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Keynote Paper: Contaminated Sites WasteMINZ, Nelson 2003. Historic part: Managing Contaminated Sites in Europe from a Dutch Perspective; Application Part: Moving from Selling Certainties to Managing Uncertainties. Background Drs Ben Keet.
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Keynote Paper: Contaminated SitesWasteMINZ, Nelson 2003 Historic part: Managing Contaminated Sites in Europe from a Dutch Perspective; Application Part: Moving from Selling Certainties to Managing Uncertainties
Background Drs Ben Keet • Free University of Amsterdam : Physics & Hydrogeology • Work experience • 5 years Ass. Lect. Physics & Groundwater Models • 5 years Shell International : UK, Algeria, Gabon, London • 16 years Geo & Hydro: New Zealand, Australia, US, Europe • Proj. manager 2500 site assessments, 1500 remediations • Design & manage : 400 in situ & biological remediations
Europe • Site identification progressing • Development of investigation and remedial tools • Integration • Partnering with project developers • Sustainable Land Management • Emerging emphasis shift Macro Micro contaminants
NZ 1997: 7000 2002: 70.000+ NZ 1997: 7000 2002: 70.000+ Plate from Bateman Contemporary Atlas New Zealand
Aim of Remediation • 1980 “B” level (at discretion of govt.) • 1984 “A” level (standard guideline) • 1989 Isolate or “A” level • 1993 Re-use of A+ cont. soil permitted • 1995 Aim = make site fit for intended use & add Active Soil Management • 2003 Decision model dep. on land use
Role of Government • 1980 Organizes, Finances, Manages and makes Legislation • 1985 Decentralization to Reg./City councils • 1995 intro: Polluter Pays Principle • 1996 Govt still pays 75% of all remediation • 2002 Large (and complex) subsidy schemes set up to encourage private participation
Industry Participation • Remedial action based on financial incentive • Area schemes • Historical areas: mining / tanning /zinc smelting • Branch related actions • Fuel SUBAT • Railways • Gasworks
Example trade scheme: SUBAT • Project Management Organization (Co-op) • Contracts all consultants & contractors • Own central expertise • Funded by members + extra fuel tax • 10 year ‘life’ 1991 – 2001 • Closed / Remediated 1000 service stations • Total cost 1.5 Billion $NZ
What we know is not muchWhat we know we don’t know is limitedBut what don’t we know we don’t know ? Uncertainties
Groups of Uncertainties • Initial conditions • Heterogeneity : soil / contaminants / time • ESA not made with alternative remediation in mind • Effect of chosen remedial technique(s) • Quality of implementation • Changes in legislation
10 1 ,1 ,01 ,001 1950 1960 1970 1980 1990 2000 2010 ‘Contamination only exists when it can be analyzed Detection limit EVOLUTION OF DETECTION LIMIT micro 10E-9 10E-12 nano 10E-15 pico 10E-18 femto
ES PFOS: perfluorooctanesulfonate
Phase-out of PFOS • 3M recently announced its phase-out of Scotchgard products after it was found that its primary ingredient - a fluorinated compound called perfluorooctanyl sulfonate (PFOS) - was found in all tested blood bank examinations. 3M research had found that the substance showed strong tendencies to persist and bioaccumulate in animal and human tissue. • average concentrations fish blood surface waters Lake biwa 345 µg/L 7.4 ng/L • Tokyo Bay 172 µg/L 26 ng/L • Osaka Bay 100 µg/L 12 ng/L • Seto Inland Sea 29 µg/L <4.3 ng/L • Ariake Bay 28 µg/L 9.0 ng/L
Insect repellent Pesticides /herbicides Solvents Fire retardants PAH's Reproductive hormones Detergent metabolites Other prescription drugs Fragrances Antioxidants Disinfectants Antibiotics Nonprescription drugs Plasticizers Steroids Composition of organic wastewater contaminants in surface waters in the U.S. in 1999-2000 Are we looking at the right compounds ?
Ranking Uncertainties First consider the Action options: Any uncertainty can only be: Removed Reduced Accepted
Characterizing Uncertainties Main properties: Nature Hardness Size Essence
Teken cirkel Nature of Uncertainties Example: Legal Procedural Technical Economical Split further (e.g.. Technical) Distribution of Contaminants Heterogeneity of Soil Remedial Techniques
Hardness of Uncertainties Determined by amount of effort to solve it May require: • Lots of time • Lots of resources • Lots of money • Types: Hard - Half Hard - Soft
Size of Uncertainties Is order of magnitude of uncertainty Often depends on given ranges: 1000 – 10.000 is large uncertainty 1000 – 1100 is small uncertainty When small often accepted as “calculated risk”
Essence of Uncertainties Level of essence of uncertainty: Essential: of vital importance Less essential: of minor importance Not essential: only nice to know Given graphically as position of uncertainty relative to center
= =HARD = SOFT = HALF HARD = HARD AND SMALL = HARD AND LARGE Procedure Technical Legal Economie Presentation
Example Legal Technical Procedural Uncertainty Disk applied to Remedial Decisions
Q&A spel How to use in practice ? • Estimate the size of uncertainties Ask the experts • The ' worst case' scenario approach • Decision making in the presence of doubt = a learning process
Conclusion • NZ is well placed due to existing o/s experience • Uncertainties will be part of every decision process • Aim of remediation and verification methods need to be very clear before projects start • Poorly understood are: • Effects on Nature (incl. ourselves) • Assistance from Nature • Hidden Risks • Perception of Risk
Future Key elements of Contaminated Site Management will be: • Integration in town and country planning • Demonstrable action to the public • Cost-effectiveness of solutions • Sustainable land management