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Responses to Division Concerns <br /> Page 10 <br /> Bulkhead Performance - Cont 'd <br /> Therefore the American Tunnel pressure gauge will provide <br /> the only useful information unless the mine pool surface <br /> rises above 11 , 600 feet, then the gauges can be checked <br /> against each other . <br /> The Terry Tunnel is accessible only during June - <br /> September and because of the logistics of ventilating the <br /> dead-end tunnel, SGC proposes that the bulkhead be <br /> inspected annually unless the surface elevation of the <br /> mine pool exceeds 11, 600 feet, then semi-annually. The <br /> portal will be inspected for flows quarterly, when <br /> accessible. If a flow is found, the bulkhead and tunnel <br /> will be inspected. <br /> Inspection of the American Tunnel bulkhead will also <br /> require ventilation of a dead-end tunnel but because of <br /> the head to be developed behind the bulkhead and the <br /> information to be gained about the rate of rise and <br /> elevation of the mine pool surface, SGC proposes the <br /> following inspection schedule. The American Tunnel <br /> bulkhead and tunnel will be inspected and gauge read <br /> weekly after valve closure for the first month, monthly <br /> for five months and then quarterly thereafter . <br /> These inspection schedules will be followed for five <br /> years or until the mine pool has approached equilibrium, <br /> whichever is first . <br /> 3 . Action Criteria and Contingency Plan <br /> SGC proposes the following procedures be used if bromide is <br /> detected through monitoring of the creeks or tunnel flows. <br /> 1) Locate the source . In the case of the bulkheads, this <br /> could be visual . In all other cases this would be by <br /> analysis. <br /> 2) Quantify the possible effects of the flows. In the case <br /> of the bulkheads this could be done immediately based on <br /> flow. In all other cases this would be by analysis of <br /> the quantity and quality of flow to determine if <br /> immediate or possibly no action is warranted. Each case <br /> of seepage found other than bulkhead leakage that might <br /> affect the structural integrity of a bulkhead, would be <br /> decided on a case by case basis as to the effect on the <br /> hydrologic balance with the goal being minimization of <br /> impact to the hydrologic balance. <br />