Brownfield Briefing Ra 2008 Presentation Mfc

Dr. Mengfang Chen, Royal Haskoning, UKRic Bowers, GSI Environmental, USA

RBCA Tool Kit V2 a real alternative to CLEA model

Brownfield Briefing Contaminated Land Risk Assessment 2008 29th April 2008

Brief History of RBCA and CLEA

RBCA Tool Kit V2

Key Compatibility Issues Examined

SGV Validation Testing

Summary

Outline of the Presentation

CLR10 Update with Briefing Notes

2005

DEFRA

Way Forward

DEFRA and EA: CLR11

DEFRA and EA:

CLR10, SGV, TOX Reports

DETR

No Risk Based Guidance

(ICRCL, Dutch, ASTM RBCA)

UK

No Further Guidance

ASTM E2081

ASTM P104

Chemical RBCA

ASTM E1839

Petroleum RBCA

USEPA RAGS

USA

2006200420022000199819951989Guidance

?????CLAN6/06CLEA-UKCLEA2002CLEA2000CLEA97Start of CLEA

2008

Public Debating and Continuing

Model Development

CLEA

200620052002200019971992Model

RBCA V2RBCA Tool Kit V1.3RBCA Tool Kit V1.0

Tier 2 RBCA Tool Kit

2008

Model Improvement and UK ComplianceModel Development

RBCA

200019991996Model

Brief History of CLEA and RBCA

Monte Carlo versus Deterministic

Plant Uptake

Vapours from Surface Soil

CLEA-UK Versus RBCA Toolkit V1.3

(2005)

Monte Carlo versus Deterministic

Plant Uptake

Dermal Contact

Indoor and Outdoor Vapours

CLEA2002 Versus RBCA Toolkit V1.3

(2002)

Almost Identical Except RBCA having:■ More algorithms available to choose on

vapour pathways such as mass balance and USEPA SSG Q/C model for outdoor

■ Groundwater Vapour Onsite and Offsite■ Controlled Water or Water Environment

Risk Assessment■ Soil and Groundwater Source Depletion for

DQRA

FUTURE CLEA Based on CLAN6/06 Versus RBCA Toolkit V2

(2008 and beyond)

Differences in Model Functionalities


Identical (USEPA Dermal Absorption Method)6) Dermal Contact

Identical (ASTM Johnson & Ettinger)3) Indoor Vapour2

Identical (USEPA Q/C Model)5) Particulates/Dusts

Identical (ASTM Subsurface Equation)4) Outdoor Vapours2,3

Identical (Briggs Routine for Organics and Direct Input for Metals, but Adjustments

Required for Certain Parameters)

2) Consumption of Home grown vegetable1

ASTM/USEPA1) Soil and Dust Ingestion

CLEA UKRBCA V2Exposure Pathway

Note: 1) RBCA does not have a pathway for indirect soil ingestion attached to vegetable

2) RBCA also has ASTM mass balance checks for vapour pathways

3) RBCA also has additional algorithms: ASTM surface soil and USEPA Q/C model for outdoor vapour pathway

Technical Algorithms – Human Health


INCREASING NEED FOR SITE SPECIFIC DATA AND REDUCED CLEAN-UP COST

Soil: SGV CLEA UKGW: RTM, ConSim

Soil: CLEA UKGW: RTM, ConSim

MODFLOW, RT3DMT3DMS, ADMSAEROMOD

Hazard Identification

Magnitude of Consequences

Probabilities of Consequences

Identification ofConsequences

Risk B

ased R

emed

ial So

lutio

ns

TIER 4(DQRA)

Assessment of Controlled Water Risks (SSAC)

TIER 2(GQRA)

Assessment Under Generic Conditions – GAC

RBCA Tier 1

RTM Tier 1 & Tier 2

TIER 1

CSM Risk Screening

Qualitative RA

Significance of Risk


Risk Based, Tiered Framework

Typical Model Used

Quantitative Risk Assessment

INCREASING COMPLEXITY & LEVEL OF EFFORT

TIER 3(DQRA)

Assessment Under SiteSpecific Condition - SSAC

RBCA Tier 2/3

RTM Tier 3 &Tier 4

RBCA Tool Kit Features

User-Input Target Risks

Chem/Tox Database

Standard Exposure Factors

Analytical Fate & Transport Models

x =x

RBCA Tool Kit V2 includes system of analytical models for comprehensive evaluation of air, soil, and groundwater exposure pathways

RBCA Tool Kit V2

Main Screen

Soil and Groundwater Source Depletion Algorithms for DQRA

Tiered Structures Tier 1 and Tier 2/3 Equivalent to CLR 11 Tier 2 (GQRA) and Tier 3 (DQRA)

RBCA Tool Kit V2

Chemical / Toxicological Database

600 Chemicals: Petroleum Hydrocarbons/TPH

SVOC/PAHs

Chlorinated Solvents

Pesticides

Metals

RBCA Tool Kit V2

■ Adding or Editing Chemical Data■ Save as project specific database for QA purpose■ Reserved columns for UK CLEA Tox data■ Selection of preference of tox data from USA, Dutch and UK

Exposure Pathway Input

Applicable Pathways

Multiple Receptors

Mixed Land Uses

■ Groundwater Ingestion■ Surface recreational and fish consumption■ Soil ingestion, dermal contact, inhalation of vapors and

particulates, and consumption of homegrown vegetables)■ Outdoor and indoor inhalation of vapors emanating from soil

or groundwater sources

RBCA Tool Kit V2

Exposure Factors

Exposure Rates

Risk Limits (Target Hazard Quotient/Index, and Target Cancer Risk Limits)

Defining Open Space/Parks Land Use

RBCA Tool Kit V2

Fate and Transport Models

Cross-Media Transfer with multiple fate and transport models to select from

Lateral Air and Groundwater Transport (Off-site)

RBCA Tool Kit V2

Site-Specific Inputs

Cross-Media Transfer with multiple fate and transport models to select from

Lateral Air and Groundwater Transport (Off-site)

RBCA Tool Kit V2

Output

Pathway and Depth Specific GAC/SSAC

Summary of Chemical Parameters

Detailed Exposure and NAF Calculations

Summary of Exposure, Building, Air, Soil and Groundwater Parameters

RBCA Tool Kit V2

√

√

√

√

√

√

√

√

√

√

Residential with

Plant Uptake

√Consumption of Site Grown Vegetable

√Indirect Soil Ingestion Attached to Vegetable

√√√Inhalation of Soil Derived Outdoor Dust

√√√Inhalation of Soil Derived Indoor Dust

√√√Dermal Contact with Soil (Outdoor)

√√√Dermal Contact with Soil Derived Indoor Dust

√

√

√

Allotment

√√Inhalation of Soil vapour - Outdoor

√√Inhalation of Soil Vapour – Indoor

√√Direct Soil Derived Indoor Dust Generation

√√Direct Soil Ingestion

Commercial

Residential without

Plant Uptake

Exposure Pathways

Modifications/Adjustment

Note: 1) Exposure pathways highlighted are not included in RBCA, but can be implemented by manipulating interfaces and input parameters

Standard Land Uses and Exposure Pathways


Incorporating CLR10-Specific Data: Human, Exposure, Air, Building and Soil Parameters

Converting Henry Law Constant to 10° C (Soil Temperature)

TDSI as Input (Not TDI) to Consider Background Exposure

Considering Soil Enrichment Factor and Fraction of Locally Derived Soil in Building Dust for Inhalation of Particulates

Using UK-Specific Respiratory Volumes to Adjust Exposure Frequencies for Inhalation of Indoor and Outdoor Vapours/Dusts

Manipulating Interfaces and Input parameters to include Three Missing Exposure Pathways

Integration of Pathway-Specific GAC/SSAC

Key Modifications/Adjustments Required


CLEA-UK: Briefing Note 4Harmonic Mean

RBCA Tool Kit: ASTM E2081Combined Harmonic Mean and Minimum Approach

∑=

=n

n nGAC

GAC

1

11

Where n = number of exposure pathways depending on land uses

∑=

= n

n n

SS

GAC

GAC

1

11

Where GACSS representing GAC for Surface Soil Exposures, and n = number of surface soil exposure pathways (i.e oral, dermal, vegetable consumptions, particulates and outdoor vapour from surface soil) depending on land uses

),,min( __ VOutdoorVindoorSS GACGACGACGAC =

Integration of Pathway Specific GAC/SSAC

Modifications/Adjustments Required

Residential and Allotment Land Uses Exploring Impact of CLAN6/06 on the Published SGV (i.e Soil

Ingestion Rate = 100 mg/d) Manipulating Soil Ingestion Rate and Bodyweight in order to

reproduce SGV (key parameters with PDF functions) for Metals

Use 5th percentile BW (11.15kg) and calibrate on Soil Ingestion Rate

Commercial/Industrial Land Use Fixed Soil Ingestion Rate (40 mg/d) Specifying 5th percentile Body Weight (46.4 kg) to reproduce

SGV for Metals


Soil and Dust Ingestion


Calculating UK-Specific Exposed Skin Surface Areas for Children and Adult Based on CLEA Briefing Note 1

Setting Up Two Models: Dermal Indoor and Outdoor

Incorporating FDUST for Dermal Indoor Model


Dermal Contact: Indoor and Outdoor



General Calculating UK-Specific Time Averaged Respiratory Volumes

Based on CLR10 Adjusting Exposure Frequencies incorporating UK-specific

respiratory volume and body weight Or manipulating RfC incorporating UK-specific respiratory

volumes and body weightIndoor Vapour Use of default sandy soils with SOM (1, 2.5 and 5%) and

building parameters to reproduce SGV for ethylbenzene and toluene

Outdoor Vapour Use of UK Specific Air Parameters

Inhalation of Indoor and Outdoor Vapours



General Calculating UK-Specific Time Averaged Respiratory

Volumes Based on CLR10 Adjusting Exposure Frequencies incorporating UK-specific

respiratory volume and body weight Or manipulating RfC incorporating UK-specific respiratory

volumes and body weightIndoor Particulates Incorporating Soil Enrichment Factor and FDUST for metals

and BaP; FDUST for other contaminants

Outdoor Particulates Incorporating Soil Enrichment Factor for metals and BaP

Inhalation of Particulates: Indoor and Outdoor


++=

asococwssw

HfKK

θρθρ

,,

ssw ss

T s oc oc ssK

K f

ρθ ρ

=+

Adjustments Required

Time averaged or 5th percentile BW Derive Consumption Rates for Leafy and Root

Vegetables Application of DW Conversion Factors to CF

for metals Application of Ksw (Soil to Leachate

Coefficients) Correction Factor

CLEA UK

RBCA V2

Adjustments Required

Time averaged or 5th percentile BW Derive Equivalent Soil Ingestion Rates for

Leafy and Root Vegetables Use Soil Ingestion Interface for Exposure

Calculations

Consumption of Home-Grown Vegetable

Indirect Ingestion of Soils Attached to Vegetable

CLEA Briefing Note 4Integration

NA

Ingestion of Soil Attached to Vegetable:

Leafy: 4.6 mg/d

Root: 3.7 mg/d

Ingestion of Garden Vegetable:

Leafy: 4640 mg/d

Root: 13800 mg/d

Vegetable Consumption Rates

Time Averaged

Indoor: 4.73 m3/d

Outdoor: 0.95 m3/d

Time Averaged

Indoor: 3.98 m3/d

Outdoor: 1.06 m3/d

Respiration Volumes

5th percentile: 46.4 kg5th percentile: 11.15 kgBody Weight

OfficeTwo Storey HouseBuilding

Sandy Soil

SOM – 1%, 2.5% and 5%Soil Properties

Indoor: 56 days/y

Outdoor: 8 days/y

Indoor: 351 days/y

Outdoor: 93 days/yExposure Frequencies for Vapour and Dust

SGV Contaminants

155 mg/d

Residential

40 mg/dSoil and Dust Ingestion Rate

Contaminants Evaluated

CommercialParametersAssumptions for Validation


Anticipated Outcome


Identical SGV for vapour or oral pathway driven contaminants

Variations expected for plant uptake where significant (Time averaged approach for vegetable consumption rates)

SGV Reproduced for Commercial and Residential without Plant Uptake

SGV Reproduced for Residential with Plant Uptake except for Cadmium and Selenium

788039411616Ethylbenzene

15158833Toluene

RBCACLEARBCACLEARBCACLEA

5% SOM2.5% SOM1% SOM

Soil Guideline Values (mg/kg)

COC

481564800048156480004815648000Ethylbenzene1

677680347350148150Toluene



Soil Guideline Values (mg/kg)COC

4441222199Ethylbenzene

14147733Toluene



Soil Guideline Values (mg/kg)

COC


Residential Without Plant Uptake

Residential With Plant Uptake

Commercial/Industrial

Note: 1) SGV for ethylbenzene has been derived by setting target hazard quotient = 0.36 for soil ingestion and dermal pathways due to saturated vapour concentrations predicted

51545000131130190200Chromium

82

51

7

2.8

18

RBCA

35

50

8

2

20

CLEA SGV

Residential With

Plant Uptake

RBCACLEA SGVRBCACLEA SGV

79168000259260Selenium2

497050007275Nickel

4794801615Mercury

141714003430Cadmium1,2

5525002120Arsenic

CommercialResidential Without Plant Uptake

CoC


Note: 1) only pH = 7 is evaluated and 2) Variations caused by large contributions to the total exposure representing 95% and 80% respectively for cadmium and selenium

RBCA and CLEA Having Identical Technical Algorithms

RBCA and CLEA Even More Closer Following CLAN6/06 Recommendations

Modifications/Adjustments Required to Comply with CLEA-UK Model (& RTM Soil and Groundwater)

Validation Testing Indicating Near-Perfect Match

RBCA Offering A Real Alternative to Future CLEA

Summary

RBCA V2 Training

http://www.royalhaskoning.com http://www.gsi-net.com

Brownfield Briefing Ra 2008 Presentation Mfc

Technology

Transcript of Brownfield Briefing Ra 2008 Presentation Mfc