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Table B-1. Surface Water Discharge Monitoring Requirements in NPDES Discharge <br /> Permit <br /> Parameter Monitoring Frequency Sample Type <br /> Flow Instantaneous,Monthly In-situ <br /> pH 2x/month Grab <br /> Total Suspended 2x/month Grab <br /> Solids <br /> Oil and Grease Visual 2x/month Visual <br /> Oil and Grease Contingent on visibility Grab <br /> of oil and grease <br /> Total Flow , Instantaneous, Monthly Calculated <br /> Selenium,Potentially 2x/month Grab <br /> Dissolved <br /> Total Dissolved Solids Quarterly Grab <br /> Note:these are the anticipated analytes based on operator experience at similar sites.CDPHE may issue <br /> different sampling requirements with the permit <br /> 3.2. Floodplain <br /> The entire site is outside of any floodplain or floodways. See the FEMA FIRMETTE attached to <br /> this exhibit in Appendix B-1. <br /> 3.3. Wetlands <br /> The National Wetlands Inventory aerial-based mapping indicates the potential presence of <br /> wetlands adjacent to the permit area. All activity will take place outside of these potential <br /> wetlands. Setbacks can be seen on Map E-2. <br /> 3.4. Aquifers <br /> No identified alluvium aquifer is located onsite. Groundwater is found in the underlying bedrock <br /> in fractures systems, but mining will not excavate into the bedrock. No groundwater interaction <br /> will take place at the London Borrow Pit. <br /> 3.5. Surface Water <br /> The mining operation will impact surface water in the area through the stormwater runoff that <br /> enters the site. Map E-5 shows the drainage patterns and how they are affected throughout the <br /> life of the mine. The maps include information on the drainage basins currently, during mining, <br /> and post reclamation as well as the drainage directions throughout these stages. The primary <br /> concern for surface water protection at the site is preventing the discharge of sediment, oil, <br /> and/or hydraulic fluids from the operation areas. Oils and hydraulic fluids are stored off site <br /> following the standard best management practices. These practices include the use of <br /> secondary containment at fluid storage and transfer points, spill kits, and employee training <br /> regarding safe handling practices. Sediment is trapped onsite using controls and best <br /> London Borrow Pit <br /> April 2024 B-4 Lewicki&Associates <br />