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Other possibilities of mine contamination were reviewed, mine water discharge or surface runoff. Since the mine inflow has stabilized and discharges via the sediment pond which has never discharged during the life of the mine, it is therefore infeasible that mine water is the cause. With increased precipitation and recent surface grading on the facility site, it is possible that this may have added some increase to the EC values. On review, the chemical and physical properties of calcium, magnesium, sodium and sulfate also show an increase from below the mine while remaining relatively constant above the mine. All values remain below the Colorado Department of Health recommended standards for material damage suspect criteria. However, there is an increasing trend for EC and these values to increase annually more each winter than the previous year. True to the report's summary, December 1992 data does exceed the established permit levels for pH, EC, sodium and sulfate. Recommendation Since this trend continues to show an increase in EC, Na, pH and sulfate, the Division recommends that the permit be revised to include this trend occurring on Harvey Gap irrigation creek. The proposed reason given in the report summary, that fluctuations in the water level of the reservoir may cause more concentrated salts to be added to the creek in the fall and winter months could be included. I also suspect that the regional geology and proximity to shale outcrops along the valley sides contributes to the increasing trend. The surface seep, below the Harvey Gap Reservoir, continues to show a stable trend in flow, pH, temperature and conductivity. Due to the high EC values observed (1000-1150) it can be argued, that the basal waters of the reservoir do indeed contain an increased amounts of salts and may add to the higher values observed downstream-below the mine. GROUND WATER Two monitoring sites make up the ground water monitoring program. One, the geotech well, in the area of the proposed refuse pile, has remained dry to date. The second site, mine inflow water has shown a stable EC and flow rate. pH is improving with 1992's pH average of 7.2 slightly lower than 1990's 7.5 value. Since dewatering the mine is minimal, and mining activity has ceased, chemical parameters of mine water show a slightly decreasing trend since 1990 in EC, CaCO3, TDS and sulfate. Calcium and magnesium are stable, with the quality of the water improving since bicarbonate levels are slowly increasing, up from 186 mgjl in 1990 to 282.0 mg/1 in 1992.