2012-09-09_ENFORCEMENT - M1977300

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OBSERVATIONS PERMIT #: M -1977 -300 INSPECTOR'S INITIALS: TAK INSPECTION DATE: June 28, 2012 This inspection was conducted on June 28, 2012 by Tom Kaldenbach of DRMS. John Hamrick represented the operator. The inspection was prompted by a phone call that the inspector received at approximately 11:20 on the morning of the inspection from Amory Quinn of Cotter Corporation. In the phone call, Mr. Quinn said Cotter was drilling holes at the Schwartzwalder Mine for a grout curtain that Cotter had recently proposed in their application for TR -20. He said grouting had not yet begun, and he wanted to notify DRMS before grouting begins. A short time after the phone call, the inspector called Mr. Quinn back and told him an inspection would need to be done as soon as possible because DRMS had not yet approved the drilling, and the TR -20 application was still being reviewed. (Cotter had filed the TR -20 application with DRMS on June 22, 2012, starting the maximum 30 -day review period specified by Rule 1.9.1). The inspection began at 1:15 pm. A work crew with drilling and pressure grouting equipment was active near Sump 10, the area of the grout curtain proposed in TR -20 (the "project area "). The operator's representative described the work that had been completed so far as: • An old core hole had been sealed with grout. Seven new 3 -inch diameter vertical holes had been drilled on 15 -foot spacing, to depths between 35 feet and 40 feet. • Pressure grouting the new holes had begun after the crew's lunch break. • Grouting pressure was 1 psi per foot of hole depth. In the project area, there appeared to be four smaller areas, each measuring a few square feet in area, where clear water was trickling out of the metamorphic bedrock and pooling in low areas. The total flow of water corning out of the rock in the four smaller areas was visually estimated to be between 10 and 50 gpm. Water in the lowest of the pooled areas was being pumped into a 4 -inch diameter HDPE pipe that led to the treatment plant approximately 400 feet northwest of the project area. From the treatment plant, the water is piped to the CDPS- permitted discharge into Ralston Creek (Outfall 001A, CDPS permit CO- 0001244). The inspector told the operator's representative that conducting the drilling and grouting work prior to approval of TR -20 gives DRMS a reason to believe a violation has occurred. The operator's representative explained that the drilling and grouting work had begun in advance of TR -20 approval because it was necessary to prevent a violation of the 250 mg /I sulfate standard in Ralston Creek at Outfall 001A. He explained that the water discharging from the rock in the project area had a uranium of approximately 20 mg /I and probable high sulfate concentration as indicated by electroconductivity measurements. He further explained that most of the uranium can be removed from the water at the treatment plant, but the plant has no process for removing sulfate. The work being performed in the project area appeared to be as proposed in the TR -20 application. The project area is within a previously disturbed area of the mine site where the operator has been excavating alluvial material over the last few months near Sump 10 in an effort to find sources of groundwater seepage. Surface runoff in the project area would be retained within the excavated area. Page 2 of 7