2012-02-16_HYDROLOGY - M2002004

• Permit No: M2002004
• IBM Index Class Name: HYDROLOGY
• Doc Date: 2/16/2012
• Doc Name: Second Half, 2011 Groundwater Monitoring Report
• From: GCC Rio Grande, Inc.
• To: DRMS
• Permit Index Doc Type: Hydrology Report
• Email Name: TC1
• Media Type: D
• Archive: No

TDS concentrations from the October 2011 event ranged from 1,760 mg/L to 3,060 mg/L.
TDS concentration exceeded the State Numeric Protection Level of 2,630 mg/L in wells
MW -03 (3,060 mg/L) and MW -04 (2,640 mg/L). These are the first exceedences of the
TDS standard since October 2009. The following chart shows the results of the TDS
analyses for all three wells since TDS sampling started in March 2008.
3500
3000
2500
2000
0 1500
1000
500
Total Dissolved Solids - All VtWIs
UP 11
saniepate
000000
4
M
The DRMS sent a letter to Mr. Brian McGill of GCC dated December 8, 2009. The letter
presented Numeric Protection Levels for groundwater monitoring for four parameters
(TDS, Sulfate, Radium 226, and Radium 228). DRMS generally selected the historic
maximum concentration prior to May 2009 as the numeric standard for each of the four
parameters. Table 1 lists the DRMS Numeric Protection Levels for the four constituents of
concern in the footnotes. The letter also described an approach for evaluation of potential
of exceedences, and subsequent actions, based on results from the groundwater monitoring
program. The following approach was presented.
"Sampling for each well will be conducted semi annually and results to be submitted
annually. If an upward trend above the set limits is noted, the frequency of sampling will
increase to quarterly. If the upward trend still continues, the frequency of sampling will be
conducted monthly. If two consecutive monthly samplings still show an upward trend, GCC
will present a remedial action to the Division, which will indent the source of the upward
trend and submit the actions GCC proposes to take a receive written approval from the
Division."
The TDS exceedences at wells MW -03 and MW -04 do not define an upward trend. As
shown in the TDS chart above, there is no consistent trend to the TDS data. MW -03 shows
alternating highs and lows that are most likely associated with seasonal groundwater
fluctuations. Recent TDS highs have been recorded during October sampling events that
4
= n
umLe d
2,630
....1r Alp/1W di
w
V
TDS concentrations from the October 2011 event ranged from 1,760 mg/L to 3,060 mg/L.
TDS concentration exceeded the State Numeric Protection Level of 2,630 mg/L in wells
MW -03 (3,060 mg/L) and MW -04 (2,640 mg/L). These are the first exceedences of the
TDS standard since October 2009. The following chart shows the results of the TDS
analyses for all three wells since TDS sampling started in March 2008.
3500
3000
2500
2000
0 1500
1000
500
Total Dissolved Solids - All VtWIs
UP 11
saniepate
000000
4
M
The DRMS sent a letter to Mr. Brian McGill of GCC dated December 8, 2009. The letter
presented Numeric Protection Levels for groundwater monitoring for four parameters
(TDS, Sulfate, Radium 226, and Radium 228). DRMS generally selected the historic
maximum concentration prior to May 2009 as the numeric standard for each of the four
parameters. Table 1 lists the DRMS Numeric Protection Levels for the four constituents of
concern in the footnotes. The letter also described an approach for evaluation of potential
of exceedences, and subsequent actions, based on results from the groundwater monitoring
program. The following approach was presented.
"Sampling for each well will be conducted semi annually and results to be submitted
annually. If an upward trend above the set limits is noted, the frequency of sampling will
increase to quarterly. If the upward trend still continues, the frequency of sampling will be
conducted monthly. If two consecutive monthly samplings still show an upward trend, GCC
will present a remedial action to the Division, which will indent the source of the upward
trend and submit the actions GCC proposes to take a receive written approval from the
Division."
The TDS exceedences at wells MW -03 and MW -04 do not define an upward trend. As
shown in the TDS chart above, there is no consistent trend to the TDS data. MW -03 shows
alternating highs and lows that are most likely associated with seasonal groundwater
fluctuations. Recent TDS highs have been recorded during October sampling events that
4