2015-12-03_GENERAL DOCUMENTS - M1974070 (5)

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I Page 2) MINE ID # OR PROSPECTING ID # M-1974-069 INSPECTION DATE 10/09/02 INSPECTOR'S INITIALS ESC OBSERVATIONS This was an inspection of the Larimer Pit, File No. M-1974-069 conducted by Erica Crosby of the Colorado Division of Minerals & Geology. Brad Fancher of Loveland Ready Mix Concrete, Inc. was present during the inspection. The initial Land Stabilization and Reclamation Agreement was issued to Loveland Ready Mix on August 12'h, 1974. A 112 Construction Materials permit was issued for the Larimer Pit on July 31, 1979 which also increased the permit area to 195 acres. The postmining land use is recreation and the Division holds a bond in the amount of $47,200.00. The Larimer Pit is an active operation located adjacent to the Big Thompson River. Within the 195-acre permit area, there are 17 mining pits. Pits/ponds 1-12 were mined prior to 1980 and have been reclaimed to ground water lakes. Pits/ponds 3-6 currently act as a series of siltation ponds and water supply ponds for the active mining operation. These ponds will eventually be filled with fines and converted to wetland habitat. In addition, the operator also stated that Pit/pond 14 will be filled with fines and converted to wetland habitat. The reclamation plan approved by the Division leaves all of the mining pits as groundwater lakes. By filling in these ponds with fines, the reclamation aspects have changed. The operator will need to revise the reclamation plan in the permit to reflect the construction of wetland habitats. See page 4 for further detail. The pits that remain as ground water ponds include #1, #2, #7, #9, #12, #13 and #15. All of these ponds are well vegetated with perennial grasses and trees. The operator has obtained a temporary substitute water supply plan for the evaporative loss associated with these ponds. Pit #8 is currently being used to dispose of off site backfill and concrete material. Trees and wood products were noted mixed with the concrete material. Trees and wood products are not considered inert material, and will need to be removed from the pit. Rule 3.1.5(9) of the Construction Materials Rules & Regulations states that if an operator intends to backfill inert structural fill generated outside of the approved permit area, it is the operator's responsibility to provide the Division notice of any proposed backfill activity not identified in the approved reclamation plan. This activity was not approved in the reclamation plan, and no notice was given to the Division regarding disposal of offsite material in the pit as required in the rules and regulations. Because inert fill has already been placed in the pit the Division considers this a problem that needs to be addressed. A copy of the rule regarding use of inert fill is enclosed. See page 4 for corrective action and compliance due date. Mining and reclamation is actively taking place in Pit #17. Pits #16 and #17 will be converted into two water storage reservoirs. The pits are currently lined with shale material to prevent the seepage of groundwater. The operator stated that Pit #16 has currently been approved by OSE as a sealed reservoir. The reclamation plan approved by the Division leaves all of the mining pits as groundwater lakes. By converting two of these pits to a developed water storage reservoir, the reclamation aspects have significantly changed. The operator will need to revise the reclamation plan in the form of an amendment to the permit to reflect the construction of developed water resource. See page 4 for corrective action and compliance due dates.