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n ~~ -4- II. Alluvial Wells A. Trout Creek P&M established four alluvial wells on Trout Creek. The four wells exhibited marked differences in water quality indicative of their locations. Some water quality parameters have undergone changes since baseline. TR1 is an upstream alluvial well established adjacent to the West Ridge Area. It is also adjacent to an abandoned underground mine. Water is of a calcium-magnesium sulfate type. TDS levels during baseline averaged 1,414 mg/1 (maximum of 1,797 mg/1). Water in this alluvial well has increased in levels of sulfate, phosphorus and iron (total and dissolved) in 1983. TDS levels also appear to show a marked increase in 1983. This would indicate that mining in the West Ridge Area has had an effect on these alluvial waters. TR2 is located on the west side of Trout Creek across from unreclaimed spoils. The water in this well is also of acalcium-magnesium sulfate type with somewhat decreased levels of magnesium relative to calcium. TDS levels averaged 1982 mg/1 during baseline (2,249 mg/1 maximum). Since baseline there has been a significant increase in iron (total and dissolved), phosphorus and calcium. TDS levels have also increased but not as significantly as levels in TR1. The levels in this well have been increasing since baseline. TR1.5 was established between TR1 and TR2 in 1982. The Division does not have installation data or a location for this well. In general, water quality in this well resembles the quality of water in Trout Creek. Water is of the calcium-sulfate type and appears to show a decrease in 1983 in chemical parameter levels. Iron levels are very high but other levels are comparable to Trout Creek. P&M does not offer any explanation as to why the quality of alluvial water is better in TR1.5 relative to TR1 and TR2. Without location or installation data, I would guess that TR1.5 is in direct communication with the surface water system while TR1 and TR2 are not. TR3 is located adjacent to the Moffat Area. Water in this well is primarily calcium-sulfate type with slightly lower levels of iron and bicarbonate. Other water quality parameters have shown decreased levels except phosphorus which has shown an increase. TR4 was located downstream of the permit boundary for the baseline study. Since baseline this well has been relocated upstream but P8d~9 has not submitted new well completion data or an updated location map. Water in this well is primarily calcium sulfate. All water quality parameter levels have decreased since baseline. Data collected from the alluvial wells indicate that TR1.5, TR3 and TR4 maintain a good connection with Trout Creek while TR1 and TR2 do not. This is contradicted in the permit application where it is stated that TRl is installed in an area which receives subsurface flow from Little Trout Creek as it enters Trout Creek and that should indicate a good interconnection.