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(Page 2) MINE ID # OR PROSPECTING ID # h1-1982-015 INSPECTION DATE 041t 1!7006 INSPECTOR'S INITIALS DEG OBSERVATIONS Thrs pre-operational inspection of Permit Number M-1982-015, conducted by Carl B. Mount, Rick M Wenzel, and Deb E Gbn~ma of the DMG, was prompted by a request from the operator for approval of an amendment to the current permit. Jodi Villa of Meurer and Associates, Tyler Packard and Brad Davrs of Carina LLC accompanied DMG employees on This inspection. The site is located approximately 5 miles east of Longmont, directly east of I-25 frontago road to Weld County Road 28. then east to Weld County Roatl 9 '.~>. south until d intersects with a dirt access road that leads directly to the ponds The permit sign rs posted at the intersection of Weld County Road 28 and Weld Couniy Road 9 %, No mining has occurred on silo for several years. The proposed amendment includes adding 70 acres to the permit area (bringing the amended total Io 285 acres), reshaping the three existing gravel pit ponds into two, and segregating a swimming area wdhin the larger of the two ponds using a sheet pile wall Prior to slurry wall construction tho ponds will be dewatered into the adjacent St Vrain Creek Then a slurry wall will be constructed around the perimeter of the ponds, m order to isolate the ponds Alter slurry wall constnrclion the ponds will be ref~Iled with water purchased by the operator, the slurrywall's integrity will be tested, and the area wUl be regraded. The details of the slurry wall constnrction, including dewatenng and reldling of the ponds, will be describeC in more detail once the construction contract Is brd and awarded. The following dams were discussed Bunny this pre-operational site visit, and they will be included in the upcoming adequacy review letter under separate cover, 1. Pleaso clearly mark the permit boundaries on site and submit photos of this to DMG 2. Please obtain and submil to DMG a !alter authorizing Meurer 8 Associates to negotiate with DMG on behalf of Mr 1. Please submit a Substitute water Supply Ptan to the State engineer's Onrce (USt) IOr approval - as Ot art 3/U6 Wt slates that thrs had not occurred 2. Please submit results of a groundwater modeling study, or similar mechanism, quantifying and describing the anrirvnarnrl nlfecrc n1 rhH nrnnncrrl th urv wall nn nrni indwatPr rPnharoe nrnnH drainane mnundutrt sharlowirn !n the 3. Provide a map or exhibit based on These results that shows the location of any groundwater users Q.e, wellslspnngs) andlor structure avners (i.e, of septic tanks. leach fields, sewer lines, basements) wdhin the extent of the mounding or shadowing zones Also provide an assessment of the impact to each water user or structure owner 4. Ploase provde a fist of wells wdh~n 600 feel of the pernnt area. 5. Ploase provide true quarters worth of groundwater Ievol monitoring data in accordance with Rule 3 1 6 6. Ploase provide a more detailed Storm 1h'ator and Groundwater Management Plan that includes more specfic information on various trigger points wdh timeframes - ~ e d "X" (creek breaches pond walry. operator does "Y" (constructs Throughways for outflow), by "Z" (within 3 days of breach) timetrame 7 Please provide more detailed descriptions of mitigation technlques complete wdh representalrve cross-sectional design and plan views of each erosion mitigation lechniquelstructure Also, please include specific installation lechnieues for these erOSiOn COntr01 meChaniSmS. 8. Please provide a copy of the flood control plan including information on the potential impacts of the 100-year flood, and how the operator's plan intends for water to enter and exit the permit area 9. Please submd information that cleady defines the SL Vrain Creek as a gaining or losing creek by a quatifted professional hydrologist. 10. Obtain letters from the on•site utility owners (water main, gas tine, sewer, etc.) stating who the responsible and linancially liable parry will be in the case of damage during reclamation to any of the utilities' properties (see CRS 34- 32.5-115(4)(e) 11 Please provide a vegetation description per Rule 6 4 3(e) - this can be obtained from NRCS. 12 Please reviso the estimated average depth of the slurry wall. It appears from the boring data provided in lha amendment application that the average depth from the surface to key in to bedrock is approximately 27 to 28 feet, not the 16 feet mentioned on page one. #2, of Exhibit E. 13 Based on the fault fracture survey d appears u~at bores 45.47 and 48 wero comprised mainly of sandstone bedrock that was cemented and highly fractured Please explain how ntose cond~Uons wtll be taken into wnsideration during the construction and subsequent monitoring o1 the integrity of the slurry wall 14. Pleaso explain what mitigation technlques will be employed to reduce seepage losses for the slurry cutoff walls, including the specifics of the deeper cut key ways mentioned In the amendment package information 15. Please explain how the operator will address areas of substantially coarser materials such as gravels and cobbles coupled with the site's water table.