A pumping test is a field experiment to evaluate aquifer properties by pumping water from a well and measuring the water-level response in surrounding observation wells. These tests are essential for groundwater management, helping to optimize extraction while minimizing environmental impacts. Various types of tests exist including constant-rate, step-drawdown, and recovery tests, each providing vital data on aquifer behavior and well performance.

1. PUMPING TEST
SUBMITTED BY,
AJITHA J[15BCE009]

2. What Is A
Pumping Test?
• A pumping test is a field experiment in which a well is pumped at a controlled
rate and water-level response (drawdown) is measured in one or more
surrounding observation wells and optionally in the pumped well (control
well) itself; response data from pumping tests are used to estimate the
hydraulic properties of aquifers, evaluate well performance and identify
aquifer boundaries.

3. Why we should performing Pumping Test
• Principal part in many projects and studies dealing with groundwater
exploitation, protection and remediation.
• Aim to regulate and optimize the extraction without adversely impacting
aquifer systems.
• Pumping test gives the best information on the drawdown level, flow rates
and unforeseen factors drawdown level, flow rates and unforeseen factors
generated upon pumping.

4. Principles of Pumping Test
• Principles of Pumping Test involves applying a stress to an aquifer by
extracting groundwater from a pumping well and measuring the aquifer
response to that stress by monitoring drawdown as a function of time.
• These measurements are then incorporated into an appropriate well- flow
equation to calculate the hydraulic parameters of the aquifer.
• It can be applied by Single-Well or Multi-Wells (observations)

5. Pumping Test in Field

6. Pumping tests are carried out to determine
• How much groundwater can be extracted from a well based on long--term
yield, and well efficiency.
• The hydraulic properties of an aquifer or the hydraulic properties of an
aquifers.
• Spatial effects of pumping on the aquifer.
• Determine the suitable depth of pump.
• Information on water quality and its variability with time.

7. Types of pumping tests
• Constant-rate tests maintain pumping at the control well at a constant rate. This is
the most commonly used pumping test method for obtaining estimates of aquifer
properties.
• Step-drawdown tests proceed through a sequence of constant-rate steps at the
control well to determine well performance characteristics such as well loss and well
efficiency.
• Recovery tests use water-level (residual drawdown) measurements after the
termination of pumping. Although often interpreted separately, a recovery test is an
integral part of any pumping test.

8. Stages involved in performing pumping tests
• a) Preliminary studies
• b) Estimation of Transmissivity
Hydraulic conductivity
• c) Selection of test site
• d) Discharging well
(i) Design and construction
Well diameter
Well depth
Well screen length
Gravel pack
(ii) Selection of the pump
(iii) Discharge of pumped water

9. Cntd….
• e) Piezometer
Number of piezometers
Distance of piezometers
Depth of piezometers
• f) Performance of a pumping test
(i) Measurements of the water level
(ii) Measurements of discharge rate
Analysis of data
Compilation of the data

10. Pumping Rate Measurement And Control
• A controlled pumping stress is imposed on an aquifer system during a
pumping test. Therefore, carefully measuring, controlling and recording the
flow rate throughout the test is essential for a successful outcome.
• Although a constant pumping rate is most often the goal, the rate may vary
during a pumping test. Software such as AQTESOLV can account for
variable pumping rates; however, results will depend on how closely the
recorded flow rates correspond to actual rate changes.

11. Water-Level Measurement
• During a pumping test, water levels in wells may be measured by means of
manual techniques or through the use of sensors with data loggers.
• Manual Methods:
Manual water-level measurement techniques include chalked stee
tape, electric water-level sounders and air line methods.

12. Cntd….
• Data Loggers:
Pressure transducers combined with data loggers provide rapid
and accurate measurements of water levels in wells.

13. Duration of pumping test
• It’s difficult to determine how many hours that pumping test required because
period of pumping depends on the type and natural materials of the depends on
the type and natural materials of the aquifer.
• In general pumping test is still until pseudo--steady state flow is attained or low
fluctuation in dynamic water is occur.
• In some tests, steady state occurs a few hours after pumping, in others, they never
occur. However,24--72 hours testing is enough to produce diagnostic data and to
enable the remaining wells for testing.
• Tests taking longer than 24 hours may be required for large takes, such as
community supplies, or situations where it may take to determine effects.

14. Disposal Of
Pumped Water
• Avoid direct discharge of water on the ground surface if the water is likely to
recharge the pumped aquifer (e.g., a shallow unconfined aquifer or karst aquifer with
sinkholes). Recycling of the pumped water through recharge can result in the false
identification of a constant-head boundary or leakage.
• Discharge of water to a surface water feature such as a stream is a viable option if it
is anticipated that the surface water body is hydraulically disconnected from the
pumped aquifer or if it behaves as a constant-head boundary.
• Avoid adverse thermal, biological, water-quality, erosion or sediment mobilization
impacts when discharging to groundwater or surface water and obtain appropriate
discharge permits.