INVENTORY OF HAZARDOUS SUBSTANCES IN GROUNDWATER ON

A GLOBAL SCALE

International Groundwater Resources Assessment Centre

Slavek Vasak

(As and F maps by Rianne Brunt)

International Groundwater Resources Assessment Centre, Utrecht, The Netherlands

www.igrac.nl

Arsenic in groundwater- a world problem

29 November 2006, TNO, Utrecht

Symposium

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Contents

1. Introduction to IGRAC• Organisation• Activities

2. Groundwater Quality in GGIS• Attributes (substances included)• Classification

3. Arsenic and Fluoride Maps• Approach• Continental Examples

4. Conclusions• Inventory of hazardous substances• Information sharing

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Organisation of IGRAC

Introduction

An initiative of UNESCO and WMO Financial support from the Dutch government Hosted and staffed by TNO

A centre with a non-commercial profile

United Nations Educational, Scientific and Cultural Organization

Government of The Netherlands

World Meteorological Organization

Netherlands Organisation of Applied Scientific Research

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Activities of IGRAC

Introduction

Establishing a Global Groundwater Information System (GGIS)

Producing and promoting guidelines and/or protocols

Co-operating in global or regional projects or programmes with a significant groundwater component

IGRAC promotes global sharing of information and knowledge for optimal and sustainable groundwater resources development and management

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Groundwater quality in GGIS

Attributes related to:• Occurrence of no fresh water • High fluoride• High arsenic• High nitrate• Pollution from various sources• Saline intrusion

Sources of information:Country-based, publicly available:internet, publications, reports and maps.

GW quality in GGIS

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Classification of occurrence of hazardous substances

Simple classes, based on reported casesin individual countries:• None (no occurrence, explicitly mentioned)• Few (only few locations or “assumed” risk)• Many (many locations, explicitly stressed)

Cases refer to excess of the WHO-limits:• Nitrate > 50 mg/l• Arsenic > 50 μg/l (10 μg/l)• Fluoride > 1.5 mg/l

GW quality in GGIS

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Reported high As-casesGW quality in GGIS

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Reported high F-casesGW quality in GGIS

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Continental arsenic maps

Approach:

Use of additional documentation for refiningthe (administrative) boundaries of problem regions

Probability classes:

• High Location of areas is well defined• Low Precise location not known• Uncertain Mentioned in literature; but no

locations specified

As & F maps

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Arsenic in AsiaAs & F maps

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Arsenic in North AmericaAs & F maps

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Continental fluoride maps

Approach:

Use of additional documentation andcombining geochemical knowledge with (spatial)information on geology and climate

Probability classes:

• High • Low • Medium• Assumed risk

As & F maps

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Probability classes of high F

Probability Hydrogeology Climate Additional references

High Formation with F-rich gw

Hyper-arid/arid yes

Medium Formation with F-rich gw

Semi-arid/dry-subhumid

yes

Potential F- rich + known fluoride-problem country

Hyper- to semi-arid no

Low Formation with F-rich gw

Moist-subhumid/humid

yes

Potential F-rich + known fluoride-problem country

Dry subhumid to humid

no

Assumed Risk

Potential F-rich + no known fluoride-problem country

Hyper-arid/dry-subhumid

no

As & F maps

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Fluoride in AfricaAs & F maps

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Occurrence of F-rich groundwater

Knowledge about: Geochemistry, geological environment & climate

Source: IGRAC, 2005 & Brunt et al., 2004

many

few

assumed

Information from global inventory:few or many cases

Country-wise distribution

Benefits for water management:Preventive measures & better monitoring

Detailed spatial distribution

Knowledge about: Geochemistry, geological environment & climate

Source: IGRAC, 2005 & Brunt et al., 2004

many

few

assumed

Information from global inventory:few or many cases

Country-wise distribution

Benefits for water management:Preventive measures & better monitoring

Detailed spatial distribution

As & F maps

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Conclusions

• For many countries, only “qualitative” information (problem; risk) is available; Information on concentrations, distribution in space and time is lacking.

• Proxy information (hydrogeology and climate) is very useful, providing geochemical knowledge is applied.

• Information on hazardous substances should include not only the current environmental status, but also guidelines for remediation.

• Information sharing can contribute to a proper management of hazardous substances in groundwater.

Conclusions

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Conclusions

Arsenic Remediation Technologies

Online Informational Database

 

MAIN                            OVERVIEW

                            DATABASE

                             LINKS                            

CONTACT                                              Massachusetts Institute of Technology

Copyright (c) 2001

Source: http://web.mit.edu/murcott/www/arsenic/index.html

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Impacts of information sharing • Anticipation on stakeholder perceptions and provision of customized

information will raise public awareness on hazardous substances in water

• Benefits from analogies (cases) save time in search for effective measures

• Use of information from “lessons learned” results in reduction of costs

• Concentration of information generates new insights and can lead to “breakthroughs” in knowledge/perception

Conclusions

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About IGRACReferences

International Groundwater Resources Assessment Centre facilitates and promotes global sharing of information and knowledge required for sustainable groundwater resources development and management, including the protection of ecosystems.

IGRAC is an initiative of UNESCO and WMO.

IGRAC has a non-commercial profile and receives financial support from the Dutch government.

IGRAC is hosted and staffed by TNO.

Contact: info@igrac.nl and www.igrac.nl

United Nations Educational, Scientific and Cultural Organization

Government of The Netherlands

World Meteorological Organization

Netherlands Organisation of Applied Scientific Research