inventory of hazardous substances in groundwater on a global scale international groundwater...
TRANSCRIPT
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
1-18
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
2-18
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
3-18
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
4-18
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
5-18
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
6-18
Reported high As-casesGW quality in GGIS
7-18
Reported high F-casesGW quality in GGIS
8-18
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
9-18
Arsenic in AsiaAs & F maps
10-18
Arsenic in North AmericaAs & F maps
11-18
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
12-18
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
13-18
Fluoride in AfricaAs & F maps
14-18
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
15-18
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
16-18
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
17-18
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
18-18
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: [email protected] and www.igrac.nl
United Nations Educational, Scientific and Cultural Organization
Government of The Netherlands
World Meteorological Organization
Netherlands Organisation of Applied Scientific Research