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1
Introducing the Draft CCME Protocols for the
Derivation of Groundwater and Soil Vapour Quality
Guidelines Ian Mitchell (Meridian Environmental Inc.) Miles Tindal (Axiom Environmental Inc.)
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Introduction
CCME introduced draft protocols for deriving groundwater & soil vapour quality guidelines
Complement soil guidelines protocol
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Background
A Protocol for the Derivation of Environmental and Human Health Soil Quality Guidelines • Released 1996 • Revised/updated 2006 • Basis for Canadian soil quality guidelines
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Background Many site investigations include
other media • Groundwater • Soil vapour
No Canadian guidelines for comparison
Federal Interim Groundwater Quality Guidelines (2010) • Generally based on CCME approach but
less rigour in derivation
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Background
Need for consistent, defensible approach for deriving groundwater & soil vapour guidelines
Guidelines will be used to facilitate consistent management of subsurface media at contaminated sites
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Relationship Between Protocols
Groundwater and soil vapour protocols complement and build on soil protocol • Same general framework • Matching organization • Background information not repeated
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Relationship Between Protocols
Affected media are related • Soil guidelines for the protection of
groundwater (potable water, FAL) • Soil guidelines for the protection of
indoor air • Groundwater guidelines for the
protection of indoor air • Soil vapour guidelines for the protection
of indoor air
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Key Changes from Soil Protocol
Groundwater Protocol • Land uses not considered (except for
vapour inhalation) • Single level of protection for plants and
invertebrates • Updates to fate and transport model
parameters
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Key Changes from Soil Protocol
Soil Vapour Protocol • Currently only human receptors
considered • New vapour-related pathways • Updates to fate and transport model
parameters
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Groundwater Protocol
A Protocol for the Derivation of Groundwater Quality Guidelines for Use at Contaminated Sites
Current draft: July 2010 At this time intended only for organic
substances
Soil
Groundwater
Well
Indoor Vapour Inhala-on
Surface Water
(Vola4liza4on) (Periodic Soil Inunda4on)
(Discharge to Surface Water)
(Uptake in Well or Dugout)
Domes-c or Agricultural Use of Groundwater
Exposure of Plants and Soil Organisms
Exposure of Aqua-c Life
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Groundwater Protocol – Ecological Pathways
Direct contact with plants/invertebrates based on soil guidelines and partitioning • alternative methods also discussed (inundation
model, pore water data) Protection of freshwater life based on Canadian
Water Quality Guidelines • groundwater transport: dispersion and
biodegradation • additional guidance on biodegradation rates
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Groundwater Protocol – Human Pathways
Potable water guidelines adopted from Guidelines for Canadian Drinking Water Quality • or Provisional Source Guidance Value for
Groundwater
Protection of indoor air quality based on same model as soil guidelines • some updates to input parameters
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Soil Vapour Protocol
A Protocol for the Development of Soil Vapour Quality Guidelines for Protection of Human Exposures via Inhalation of Vapours
Current draft: September 2011
Soil Vapour Contamina4on
Outdoor Vapour Inhala-on
Indoor Vapour Inhala-on
Vapour Inhala-on in Trench or Excava-on
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Soil Vapour Protocol Ecological pathways briefly discussed
but not calculated Protection of indoor air quality based on
same model as soil guidelines • updated input parameters
Outdoor air inhalation evaluated using ASTM model
Protection of trench air included in appendix • Model included but exposure limits may not
be available
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Vapour Inhalation Model Johnson & Ettinger (1991) model still
used Fixed soil gas flow rate into buildings
• 167 cm3/s for coarse-grained soils • 83 cm3/s for fine-grained soils
Default attenuation factors provided for when Tier 1 conditions do not apply or sub-slab vapours • 0.01 for residential • 0.001 for commercial
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Vapour Inhalation Model
Biodegradation adjustment (factor of 10) may be allowed on site-specific basis • petroleum hydrocarbons only • vapour source at least 1 m from building
foundation or groundwater 3 m from building foundation
• aerobic conditions
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Current Status
Both protocols issued as draft for public review • Review ended December 30, 2011
Submitted comments will be evaluated prior to finalization
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Acknowledgments CCME Soil Quality Guidelines Task Group Gordon Dinwoodie Remi Odense Doug Spry Dean Kasur Ray Morin Harvey Gaukel Dan Hemsworth Robert Eno Marius Marsh George Somers Hugues Ouellette Pritam Jain Heather Badry Gwen Waedt (CCME Secretariat) Health Canada Darcy Longpre Environment Canada Chris Allaway
Ontario Ministry of the Environment Camilio Martinez Meridian Environmental Inc. Ian Mitchell David Williams Geneva Robins Dan Stein Axiom Environmental Inc. Miles Tindal Geosyntec Consultants Inc. Todd McAlary Karen Berry-Spark Robert Ettinger Golder Associates Ian Hers Jeanette Southwood
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Questions?