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10/04/96 10:51 FA% 9709295177 0%BOW SANBORN ~ 003 Anthony Waldron Page '3 September 15, 1994 {a) The Someset Mine will monitor springs and seeps 1 through 5 monthly from `9arch throu.~h October. Sprints and seeps 7 through 11 will be monitored monthly. This will begin when practicable and will continue through the end of 1993. (b) The .springs and seeps will be monitored Por flow, pH, electric.sl conductivity and temperature. (c) The data from this monitoring and an interpretation will be submitted with the 1992 Annual Hydrological Report. (d) Monitoring will recommence one year prior to retreat mining in the area of the springs and seeps and continue for an additional two years after the area is retreat mined. An interpretation of the results and correlation with past monitoring results will be submitted with the next annual report. (e) For this permit revision, the application should identify the source and use of these springs." SMC responded by including new pages1.0~1-29xviii & xvix which incorporated 1992 spring monitoring, revised pages 2.04-38i & ii to add a discussion of Springs 1-11 and described the source and use of the springs, revised page 2.05-46iii to include hydrologic monitoring of the springs, revised pave 2.05-46iv to include interpretation and correlation of the spring monitoring data in the 1992 and 1993 annual hydrologic reports, and revised page 2.05-47 to commit to the required monitoring plan. The Division then made an additional requirement Por SMC to commit to augmenting the flows in the North Fork should any reduction inflows from the undermined ephemeral drainages or springs be attributed to effects of mining. SMC responded with, "If any reduction in flow from the undermined ephemeral drainages or springs is attributed to the effects of mining, and it is determined those reductions in flows are depleting the flow in the North Fork of the Gunnison River, then the operator will augment the flow in the river as required by applicable State laws." The Division included a discussion oP the springs in the Proposed Decision and Findings of Compliance for Permit Revision No. 2., and in the Cumulative Hydrologic Impact Study - North Fork oP the Gunnison River (Revised 9/25/921. The CHIS states in parts: "The underground mining operations, through subsidence effects, may reduce stream flows or Plows from springs and seeps." "Streamflow reduction could develop from three seperate scenarios - increased infiltration of runoff through subsidence fractures, direct. stream recharge to the mine in zones of stream undermining, and loss of spring flow." "Despite the presence of subsidence features at several of the mine sites, this impact has not been identified by any of the monitoring programs."