2013-02-06_HYDROLOGY - M1977348

• Permit No: M1977348
• IBM Index Class Name: HYDROLOGY
• Doc Date: 2/6/2013
• Doc Name: Proposed Changes to the Analytical List for Groundwater Sampling.
• From: Golder Associates
• To: DRMS
• Permit Index Doc Type: Hydrology Report
• Email Name: ECS
• Media Type: D
• Archive: No

Mr. Eric Scott 2 February 5, 2013
Colorado Division of Reclamation Mining and Safety 103 -81640
Sincerely,
widely within each well and between wells. Therefore, the gross alpha and gross beta
results have been ineffective parameters with regard to assessing groundwater quality.
2.0 GROUNDWATER MONITORING WELLS MW -5, MW -6 AND MW -7
Three new groundwater monitoring wells (MW -5, MW -6 and MW -7) were installed in December 2012 and
will be sampled quarterly for at least one year. Golder proposes to commence monitoring with a more
extended suite of constituents for the first four quarterly monitoring events then proposed for MW- through
MW -4. Following four quarters of monitoring with this extended analytical suite the monitoring program
will be reassessed.
Golder proposes the following modifications to the historical constituent list for the first four quarters of
monitoring:
• Metals:
Removal of lithium and uranium from the current analytical list is proposed as these
metals have remained consistently below the respective benchmark levels in the existing
groundwater monitoring wells during 2011 and 2012 and these metals are not typically
associated with CKD.
• Nutrients:
Nitrate as N, Nitrite as N and Nitrate +Nitrite as have remained consistently below their
respective benchmark values in the existing groundwater wells, and for the most part
have not been detected above the laboratory's PQL in the downgradient wells MW -2,
MW -3 and MW -
• Radionuclides:
As stated for the existing monitoring wells, gross alpha and gross beta results have been
ineffective parameters with regard to assessing groundwater quality as related to the
Boettcher Quarry. For this reason, gross alpha and beta are not recommended for the
first four quarters of monitoring.
The analytical list proposed for the first four quarters of monitoring in the new groundwater monitoring
wells MW -5, MW -6 and MW -7 is presented in Table 2.
3.0 CLOSURE
If you have any questions or comments about this request, please contact Joel Bolduc of Holcim at
855 - 719 -6947.
GOLDER ASSOCIATES INC.
ara Harkins
Geologist /Geochemist
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Mark/McClain
Proj Director and Principal
Attachments:
Table 1 — Proposed analyte list for groundwater monitoring wells MW - MW -2, MW -3 and MW
Table 2 — Proposed analyte list for groundwater monitoring wells MW -5, MW -6 and MW -7
a ssociates