2012-04-03_REPORT - C1981028 - Laserfiche WebLink

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Don Macdonald; CEC 2011; ARR Review April 3, 2012 Mass Balance Page 2 of 6 CEC submits results of ash disposal with the ARR. The volume of ash placed in the disposal area, and the results on the chemical analysis sample of bottom ash and flyash are included with the report. In 2011, CEC reports that 36,961 tons of mixed flyash and bottom ash were disposed of in the B Pit at the Keenesburg Strip Mine. Two samples, one flyash sample and one bottom ash sample, were analyzed for Toxicity Characteristic Leaching Procedure (TCLP). Results of the bottom ash sample recorded Barium at 2.1 mg /L and 1.2mg /L for flyash. Per the laboratory report in the ARR, the reporting limit for Barium is 1.0 for the reported method, and the Maximum Contaminant Level for Barium is 100 mg /L. The measured value for Barium for the bottom ash and flyash sample is not identified as a concern. All other parameters analyzed for the bottom ash and flyash samples were below the reporting limits for the associated analyses. Review of the reported spoil mass balance (page 107) revealed one discrepancy. According to the 2010 ARR, the remaining long -term spoil on the site was 340,895 bank cubic yards (BCY). The 2011 ARR indicated 9,563 BCY were used primarily for cover for the ash disposal area. Given this, only 331,332BCY should be remaining at the site as of the end of 2011. However, the report indicated 331,832 BCY remain. There is a discrepancy of 500 BCY. Please see the summary table below: Description Value Units Long -term spoil remaining on site - per 2010 ARR 340,895 BCY Spoil used for cover in 2011 — per 2011 ARR 9,563 BCY Remainder 331,332 BCY Long -term spoil remaining on site - per 2011 ARR 331,832 BCY "Please correct this discrepancy. Mapping The contours on the Reclamation Contour and Drainage Plan Map (Appendix Q -1) submitted with the 2011 ARR match the contours from the previous contour map Appendix Q -1 from the 2010 ARR with minor exceptions. Pit B topography has changed as ash has been disposed in the pit. Likewise, minor changes in the long -term spoil pile topography are noted due to the extraction of this material for cover of the ash disposal area. Vegetation Monitoring Review; 2011 CEC hired Savage and Savage, Inc. to conduct vegetation monitoring on Reclamation Areas (RA) 29, 30 and 31. Vegetation monitoring occurred in August of 2011. RA 29 is 8.10 acres in size and was seeded in the autumn of 2003. RA 30 is 9.68 acres in size and was seeded in November 2006. RA 31 is 11.92 acres in size and was seeded in the fall of 2009. Vegetation cover, total herbaceous production and species composition were sampled. These parameters were sampled using the approved methods described in the permit. The reported total mean vegetative cover for each of the Reclamation Areas included contributions of a noxious weed species (Bromus tectorum, Cheatgrass) and several annual species. Cheatgrass is considered a noxious weed on the State Noxious Weed list and the Weld County Noxious Weed list. Although, CEC is not requesting bond release on these parcels, the Division does not consider noxious weeds as contributing to reclamation success. Also, the Division only allows a maximum of 10% relative cover contributions from annual and biennial species to count toward revegetation success. Annual or biennial cover in excess of this threshold should be deleted from the reclaimed area data prior to success comparisons. Given these two issues, the Division