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hie Jim Stevens, CMLRD • • +November 13, 1990 -page 2 7. During [he inspection of Trapper's equipment storage area (facili[ies) two unmarked containers were identified. The content of the barrels was Penta, a wood preservative commonly used [o treat (cote posts. Both barrels were appropriately marked identifying their contents on 11/1.;90. 8. Mr. Gary Fritz, OSM, had a question concerning the use of rip rap in our sediment pond construc- tiondesigns. As explained, rip rap is used in principal and emergency spillways only if excessive ero- sion is identified as being a problem. According [o Trapper's Mining and Reclamation Permit (page 4-192) "outflow channels will be lined with suitable rip rap or other appropriate materials to pre- ventexcessive erosion." In the case of Johnson Pond #10's emergenry spillway, the existing vegeta- tion is appropriate materials to prevent excessive erosion. Standard drawings (figures 4.8-4 and 4.8- 5, pages 4-194 and 4-195) do no[ show rip rap as a design fea[ure in any of our sediment ponds. Appendix O, Section `G`C, does show some design modifications for the use of rip rap as a construc- tion specification on West Buuard Gulch No. 3. 9. Mr. Fritz, OSh[, requested information on the sampling measurement requirement for the piezo- meters established on Coyote Dam. In accordance with our approved Mining and Reclamation Plan, no such measurements are required. Discussions wi[h Trapper's engineers, who have been inspecting this structure since its cons ruction in 1977, indicate tha[ piezometer sampling has been conducted following cons ruction of this dam but at in[requent intervals. This pond is examined by a qualified person at intervals not exceeding 7 days. The pond is inspected for structural weaknesses and other hazardous conditions weekly. If any structural or hazardous conditions were to be identi- fied, piezometer measurements would commence. Unless required by the Division, Trapper does not intend to initiate a new piezometer sampling program at Coyote Dam. 10. hir. Fritz, OShf, requested information pertaining to our permit requirement for permanently attaching collars on principal spillway discharge pipes. The typical standpipe design can be found on page 4-193 (figure 4.8-3) of our Mining and Reclamation Permit. According to our permit, no such permanent establishment of collars is required. The only potential for the collar to ever move would be if ice were to build up on the pond and force the collar out of place. Trapper had the fore- sight to recognize this possible problem and has established wooden ice breaks on all sediment ponds with standpipes for the principal spillway. 11. During your records inspection of "Cropper, it was noted that sketches of the blast delay pattern were not available on all shots. Trapper's response was that a generic delay pattern was used far nearly all shots with little to no deviation between patterns. Apparently this generic diagram was approved by the Division as an acceptable means to show blasting delay patterns. Since the records review of 11/7/90, Trapper has gone back through all blasting records and sketched appropriate blast patterns thoroughly and accurately for each individual blast. These sketches are available for [he Division review at your earliest convenience. Jim, I believe Trapper has made every effort to ensure no NOV's will result from your joint inspection wi[h OSM. If you have any questions or concerns, please con[act me. Sincerel~r ti William Agnew ' Sr. Environmental Engineer WSH/WA/jb [CMLRDVYO V 13] c G.M. Stubblefield E.C. Johnson J.hl. Mattcrn R.W. Fish W.S. Harding B.D. Nicholson R.L Fanyo file