4. For a confined well with 1000gpd withdrawal the draw dawn from several observation well was given in table below. Calculate the following: (a) Using the Thiem formula, complete the table; (b) On semi-log graph paper, plot the final draw-down for each observation well with the log distance from the pumping well. Draw the best fitting line through the four points and obtain the rate of draw-down per log cycle Then obtain the transmissivity value using Thiem equation and finally compare with the values obtained in parts (a) and (b). r₁ (feet) r2(feet) s2(feet) kB(gpd/ft) $₁(feet) 3.57 295.0 98.0 7.34 7.34 3.57 2.35 7.34 98.0 2.6 2.6 98.0 295.0 2.6 295.0 705.0 705.0 705 2.35 3.57 2.35 0.82 0.82 0.82 Mean kB

You've been tasked with siting a new well in a confined aquifer that already has several operating wells. Drilling logs indicate that the aquifer is primarily sand and gravel with an average thickness of approximately 200 ft. You have specific capacity data from several drilling logs in the area (table 1), as well as data from a 48-hour single well pump test that was previously performed at well AG-1 several years ago (table 2). At the end of the single well test, simultaneous drawdown measurements were taken in several monitoring wells surrounding the pumping well (table 3). Estimate the transmissivity and storativity of the aquifer, along with a realistic range of uncertainty around those numbers. Table 1: Specific capacity data for nearby wells WELL BOREHOLE PUMPING STABILIZED DIAMETER DRAWDOWN 24 inches 16 inches 8 inches MW-1 AG-1 HH-1 Table 2: Single-well pump test on AG-1 at 500 gpm Time (min) Drawdown (ft) 1 2 3 4 5 6 7 8 9 10 20 30 40 50 60 120 180 240 300 360 540 720 1440…

Can you calculate the concentration at the end of the well using the 1-D steady advection-dispersion-reaction equation. The given parameters are distance = 200 m, Initial concentration = 10 mg/L, reaction = 0.0062 / day, dispersion = 1.5 m^2/d, and velocity = 0.5 m/d.

Estimate the Q that produced a drawdown in a 1 ft diameter well of 5 feet above the bottom of a pressurized aquifer with a 35 ft thickness and a head in a monitoring well 55 ft away 25 ft above the bottom of the aquifer in a clean course sand aquifer with K ~ 3*10^(-3) ft/sec.