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120 pcf. If appropriate, please submit a revised stability analysis, and submit <br />corrected pages for insertion into the Permit Application Package. <br />19. The applicant also submitted amended narrative within Tab 13 to address stock tank <br />impoundments and typical "worst case" design and stability analysis based on the worst <br />case design (new Attachment 13-11). The stability analysis for worst case demonstrates <br />that the embankments have a greater stability factor of safety than is required. We have <br />the following specific comments regarding the stock tank information provided. <br />a) First, part of the amended narrative appears to be missing. The amended table of <br />contents for Tab 13 indicates that Stock Tanks, Discharge Structures, and Transportation <br />Facilities are all addressed, beginning on amended page 7 of Tab 13. However this is <br />not the case. The amended page 7 submitted with the revision application appears to <br />contain an incomplete discussion of stock tanks. The last line on page 7 ends in the <br />middle of a sentence addressing pond stability, while page 8 is a curve number table, and <br />no subsequent page amendments addressing stock tanks were provided. The amended <br />page 7 includes no discussion of discharge structures or Transportation Facilities as <br />indicated in the amended table of contents. <br />Please submit appropriately amended Tab 13 table of contents and revised pages <br />to incorporate a complete discussion of stock tank design, construction and <br />stability, along with associated page amendments as necessary for the amended <br />sections to "flow" into the subsequent pages of the Tab 13 narrative. <br />b) Please note that all stock tanks regardless of size and whether temporary or <br />permanent are impoundments, subject to the requirements of Rule 4.05.9. As such, each <br />stock tank impoundment requires an individual design and construction certification <br />[Rules 4.05.9(2)(e) and 4.05.9(14)]. The "worst case" stability analysis is acceptable, as <br />long as individual stock tank designs and construction certification demonstrate <br />conformance with the worst case assumptions. Accordingly, we request that the following <br />concerns be addressed, either within the context of this permit revision or within a <br />separate technical revision to be submitted by a specified date. <br />i) Please ensure that all temporary and permanent impoundments are in <br />compliance with Rule 4.05.9. Please provide appropriate design information for <br />existing and proposed stock tanks and submit construction certifications for all <br />existing stock tanks. Please note that, in addition to construction certification, <br />each impoundment will need to be certified on an annual basis in accordance with <br />4.05.9(14). <br />ii) Amended application text is confusing regarding whether stock tanks are <br />intended as temporary or permanent structures, or whether certain stock tanks are <br />intended as permanent and others as temporary structures (which apparently is <br />the case). In the first paragraph on page 7 SCC indicates that the stock tanks are <br />temporary. In the second paragraph of page 7 SCC indicates that the stock tanks <br />are to enhance postmine livestock and wildlife utilization. This is inconsistent with <br />the statement in the first paragraph, and the narrative needs to be appropriately <br />amended. <br />iii) All existing and proposed stock tanks need to be listed and identified as <br />permanent or temporary, and all stock tank locations need to be depicted on <br />designated operational or postmine topography maps as appropriate. <br />