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. 7.0 Site 1 - South Metro Area 7.1 Well Background Castle Pines Arapahoe well A3 is a water supply well drilled in 1985. Additional analysis were perfonned in 1987 by various local and govemmental entities as described in the report by Robson and Banta (1993). Extensive geophysical and strain analyses were perfonned at holes quite close to the supply well. One nearby well was completed for water level monitoring in various individual zones for analysis during pumping of the multi-completion supply well. . A high production well at this s~e is located in Banta's model in layer 2, row 31, column 10, Pumping in the SIMGRO simulation at this s~e starts in 1995. Pumping rate varies from 162 gpm for the period from 1996 to 2005 to 503 gpm from 2046 to 2085. Banta's SIMGRO simulation shows drawdown at this site, but simulated water level in cells never reaches top of aquifer, and the system remains confined. Aquifer test results imply a transmissivity of a little over 2000 sqtVd. Banta's model has transmissivity in this cell at 500 sqft/d. It is our feeling that the higher value from the test is likely more appropriate for this s~e, but we have estimated water levet in the well for both transmissivity values. 7.2 Radial Model Setup A cross sectional radial flow model of near well area was set up with: 15 layers, 1 row, 90 columns, and 13 well completion zones. Each completion zone is represented by one layer w~hin the Arapahoe. The upper two layers have no completion in the well. In some cases, a single sandstone layer may have two completion zones at the well. In these cases, a break between layers is defined to match the break between completion zones and the layers are simulated with a high vertical conductance between them. A . conceptual diagram of the well is presented in Figure 7.1. The well completion zones 19