Laserfiche WebLink
<br />Decemdrr 1992 79~e Rorkrastle Company • Gracry Gap Mine " /99I Annual Hydrology Report ~ 7 <br />3.0 SEEP AND SPRING SURVEY <br />ACZ performed the annual seep and spring survey for the spoil areaz of the Grassy Gap Mine. <br />' The survey was conduced by Robert Peterson, ACZ engineer, on June 23, 1992. At that time, <br />all mined areas had been reclaimed and the downgradient perimeters of the spoils were inspected <br />for moist soil (seep) and springs. <br />' 3.1 FIELD METHODS <br />Pits 1, 2, 3, 4, 5, and 6 spoils were inspected for seeps and springs. Seeps were identified by <br />moist soils and vegetation changes. Ground water flows observed at the ground surface were <br />considered springs. The areas inspected included roadcuts, diversions, sediment ponds and the <br />' naturally vegetated areas downslope and/or down geologic dip from the reclaimed pits. <br />The survey was performed on foot with access to each pit in a 4-wheel drive vehicle on existing <br />' access roads. Field parameters including temperature, pH, and electrical conductivity were <br />measured direcly from springwaters using a Hydac digital conductivity, temperature, pH meter. <br />The meter was calibrated using pH controlled buffer solutions prior and subsequent to the field <br />measurements. The meter sample basin and probe were rinsed with distilled water prior to each <br />' meazurement. Where possible, the spring flow was measured using a known capacity container <br />and a stop watch. No field parameters or flow measurements were taken for the seeps. <br /> 3.2 RESULTS <br /> ~ <br />~ <br /> s d 8 seeps the perimeter of Pits 2, 4, 5, and 6. No <br />The field survey identifie¢',° sp <br />rtn~ <br /> identified seeps or springs `4rrc~ociate tts 1 or 3. In comparison with the 1991 survey <br /> conduced by ACZ, 2 additional springs and 3 seeps were identified. The new springs and seeps <br /> were located along the south and west side of the Pit 4 access road, down grade from the <br /> previous slide area and bend in the road. Refer to Map 1, for the location of all seeps and <br />' springs identified during this survey. <br />~, 9P"` <br /> The spring with the greatest flow rate was Spring 3, located at the base of Pit 5 just above Pond <br />' 5/6 and associated with a slump located along the south slope of Pond 5/6. It was observed to <br /> be discharging direttly into the sediment pond at a rate of 6 gallons per minute (gpm). Pond <br /> 5/6 waz discharging at the time of this survey. Spring 5, located along the access road to Pits <br />2 and 3, had a flow of approximately 2 gpm, an increase over the 1991 measurement of 1.2 gpm. <br /> Spring 1, on the north side of Pit 5 had red soil staining associated with the discharge. A water <br /> sample was colletted (S-1) and submitted to an analytical laboratory to analyze for total iron. <br /> The spring was absorbed into the soil prior to entering any surface drainage. Laboratory results <br /> indipte 0.4 mg/1 total iron concentration and are included in Appendix C of this report for <br />' reference. <br /> All of the springs except Spring 4, nearest co Pit 6, were found both down slope and down <br /> geologic dip from the nearest spoils. The spring farthest from the rela[ed spoil area was Spring <br /> 5 which was approximately 400 ft. west of the Pit 2 western perimeter. It was, however, located <br /> in a natural drainage which could drain groundwaters from the spoil. <br /> <br />un~nxranrr ACZ Int. " P.O. Box 774018 "Steamboat SpnrsBs, Colorado 80477 ' (303J 879-6260 <br />~/~an11p~ <br />