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Groundwater Sampling Report <br />May 12, 1997 <br />Page 2 <br />general schematic of the well construction was obtained from BME but individual well <br />completion logs were not available. The wells reportedly have limited screen length neaz the <br />bottom of the casing and have been sealed within a lithologic transition zone between an upper <br />sandstone and a lower coal/silt facies. Nitrogen gas lifring of water from the wells was <br />determined to be a good alternative technique for purging based on these conditions. The <br />analytical program includes only dissolved metals so little affect on the results is expected. <br />Nitrogen lifring was not available during the first day of field sampling for well 30-8M and also <br />did not work on well 31-7M possibly due to poor construction of the seal. The purging and <br />sampling techniques used for each well are also noted on Table 1. <br />Due to the equipment safe depth limitation in several of the wells, slow recharge rates and the <br />gas lift technique, a minimum of 1 well volume of water was purged from each well. Water <br />quality parameters were measured in field periodically to determine if fresh inflow of <br />groundwater into the well was occurring. Field parameters included temperature, pH and <br />specific conductance and were measured using a calibrated YSI 3500 water quality meter. <br />Results of the field measurements are included on the field report for each well. Water quality <br />in the wells were very similar. Specific conductance ranged from 2100 to 3400 mili-ohms per <br />centimeter suggesting fairly good water quality. The water were slightly basic with a pH range <br />of 8.2 to 9.0. Water from all of the wells except for 32-7M were dark gray co black due to coal <br />fines. The wells have not been developed and also may not have been constructed with a sand <br />filter pack surrounding the screened interval. These conditions would be expected to allow a <br />high turbidity in the waters when sampled. <br />TABLE 1 <br />WELL SAMPLING INFORMATION <br />Well No. Water Depth Problem Depth Purge Field Parameters"' <br /> (feet btoscl (feet btoscl Technique Temp.IConduct./pH <br /> IC, m.ohms/cm, H units) <br />30-BM 55.59 150-200"' um /bail 11.4/2450/9.0 <br />32-7M 50.06 nitro en lift 13.1/2221/8.3 <br />31-7M 108.92 150 um 15.3/2120/8.2 <br />29-4M 240.73 nitro en lift 12.3/2940/8.7 <br />33-8M 225.12 300 nitro en lift 11 .7/3360/8.6 <br />NOTES: <br />btosc =below top of surface casing <br />111 bailer temporarily stuck at 200 feet <br />121 measurement coincident with sample collection <br />Groundwater samples were collected from each well using a decontaminated 2-inch bailer. A <br />peristaltic pump with a new 45 micron size filter for each well was used to filter the samples <br />into the laboratory supplied sample containers. For well 31-7M, water was filtered and sampled <br />FILE: ];\9J5\FLDRPT.LTR <br />