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~. June 25, 1992 North Thompson Creek mine Minrec, Inc. 743 Horizon Ct Suite 205 Grand Junction, Colo 81056 Weather and Ground Conditions during the Inspection: overcast, warm and dry Personnel Present During the Inspection: Jim Stover: Minrec Inc. Shawn Smith; Colorado Mined Land Reclamation Division Larry Routten: Colorado Mined land Reclamation Division Gary Fritz: Office of Surface Mining\Albuquerque Field Office #244 GENERAL COMMENTS This was a complete oversight inspection. State officials were notified regarding my schedule and were able to join me at the mine to conduct a joint inspection. Mine records are on file at the County courthouse in Glenwood Springs, Colorado. The mine has been reclaimed since 1987. A Phase I bond release was granted in March of 1988. In May of 1988 the main seal broke on the Number 1 mine manway. which resulted in an acid water discharge. Since then, that entry face as well as the face of the beltway for the #1 mine were dug out by the operator so he could access the seal faces. They installed pipes through the seal so water discharging through the seals could be treated. Initially the discharge was treated with caustic soda to raise the pH # and drop out some of the iron. The container for the soda was set inside of the manway behind doors on the portal to protect it from harsh winter weather that is often encountered in the valley. That treatment system has been abandoned tempororarily because of the expense and maintenance problems. Since then, a cattail bog was put in across the creek from the portals for water treatment. "The .pipes through the seal that were put in for the soda treatment system are still being used to carry water acros tt~e-cxeek-t-a the - ~-- bog. The bog is a long narrow, shallow sediment pond that empties into another ^finishing pond" which then discharges water into Thompson Creek. The system has been inplace for several years and remains ~ functional through the winter according to Mr. Stover. According to Mr. Stover, algal blooms growing in the bog appear to be expanding. Atpparently there is some concern that this growth may impede or even restrict flow through the system if they grow completely across the pond. Mr. Stover said that he was going to watch the blooms and check the disharge for a change in pH or iron precipitate. In addition, he intends to talk to State officials and other industry representatives familiar with the systems to see if he should do something about the growth. The operator has also applied for a modification in the design of the bog pond because a wet spot has formed below the embankment. He wants to reinforce the dam by widening the perimeter embankment which may affect the seepage. This should be watched. I asked several questions and made some comments during the inspection