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Increased Erosion and Sediment Yield During the active mining phase, and until sufficient vegetation can be established in the watershed, sediment yields above pre-mining levels are expected. Annual sediment surveys of the sediment ponds at the Seneca II Mine were initiated in 1985. These surveys will allow actual amounts of sediment deposited to be quantified. With continued monitoring, compazisons to estimated design volumes and erosion rates can be made. Throughout mining, the ponds have ensured compliance with effluent limitations prior to dischazge from the mine site, and only once during the last ten years has limitations for total suspended solids been exceeded. This occurred in June 2006, at Pond 003, as a result of an algae bloom. The total suspended solids value on June 7, 2006 was 36 mg/1; the standazd is 35 mg/1. Water Quality Standards A comparison of Grassy Creek water quality at SW-S2-1, upstream ofmining activities, to that of S W-S2-2, downstream of mining shows a slight degradation of water quality. SW-S2-2 shows a slight increase in metals concentration, sulfate, and total dissolved solids. These increases can be attributed to mining in the drainage and to the installation of a truck washing facility ofNPDES outfa11003, immediately upstream of SW-S2-2. There are no receiving stream standards designated for Grassy Creek but water quality in Grassy Creek generally meets the standards established for Fish Creek. Water quality in Fish Creek shows no significant impact associated with mining. Data collected atsite SW-S2-13, downstream from mining activities meets receiving stream standards. Pond outfalls (NPDES outfalls 002, 003, 004, and 008) are monitored according to the requirements of the Seneca II Mine NPDES permit (see section B of this document "Monitoring"). Increased Total Dissolved Solids Loading An increase in salinity, as represented by TDS concentrations, is the major surface water impact caused by the Seneca II Mine. The disturbance of sedimentary rocks during the mining and reclamation process exposes more surface area for the solution of minerals and increases the amount of solute available for transport to surface streams. An increase in TDS concentration between upstream and downstream stations on Grassy Creek has been observed at the Seneca II Mine. This effect has been apparent throughout the monitoring period, 1981 to 2006. In 1981 an average TDS concentration of 582 mg/l was observed at the upstream site and an average TDS concentration of 1,600 mg/1 was observed at the downstream location. In 2006, a TDS concentration of 720 mg/I was observed at the upstream location and a concentration of 3,360 mg/1 was 24