Calculating Recharge and Contaminant Transport in a Confined Groundwater Aquifer

Click For Summary
SUMMARY

This discussion focuses on calculating recharge and contaminant transport in a confined groundwater aquifer characterized by a hydraulic conductivity (K) of 3 x 10-2 cm/sec. The aquifer's dimensions include a hydraulic head of 500 m, a length of 10 km, and a cross-sectional area of 100 m x 100 m. Key calculations involve determining the annual rainfall required to recharge the aquifer's discharge and the time it takes for an organic contaminant to travel 500 m within the aquifer, factoring in a partitioning ratio of 9:1 and a retardation factor of 90%.

PREREQUISITES
  • Understanding of hydraulic conductivity and its implications in groundwater flow.
  • Knowledge of contaminant transport principles, including partitioning ratios and retardation.
  • Familiarity with aquifer dimensions and hydraulic head calculations.
  • Ability to apply basic equations related to groundwater flow and contaminant movement.
NEXT STEPS
  • Learn about groundwater recharge calculations and methods for estimating rainfall contributions.
  • Study contaminant transport modeling in groundwater, focusing on retardation and partitioning effects.
  • Explore the relationship between hydraulic conductivity, head gradient, and superficial velocity in aquifers.
  • Investigate the use of software tools for simulating groundwater flow and contaminant transport scenarios.
USEFUL FOR

Environmental scientists, hydrologists, civil engineers, and students studying groundwater management and contaminant transport dynamics will benefit from this discussion.

Lois Chang
Messages
1
Reaction score
0

Homework Statement


The following questions apply to a confined groundwater aquifer consists of a homogeneous sandy soil with hydraulic conductivity, K, of 3 x10-2cm/sec. In the area of interest, the hydraulic head is 500 m, the aquifer length is 10 km, and the cross-sectional area of the aquifer is 100 m x 100 m.

2.
Question A:
If the watershed (the surface area over which rainfall is collected by the aquifer) for this aquifer is 10 km long x 1 km wide, how much rainfall per year must fall in order to recharge the aquifer discharge? Hint: Figure out the volume the aquifer delivers in a year and match that to the volume of rainfall in the catchment area.

Question B:
Since the fraction of time an organic contaminant spends in the moving aquifer determines how fast it moves through the environment. Consider a spill of an organic contaminant into this aquifer 500 m the delivery surface of the aquifer. The contaminant has a partitioning ratio of 9:1 between soil and water respectively. How much time will pass between the spill of this contaminate at the upstream end and the contamination of a well found at the end of the aquifer so described? Hint: Material only moves when in the water phase. Figure out how long it takes for the aquifer to move the final 500 m then use the retardation (90%) determine how long it takes the contaminant to move the same distance.
 
Physics news on Phys.org
I haven't seen any equations from you yet. How is the superficial velocity related to the head gradient and the hydraulic conductivity?
 

Similar threads

Seepage, Velocity, Hydraulic Conductivity
  • · Replies 1 ·
Replies
1
Views
6K
How much contaminant escapes through a barrier in 30 days?
  • · Replies 2 ·
Replies
2
Views
2K
Solaculture: A novel biological approach for low cost energy?
  • · Replies 3 ·
Replies
3
Views
4K
How Can We Design a Compressed Air Car for 300 km Travel?
  • · Replies 82 ·
3
Replies
82
Views
28K
How Can Plasma Be Created and Ignited in Toroidal Fusion Reactors?
  • · Replies 4 ·
Replies
4
Views
4K
Do Movies Teach Us Realistic Life Skills?
  • · Replies 1 ·
Replies
1
Views
10K