Groundwater Monitoring

Kaan Tunçok

Antalya, 2015

Module 2: Water Budget, Pressures and Impacts, Significant Water Management Issues,

Monitoring, Characterization Report

Groundwater Resources

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?

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...(contd.)

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 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.

Effectiveness 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

Monitoring data

Historic data reveals over-abstraction..

Many cities have experienced rapid growth of urban & industrial waste disposal to the ground....

Early warning of potential threats to Aquifer + Grdwater supply quality

.....thus, necessitating a focused groundwater quality management

monitoring, using sampling piezometers.

Early warning of potential threats to Aquifer + Grdwater supply quality

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 programme

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

Design of groundwater monitoring programmes

Monitoring Guidance for GW-GD 15

3 GENERAL PRINCIPLES

3.1 CONCEPTUAL MODELS AS BASIS FOR MONITORING

3.2 AQUIFER TYPES

3.3 GROUPING OF GROUNDWATER BODIES

3.4 INTEGRATED MONITORING

3.5 NETWORK REVIEW AND UPDATE

4 CHEMICAL STATUS AND TREND MONITORING

4.1 DESIGN OF THE SURVEILLANCE MONITORING PROGRAMME 4.1.1 Selection of surveillance monitoring determinands 4.1.2 Selection of representative surveillance monitoring sites 4.1.3 Monitoring frequency

4.2 DESIGN OF THE OPERATIONAL MONITORING PROGRAMME 4.2.1 Selection of operational monitoring determinands 4.2.2 Selection of representative operational monitoring sites 4.2.3 Monitoring frequency

5 QUANTITY MONITORING 5.1.1 Monitoring parameters 5.1.2 Selection of monitoring density 5.1.3 Monitoring frequency

6 PROTECTED AREA MONITORING 6.1 DRINKING WATER PROTECTED AREA MONITORING

7 PREVENT AND LIMIT MONITORING

8 ENSURING QUALITY OF MONITORING DATA 8.1 QUALITY REQUIREMENTS 8.2 QUALITY CONTROL

9 METHODS FOR SAMPLING AND ANALYSIS

10 REPORTING

Monitoring Programme Design

Article 5 characterisation and risk assessment procedure and conceptual model/understanding of GW establish monitoring network representative for groundwater body focus on phenomena affecting overall state of groundwater body. Local scale pollution processes: target of different monitoring activities by authorities local impacts not relevant unless evolution in t and x endangers environmental objectives

Consider three-dimensional nature of GW system, spatial and temporal variability, to determine location of monitoring sites and selection of appropriate site density existing quality and/or quantity data (length, frequency, range of parameters) construction characteristics of existing sites and abstraction regime spatial distribution of existing sites compared to the scale of groundwater body practical considerations relating to long-term access, security, health and safety.

Appropriate monitoring site types: understanding of objectives of monitoring and understanding of travel times and/or groundwater ages

Integrated monitoring: cost-efficient monitoring by using appropriate components of existing monitoring networks and operating integrated groundwater and surface networks

Conceptual models as basis for monitoring regional conceptual model – an understanding of the factors at

groundwater body scale that identifies the need to establish a monitoring network/point and how the data will be used;

local conceptual model – an understanding of the local factors influencing the behaviour, both in chemical and quantitative terms, of individual monitoring points.

Conceptual Model-Basis for Monitoring

Overview of monitoring objectives

1) Results will support characterisation in future RBMP cycles 2) Assumes new Groundwater Directive will require DWPA objectives to meet good status

What parameters and quality elements should be monitored?

Groundwater quantitative status Most appropriate parameters to monitor quantitative status will depend

on conceptual model/understanding of the groundwater system.

spring flows or even base-flows in rivers may be more appropriate than the use of boreholes in low permeability fractured media

where the risks of failing to achieve good quantitative status are low and information from the surface water monitoring network can adequately validate this assessment.

Groundwater chemical status and trends Where surveillance monitoring is required, the Directive requires that a

core set of parameters be monitored. These parameters are oxygen content, pH value, conductivity, nitrate and ammonium.

Other monitored parameters for both surveillance and operational monitoring must be selected on the basis of

(a) the purpose of the monitoring programme,

(b) the identified pressures and

(c) the risk assessments made using a suitable conceptual model/understanding of the groundwater system and the fate and behaviour of pollutants in it.

How often should monitoring be undertaken?

Groundwater quantitative status

Most appropriate monitoring frequency will depend on conceptual model/understanding of the groundwater system and the nature of the pressures on the system.

Frequency chosen should allow short-term and long-term level variations within the groundwater body to be detected.

Where monitoring is designed to pick up seasonal or annual variations, the timing of monitoring should be standardised from year to year.

Groundwater chemical status

Guidance documents provide examples of frequencies that Member States have found appropriate in a number of hydrogeological circumstances and in relation to different pollutant behaviours.

No minimum duration for groundwater chemical status surveillance programme is specified.

Surveillance monitoring is only specified in the Directive for bodies at risk or which cross a boundary between Member States.

However, to adequately supplement and validate Annex II risk assessment procedure, validation monitoring will also be needed for bodies, or groups of bodies, not identified as being at risk.

Methodologies applied for the establishment of threshold values

Methodologies applied for the establishment of threshold values

126 groundwater threshold values established at Member State level 79 at Groundwater body level Germany and Belgium established on administrative level (region), an

additional level to GWD Article 3.2.

15 Member States established all their threshold values at the same level,

9 Member States established their threshold values at different levels.

Most Member States procedure for threshold values considered: both protection of associated aquatic and dependent terrestrial ecosystems (15) uses and functions of groundwater – mainly drinking water use (23)

4 Member States took regard of saltwater intrusion, where this problem was relevant.

Methodologies applied for the establishment of threshold values

15 Member States based on environmental quality objectives - international or national (e.g. EQS Directive 2008/105/EC)

Drinking water standards as basis of threshold values, EU Drinking Water Directive (98/83/EC7) or international (e.g. WHO)

4 Member States mentioned Directive 2008/105/EC6 for establishing environmental quality standards.

2 Member States did not consider environmental objectives due to no risk or non-substantial impact;

2 other Member States this is due to limited knowledge about groundwater-surface water interactions.

1 Member State reported on transboundary cooperation within the establishment of threshold values.

Pollutants/indicators for which at least 10 Member States have established threshold values, including the range of threshold values

5 Member States reported more stringent threshold values for nitrates than groundwater quality standard (Annex I.1 GWD (50 mg/l))

Range from 18 mg/l to 50 mg/l –

6 Member States - threshold values for 36 different active substances in pesticides, below the quality standard of 0.1 μg/l. (0.0001 μg/l to 0.1 μg/l)

1 Member State reported a stricter threshold value (0.375 μg/l) thanin GWD for total pesticides (0,5 μg/l).

20 Member States established threshold values in total for 106 substances which do not belong to the Annex I (nitrates and pesticides) and II substances of the GWD.

62 belong to the group of synthetic substances.

Pollutants posing risk to more than 100 groundwater bodies or causing poor status to more than 50 groundwater bodies in Europe