1992-09-10_REVISION - M1988112 (2)

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RESPONSE TO COM]~IENTS BY JAMES STEVENS I. BMRI's response indicates t{wt the low Ieve1 of flow, rather than lack of evidence of cyanide, is justification for mairaaining the sampling frequency for the leak detection system on a monthly basis rather than increasing it to bi-weekly. 777e Division has not had any problem in securing adequate fluid from the system during the Division's bi-weekly sampling trips, so the Division does not feel drat the flow is inadequate. If it is, then bi-weekly sampling and analysis can be conditioned on the basis of there being insu~'icieru sample availpble. Since the leak detection system already shows evidence of cyanide, its monitoring on a more frequem basis is desirable in order to be able to better correlate any variations that it may show in cyanide contera with those appearing at other bi-weekly smnpling sites. RESPONSE: BMR believes that bi-weekly sampling of the collection pond leak detection system is not necessary at this time because increased sampling frequency will not provide additional information concerning site water quality. The primary reason for sampling the collection pond leak detection system is to evaluate the pond's ~ ~ structural integrity and not to establish process system or collection pond cyanide concentrations. Bi-weekly sampling to determine cyanide concentration occurs '~~,_ ,~~•~ ~ at five process system points (pre-detox, post-detox, upper impoundment area, J lower impoundment area and the collection pond feeder ditch). An extensive ground water monitoring system is in place to detect the presence of cyanide outside of the collection pond's containment azea. BMR believes that bi-weekly sampling of these locations provides sufficient information regazding cyanide concentrations in the process system and should allow BMR to respond in an appropriate manner to a release from the collection pond. Bi-weekly sampling of the leak detection system will not provide additional data that addresses either of these concerns. For this reason, BMR believes that bi-weekly sampling of the leak detection system is unnecessary. BMR acknowledges thdt if significant increased amounts of collection pond solution are identified in the leak detection system, more frequent sampling may be necessary. 2. [No response required. J 3. [No response required./ RESPONSE TO COMMENTS BY DAVID HYATT (DRAFTED BY HARkY POSEY) 1. [No response required./ 2. [No respaue required./ -a-