The document outlines methods for groundwater assessment including initial reconnaissance, detailed investigations, and ongoing monitoring techniques for water levels and quality. It describes various measurement tools like dip meters and pressure sensors for periodic and continuous data collection. Additionally, it covers sampling methods and water quality testing protocols, highlighting the importance of accurate readings for sustainable water management.

1. By
SATHISHKUMAR G
(sathishsak111@gmail.com)

2. Groundwater Assessment
Methods
 •Initial (reconnaissance) assessment….
 ♦Basic knowledge of geological and environmental conditions
 ♦Review of previous investigation results
 ♦Measurements of water levels
 ♦Sampling & preliminary assessment of water quality
 •More detailed investigations….
 ♦More extensive study of water levels and water chemistry
 ♦Geophysical methods
 ♦Drilling and testing of monitoring boreholes (to assess
keyhydrogeologicalproperties)
 ♦Water budget , recharge & sustainable yield estimation

3.  ♦Ongoing monitoring and review….
 ♦Long-term monitoring of water level and water
quality
 ♦Ongoing feedback of additional information

4. Water level measurements
 •Periodic measurements….
 ♦standard tape measure (shallow wells)
 ♦‘dipmeter’: tape measure on reel with optiona
& buzzer (deep wells and boreholes)

5.  •Continuous measurements….
 ♦float connected to chart recorder or shaft
encoder and data logger. Instrumentation at
surface.
 ♦electronic pressure sensor with in-built data
logger. Installed below surface with cable to
surface to enable downloading of data from the
surface.

6. Water level measurements using
Dip meter….

8. General……….
 The Geosystems Water L e v e l I n d i c a t o r s
(Dipmeters) Model 1680- GS-DM Series are typically
used to measure the depth of water levels in boreholes,
standpipes or observation wells

9. Features………..
 Stretch resistant survey tape
 Tape marked in m, cm,mm
 Clear polyethylene coating on tape
 Corrosion resistance construction
 Sensitivity control test button
 Visible and audible indicators
 Replaceable 9V battery
 16 mm diameter probe

10. Description….
 The Water Level Indicator consists of a stainless steel
probe attached to a flat steel survey tape. The conductors
are stainless steel and the tape/conductor assembly is
encapsulated in a tough, clear plastic coating.
 The tape and indicator unit are fitted with high grade
bearings for ease of operation.
 The reel is supplied with a roller guide to protect the tape
from damage at the top of the standpipe.

11. Operation….
 In operation, the probe is lowered down the open bore
until it comes into contact with the water surface. This
completes the circuit and activates an alarm.
 The operator then reads the depth of the probe off the
tape at the collar.
 The probe features a sensitive control to eliminate false
water level readings due to dripping water.

12. Water quality measurements ….
 •Periodic measurements
 ♦sampling using appropriate bottles and
methods:
 -bailer
 -sampling pump
 and testing on-site or later in laboratory.
 ♦using portable instruments (e.g. salinity
meter)

13.  •Continuous measurements
 ♦selected water quality parameters (e.g. salinity,
dissolved oxygen, specific ions) using sensors with in-
built data logger. Can download data from the surface.

15. Bacteria testing….

16. Result…….presence or absence

17. THANK YOU