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Battle Mountain Resources—San Luis SL-SOP-Groundwater Well Decommissioning <br /> STANDARD OPERATING PROCEDURES REVISION: 0-May 6,2019 <br /> 1. PURPOSE and SCOPE <br /> The purpose of the procedure is to establish a monitoring well decommissioning <br /> procedure and provide technical guidance. Synonyms for well decommissioning include <br /> "plugging," "capping" and "abandoning." For consistency, only the term <br /> "decommissioning" is used within this document. <br /> Unprotected, neglected and improperly abandoned monitoring wells are a serious <br /> environmental liability. They can function as a pollution conduit for surface contaminants <br /> to reach the subsurface and pollute our groundwater. They also can cause unwanted <br /> mixing of groundwater, which degrades the overall water quality within an aquifer. <br /> Improperly constructed, poorly maintained or damaged monitoring wells can yield <br /> anomalous poor data that can compromise the findings of an environmental investigation <br /> or remediation project. Unneeded or compromised monitoring wells should be properly <br /> decommissioned in order to prevent harm to our groundwater. <br /> Within its boring zone, a successfully decommissioned well prevents the following: <br /> 1. Migration of existing or future contaminants into an aquifer or between aquifers; <br /> 2. Migration of existing or future contaminants within the vadose zone; <br /> 3. Potential for vertical or horizontal migration of fluids in the well or adjacent to the <br /> well; and <br /> 4. Any change in the aquifer yield and hydrostatic head, unless due to natural <br /> conditions. <br /> 2. RESPONSIBILITY <br /> All personnel who decommission groundwater wells or provide oversight are responsible <br /> for implementing this procedure. Prior to well decommissioning all measurement <br /> equipment shall be verified that it is in good working order and ready for use. Additionally, <br /> all appropriate regulatory agencies shall be notified in accordance with applicable <br /> regulations. <br /> 3. PREPARATION <br /> The first step in the well decommissioning process is to review all pertinent well <br /> construction information. One must know the well depth and construction details. GPS <br /> coordinates and permanent labeling (if available) will be useful in confirming the well to <br /> be decommissioned. An inspection must be performed prior to decommissioning in order <br /> to verify the construction and condition of each well. Specific details and subsurface <br /> conditions form the basis for decisions throughout the decommissioning process. <br /> Well Details <br /> 1. Is the well a single stem riser (all one diameter)? <br /> 2. Is the well a simple overburden well (no penetration into bedrock)? <br /> 3. Does the well riser consist of telescoping diameters of pipe which decrease with <br /> depth? <br /> 4. Is the well seal compromised (leaking, inadequate or damaged)? <br /> 5. If the well is PVC, is it 25 feet or shallower and not grouted into rock? <br /> SL-SOP Well Decommissioning EA, Inc. <br /> a <br /> Battle Mountain Resources, Inc. Page 4 of 21 M 6,2019 <br />