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Rationale-Recommendation for Approoa[ <br />Jtc[y 26, 2000 Page 7 <br />19. Toxins like cyanide should not be averaged. (J. Minkler, R. Flynn (CFV); R. Fay; K. Hughes ) <br />DMG Response: DMG does not average geochemical monitoring results. Results are compared and <br />sampled for each quarter and are reported as such. <br />20. Potential for acid mine drainage exists. (J. Kuipers) <br />DMG Response: Conservative geological, mineralogical and geochemical modeling considerations <br />indicate that the potential for ARD is low. The diatreme appears to have adequate neutralization many times <br />over to accommodate the acid already produced and stored in the diatreme as well as that which may be <br />produced in the future. <br />2l. Inadequate spent ore detoxification plans. (R. Fay) <br />DMG Response: The detoxification plan, which was approved under Amendment No.7 will apply to <br />Amendment No. 8. This plan meets the requirements of the Act and Rules. <br />22. Groundwater (in Carlton and Roosevelt Tunnels) must be protected pursuant to MLRB Rules 3 and 6 <br />and the rest of the Rules and Act. Establish monitoring and compliance points for groundwater in the <br />tunnels. Investigate whether Tunnel waters meet groundwater standards. Assure that seepage from <br />settling ponds outside Cazlton Tunnel meets ground and surface water standards. (Roger Flynn) <br />DMG Response: As indicated previously in Amendments 7 and now in Amendment 8, ambient <br />groundwater quality in the tunnels has not changed measurably in the several decades that it has been <br />monitored. The groundwater numeric protection levels have been established from ambient conditions and <br />are currently being met. <br />The possibility of any seepage from the ponds is of no consequence. Whether Carlton Tunnel water moves <br />from the ponds to the receiving stream via seepage or direct discharge, it still degasses, precipitating calcite <br />which adsorbs zinc. Whether the zinc inside the tunnels is higher or meets surface water standards <br />underground is moot because inside the tunnels it is groundwater and there must meet ambient conditions. <br />Currently, at the point of discharge, surface water standards are being met. In addition, the Division has in <br />place ground water compliance points around the diatreme approximately 4 miles upgradient of the <br />discharge from the Carlton Tunnel. Any change in groundwater quality will be detected by these wells. To <br />date, the Division has not seen any adverse changes to ground water quality. <br />23. The Division should not approve a permit without first obtaining the required baseline information. <br />(R. Flynn (CFV)) upon further <br />DMG Response: Upon further analysis, the Division has determined that the monitoring wells, which <br />the Division proposed as compliance points in Poverty Gulch (PGMW-1A and B), are not needed at this <br />time. The only activity proposed in the area is mining. Until the pit is backfilled, most of the water, if any, <br />will drain towards the pit. However, if and when [he pit is backfilled and drainage is routed to the Gulch, <br />the Division will require CC&V [o submit a technical revision application (TR). The TR will require [ha[ the <br />operator submit adequate ground water data, in order [o establish a ground water compliance point. As for <br />the external pond, Well ESPMW-1, the compliance parameters have been set a[ pH between 6 and 9 and a <br />