditions on May 2, 1999 river water filled the Western pit and overflowed into the Eastern pit across the marrow strip of land containing the pipeline. The subsequent erosion undermined the pipeline causing Sinclair to shut it down. Sinclair contends they have been damaged (inspection and repair cost) by the gravel mining operation and that Hall- Irwin should provide an engineering remedy that will prevent the situation from reoccurring. The Sinclair petroleum pipeline is located between Pits ~g and #~'as noted on the Reclamation Plan Map. The pipeline corridor runs north-south through the permit area. Pond #yJyis located to the west of the pipeline and Pond #,6'sis towards the east. The berm located between the two ponds is roughly 50-60 feet wide. Jeff Gregg estimates the Sinclair pipeline is roughly 4 feet deep in they middle of the berm. It appears that mining activities were within 25 feet on either side of the pipeline. According to the operator, the Poudre River overtopped its banks in two locations; through the mine entrance to the west and over State Hwy 392 to the north. The breach from the west filled up Pit #~~ which was erzipty at the time. The operator stated that mining activity is complete and the pit was recently backfilled and graded to 3h:ly slopes. Pit #~,SYfilled with water within 4-6 hours and ova=_rtopped towards the east into Pit #~'.~ The water eventually breached through the narrow strip of land roughly 50 feet wide by 30 feet long exposing the pipeline. Prior to the Division's inspection, the pipeline corridor was partially backfilled by the Sinclair Pipeline Company to minimize exposure. The approved reclamation plan map notes a 30-foot wide buffer between the pits with a final grading of 3h:ly. A 24" culvert connecting the two pits is also included in the design, but was not in place during the time of the inspection. It is apparent thaC the reclamation plan does not adequately address protection of the pipeline from slides or damage as a result of the mining or reclamation operations. Under the Construction Material Rules and Regulations, areas outside of the affected land shall be protected from slides or damage occurring during the mining and reclamation operation [C.R.S. 34-32.5-116 (4)(i)]. The operator will need to file a revision to the permit to adequately address stability of the pipeline corridor. Please see page 4 for compliance due dates. However, in the meantime the operator will need to provide a short term solution while the revision is in the process of being filed and reviewed. During the inspection, it was noted that a slurry wall has been constructed around Pits #5 ~~' and #d5 A review of the permit file notes that the current final land use after reclamation is open space, conservation an3 recreation. The Division considers construction of a water reservoir to be a `significant change' to the reclamation plan and approved post mine land use, which as defined by Rule 1.1(6) requires that an amendment to the permit be obtained from the Division to change the final land use.