2010-05-26_REVISION - C1981008 (2)

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C -1981 -008 - SL -12 Preliminary Adequacy Review 26 May 2010 Page 3 of 7 Please correct the narrative in the 3 rd paragraph of page 11 to delete the reference to Dryland Pasture. 3. The Division does not agree with the conclusion in the application narrative on page 11, that successfal cover has been demonstrated. The conclusion is based on incorrect interpretations of the sampling data. a) The reference area was sampled in early June but the reclaimed area was sampled at least two months later, sometime in August. Reference area/reclaimed area sampling should be conducted as closely as possible in time, so that the stage of vegetative growth is comparable between the two areas. The approved permit (as revised in TR- 58) specifies that both reclaimed and reference area measurements are to be made in late May to early June. The reference area comparison is not valid because the two areas were sampled two months apart. Therefore, the Division recommends that the Phase II cover success demonstration be based on a comparison to the technical standard (90% of 71.8 %), that was in effect at the time of sampling. b) The table on page 11 of the SL -12 application titled "Vegetation Reference Area Values" is confusing, and the data is incorrect. The table presents cover sampling results from the Phase II Irrigated Pasture reclaimed area, and the Irrigated Pasture Reference Area. The values presented are mean percent desirable perennial cover for the reclaimed area (72.1 %) and the reference area (57.8 %). Please revise the table on p. 11 to eliminate confusion and to provide the technical standard reference. "2008 Phase 2 Release Reclaimed and Technical Standard for Cover ", would be an appropriate title, and the right side column heading would more accurately be stated as "Mean % Desirable Perennial Cover ". Please amend the table as appropriate. c) In the application narrative, the incorrect conclusion is drawn that cover success has been demonstrated because "...reclaimed area vegetation is 124% of the reference area ". The narrative references the Bio -Logic reports for details of the statistical analysis. The Division does not concur that the reports provide the correct demonstration for cover success. The reports document that sample adequacy for the reclaimed area and the reference area were achieved. However, they do not provide a correct statistically based comparison between the two sampling units. In the December 12 BIO -Logic report documentation is provided documenting that the reference area was sampled to statistical adequacy for cover in June 2008, and mean desirable perennial cover was indeed 57.8 %. In the September 30 BIO -Logic report, documentation is provided that the reclaimed parcel was sampled to statistical adequacy in August 2008, and mean desirable perennial cover was indeed 72.1 %. The "Reclaimed Parcel Results" section of the September 30 Bio -Logic report contains no statistically based comparison to the reference area cover data, and includes the following statement: No conclusions are drawn from these data for Phase 2 studies, as they are intended to be provided to Lewicki & Associates to analyze in order to determine adequacy for bond release.