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 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 l An initiative of UNESCO and WMO l Financial support from the Dutch government l 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 l Establishing a Global Groundwater Information System (GGIS) l Producing and promoting guidelines and/or protocols l 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 cases in 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-cases GW quality in GGIS 7-18

Reported high F-cases GW quality in GGIS 8-18

Continental arsenic maps Approach: Use of additional documentation for refining the (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 Asia As & F maps 10-18

Arsenic in North America As & F maps 11-18

Continental fluoride maps Approach: Use of additional documentation and combining 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 ProbabilityHydrogeologyClimateAdditional references HighFormation with F-rich gwHyper-arid/aridyes MediumFormation with F-rich gwSemi-arid/dry-subhumidyes Potential F- rich + known fluoride-problem country Hyper- to semi-aridno LowFormation with F-rich gwMoist-subhumid/humidyes Potential F-rich + known fluoride-problem country Dry subhumid to humidno Assumed RiskPotential F-rich + no known fluoride-problem country Hyper-arid/dry-subhumidno As & F maps 13-18

Fluoride in Africa As & F maps 14-18

Occurrence of F-rich groundwater 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:

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 IGRAC References 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: and United Nations Educational, Scientific and Cultural Organization Government of The Netherlands World Meteorological Organization Netherlands Organisation of Applied Scientific Research