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been developed by the CDPHE and this activity will be done by them and FMM. No site runoff will <br />be allowed to enter the trenches. <br />If it is not necessary to install the trenches, the trench area may be mined. If this occurs, any <br />contaminated overburden will be treated as described in this section (farmed off site). <br />Prior to any pumping of water into the sediment pond and the trenches, portable petroleum <br />hydrocarbon sniffers wilt be used on all exposed areas of the trenches and sediment pond. The data <br />will be reviewed by CDPHE and evaluated. A written evaluation of the tests will be made by <br />CDPHE. When deemed safe or "clean", the data will be submitted to CDMG for evaluation and <br />approval. Only after CDMG approves the documentation will water be allowed to be pumped into <br />the sediment pond and the trenches. <br />Once the sediment pond is in place, the pit pump will be located below ground water level in the <br />Phase 1 mining area. Water pumped from the pit will be pumped in a plastic pipe to the sediment <br />pond east of Phase 1. The inlet to this pump will have a gravel filter of 3' width on all sides to <br />prevent [he pumping of silty water. A float control device will be located in Trench #1 (if it is <br />installed) to control a pump located at the north end of the sediment pond to feed water in the <br />trench if it falls below the desired level of 4452 to 4458'. This level is approximately 4 to10 feet <br />above the existing groundwater level. Initially, the water level in the trench will only be raised to 4 <br />feet above the existing water level. If ongoing water monitoring shows undesirable movement of <br />the contaminant plume in any direction, the water level will be adjusted in the trench to get the <br />desired stability of the plume. The CDPHE firmly believes that the plume to the north will stay in <br />place without any significant movement, since past testing of the plume has shown very little <br />movement in many years. For this reason, the trenches may not be installed. The existing <br />monitoring well layout and sampling program is more than adequate to determine if the plume <br />moves. <br />The inlet to the pump to Trench #1 will have a 3' wide gravel filter or other pre-fabricated filter so <br />that all water entering Ttench #1 is free of silt, thereby preventing the Trench from becoming less <br />Gitsonite Pit 1/04 11 <br />