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-~- ~~'~'&~~ RECEIVED ~~ APR d 9 2~`~ April 3, 2002 Division of Minefe~s a"~ Ger" :.t Mr. Gregg Squire Colorado Division of Minerals and Geology Depamnent of Natural Resources 1313 Sherman Street, Room 215 Denver, CO 80203 RE: Logan Wash Mine Evaporation Pond Maintenance Costs Dear Gregg: It was apleasure talking with you and Carl Mount on Tuesday, Man;h 26, 2002. As peryour request, I have estimated the annual ataintenance hours required for maintenance ofthe evaporation pond and related structures at the Logan Wash Mine facility owned and operated by Crccidental Oil Shale, Inc. To date, the maintenance work that has been conducted on a weekly basis includes the following: 1. Monitor and measure flows in retort discharge pipeline at upper and lower manholes, 2. Check and record condition of leak detection vanlt at evaporation pond, and 3. Inspect general condition of pond (security fencing, pond volume, liner condition, etc). In addition, National Pollution Discharge Elimination System (NPDES) sampling is currently conducted at Crtrtfall 002 (the Research Mine). When discharge is pn;sem, usually April through August' sampling is conducted on weekly (2 constituents), monthly (11 consstiutents), and quarterly (14 constituents) schedules. The sample events r+equine more torte because of the preparation for, acrd the collection and handling of a water sample at Outfall 002. Up to 14 constituents are analyzed by the contracted laboratory. Should this permit remain active far a period oftime after fomral mime clostue, additional labor will be required to conduct the required sampling. Also, rt is likely that some monitoring will be required of any passive mine water treatment discharge (this may be aNPDES-type of permit). The above tasks are curtently being conducted by two field personnel as this simplifies the tasks of flow measurement in the manhole locations and addresses health and safety concerns. However, the work can be conducted by one person. The estimated time to conduct tasks 1 through 3 above by one person, irtchtding travel time from Grand Junction, is 3 hours per week. Sampling of the existing Outfall 002 requires an additional 1.5 to 2 hours of labor per week during the discharge period. Therefore, the total annual labor hours required for Logan Wash Mine monitoring is 156 to 196 hours. Under a differerrt closure progrun the above maintenance schedule could conceivably be reduced This work does not include underground, inspections or other general surface inspections ofthe mine property. Approximate field labor rates would typically range from $50 to $70/hour. I hope this estimate is useful in recalculating bond amounts for the Logan Wash Mine facility. If you have any further questions, please contact me at 970-242-0170. Applied Eanh Sciences 743 Horizon Court Suite 330, Grand Junction, CO 81.506 Phone: (970) 7A2-0170 Pax: (970) ?A?d1270