Answer the following environmental engineering practice questions. QUESTION No. 1A confined aquifer 20.0 m thick has two monitoring wells spaced 500m apart along thedirection of groundwater flow. The difference in water level in the wells is 2.0m (thedifference in piezometric head). The hydraulic conductivity is 50m/day. Estimate the rateof flow per meter of distance perpendicular to the flow. Aquifer porosity is 0.2Suppose the aquifer becomes contaminated and the upgradient well is used as amonitoring well, whose purpose is to provide early detection of the approachingcontaminant plume, how long after the monitoring well is contaminated would thedrinking water from the second well become contaminated?QUESTION No. 2Consider a contaminant plume that is 200m wide x 20m thick x 1000m long. If d'Arcy'svelocity is 2.0 x 106 m/s and the aquifer porosity is 0.4, what minimum pumping ratewould assure full plume capture, and how far apart should two wells be placed foroptimal location and alignment along the leading edge of the plume? (10+ 15 marks)How long would it take to pump an amount of water equal to the volume of the watercontained in the plume?QUESTION No. 3A wastewater treatment plant serving a city of 600,000 persons discharges 4.0cu.m/s oftreated effluent having an ultimate BOD of 20.0mg/L into a stream that has a flow of10.0cu.m/s and a BOD of its own equal to 6.0mg/L. The deoxygenation constant, kis0.20/day. Assuming complete and instantaneous mixing, estimate the ultimate BOD ofthe river just downstream from the outfall.If the stream has a constant cross section, so that it flows at a fixed speed equal to0.50m/s, estimate the BOD remaining in the stream at a distance 43,200m downstream.GIVEN: L₁ = Loe-kdi

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A confined aquifer 20.0 m thick has two monitoring wells spaced 500m apart along the direction of groundwater flow. The difference in water level in the wells is 2.0m (the difference in piezometric head). The hydraulic conductivity is 50m/day. Estimate the rate of flow per meter of distance perpendicular to the flow. Aquifer porosity is 0.2 Suppose the aquifer becomes contaminated and the upgradient well is used as a monitoring well, whose purpose is to provide early detection of the approaching contaminant plume, how long after the monitoring well is contaminated would the drinking water from the second well become contaminated?

A confined aquifer 20.0 m thick has two monitoring wells spaced 500m apart along the direction of groundwater flow. The difference in water level in the wells is 2.0m (the difference in piezometric head). The hydraulic conductivity is 50m/day. Estimate the rate of flow per meter of distance perpendicular to the flow. Aquifer porosity is 0.2 Suppose the aquifer becomes contaminated and the upgradient well is used as a monitoring well, whose purpose is to provide early detection of the approaching contaminant plume, how long after the monitoring well is contaminated would the drinking water from the second well become contaminated?

Fundamentals of Geotechnical Engineering (MindTap Course List)

5th Edition

ISBN:9781305635180

Author:Braja M. Das, Nagaratnam Sivakugan

Publisher:Braja M. Das, Nagaratnam Sivakugan

Chapter6: Hydraulic Conductivity

Section: Chapter Questions

Problem 6.15P

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Don't copy from other solutions thank you. Three piezometers have been installed in the confined aquifer having a uniform thickness of 4.6 m. and hydraulic conductivity of 2 x 104 m/s. a) Compute the hydraulic grądient. b) Compute the transmissivity in m2/day. c) Compute the flow rate per unit width of the aquifer in liters/day.
A confined aquifer is 50 m thick and 0.5 km wide. Two observation wells are located 1.4 km apart in the direction of flow. Head in well No. 1 is 50m and in well No. 2 is 42m. Hydraulic conductivity is 0.7 m/day. Effective porosity is 25%. A ship carrying chemicals sank near the observation well no 1 and chemicals somehow reach the groundwater. How long it will take forthe chemicals to reach Well no 2?
Please answer with complete solution and Fbd. A field sample of an unconfined aquifer is packed in a test cylinder. The length and diameter of the cylinder are 60cm and 8cm, respectively. The field sample is tested for a period of 2min under a constant head difference of 18.5 cm. As a result, 50cm3 of water is collected at the outlet. Determine the hydraulic conductivity of the aquifer sample.
2. An aquifer has a hydraulic conductivity of 180 ft/day, and effective porosity of 33% and is under a hydraulic gradient of 0.0004. a) Compute the Darcy velocity (also called Darcy flux). b) Compute the actual velocity (also known as the average linear velocity). c) The water temperature was 14 Degree C, and the mean pore diameter was 0.30 mm. d) Was it permissible to use Darcy's law under these circumstances? e) What is the reason for your answer?
A pump well is dug through a confined aquifer having a thickness of 32 meters. The piezometric surface of the aquifer is 18 meters measured from the top impermeable layer. The first observation well is 75 feet directly west of the pump well and the second observation well is 75 feet directly north of the first observation well. Determine the hydraulic conductivity of the aquifer if it supplies a discharge of 10 liters per second and the drawdown of the observation wells are 13 feet and 23 feet.
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A sand sample of 35m cm^2 cross sectional area and 20cm long was tested in a constant head permeameter. Under a head of 60 cm, the discharge was 120 ml in 6min. The dry weight of sand used for the test was 1120 g, and Gs= 2.68 A. Determine the hydraulic conductivity in cm/sec. B.Determine the discharge velocity in cm/sec. C. Determine the seepage velocity in cm/sec.
Determine the drawdown at a distance of 50 m from a well pumping constantly at 50 US gpm after one year of pumping. The confined aquifer saturated thickness is 12 m, the hydraulic conductivity is 0.004 cm/s, and the storativity is 0.0004.
An unconfined aquifer is 100 feet thick was evaluated using a field pumping test. The depth to groundwater is 10 feet. At a distance of 1000 feet, the drawdown was 40 feet, and at a distance of 5000 feet it was 20 feet. Find the permeability of the aquifer assuming that a steady-state of 960 gal/minute during the test in ft/sec.
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