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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?