1988-02-01_REPORT - C1981008 - Laserfiche WebLink

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An additional surface water monitoring site is being considered for the Nucla Mine in the postlaw reclaimed area above County Road 124A-A. Because regrading and seeding in this area will not be completed until the latter part of 1988 or the first part of 1989, the monitor instrumentation and location specifics will be deferred until then. Data obtained from this site will serve to evaluate the success of reclamation practices with regard to controlling drainage, chemical and sediment loads from postlaw reclaimed areas. During the 1987 water year, spoil spring surveys were conducted within and adjacent to the Nucla permit boundary. The first survey was conducted during May of 1987, and the second during September of 1987. Both surveys involved visual observations for seeps and springs, and resulted in no discovery of any additional seeps or springs within the surveyed area. The field equipment used for sampling conductivity and temperature at the Nucla Mine and the Nucla East mining area (YSI conductivity meter) was tested for accuracy on December 10, 1987. The testing was performed by comparing the Nucla conductivity meter against an identical meter used for similar measurements at Peabody's Seneca Mine in northern Colorado. Both meters were used to measure the conductivity and temperature of tap water. The Seneca meter measured the water as 380 umhos at 10°C, while the Nucla meter registered readings of 360 umhos at 10°C. Temperature readings for both meters were identical, and the Nucla conductivity meter measured the conductivity of the water within 5.3 percent of the Seneca meter. The Seneca conductivity meter was calibrated on July 31, 1987. The calibration was performed by measuring the conductivity of a 0.01 demal potassium chloride (KCI) solution at 21°C (YSI , 1979). Based on the conductivity table for this solution at 210C (YSI, 1979), the conductivity of the solution was 1300 umhos. The Seneca meter registered a conductivity of 1300 umhos at 210C for the prepared solution, which indicated accurate calibration of the Seneca conductivity meter. The pH meter used to measure field-determined pH values at the Nucla Mine and Nucla East mining area is calibrated by performing two-point calibrations prior to each daily round of monitoring activities and one-point calibrations prior to each measurement using buffer solutions of known pH values obtained from outside laboratories. Three buffer solutions are used for calibration: 1) pH 10; 2) pH 7 and 3) pH 4. The buffer solutions are replaced monthly to ensure accurate calibration of the meter. Most of the two point 7