1995-05-16_REVISION - M1977378 (2)

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05/16/1995 13:02 303-782-0390 CDH WQCD WQCC PAGE 05 Mr.William Goodhard May 12, 1995 Page No.4 Mmtoring Requirements The Division needs more information relative to the monitoring plan This is an important part of the agreernent. It is important that the elements of the plan be outlined in detail to ensure that there will not be confusion in the future as to what is required. It is very important that both the Division and SGC have good data on which to base decisions. It is suggested that the monitoring plan required by DMG be combined with that proposed to meet our concerns. This would provide everyone with a good understanding of the area's water quality,avoid duplication of work and allow SGC to provide the same information to both agencies.The monitoring information required by DMG is also important to us. We have assumed that our monitoring program requirements would be in conjunction with DMG's requirements. Therefore we would expect that the data from the plans would be sent to both agencies and that the monitoring plan would be in place until both agencies agreed to any changes.The Agrocment will need to specify the sampling and analysis techniques which will be used Specific coammmu on your proposal are: SGC Permitted Areas: It is not clear if the monitoring listed is in addition to CDPS permit requirements or are the permit requircinonts that SGC wishes to have included in the permit. Thera is not a list of what awtals are mem by "dissolved and total metals". The specific parameter hood to be listed in the final agreement. We would appreciate some clarification on the parameters which SGC was planing to include. There is concern that the quality of Cerncat Creek may change quickly especially during different portions of the year such as during spring runoff. Monthly monitoring may not be adequate to note changes in quality. Additional information is needed on how the diversion of Cement Creek will function before we can come to agreement on the proposed monitoring program. Mitigation Sites: The time frame for monitoring at the mitigation sites should be based on the type of mitigation to be expected. The monitoring program proposed for these sites may be adequate for some however,others may need additional monitoring sites,additional parameters or need to be monitored for a longer period of time. It is suggested that the monitoring program bo part of the submittal for each mitigation site. Reference Point: The discussion on the reference point includes a discussion on the calculation of the reference point level and the necessary monitoring. It is proposed that SGC use only A-72 as a reference point. The WQCC - adopted ambient standards for the Animas River between Maggie Gulch and Cement Creek. Mine closure may affect the zinc concentration in this segment,therefore a monitoring point should be established for this segment. A- 68 would be a good location. Besides.points at A-72 and A-68, it is moommended that a monitoring point on Cement Crook,preferable at C-48 be established. Cement Creek has a similar flow/sac comcenfrofm relationship as A-72. This point could be used to establish the amount of zinc level reductions required from the Cement Creek treatment plan. Monitoring at C-48 benefits SGC in that the ncvd for additional mitigation projects could be mote reliably detummed than by depending on A-72 alone,and the Division would know the effectiveness of the plug. Cement Croak should not become a refermce point because the possibility of the zinc caneentration increasing in Cement Crak,however we do need to know what is happening in this segment. It is not clear low SGC will determine if there are adverse impacts on the Animas from other parties. This is very important to SGC so that it is not held responsible for the=400dances of the 520 ug/l which are not the result of its activities. The Division feels that the burden must be on SGC for providing an affirmative defense on any exceedances. The Division would like to we the procedures that will be used to determine if there are adverse impacts.