Laserfiche WebLink
• Rule 1: Prmws <br />equation T = Kb, where T is uansmissivity, K is hydraulic conductivity, and b is the interburden <br />thickness. Therefore: <br />T=Kb <br />T = (1.28 x 10"' ft/day) (5 ft) <br />T = 6.40 x 10~' ft1/day or 4.78 x 10-Z g/d/ft <br />Comparing this to the regional values: <br />T=Kb <br />T = (0.0408 ft/day) (5 ft) <br />T = 0.204 ft1/day or 1.53 g/d/ft <br />Comparing this value to the established values determined in the regional study by Howard, this <br />value is one order of magnitude lower. Based upon field data from bailing the wells at the site, <br />the value determined from site specific slug test would appear extremely low. Comparison of field <br />data, the potential pumping rates based upon site-specific data, and the data from the regional <br />study indicates that the regional values may be more consistent with field data from bailing. The <br />potential pumping rate from the well can be estimated from the equation Q=Ts/2000 (derived <br />from Fetter, 1980). In this calculation Q is the flow rate, T is the transmissivity (determined from <br />• the hydraulic conductivity T=Kb), s the available drawdown, and 2000 is a constant (accounts for <br />conversion of T in g/d/fr). Therefore: <br />Q = (4.78 x 101 g/d/ft) [187 ft (for MW-4I)]/2000 <br />Q = 0.0045 gpm (for site-specific data) <br />Q = 36.6 g/d/ft [187 ft (for MW-4I)]/2000 <br />Q = 0.14 gpm (for regional data) <br />Generally, the rate of evacuation for the wells during the sampling events is estimated as 1.0 gpm. <br />This value and the potential pumping rate for the well (determined above utilizing regional data) <br />compare more favorably; therefore the range of the transmissivity in this zone is 4.78 x 101 g/d/ft <br />to 0.14 g/d/ft. <br />Storativity estimated by this method (Cooper, Pappadapoulous) was 2.25 x lOd. The storage value <br />is within the range for a confined zone (Heath, 1983). The hydraulic conductivity determined was <br />one order of magnitude higher than the value determined by Howard (1982) for the Raton <br />Formation sandstone. <br />Groundwater seepage velocity (v6) can be determined from the gradient (dh/dl, or I), effective <br />porosity (rte, and hydraulic conductivity (K). Seepage velocity represents the rate at which water <br />CJ <br />PERMR.<]S\Dmcmba 30. 1996 2.04-16 <br />