2017-06-26_HYDROLOGY - M1980244

• Permit No: M1980244
• IBM Index Class Name: Hydrology
• Doc Date: 6/26/2017
• Doc Name: Demonstration of Compliance with WQCC Regulation No 41
• From: Newmont
• To: DRMS
• Email Name: TC1
• Media Type: D
• Archive: No

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8 S 8 8 8 8 8 8 8 8 8 8 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
—+—VIN 2A-270 -+—VIN 28-140 + Precip —Poly.(VIN 26-140) —Poly.(Precip)
Figure 13: Precipitation(total between sampling events)and field pH in Vindicator Valley.
5.4 Poverty Gulch
The Poverty Gulch compliance monitoring well is PGMW 2. However, this well has been dry since it was
constructed 19 December 2001. Two other monitoring wells in Poverty Gulch, PGMW 1A-200 and
PGMW 113-55, were sampled from 31 March 2000 through 10 April 2001, with one additional sample
taken from PGMW 1 B-55 on 9 July 2001 (these wells were subsequently dry until the last attempts were
made to sample them in October 2005). Both of the PGMW 1 wells were plugged and abandoned
sometime after October 2005. In the absence of data from PGMW 2, the data from the other two wells
were used in the analysis.
Groundwater sampled in Poverty Gulch has the fourth highest geometric mean concentration of sulfate,
the lowest field pH, highest zinc, and second highest manganese geometric mean concentrations of the
six drainages, but the time period represented by the data is less than 1.5 years. Identification of trends
for each of the analytes is difficult due to the short record of data.
Sulfate, field pH, and precipitation (measured at the Rigi meteorological station, totaled between sampling
events) data are shown in Figure 14. No clear relationship between precipitation and sulfate or pH is
evident. It appears that sulfate concentrations and pH are relatively stable.
Figure 15 presents the manganese and zinc concentrations, and precipitation totaled between sampling
events, for the Poverty Gulch monitoring wells. No clear relationship is apparent between precipitation
and either manganese or zinc. In general, concentrations are relatively stable, although both manganese
and zinc were declining in PGMW 1 B-55 during the last three sampling events.