Appendix D Risk Calculations – Main Plumes

Consolidated Human Health Risk Assessment - 2010 Ref: O/10/CR001-C

Appendix D Risk Calculations – Main Plumes

Consolidated Human Health Risk Assessment – 2010 Ref: O/10/CR001-C

General ParametersAll Calculations NOTES:

Vs = Volume of Air within Irrigation zone (m3) 21600 Chemical Parameters (H and MW) for taken from RAIS in August 2010

Q = Volumetric Flow rate of Water (L/min) 30 H (atm.m3/mol) = H' (dimensionless) / 41

Time = Duration of Irrigation (min) 60

d = Droplet diameter (cm) 0.2

t = Droplet drop time (s) 10

R = Gas Constant (atm.m3/mol/K) 8.20E-05

T = Absolute Temperature (K) 293

Ts = Sprinkler Water Temperature (K) 288

m1 = Water viscosity at 20oC (g/m.s) 1.0020

m2 = Water viscosity at Sprinkler Water Temperature (g/m.s) 1.1385

Chemical Parameters Calculations

COPC

Concentration in

Water (mg/L)

Henry's Law

(atm.m3/mol)

Molecular

Weight

Liquid Mass

Transfer

Coefficient

(cm/hr)

Gas Phase Mass

Transfer

Coefficient

(cm/hr)

Overall Mass

Transfer

Coefficient

(cm/hr)

Adjusted Overall

Mass Transfer

Coefficient

(cm/hr)

Fraction

Volatilised

(mg/mg)

Mass

Volatilised

(mg)

Concentration

in Air (mg/m3)

Concentration

in Soil Water

(mg/L)

Cw HL MW Kl Kg KL KL' fv Ms Cair Cwater

Hexachlorobutadiene (HCBD) 0.11 0.010268293 261 8.21E+00 7.88E+02 8.02E+00 7.46E+00 4.63E-01 9.16E+01 4.2E-03 5.9E-02

1,1-Dichloroethene 1.9 0.026097561 96.9 1.35E+01 1.29E+03 1.33E+01 1.24E+01 6.45E-01 2.20E+03 1.0E-01 6.8E-01

1,2-Dichloroethane (EDC) 623 0.00117561 99 1.33E+01 1.28E+03 1.10E+01 1.02E+01 5.73E-01 6.43E+05 3.0E+01 2.7E+02

cis-1,2-Dichloroethene 10.3 0.004073171 96.9 1.35E+01 1.29E+03 1.27E+01 1.18E+01 6.26E-01 1.16E+04 5.4E-01 3.9E+00

trans-1,2-Dichloroethene 0.9 0.004073171 96.9 1.35E+01 1.29E+03 1.27E+01 1.18E+01 6.26E-01 1.01E+03 4.7E-02 3.4E-01

Vinyl chloride 27 0.027804878 62.5 1.68E+01 1.61E+03 1.66E+01 1.55E+01 7.24E-01 3.52E+04 1.6E+00 7.4E+00

Dichloromethane 0.68 0.003243902 84.9 1.44E+01 1.38E+03 1.34E+01 1.24E+01 6.45E-01 7.90E+02 3.7E-02 2.4E-01

Chloroform 2.9 0.003658537 119 1.22E+01 1.17E+03 1.14E+01 1.06E+01 5.86E-01 3.06E+03 1.4E-01 1.2E+00

Carbon tetrachloride 2.8 0.027560976 154 1.07E+01 1.03E+03 1.06E+01 9.85E+00 5.60E-01 2.82E+03 1.3E-01 1.2E+00

Trichloroethene (TCE) 5.4 0.009829268 131 1.16E+01 1.11E+03 1.13E+01 1.05E+01 5.84E-01 5.67E+03 2.6E-01 2.2E+00

Tetrachloroethene (PCE) 1.9 0.017658537 166 1.03E+01 9.88E+02 1.02E+01 9.44E+00 5.45E-01 1.86E+03 8.6E-02 8.6E-01

1,1,2-Trichloroethane 2.9 0.000821951 133 1.15E+01 1.10E+03 8.82E+00 8.20E+00 4.95E-01 2.58E+03 1.2E-01 1.5E+00

1,1,2,2-Tetrachloroethane 0.8 0.000365854 168 1.02E+01 9.82E+02 6.08E+00 5.65E+00 3.76E-01 5.41E+02 2.5E-02 5.0E-01

Mercury (as methyl mercury) 0.000052 5.2E-05

Mercury (as total, inroganic) 0.254 2.5E-01

Mercury (as elemental) 0.00012 0.0071 200.6 9.37E+00 8.99E+02 9.05E+00 8.41E+00 5.04E-01 1.09E-01 5.0E-06 6.0E-05

Air Concentrations During Irrigation - Main Plumes(Reference: Guidelines for the Assessment and Management of Petroleum contaminated Sites in New Zealand)


VAPOUR PARTITIONING, EMISSION AND AIR DISPERSION MODEL FOR SUBSURFACE IMPACTS

Using Vapour Migration Model Presented by Farmer (1980) and DEH (2000)

Site Specific Physical Input Parameters Units Abbrev. Value Comments

Vadose Zone Layer 1 Characteristics Sand

Depth of Layer 1 [m] vd1 0.3 Depth to most shallow soil gas measurement

Moisture Content [g/g] mocon 0.08 Relevant for dry sand

Organic Carbon Fraction - foc 0.003 Relevant for sand

Soil Bulk Density [g/ml] rhob 1.7 Relevant for sand

Density of Solids [g/ml] sd 2.65 default

Total Soil Porosity [ml/ml] theta 0.36 1 - (rhob/sd)

Volumetric Water Content [ml/ml] wacon 0.136 mocon*rhob

Volumetric Air Content [ml/ml] acon 0.222 theta-wacon

Receptor Specific Input Parameters Units Abbrev. Value Comments

Building Characteristics

Area of Emission - Building Area [m2] emarea 150 Assumed size of building in area (10mx15m)

Height of Room [m] boxh 3 Assumed for commercial/industrial building

Hourly Volume Exchange of Fresh Air [exch/hr] exchanges 2 Minimum Australian Std for Commercial Bldgs

Air Exchange Rate [exch/s} er 0.00056 Calculated

Floor Attenuation Factor - faf 0.1 Conservative value for range of commercial bldgs

Outdoor Air Characteristics

Length of Contaminated Area [m] length 10 Area contributing to outdoor air concentration

Width of Contaminated Area [m] width 10 Area contributing to outdoor air concentration

Outdoor Area [m2] oarea 100 calculated

Q/C Dispersion term [g/m2/s per kg/m3] qc 1.23E+02 Calculated for climate similar to East coast of Australia

Chemical Specific Parameters Water Solubility

(mg/L)

MW (g/mol) Koc (cm3/g) Air Diffusion

Coefficient

(cm2/s)

Water Diffusion

Coefficient

(cm2/s)

Vapour Pressure

(mmHg)

Henry's Law

Constant

(unitless)

trichloroethene (TCE) 1100 131.4 166 0.079 9.1E-06 74 0.422

tetrachloroethene (PCE) 200 165.83 155 0.072 8.2E-06 18.5 0.754

Vapour Transport

Calculations for COPC

Identified

Deff Layer 1

(cm2/s)

Deff Layer 2

(cm2/s)

Deff Capillary

Fringe (cm2/s)

Total Effective

Diffusion (GW to

surface) (cm2/s)

trichloroethene (TCE) 4.10E-3 4.10E-3 5.17E-3 4.10E-3

tetrachloroethene (PCE) 3.74E-3 3.74E-3 4.71E-3 3.74E-3

Vapour migration into Commercial Buildings and Outdoor areas (above main plumes)


Calculated Air Concentrations -

Commercial/Industrial Area

Vapour Phase

Concentration

at Source

(ug/m3)

Vapour Phase

Concentration at

Source (g/cm3)

Calculated

Emission Rate

from Surface of

Ground (g/s/m2)

Measured

Emission Rate

from Surface of

Ground (g/s/m2)

Enclosed Space

Concentration

Farmer (mg/m3)

Outdoor Air

Concentration

Box (mg/m3)

Outdoor Air

Concentration

Q/C (mg/m3)

Measured Emission

Rate from Surface of

Ground (ug/min/m2)

1,1-Dichloroethene 0.0E+00 0.0E+00 5.5E-09 3.3E-04 0.0E+00 4.5E-05 0.33

1,2-Dichloroethane (EDC) 0.0E+00 1.3E-08 8.0E-04 0.0E+00 1.1E-04 0.8

Dichloromethane 0.0E+00 0.0E+00 3.0E-08 1.8E-03 0.0E+00 2.4E-04 1.8

Chloroform 0.0E+00 0.0E+00 6.0E-09 3.6E-04 0.0E+00 4.9E-05 0.36

Carbon tetrachloride 0.0E+00 0.0E+00 6.7E-10 4.0E-05 0.0E+00 5.4E-06 0.04

Trichloroethene (TCE) 0.0E+00 0.0E+00 1.2E-08 6.9E-04 0.0E+00 9.3E-05 0.69

Tetrachloroethene (PCE) 0.0E+00 0.0E+00 7.0E-08 4.2E-03 0.0E+00 5.7E-04 4.2

1,1,2-Trichloroethane 0.0E+00 0.0E+00 3.2E-10 1.9E-05 0.0E+00 2.6E-06 0.019

1,1,2,2-Tetrachloroethane 0.0E+00 0.0E+00 5.0E-10 3.0E-05 0.0E+00 4.1E-06 0.03


Botany Golf Course

Vapour Phase

Concentration

at Source

(ug/m3)

Vapour Phase

Concentration at

Source (g/cm3)

Calculated

Emission Rate

from Surface of

Ground (g/s/m2)

Measured

Emission Rate

from Surface of

Ground (g/s/m2)

Enclosed Space

Concentration

Farmer (mg/m3)

Outdoor Air

Concentration

Box (mg/m3)

Outdoor Air

Concentration

Q/C (mg/m3)

Measured Emission

Rate from Surface of

Ground (ug/min/m2)

1,1-Dichloroethene 0.0E+00 5.5E-09 3.3E-04 0.0E+00 4.5E-05 0.33





Trichloroethene (TCE) 56 5.6E-11 6.3E-11 5.8E-10 3.5E-05 2.8E-09 4.7E-06 0.035

Tetrachloroethene (PCE) 110 1.1E-10 1.9E-10 1.3E-08 7.8E-04 8.3E-09 1.1E-04 0.78

Maximum soil gas concentration from source zone Calculated based on maximum emission rate, then

maximum soil gas data

Maximum emissions rate from source sone


(mg/m3)

Exposure Time Indoors (ET, hr/day) 9 Assumed time spent indoors

Exposure Time Outdoors (ET, hr/day) 1 Assumed time spent outdoors

Fraction Inhaled from Contaminated Source (FI, unitless) 1 Assume all areas affected by impacted groundwater

Exposure Frequency (EF, days/yr) 240 Wordays each year

Exposure Duration (ED, years) 30 Duration of exposure as per NEPM 1999 and USEPA 1989

Averaging Time - NonThreshold (Atc, hours) 613200 USEPA 2009

Averaging Time - Threshold (Atn, hours) 262800 USEPA 2009

Concentration Daily Exposure Calculated RiskInhalation

Unit Risk

Chronic TC

air

Background

Intake (%

Chronic TC)

Chronic TC Allowable

for Assessment (TC-

Background)

in Air (Ca) Inhalation Exposure

Concentration -

NonThreshold

Inhalation Exposure

Concentration -

Threshold

Non-

Threshold

Risk

% Total

Risk

Chronic Hazard

Quotient

% Total

HI

(mg/m3)-1

(mg/m3) (mg/m

3) (mg/m

3) (mg/m

3) (mg/m

3) (unitless) (unitless)

1,1-Dichloroethene 2.0E-01 2.0E-01 3.0E-04 3.2E-05 7.4E-05 -- 0.00037 1%

1,2-Dichloroethane (EDC) 2.8E-03 7.3E-04 7.7E-05 1.8E-04 2.2E-7 85% --

Dichloromethane 2.0E-01 20% 1.6E-01 1.6E-03 1.7E-04 4.1E-04 -- 0.0025 4%

Chloroform 1.4E-01 50% 7.0E-02 3.3E-04 3.5E-05 8.1E-05 -- 0.0012 2%

Carbon tetrachloride 6.1E-03 40% 3.7E-03 3.7E-05 3.9E-06 9.0E-06 -- 0.0025 4%

Trichloroethene (TCE) 4.3E-04 4.0E-02 4.0E-02 6.3E-04 6.7E-05 1.6E-04 2.9E-8 11% 0.0039 6%

Tetrachloroethene (PCE) 2.0E-02 10% 1.8E-02 3.8E-03 4.1E-04 9.5E-04 -- 0.053 83%

1,1,2-Trichloroethane 1.4E-02 1.4E-02 1.7E-05 1.8E-06 4.3E-06 -- 0.00031 0%

1,1,2,2-Tetrachloroethane 3.0E-03 2.7E-05 2.9E-06 6.8E-06 8.7E-9 3% --

TOTAL 2.5E-7 0.063

Ca = weighted average for exposures indoors and outdoors

Inhalation of Volatiles (derived from Groundwater Source)

Parameters Relevant to Quantification of Exposure by Adult Workers - Main Plumes - Slab on Grade

Key Chemical

Toxicity Data

AT

EDEFFIETCConcExposureInhalation aV


(mg/m3)

Exposure Time in Basement (ET, hr/day) 9 Assumed time spent indoors



Exposure Frequency (EF, days/yr) 240 Wordays each year





Unit Risk

Chronic TC

air

Background

Intake (%

Chronic TC)


for Assessment (TC-

Background)


Concentration -

NonThreshold

Inhalation Exposure

Concentration -

Threshold

Non-

Threshold

Risk

% Total

Risk

Chronic Hazard

Quotient

% Total

HI

(mg/m3)-1

(mg/m3) (mg/m

3) (mg/m

3) (mg/m

3) (mg/m











TOTAL 2.5E-6 0.62

Ca = weighted average for exposures indoors (assumed to be 10 times higher than for slab on grade) and outdoors


Parameters Relevant to Quantification of Exposure by Adult Workers - Main Plumes - Basement Bldg

Key Chemical

Toxicity Data

AT



VAPOUR PARTITIONING, EMISSION AND AIR DISPERSION MODEL FOR SUBSURFACE IMPACTS

Using Vapour Migration Model Presented by Farmer (1980) and DEH (2000)

Site Specific Physical Input Parameters Units Abbrev. Value Comments

Vadose Zone Layer 1 Characteristics Sand

Depth of Layer 1 [m] vd1 0.3 Depth to most shallow soil gas measurement

Moisture Content [g/g] mocon 0.08 Relevant for dry sand

Organic Carbon Fraction - foc 0.003 Relevant for sand

Soil Bulk Density [g/ml] rhob 1.7 Relevant for sand

Density of Solids [g/ml] sd 2.65 default

Total Soil Porosity [ml/ml] theta 0.36 1 - (rhob/sd)

Volumetric Water Content [ml/ml] wacon 0.136 mocon*rhob

Volumetric Air Content [ml/ml] acon 0.222 theta-wacon

Receptor Specific Input Parameters Units Abbrev. Value Comments

Building Characteristics

Area of Emission - Building Area [m2] emarea 25 Assumed size of building in area (5mx5m)

Height of Room [m] boxh 2.7 Assumed for demountable

Hourly Volume Exchange of Fresh Air [exch/hr] exchanges 1 Assumed for demountable

Air Exchange Rate [exch/s} er 0.00028 Calculated

Floor Attenuation Factor - faf 0.3 Relevant for demountable type of building

Outdoor Air Characteristics

Length of Contaminated Area [m] length 10 Area contributing to outdoor air concentration

Width of Contaminated Area [m] width 10 Area contributing to outdoor air concentration

Outdoor Area [m2] oarea 100 calculated

Q/C Dispersion term [g/m2/s per kg/m3] qc 1.23E+02 Calculated for climate similar to East coast of Australia


Rail Area

Vapour Phase

Concentration

at Source

(ug/m3)

Vapour Phase

Concentration at

Source (g/cm3)

Calculated

Emission Rate

from Surface of

Ground (g/s/m2)

Measured

Emission Rate

from Surface of

Ground (g/s/m2)

Enclosed Space

Concentration

Farmer (mg/m3)

Outdoor Air

Concentration

Box (mg/m3)

Outdoor Air

Concentration

Q/C (mg/m3)

Measured Emission

Rate from Surface

of Ground

(ug/min/m2)

Hexachlorobutadiene (HCBD) 0.0E+00 5.3E-10 2.1E-04 0.0E+00 4.0E-06 0.032


Vinyl chloride 0.0E+00 0.0E+00 2.0E-08 8.0E-03 0.0E+00 1.6E-04 1.2




Trichloroethene (TCE) 0.0E+00 0.0E+00 4.2E-08 1.7E-02 0.0E+00 3.4E-04 2.5

Tetrachloroethene (PCE) 0.0E+00 0.0E+00 3.3E-07 1.3E-01 0.0E+00 2.7E-03 20

1,1,2-Trichloroethane 0.0E+00 0.0E+00 1.7E-09 6.7E-04 0.0E+00 1.4E-05 0.1

1,1,2,2-Tetrachloroethane 0.0E+00 0.0E+00 3.3E-09 1.3E-03 0.0E+00 2.7E-05 0.2

Vapour migration into Commercial Buildings and Outdoor areas (above main plumes)


(mg/m3)

Exposure Time Indoors (ET, hr/day) 2 Assumed time spent indoors



Exposure Frequency (EF, days/yr) 24 Assume 10% of the work year is spent in area above main plumes





Unit Risk

Chronic TC

air

Background

Intake (%

Chronic TC)


for Assessment (TC-

Background)


Concentration -

NonThreshold

Inhalation Exposure

Concentration -

Threshold

Non-

Threshold

Risk

% Total

Risk

Chronic Hazard

Quotient

% Total

HI

(mg/m3)-1

(mg/m3) (mg/m

3) (mg/m

3) (mg/m

3) (mg/m


Hexachlorobutadiene (HCBD) 7.0E-04 7.0E-04 4.6E-05 1.1E-07 2.5E-07 -- 0.00036 1%


Vinyl chloride 8.8E-03 1.7E-03 4.1E-06 9.5E-06 3.6E-8 74% --








TOTAL 4.8E-8 0.024



Parameters Relevant to Quantification of Exposure by Adult Workers in Rail Area - Main Plumes

Key Chemical

Toxicity Data

AT



(L/kg/day)

Ingestion Rate (Irw, L/day) 0.05 Incidental ingestion of 50 mL water

Fraction Ingested from Source 100% Assumed to be 100%

Bioavailability (B) 100% Assume 100% bioavailability via ingestion of chemicals in water.

Exposure Frequency (EF, days/year) 96 Assume contact with industrial water 2 days per work week


Body Weight (BW, kg) 75 ABS 2008

Averaging Time - NonThreshold (Atc, days) 25550 USEPA 1989 and CSMS 1996

Averaging Time - Threshold (Atn, days) 10950 USEPA 1989 and CSMS 1996

Daily Intake Calculated RiskNon-Threshold

Slope Factor

Threshold

TDI

Background

Intake (% TDI)

TDI Allowable for

Assessment (TDI-

Background)

NonThreshold Threshold Non-Threshold

Risk

% Total

Risk

Chronic Hazard

Quotient

% Total

HI

(mg/kg-day)-1

(mg/kg/day) (mg/kg/day) (mg/L) (mg/kg/day) (mg/kg/day) (unitless) (unitless)

Hexachlorobutadiene (HCBD) 2.0E-04 2.0E-04 0.11 8.3E-06 1.9E-05 -- 0.10 6%

1,2-Dichloroethane (EDC) 1.0E-02 623 4.7E-02 1.1E-01 4.7E-4 17% --

Vinyl chloride 1.2E+00 27 2.0E-03 4.7E-03 2.3E-3 83% --

Dichloromethane 1.2E-03 20% 9.6E-04 0.68 5.1E-05 1.2E-04 -- 0.12 7%

Chloroform 1.5E-02 50% 7.5E-03 2.9 2.2E-04 5.1E-04 -- 0.068 4%

Carbon tetrachloride 1.4E-03 40% 8.5E-04 2.8 2.1E-04 4.9E-04 -- 0.58 34%

Trichloroethene (TCE) 7.8E-04 1.5E-03 1.5E-03 5.4 4.1E-04 9.5E-04 3.2E-7 0% 0.65 38%

Tetrachloroethene (PCE) 1.4E-02 10% 1.3E-02 1.9 1.4E-04 3.3E-04 -- 0.026 2%

1,1,2-Trichloroethane 4.0E-03 4.0E-03 2.9 2.2E-04 5.1E-04 -- 0.13 8%

1,1,2,2-Tetrachloroethane 8.3E-03 0.8 6.0E-05 1.4E-04 5.0E-7 0% --

Mercury (as methyl mercury) 2.3E-04 80% 4.6E-05 0.000052 3.9E-09 9.1E-09 -- 0.00020 0%

Mercury (as total, inroganic) 2.0E-03 10% 1.8E-03 0.254 1.9E-05 4.5E-05 -- 0.025 1%

TOTAL 2.8E-3 1.7

Exposure to Chemicals via Incidental Ingestion of Water (Extracted Groundwater)

Parameters Relevant to Quantification of Exposure by Adult Workers - Industrial/Irrigation Water

Toxicity Data

Key Chemical

Concentration

in Water (Cw)

ATBW

EDEFBFIIRCIntakeChemicalDaily WWIW


Dermal Exposure to Chemicals via Contact with Water (Extracted Groundwater)

(L/kg/day)

Surface Area (Saw, cm2) 990

Exposure Time (ET, hr/day) 8 Assume hands remain wet all day when used

Conversion Factor (CF, L/cm3) 1.E-03 Conversion of units

Dermal Permeability (cm/hr) Chemical-specific (as below)

Exposure Frequency (EF, days/yr) 96 Assume contact with industrial water 2 days per work week






Slope Factor

Threshold

TDI

Background

Intake (% TDI)

TDI Allowable for

Assessment (TDI-

Background)

Dermal

Permeability

(DP)

Non-

Threshold

Threshold Non-

Threshold

Risk

% Total

Risk

Chronic

Hazard

Quotient

% Total

HI

(mg/kg-day)-1

(mg/kg/day) (mg/kg/day) (cm/hr) (mg/L) (mg/kg/day) (mg/kg/day) (unitless) (unitless)

Hexachlorobutadiene (HCBD) 2.0E-04 2.0E-04 8.1E-2 0.11 1.1E-04 2.5E-04 -- 1.2 29%

1,2-Dichloroethane (EDC) 1.0E-02 4.2E-3 623 3.1E-02 7.3E-02 3.1E-4 9% --

Vinyl chloride 1.2E+00 8.4E-3 27 2.7E-03 6.3E-03 3.1E-3 91% --

Dichloromethane 1.2E-03 20% 9.6E-04 3.5E-3 0.68 2.9E-05 6.7E-05 -- 0.070 2%

Chloroform 1.5E-02 50% 7.5E-03 6.8E-3 2.9 2.4E-04 5.5E-04 -- 0.073 2%

Carbon tetrachloride 1.4E-03 40% 8.5E-04 1.6E-2 2.8 5.4E-04 1.3E-03 -- 1.5 35%

Trichloroethene (TCE) 7.8E-04 1.5E-03 1.5E-03 1.2E-2 5.4 7.5E-04 1.7E-03 5.8E-7 0% 1.2 28%

Tetrachloroethene (PCE) 1.4E-02 10% 1.3E-02 3.3E-2 1.9 7.6E-04 1.8E-03 -- 0.14 3%

1,1,2-Trichloroethane 4.0E-03 4.0E-03 5.0E-3 2.9 1.7E-04 4.1E-04 -- 0.10 2%

1,1,2,2-Tetrachloroethane 8.3E-03 6.9E-3 0.8 6.6E-05 1.5E-04 5.5E-7 0% --

Mercury (as methyl mercury) 2.3E-04 80% 4.6E-05 1.0E-3 0.000052 6.2E-10 1.4E-09 -- 0.000031 0%

Mercury (as total, inroganic) 2.0E-03 10% 1.8E-03 1.0E-3 0.254 3.0E-06 7.1E-06 -- 0.0039 0%

3E-3 4.3

Toxicity Data


Key Chemical

Concentration

in Water (Cw)

Workers get hands wet (50% for adult males, USEPA 1997) during operation of

the bore and watering activities

ATBW

EDEFCFDPETSAwCIntakeChemicalDaily WDW


(mg/m3)

Exposure Time (ET, hr/day) 8 Assume use of water for 8 hours each time

Fraction Inhaled from Contaminated Source (FI, unitless) 1 All derived from impacted groundwater

Exposure Frequency (EF, days/yr) 96 Assume contact with industrial water 2 days per work week





Unit Risk

Chronic TC

air

Background

Intake (%

Chronic TC)


for Assessment (TC-

Background)


Concentration -

NonThreshold

Inhalation Exposure

Concentration -

Threshold

Non-

Threshold

Risk

% Total

Risk

Chronic Hazard

Quotient

% Total

HI

(mg/m3)-1

(mg/m3) (mg/m

3) (mg/m

3) (mg/m

3) (mg/m



1,2-Dichloroethane (EDC) 2.8E-03 3.0E+01 1.1E+00 2.6E+00 3.1E-3 92% --

Vinyl chloride 4.4E-03 1.6E+00 6.1E-02 1.4E-01 2.7E-4 8% --








Mercury (as elemental) 2.0E-04 10% 1.8E-04 5.0E-06 1.9E-07 4.4E-07 -- 0.0025 0%

TOTAL 3.4E-3 5.6

Inhalation of Volatiles (derived from Irrigation of Groundwater)


Key Chemical

Toxicity Data

AT



(mg/m3)

Exposure Time Indoors (ET, hr/day) 0.5 Assumed time spent indoors


Exposure Frequency (EF, days/yr) 20 Assume visits to the premises in the area over 20 days each year

Exposure Duration (ED, years) 10 Assume visits occur over 10 separate years




Unit Risk

Chronic TC

air

Background

Intake (%

Chronic TC)


for Assessment (TC-

Background)


Concentration -

NonThreshold

Inhalation Exposure

Concentration -

Threshold

Non-

Threshold

Risk

% Total

Risk

Chronic Hazard

Quotient

% Total

HI

(mg/m3)-1

(mg/m3) (mg/m

3) (mg/m

3) (mg/m

3) (mg/m











TOTAL 4.1E-9 0.00067



Parameters Relevant to Quantification of Exposure by General Public - Adults

Key Chemical

Toxicity Data

AT



(L/kg/day)

Ingestion Rate (Irw, L/day) 0.005 Incidental ingestion of 5 mL water during irrigation of gardens



Exposure Frequency (EF, days/year) 90






Slope Factor

Threshold

TDI

Background

Intake (% TDI)

TDI Allowable for

Assessment (TDI-

Background)


Risk

% Total

Risk

Chronic Hazard

Quotient

% Total

HI

(mg/kg-day)-1



1,1-Dichloroethene 4.6E-02 4.6E-02 1.9 2.4E-05 3.1E-05 -- 0.00068 0%


cis-1,2-Dichloroethene 6.0E-03 5% 5.7E-03 10.3 1.3E-04 1.7E-04 -- 0.030 16%

trans-1,2-Dichloroethene 1.7E-02 5% 1.6E-02 0.9 1.1E-05 1.5E-05 -- 0.00092 0%



Chloroform 1.5E-02 50% 7.5E-03 2.9 3.7E-05 4.8E-05 -- 0.0064 3%








TOTAL 8.7E-4 0.19


Parameters Relevant to Quantification of Exposure by Adults - General Public - Irrigation

Key Chemical

Toxicity DataConcentration

in Water (Cw)

Frequency relevant to garden irrigation (more conservative than municipal

ATBW




(L/kg/day)


Exposure Time (ET, hr/day) 1 Assume adults remain wet for 1 hour each time



Exposure Frequency (EF, days/yr) 90






Slope Factor

Threshold

TDI

Background

Intake (% TDI)

TDI Allowable for

Assessment (TDI-

Background)

Dermal

Permeability

(DP)

Non-

Threshold

Threshold Non-

Threshold

Risk

% Total

Risk

Chronic

Hazard

Quotient

% Total

HI

(mg/kg-day)-1



1,1-Dichloroethene 4.6E-02 4.6E-02 1.2E-2 1.9 1.2E-03 1.6E-03 -- 0.035 0%


cis-1,2-Dichloroethene 6.0E-03 5% 5.7E-03 1.1E-2 10.3 6.3E-03 8.1E-03 -- 1.4 11%

trans-1,2-Dichloroethene 1.7E-02 5% 1.6E-02 1.1E-2 0.9 5.5E-04 7.1E-04 -- 0.044 0%











3.0E-2 13

Parameters Relevant to Quantification of Exposure by Adults - General Public - IrrigationWhole adult body surface area, assuming that the adult gets completely wet

during irrigation or recreational use of area where grass is wet following

irrigation. A more realistic exposure would be to hands only (1068 cm2)

Key Chemical


in Water (Cw)


ATBW



(mg/m3)

Parameters Relevant to Quantification of Exposure by Adults - General Public - IrrigationExposure Time (ET, hr/day) 1 Assume adultes near irrigation for 1 hour each time







Unit Risk

Chronic TC

air

Background

Intake (%

Chronic TC)


for Assessment (TC-

Background)


Concentration -

NonThreshold

Inhalation Exposure

Concentration -

Threshold

Non-

Threshold

Risk

% Total

Risk

Chronic Hazard

Quotient

% Total

HI

(mg/m3)-1

(mg/m3) (mg/m

3) (mg/m

3) (mg/m

3) (mg/m




1,2-Dichloroethane (EDC) 2.8E-03 3.0E+01 2.4E-01 3.1E-01 6.6E-4 85% --

cis-1,2-Dichloroethene 3.0E-02 5% 2.9E-02 5.4E-01 4.3E-03 5.5E-03 -- 0.19 22%

trans-1,2-Dichloroethene 6.0E-02 5% 5.7E-02 4.7E-02 3.7E-04 4.8E-04 -- 0.0085 1%










TOTAL 7.8E-4 0.86


Key Chemical

Toxicity Data

Frequency relevant to garden irrigation (more conservative than municipal irrigation)

AT



(mg/m3)




Exposure Duration (ED, years) 10 Assume visits occur over 10 separate years

Age Dependant Adjustment Factor (ADAF) - where relevant 3 Relevant for children aged 2 to <16 years as per USEPA 2005




Unit Risk

Chronic TC

air

Background

Intake (%

Chronic TC)


for Assessment (TC-

Background)


Concentration -

NonThreshold

Inhalation Exposure

Concentration -

Threshold

Non-

Threshold

Risk

% Total

Risk

Chronic Hazard

Quotient

% Total

HI

(mg/m3)-1

(mg/m3) (mg/m

3) (mg/m

3) (mg/m

3) (mg/m











TOTAL 2.2E-9 0.00033


Includes consideration of early life suseptability for non-threshold calculation


Parameters Relevant to Quantification of Exposure by General Public - Older Children

Key Chemical

Toxicity Data

AT



(L/kg/day)






Body Weight (BW, kg) 34.5 As per USEPA 1997





Slope Factor

Threshold

TDI

Background

Intake (% TDI)

TDI Allowable for

Assessment (TDI-

Background)


Risk

% Total

Risk

Chronic Hazard

Quotient

% Total

HI

(mg/kg-day)-1









Chloroform 1.5E-02 50% 7.5E-03 2.9 1.5E-05 1.0E-04 -- 0.014 3%








TOTAL 3.5E-4 0.41



Parameters Relevant to Quantification of Exposure by Older Children - General Public - Irrigation


Key Chemical


in Water (Cw)

ATBW




(L/kg/day)

Surface Area (Saw, cm2) 15300 Whole body surface area (male child 11-12 yrs, 90 percentile, USEPA 1997)






Body Weight (BW, kg) 34.5 As per USEPA 1997

Age Dependant Adjustment Factor (ADAF) - where relevant3 Relevant for children aged 2 to <16 years as per USEPA 2005




Slope Factor

Threshold

TDI

Background

Intake (% TDI)

TDI Allowable for

Assessment (TDI-

Background)

Dermal

Permeability

(DP)

Non-

Threshold

Threshold Non-

Threshold

Risk

% Total

Risk

Chronic

Hazard

Quotient

% Total

HI

(mg/kg-day)-1














1,1,2,2-Tetrachloroethane 8.3E-03 6.9E-3 0.8 8.7E-05 6.1E-04 7.2E-7 --



8.5E-3 19




Key Chemical


in Water (Cw)

ATBW



(mg/m3)

Exposure Time (ET, hr/day) 1 Assume adults near irrigation for 1 hour each time








Unit Risk

Chronic TC

air

Background

Intake (%

Chronic TC)


for Assessment (TC-

Background)


Concentration -

NonThreshold

Inhalation Exposure

Concentration -

Threshold

Non-

Threshold

Risk

% Total

Risk

Chronic Hazard

Quotient

% Total

HI

(mg/m3)-1

(mg/m3) (mg/m

3) (mg/m

3) (mg/m

3) (mg/m
















TOTAL 1.4E-4 0.86

Includes consideration of early life susceptibility for non-threshold calculation



Key Chemical

Toxicity Data


AT



(mg/m3)




Exposure Duration (ED, years) 6 Assume visits occur over 6 separate years as young child (0-5 years)

Age Dependant Adjustment Factor (ADAF) - where relevant 10 Relevant for children aged <2 years as per USEPA 2005

3 Relevant for children aged <2 to <16 years as per USEPA 2005




Unit Risk

Chronic TC

air

Background

Intake (%

Chronic TC)


for Assessment (TC-

Background)


Concentration -

NonThreshold

Inhalation Exposure

Concentration -

Threshold

Non-

Threshold

Risk

% Total

Risk

Chronic Hazard

Quotient

% Total

HI

(mg/m3)-1

(mg/m3) (mg/m

3) (mg/m

3) (mg/m

3) (mg/m











TOTAL 1.4E-9 0.00033




Parameters Relevant to Quantification of Exposure by General Public - Young Children

Key Chemical

Toxicity Data

AT



(L/kg/day)






Body Weight (BW, kg) 13.2 Asper NEPM 1999 and enHealth 2002

Age Dependant Adjustment Factor (ADAF) - where relevant10 Relevant for children aged <2 years as per USEPA 2005





Slope Factor

Threshold

TDI

Background

Intake (% TDI)

TDI Allowable for

Assessment (TDI-

Background)


Risk

% Total

Risk

Chronic Hazard

Quotient

% Total

HI

(mg/kg-day)-1









Chloroform 1.5E-02 50% 7.5E-03 2.9 2.3E-05 2.7E-04 -- 0.036 3%








TOTAL 5.5E-4 1.1



Parameters Relevant to Quantification of Exposure by Young Children - General Public - Irrigation


Key Chemical


in Water (Cw)

ATBW




(L/kg/day)







Body Weight (BW, kg) 13.2 As per NEPM 1999 and enHealth 2002

Age Dependant Adjustment Factor (ADAF) - where relevant10 Relevant for children aged <2 years as per USEPA 2005





Slope Factor

Threshold

TDI

Background

Intake (% TDI)

TDI Allowable for

Assessment (TDI-

Background)

Dermal

Permeability

(DP)

Non-

Threshold

Threshold Non-

Threshold

Risk

% Total

Risk

Chronic

Hazard

Quotient

% Total

HI

(mg/kg-day)-1

















6.4E-3 24




Key Chemical


in Water (Cw)

Whole body surface area (male child 3-4 yrs, 90 percentile, USEPA 1997)

ATBW



(mg/m3)

Exposure Time (ET, hr/day) 1 Assume adults near irrigation for 1 hour each time




Age Dependant Adjustment Factor (ADAF) - where relevant 10 Relevant for children aged <2 years as per USEPA 2005





Unit Risk

Chronic TC

air

Background

Intake (%

Chronic TC)


for Assessment (TC-

Background)


Concentration -

NonThreshold

Inhalation Exposure

Concentration -

Threshold

Non-

Threshold

Risk

% Total

Risk

Chronic Hazard

Quotient

% Total

HI

(mg/m3)-1

(mg/m3) (mg/m

3) (mg/m

3) (mg/m

3) (mg/m
















TOTAL 8.7E-5 0.86




Key Chemical

Toxicity Data


AT



(mg/m3)

Exposure Time Outdoors (ET, hr/day) 4 Assumed time spent outdoors above main plumes


Exposure Frequency (EF, days/yr) 208 Assume playing golf 4 times each week





Unit Risk

Chronic TC

air

Background

Intake (%

Chronic TC)


for Assessment (TC-

Background)


Concentration -

NonThreshold

Inhalation Exposure

Concentration -

Threshold

Non-

Threshold

Risk

% Total

Risk

Chronic Hazard

Quotient

% Total

HI

(mg/m3)-1

(mg/m3) (mg/m

3) (mg/m

3) (mg/m

3) (mg/m









TOTAL 1.4E-9 0.0010



Parameters Relevant to Quantification of Exposure by Adults - Recreational Use of Golf Course

Key Chemical

Toxicity Data

AT



(mg/m3)

Exposure Time Outdoors (ET, hr/day) 4 Assumed time spent outdoors above main plumes


Exposure Frequency (EF, days/yr) 104 Assume playing golf 2 times each week






Unit Risk

Chronic TC

air

Background

Intake (%

Chronic TC)


for Assessment (TC-

Background)


Concentration -

NonThreshold

Inhalation Exposure

Concentration -

Threshold

Non-

Threshold

Risk

% Total

Risk

Chronic Hazard

Quotient

% Total

HI

(mg/m3)-1

(mg/m3) (mg/m

3) (mg/m

3) (mg/m

3) (mg/m









TOTAL 1.6E-10 0.00051



Parameters Relevant to Quantification of Exposure by Older Children- Recreational Use of Golf Course

Key Chemical

Toxicity Data

AT



(L/kg/day)

Ingestion Rate (Irw, L/day) 0.005 Incidental ingestion of 5 mL water



Exposure Frequency (EF, days/year) 10 Assume intrusive works on services occur over 10 days each year

Exposure Duration (ED, years) 5 Assume works occur on the same site over 5 years





Slope Factor

Threshold

TDI

Background

Intake (% TDI)

TDI Allowable for

Assessment (TDI-

Background)


Risk

% Total

Risk

Chronic Hazard

Quotient

% Total

HI

(mg/kg-day)-1







Vinyl chloride 1.2E+00 3.1 4.0E-07 5.7E-06 4.7E-7 98% --


Chloroform 1.5E-02 50% 7.5E-03 0.93 1.2E-07 1.7E-06 -- 0.00023 4%







TOTAL 4.7E-7 0.0058

Exposure to Chemicals via Incidental Ingestion of Water (shallow groundwater)

Parameters Relevant to Quantification of Exposure by Workers involved in Excavations

Key Chemical


in Water (Cw)

ATBW



(L/kg/day)


Exposure Time (ET, hr/day) 3.3 Assume workers in excavation and wet for 33% of time on site (total 10 hrs/day)



Exposure Frequency (EF, days/yr) 10 Assume intrusive works on services occur over 10 days each year






Slope Factor

Threshold

TDI

Background

Intake (% TDI)

TDI Allowable for

Assessment (TDI-

Background)

Dermal

Permeability (DP)

Non-

Threshold

Threshold Non-

Threshold

Risk

% Total

Risk

Chronic

Hazard

Quotient

% Total

HI

(mg/kg-day)-1







Vinyl chloride 1.2E+00 8.4E-3 3.1 7.5E-06 1.0E-04 8.6E-6 99% --









8.6E-6 0.24

Parameters Relevant to Quantification of Exposure by Workers involved in Excavations

Key Chemical


in Water (Cw)

Exposure to Chemicals via Incidental Ingestion of Water (shallow groundwater)

Exposed surface area for construction workers as per USEPA 2001

ATBW



(mg/m3)

Exposure Time (ET, hr/day) 10 Assume working day is 10 hours


Exposure Frequency (EF, days/yr) 10 Assume intrusive works on services occur over 10 days each year





Unit Risk

Chronic TC

air

Background

Intake (%

Chronic TC)


for Assessment (TC-

Background)


Concentration -

NonThreshold

Inhalation Exposure

Concentration -

Threshold

Non-

Threshold

Risk

% Total

Risk

Chronic Hazard

Quotient

% Total

HI

(mg/m3)-1

(mg/m3) (mg/m

3) (mg/m

3) (mg/m

3) (mg/m















TOTAL 3.3E-6 0.92

Ca = weighted concentration assuming 1/3 time in excavation and 2/3 outdoors (not in excavation)


Parameters Relevant to Quantification of Exposure by Adult Workers - Industrial Water

Key Chemical

Toxicity Data

AT



(mg/m3)

Exposure Time (ET, hr/day) 10 Time indoors and outdoors - exposure concentration the same


Exposure Frequency (EF, days/yr) 240 Workdays each year





Unit Risk

Chronic TC

air

Background

Intake (%

Chronic TC)


for Assessment (TC-

Background)


Concentration -

NonThreshold

Inhalation Exposure

Concentration -

Threshold

Non-

Threshold

Risk

% Total

Risk

Chronic Hazard

Quotient

% Total

HI

(mg/m3)-1

(mg/m3) (mg/m

3) (mg/m

3) (mg/m

3) (mg/m










TOTAL 1.7E-5 0.18

Ca = average of maximums and TWA concentrations to 2009

Inhalation of Volatiles (derived from Springvale Drain)

Parameters Relevant to Quantification of Exposure by Adult Workers - MCS Area - Chronic Assessment

Key Chemical

Toxicity Data

AT



(mg/m3)








Unit Risk

Chronic TC

air

Background

Intake (%

Chronic TC)


for Assessment (TC-

Background)


Concentration -

NonThreshold

Inhalation Exposure

Concentration -

Threshold

Non-

Threshold

Risk

% Total

Risk

Chronic Hazard

Quotient

% Total

HI

(mg/m3)-1

(mg/m3) (mg/m

3) (mg/m

3) (mg/m

3) (mg/m










TOTAL 2.8E-6 0.090



Parameters Relevant to Quantification of Exposure by Adult Workers - MCS Area - Post GTP

Key Chemical

Toxicity Data

AT



(mg/m3)








Unit Risk

Chronic TC

air

Background

Intake (%

Chronic TC)


for Assessment (TC-

Background)


Concentration -

NonThreshold

Inhalation Exposure

Concentration -

Threshold

Non-

Threshold

Risk

% Total

Risk

Chronic Hazard

Quotient

% Total

HI

(mg/m3)-1

(mg/m3) (mg/m

3) (mg/m

3) (mg/m

3) (mg/m










TOTAL 3.1E-5 0.28



Parameters Relevant to Quantification of Exposure by Adult Workers - Discovery Cove Area - Chronic Assessment

Key Chemical

Toxicity Data

AT



(mg/m3)








Unit Risk

Chronic TC

air

Background

Intake (%

Chronic TC)


for Assessment (TC-

Background)


Concentration -

NonThreshold

Inhalation Exposure

Concentration -

Threshold

Non-

Threshold

Risk

% Total

Risk

Chronic Hazard

Quotient

% Total

HI

(mg/m3)-1

(mg/m3) (mg/m

3) (mg/m

3) (mg/m

3) (mg/m










TOTAL 2.3E-6 0.083



Parameters Relevant to Quantification of Exposure by Adult Workers - Discovery Cove Area - Post GTP

Key Chemical

Toxicity Data

AT



Summary of Risk for RME Exposure - Main Plumes

Pathway NonThreshold Risks Threshold Risks

Hazard Index

Commercial/Industrial Workers

Inhalation of CHCs indoors and outdoors (from GW source) 2.5E-07 0.063

Incidental ingestion of CHCs during use of extracted GW 2.8E-03 1.7

Dermal contact with CHCs during use of extracted GW 3.4E-03 4.3

Inhalation of CHCs during irrigation of extracted GW 3.4E-03 5.6

Total Risk (including exposures associated with extraction and use of GW) 1E-02 12

Total Risk (no GW use) 3E-07 0.06

Inhalation of CHCs derived from SVD - MCS Chronic 1.7E-05 0.18

Inhalation of CHCs derived from SVD - MCS Post GTP 2.8E-06 0.090

Inhalation of CHCs derived from SVD - Discovery Cove Chronic 3.1E-05 0.28

Inhalation of CHCs derived from SVD - Discovery Cove Post GTP 2.3E-06 0.083

Total Risk - Maximum Chronic 3E-05 0.3

Total Risk - Maximum post operation of the GTP - current 3E-06 0.09

Intrusive Workers

Incidental ingestion of CHCs in shallow GW 4.7E-07 0.0058

Dermal contact with CHCs in shallow GW 8.6E-06 0.24

Inhalation of CHCs from shallow GW (from seepage) 3.3E-06 0.92

Total Risk 1E-05 1


Summary of Risk for RME Exposure - Main Plumes

Pathway NonThreshold Risks Threshold Risks

Hazard Index

General Public - Adults

Inhalation of CHCs outdoors (from GW source) 4.1E-09 0.00067


Dermal contact with CHCs during use of extracted GW 3.0E-02 13




General Public - Older Children







General Public - Young Children







Lifetime Risk (including exposures associated with extraction and use of GW) 5E-02 26

Lifetime Risk (no GW use) 8E-09 0.0007

Recreational Use of Golf Course

Inhalation of CHCs outdoors (from GW source) - Adults 1.4E-09 0.0010

Inhalation of CHCs outdoors (from GW source) - Older Children 1.6E-10 0.00051

Lifetime Risk (no GW use) 2E-09 0.001

Appendix D Risk Calculations – Main Plumes

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Transcript of Appendix D Risk Calculations – Main Plumes