1999-06-07_GENERAL DOCUMENTS - C1981048 (3)

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STATE OF COLORADO DIVISION OF MINERALS AND GEOLOGY Department of Natural Resources 1313 Sherman St., Room 215 Denver,Colorado 80203 D I V I S I O N O F Phone:(303)866-3567 M I N E RA L S FAX:(303)832-8106 st GEOLOGY RECLAMATION MINING-SAFETY DATE: June 7, 1999 Bill Owens TO: All Bidders on the Trinidad Basin Mine Project Governor Greg E.Walcher Executive Director FROM: Gary Curtiss, Division of Minerals and Geology Michael B.Long Division Director RE: Amendment No. 2 to PKA-9-440 Thank you for your interest in the Pre-Bid Meeting. The following clarifications and amendments should be noted and incorporated into the bid documents: 1. Task 2, Removal of Pond 15-P1 —The embankment material may be placed to the north, northwest and northeast to achieve a uniform slope. Material may be placed in low spots in the weed covered area to the northeast to achieve a uniform grade. Portions of the weed infested area filled with at least 2 feet of pond embankment material will not need to be sprayed as required in Task 14. 2. Task 4—The overall width of the channel cross-section, including the side slopes is 24 feet, not 30 feet as shown on Drawing 2 of the original bid document. The check dam footprint has been changed slightly. Enclosed are Figures 1 A and 2A to clarify the channel and check dam construction. The crest andtkey of each check dam will now be curved in an upstream direction (See figure 1A). Disregard the reference to geotextile placement in Drawing 2 of the original bid document. The geotextile is shown on Figure 2A enclosed. The original bid document discusses armoring the area where the new channel meets the culvert at the county road and references Drawing 4. Some changes have been made to the armoring requirements, therefore, disregard the reference to Drawing 4 and refer instead to Figure 3A, enclosed. The road embankment around the culvert on both sides of the road will be armored with a grouted rock wall. The wall will be at least 12 inches thick and will be constructed of durable rip-rap having a minimum D-50 of 9 inches and a D maximum of 18 inches. At least the outer 4 inches of the rock wall will be cement-grouted with a commercially available sand and cement mix with a minimum compressive strength of 3,500 psi at 28 days. 3. Task 6— Please delete the Culvert Maintenance portion of the task. This is no longer required. 4. Task 7 -The single fence rock check dam will not be constructed at the drainage crossing near the crest of the access road. Instead, the gully below the road will be backfilled with on site material to the approximate original embankment contours. Material will be backfilled in the deep gully which has a slope length of approximately 37 feet and in the shallow gully below which has an approximate slope length of 20 feet below the deep cut. Backfill will end at the point at which the slope of the gully begins to level out. This is near the pinon tree 1