GROUNDWATER MONITORING GROUNDWATER MONITORING REQUIREMENTSREQUIREMENTS
Comment on the differences
between monitoring for
surface and groundwater.
Groundwater’s Status QuoGroundwater’s Status Quo
Millions of m3 pumped every year: Monitored? Who? How?
100’s of thousands of users: Registered? Controlled?
10’s of thousands of wells/boreholes: Registered? Maintained? Info. about location, abstraction levels, water levels, water quality, formation, etc -
1000’s of sources of pollution: Location, nature & quantity of pollutants? aquifer
vulnerability? Many governing departments/institutions:
Joint management ? Coordination / cooperation?
Groundwater is:an extensive, concealed and relatively inaccessible resource.
INVISIBLE..!
General IntroductionGeneral Introduction
One way to make groundwater visible...One way to make groundwater visible... by MONITORING it, e.g: Monitoring groundwater
level shows a declining water table – which allows water managers to obtain an appreciation of the status of the resource.
Year-wise depletion of groundwater
Some Consequences of GW abstraction
Normal consequences of any groundwater
pumping
When pumping is
further increased
Excessivepumping
One way to make grdwater visible...One way to make grdwater visible...(contd.)(contd.)
SYSTEM BASIC FUNCTION WELL LOCATIONS
Primary(Referen
ce)Monitorin
g
evaluation of general groundwater behaviour, e.g.:trends resulting from land-use change + climatic variationprocesses such as recharge, flow and diffuse contamination
in areas withuniform
hydrogeologyand land use.
Secondary
(Protection)
Monitoring
protection against potential impacts to:strategic groundwater resourcewell-fields/springheads for public WSurban infrastructure from land subsidencearchaeological sites against rising WTgroundwater-dependent ecosystems
around facilities/areas/
features requiring
Protection.
Tertiary(Pollutioncontainm
ent) Monitorin
g
early warning of groundwater impacts from:• intensive agricultural land use• industrial sites• solid waste landfills• land reclamation areas• quarries and mines
immediately down +
up-gradient from hazard
Groundwater Monitoring Systems by Groundwater Monitoring Systems by FunctionFunction
Types of data for Groundwater Management Types of data for Groundwater Management
DATA TYPE BASELINE DATA (from archives)
TIME-VARIANT DATA (from field stations)
Groundwater Occurrence & Aquifer Properties
hydrogeologic logs, grdwater levels, quality, etc.
well & aquifer pumping tests
grdwater level monitoring
grdwater quality monitoring
Groundwater use
water well pump installations
Water use inventoriesPopulation registers &
forecasts Irrigation energy
consumption
water well abstraction monitoring (direct/indirect)
grdwater level variations
Supporting Information
climatic data land-use inventories geologic maps/sections
riverflow gauging meteorologic
observations satellite land-use
surveys
The Monitoring CycleThe Monitoring Cycle
static & dynamic water levels, water quality
Mgt question &
monitoring objectives, e.g.
trends & changes, impacts & risks, etc.
Mgt of info. & actions
Define actual info. needed, what for, wherefrom..? etc.
needsneeds
ofof
When is groundwater monitoring considered When is groundwater monitoring considered
cost-effective?cost-effective?
it is driven by a specific objective – monitoring for its own sake often leads to inefficient use of manpower and budgets
data collected is: NOT only used for the explicit purpose of
the monitoring programme, but Also systematically stored for future use –
there are far too many cases of monitoring data being lost along the way.
Effectiveness of groundwater monitoringEffectiveness of groundwater monitoring
....is improved by careful attention to: network design system implementation data interpretation data storage from past monitoring activities accessibility of monitoring stations... participatory monitoring amongst water
users interpretation and use of data to formulate
management actions
Measuring GW Use Measuring GW Use && Aquifer BehaviourAquifer Behaviour
Primary goal of aquifer management is to:develop groundwater resources on the basis of a policy plan.monitor & control impacts of abstraction on groundwater systems.
Thus, monitoring grdwater abstraction + aquifer water levels provides key information for management of grdwater resources.
Monitoring of:
grdwater abstraction, and
aquifer water levels
combined with management actions –
reduction of pumping – can contribute to
more stable development of groundwater
resources.
Measuring GW Use Measuring GW Use && Aquifer Behaviour Aquifer Behaviour (contd.)(contd.)
Monitoring data
Example: Where historic data reveals over-abstraction.. Establishment of baseline situation: Application of mgt actions, & monitor
QuestionsQuestions
Is there any dedicated monitoring
network in your country, or are
existing production
boreholes used?
Which parameters
are monitored,
and why this choice?
Who is responsible for data collection,
storage, interpretation
and management?
Detecting Groundwater Quality changesDetecting Groundwater Quality changes
Grdwater monitoring requires special sampling procedures as:well pumping + sample handling may cause major sample modification through;
air entry degassing + volatile losses
NEED for appropriate sampling procedures.
Summary of sampling procedures and precautions for Summary of sampling procedures and precautions for specific groups of groundwater quality parametersspecific groups of groundwater quality parameters
In designing a monitoring network,
what key steps would you take in
terms of installation/selection of monitoring wells;
data acquisition (who-by, frequency, etc.); data storage and interpretation
Early warning potential threats to Aquifer Early warning potential threats to Aquifer ++ Groundwater supply quality Groundwater supply quality
a critical requirement for detecting any threats to groundwater quality
Design of monitoring networks necessary, which...
relates to the spatial variation of grdwater flow + quality of more recent recharge....
Early warning of potential threats to Aquifer Early warning of potential threats to Aquifer ++ Grdwater supply quality Grdwater supply quality (contd.) (contd.)
Detection of groundwater quality trends in aquifer replenishment in vicinity of a public-
supply water well
Many cities have experienced rapid growth of urban & industrial waste disposal to the
ground....
Early warning of potential threats to Aquifer Early warning of potential threats to Aquifer ++ Grdwater supply quality Grdwater supply quality (contd.) (contd.)
.....thus, necessitating a focused groundwater quality management monitoring, using sampling piezometers.
Early warning of potential threats to Aquifer Early warning of potential threats to Aquifer ++ Grdwater supply quality Grdwater supply quality (contd.) (contd.)
Some objectives of such sampling piezometers:
to facilitate early warning of the onset of groundwater pollution........ – to allow timely introduction of necessary control measures.
to provide advance warning of the arrival of polluted water at an important groundwater supply source and make provision for treatment or other mitigation.
Early warning of potential threats to Aquifer Early warning of potential threats to Aquifer ++ Grdwater supply quality Grdwater supply quality (contd.) (contd.)
Who carries out
the monitoring
?
What important natural or
anthropogenic water quality
problems are in your country?
Network Design
objectives must be defined and program adapted accordingly
groundwater flow system must be understoodsampling locations and monitoring parameters must
be selected by objectives
Systemimplementation
appropriately-constructed observation + abstraction wells must be used
field equipment + laboratory facilities must be appropriate to the objectives
a complete operational protocol + data handling system must be established
groundwater + surface water monitoring should be integrated where applicable
Datainterpretation
data quality must be regularly checked through internal and external controls
decision makers should be provided with interpreted management-relevant datasets
program should be periodically evaluated and reviewed
Basic rules for a successful groundwater monitoring Basic rules for a successful groundwater monitoring programme - summaryprogramme - summary
Network Design
Systemimplementati
on
Datainterpretation
objectives must be defined and program adapted accordingly
groundwater flow system must be understoodsampling locations and monitoring parameters
must be selected according to objectives
appropriately-constructed observation + abstraction wells must be used
field equipment + laboratory facilities must be appropriate to the objectives
a complete operational protocol + data handling system must be established
groundwater + surface water monitoring should be integrated where applicable
data quality must be regularly checked through internal and external controls
decision makers should be provided with interpreted management-relevant datasets
program should be periodically evaluated and reviewed
Thank you for your attentionThank you for your attention