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<br /> �:vy �COLORADO LEGACY LAND
<br /> Streamlined Groundwater Sampling Methodology and Reporting
<br /> In an effort to streamline field work and reporting practices,CLL would like to revise Land Reclamation Permit
<br /> M-1977-300 to promote pragmatic compliance sampling as well as clear communication and reporting.
<br /> 1. Streamlined Reporting and Analytical Sampling Suite:
<br /> Currently CLL collects surface water and groundwater samples for DRMS in accordance with Mine Land
<br /> Reclamation Permit M-1977-300, Technical Revision 11 Environmental Protection Plan (Whetstone, 2016).
<br /> Table 1 summarizes the current surface water and groundwater sampling requirements, redundancies,
<br /> analytical data gaps between surface water and groundwater media,and the recommended sampling suite
<br /> to monitor water quality in and around Ralston Creek.
<br /> Beginning January 1, 2019, CLL's subcontractor Alexco intends to conduct a quarterly surface water and
<br /> groundwater sampling event for analytes identified in Table 1. Surface water and groundwater samples will
<br /> be collected from locations identified in the Mine Land Reclamation Permit M-1977-300, Environmental
<br /> Protection Plan(Whetstone,2016). These required locations are listed below for reference:
<br /> • Surface Water Sample Locations: SW-AWD, SW-A001, SW-BDIS, SW-PL, SW-OS, SW-BOS, SW-GS,
<br /> SW-BPL,SW-FBRG,SW-ARH,and SW-LLHG.
<br /> • Groundwater Sample Locations:MW-00,MW-0,MW-1,MW-1,MW-3A,MW-4,MW-5,MW-6,MW-7,
<br /> MW-12,MW-13,MW-14,MW-15,MW-17,MW-18,MW-19,and MW-20. (Note:MW-8 is not sampled
<br /> because it was replaced with MW-12,MW-9 is not sampled because it is tied into the sumps,MW-
<br /> 10 is not sampled because bentonite has fouled the screen,MW-11 is not sampled because bentonite
<br /> has fouled the screen,and MW-16 is not sampled because of poor casing construction.)
<br /> Results of the quarterly sampling event will be provided to DRMS as one quarterly sampling report.
<br /> Attachment A contains an example/template of the proposed deliverable. Highlighted text(e.g. "TBD") is
<br /> used to indicate site-specific data that will be presented in the quarterly report.
<br /> 2. Streamlined Groundwater Sampling Methodology:
<br /> Current,Mine Land Reclamation Permit M-1977-300 permits four different groundwater sampling methods:
<br /> low flow sampling,PVC-bailer,air-driven bladder pump or piston pumps,and dedicated submersible
<br /> pump. Below are the specific sections that reference each approved method:
<br /> • Application Amendment 4, Mine Permit M-1977-300, Schwartzwalder Mine,Attachment 1 - Water
<br /> Quality Monitoring Plan (Cotter, May 2012) and Technical Revision 11Environmental Protection
<br /> Plan, Section 12 Water Quality Monitoring Plan (Whetstone Associates, 2016) describe a well -
<br /> volume purge method which may be implemented with PVC-bailer, air-driven bladder pumps or
<br /> piston pumps,and dedicated submersible pumps.
<br /> • Technical Revision 19, Standard Operating Procedure for Low-Flow Groundwater Sampling at the
<br /> Schwartzwalder Mine(Whetstone Associates,2013) describes the low-flow sampling process used
<br /> at deep,bed-rock wells MW13-MW19.
<br /> Beginning in January 1, 2019 and in accordance with Technical Revision 19, CLL intends to sample all
<br /> groundwater wells onsite using low-flow sampling methods. Utilizing a consistent sampling method will
<br /> improve the comparability between results from alluvial and deep bedrock groundwater wells. Deep
<br /> bedrock wells will continue to be sampled using the method described in Technical Revision 19. Attachment
<br /> B contains Alexco's Standard Operating Procedure (SOP) for low-flow groundwater sampling that will be
<br /> utilized by the field staff onsite for the alluvial wells. This SOP was developed in accordance with United
<br /> States Environmental Protection Agency(USEPA) guidance document, Low Stress(Low Flow) Purging and
<br /> Sampling Procedure for the Collection of Groundwater Samples from Monitoring Wells(September 2017). The
<br /> Colorado Department of Public Health and Environment does not currently maintain an SOP for low-flow
<br /> groundwater sampling. Additionally,Alexco has conducted a desktop study of published low-flow SOPS to
<br /> identify pertinent stabilization parameters and ensure that a representative sample is collected by field staff.
<br /> A summary of this evaluation is included in Attachment B for reference.
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