Groundwater flows from a well toward a river in a confined aquifer that is 20 meters thick (see picture). The hydraulic conductivity is 10-4m/s, the head at the well is 50m and the head at the river is 40m, the distance between the river and the well is 1km. Assume a porosity of 0.35, effective porosity of 0.3 and that the aquifer is 150m wide.
(10pts) What is the volumetric flow rate (Q) of water flowing in the aquifer?
(5pts) What is the Darcy velocity (q)?
(5 pts) What is the true groundwater velocity (vâ)?
(20pts) Your neighbor and you each have groundwater wells that you use to irrigate your fields. You both draw from an unconfined aquifer. Your well has a radius of 0.05m, your neighborâs well is located 50m away. The hydraulic conductivity of the soil is
Perchloroethylene (PCE) is dumped into a pond. PCE that has a retardation factor (R) of 5.9. The PCE seeps down into the unconfined aquifer below the pond. There is a well 50m away. How long it will take the PCE in the groundwater below the pond to reach the well if the well pumping causes a hydraulic gradient of 0.025. Assume a porosity of 0.18 and a K of 0.04m/d.
Assume there is a plume of Trichloroethylene (TCE) heading toward a towns drinking water well in a confined aquifer. Building a physical containment unit is decided to be too expensive so hydrodynamic containment is considered. The plume is estimated to be 15m wide. The city can afford to install one well and plan to pump at a rate of 0.05m3/s. The hydraulic gradient in the region is 0.004, the hydraulic conductivity is 5.5×10-3m/s. The aquifer has a consistent thickness of 25m.
(25pts) Calculate key points of the capture zone assuming the planned pumping rate. Key points should include your well location, the leading edge of your capture zone (y=0), the width of your capture zone at the well location (x=0), and the maximum width of the capture zone (x -> â). Mark the values on the capture zone diagram.
(5pts) Will this single well pumping at this rate be enough to capture the plume?
(5pts) What do you propose the pumping rate should be in order to capture the plume?
10-3m/d. Assuming you pump at a rate of 3m3/day and measure the head in your well to be 15m, what will be the steady-state head of the water in your neighbors well?
(10pts) Draw a cross-sectional diagram of the situation
(5pts) Use the hydraulic gradient to find the true velocity of the water
(5pts) Calculate the velocity of the PCE using R
(5 pts) Calculate the time it would take the PCE to travel from the pond to the well.
Sample Solution
order. Central Government employees were already enjoying the benefit of this child care leave. Several leading private companies voluntarily amended their maternity benefit policy to increase the maternity benefits and also introduced new age benefits such as adoption leaves, surrogacy leaves and paternity leaves. This was done even prior to the amendment in the Act was under consideration. The Ministry of Labour and Employment, in its 44th, 45th and 46th sessions of the Indian Labour Conference recommended amendments to the Maternity Benefit Act, 1961. The recommendations were in line with those made by the Ministry of Women and Child Development. The Act was thereafter amended and approved by both the houses. It received the Presidential approval on 3rd April, 2017. The changes in the Act were made so as to encourage women to participate in the labour force and to improve their work-life balance. Infants can now be looked after by their mothers during their most important and formative months. This would lead to healthy mothers and healthier children. With the changes being implemented, India now ranks third on the list of countries with most maternity leave i.e., 26 weeks after Canada (50 weeks) and Norway (44 weeks). Key amendments include: 1. Enhancement of the maternity leave: Paid maternity leave for women employees working in any establishment, with 10 or more employees, has been increased from 12 weeks to 26 weeks. Further, not more than 8 weeks of leave to the women employee shall precede the date of her expected delivery. The enhanced maternity leave will not apply to a mother of two or more children and such women employees will be eligible to only paid maternity leave for 12 weeks (of which not more than 6 weeks shall precede the date of her expected delivery). 2. Surrogacy/Adoption Leave: The Amended Act introduces 12 weeks of maternity leave to commissioning mothers who use a surrogate to have a child as well as to working women adopting a baby below the age of three months. 3. Introduction of Work from Home option: âWork from homeâ option post 26 weeks of the maternity leave for nursing mothers may be considered by the employer, subject to the job profile and on terms mutually agreed between the employer and the concerned woman employee. 4. Mandatory crèche facility: All establishments having 50 or more employees are mandated to provide a facility, either separately or along with other facilities offered in the office premises. The concerned women employee has to be permitted four visits a day to the crèche during work hours. Such visits shall include the woman employeeâs rest interval. This provision alone will come into effect from July 1, 2017. 5. Obligation of the Employer: The employer is required to notify to every woman employee the maternity benefits and the company policy in writing and electronically. Practically, companies can >
order. Central Government employees were already enjoying the benefit of this child care leave. Several leading private companies voluntarily amended their maternity benefit policy to increase the maternity benefits and also introduced new age benefits such as adoption leaves, surrogacy leaves and paternity leaves. This was done even prior to the amendment in the Act was under consideration. The Ministry of Labour and Employment, in its 44th, 45th and 46th sessions of the Indian Labour Conference recommended amendments to the Maternity Benefit Act, 1961. The recommendations were in line with those made by the Ministry of Women and Child Development. The Act was thereafter amended and approved by both the houses. It received the Presidential approval on 3rd April, 2017. The changes in the Act were made so as to encourage women to participate in the labour force and to improve their work-life balance. Infants can now be looked after by their mothers during their most important and formative months. This would lead to healthy mothers and healthier children. With the changes being implemented, India now ranks third on the list of countries with most maternity leave i.e., 26 weeks after Canada (50 weeks) and Norway (44 weeks). Key amendments include: 1. Enhancement of the maternity leave: Paid maternity leave for women employees working in any establishment, with 10 or more employees, has been increased from 12 weeks to 26 weeks. Further, not more than 8 weeks of leave to the women employee shall precede the date of her expected delivery. The enhanced maternity leave will not apply to a mother of two or more children and such women employees will be eligible to only paid maternity leave for 12 weeks (of which not more than 6 weeks shall precede the date of her expected delivery). 2. Surrogacy/Adoption Leave: The Amended Act introduces 12 weeks of maternity leave to commissioning mothers who use a surrogate to have a child as well as to working women adopting a baby below the age of three months. 3. Introduction of Work from Home option: âWork from homeâ option post 26 weeks of the maternity leave for nursing mothers may be considered by the employer, subject to the job profile and on terms mutually agreed between the employer and the concerned woman employee. 4. Mandatory crèche facility: All establishments having 50 or more employees are mandated to provide a facility, either separately or along with other facilities offered in the office premises. The concerned women employee has to be permitted four visits a day to the crèche during work hours. Such visits shall include the woman employeeâs rest interval. This provision alone will come into effect from July 1, 2017. 5. Obligation of the Employer: The employer is required to notify to every woman employee the maternity benefits and the company policy in writing and electronically. Practically, companies can >
