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o l'\) ~ <.N. . , 4. Drilling Tests From Geldon The U.S. Geological Survey became involved in the tests in 1984 when Terra Therma, Inc., the successor to Chaffee Geothermal Ltd., decided to determine the effects of discharge from the Redstone 21-9 wen on surrounding wens and springs. The U.S. Geological Survey volunteered monitoring equipment and personnel for the test and was authorized by Redstone Corporation to use the test data in conjunction with its ongoing study of the regional hydrology. Mter an extended shut- in period, the Redstone 21-9 wen was flow tested during November 12-20, 1984. This test is caned the second Redstone well test in this report. Test results are discussed in the section "Second Redstone Wen Test" and interpreted in the section "Interpretation of Test Data." The Wright no. 1 well, three U.S. Bureau of Reclamation wells (USBR nos. 1, 3, and 11), and three springs (Hobo, Graves B, and Yampa) were monitored also. First Redstone Well Test -- The first Redstone well test was a flowing-wen test (see Lohman, 1979, p. 23-27, for discussion of test principles, derivation of analytical solutions, and examples of use for this kind of test). The monitoring network for this test included the Redstone 21- 9 well (production) and the Wright no. 1 well (observation). In addition, a recording barometer was set up near the test site. The Redstone 21-9 wen was instrumented for indirect measurement of potentiometric head. A 12-ft-high insulated standpipe was erected next to the well casing and connected to the casing by a 1.5-in.-diameter plastic pipe. A Stevens Type F continuous analog recorder was placed on top of the standpipe to record water levels. A 0.375-in. plastic piezometer tube and steel tape calibrated in hundredths of a foot were attached to the outside of the standpipe to visually verify the recorder readings. Potentiometric heads were calculated from water levels in the standpipe. Discharge from the well was measured with a 9-in.-orifice plate attached to a horizontal steel discharge pipe. The discharge pipe had a diameter of 12 in. As recommended by the U.S. Water and Power Resources Service (1981, p. 234), a 0.375-in.-diameter plastic piezometer tube was inserted into the discharge pipe 3 diameters (36 in.) behind the orifice plate. The piezometer tube and a steel tape calibrated in hundredths of a foot were attached to a vertical support at the point where the piezometer tube was inserted into the discharge pipe. Discharge was calculated from an equation developed by the U.S. Water and Power Resources Service (1981, p. 235). Potentiometric heads in the Wright no. 1 wen also were calculated from water levels. A Stevens Type F recorder placed directly on the wen casing was used to record water levels in the well. Recorder readings were verified periodically by lowering a weighted measuring tape into the well. The first Redstone well test lasted from January 5 to 14, 1982, and included a flow period of 6.8 days and a recovery period of 1.8 days. Dis-chargefrom the Redstone 21-9 wen decreased from 1,860 gal/min at the start of the flow period to 1,480 gal/min at the end of the flow period. The average discharge during the flow period was 1,540 gal/min. Potentiometric head in the Redstone 21- 9 well, adjusted for atmospheric pressure changes, decreased 5.72 ft during the flow period; the residual drawdown 1.8 days later was 0.79 ft. Potentiometric head in the Wright no. 1 well, adjusted for atmospheric pressure changes, decreased 1.02 ft during the flow period and recovered completely 1.6 days later. Second Redstone Well Test -- The second Redstone well test was similar to the first test but involved a more extensive monitoring network. Additional observation points included alluvial wells USBR no. 1,3, and 11, the Yampa, Graves B, and Hobo Springs, and the U.S. Geological Survey's streamflow-gaging station 09085100. Except for minor changes, instrumentation for the production A-lO