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Air Emissions fromAshbridges Bay Treatment Plant

ByAnthony Ciccone, Ph.D., P.Eng. –Golder AssociatesCiara De Jong, MES –Golder AssociatesAngela Li-Muller, Ph.D. –Toronto Public HealthMark Rupke, P.Eng. –WESDiane Michelangeli, Ph.D. –York UniversityJean Yves Urbain, P.Eng. –Earth Tech

Policy Analysis Tools for Air Quality and Health

19 May 2005

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Objective of Emission Study

Evaluate the past, current and future impacts of air emissions South Riverdale and Beach Communities

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Methodology1. Data collection and review

Plant process information (including previous studies) Ambient air monitoring data Meteorological data

2. Develop an air emission inventory Determine chemicals released Location of releases Stack and area characteristics Mass emissions into air

3. Process meteorological data4. Build input data for CALPUFF5. Select 17 chemicals for modelling6. Model chemical impact on communities 7. Analyze results

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The Modelling Process

CALMET PredictedWind Direction Frequency

0%

2%

4%

6%

8%

10%

12%N

NNE

NE

ENE

E

ESE

SE

SSE

S

SSW

SW

WSW

W

WNW

NW

NNW

CALMET PredictedWind Speed (m/s) by Direction

0

5

10

15

20N

NNE

NE

ENE

E

ESE

SE

SSE

S

SSW

SW

WSW

W

WNW

NW

NNW

Average Maximum

Wind Direction Frequency - ABTP OnSite 1996

0%2%

4%

6%

8%10%

12%

14%

16%N

NNE

NE

ENE

E

ESE

SE

SSE

S

SSW

SW

WSW

W

WNW

NW

NNW

Wind Speed (m/s) by Direction - ABTP OnSite

0

5

10

15

20N

NNE

NE

ENE

E

ESE

SE

SSE

S

SSW

SW

WSW

W

WNW

NW

NNW

Average Maximum

CALPUFF

Emissions

Meteorology

Receptors

Concentrations

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ABTP Historical Scenarios

1. Incinerator was in full operation (pre-1996)

2. Incinerator was in partial operation (2000-2002)

3. After incinerator was discontinued (2003-2004)

4. After incinerator was discontinued and odour control fully implemented (by 2010)

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Concept Plan for Key Plant Areas

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Protocol to Select Chemicals

Prioritize chemicals Ranking

• Method 1a - Calculated Toxicity Equivalent for Cancer effects

• Method 1b - Calculated Toxicity Equivalent Non-Cancer effects

• Method 1c - Ranked chemicals based on toxicity, emissions, persistence, and bioaccumulation

Select top 25 from rankings Above laboratory detection limits Important to communities

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17 Chemicals Modeled

Arsenic Benzene Benz[a]pyrene (B[a]P) Bis(2-ethylhexyl)-

phthalate Cadmium Di-n-octyl phthalate Hexachlorobutadiene Hydrogen sulphide Lead

Mercury Nitrogen oxides PM2.5

PCBs Sulphur dioxide Total dioxins and furans Total polyaromatic

hydrocarbons (PAHs) Vinyl chloride

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Hydrogen Sulphide24 Hr Concentration Isopleths

AAQC – N/A ug/m3

Health Benchmark

– 10 to 2 ug/m3

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Summary of Impacts on Communities

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Conclusions - 1

Little difference between air quality on South Riverdale vs Beaches due to ABTP Elevated stack has slightly higher

impact to the northeast because of high velocity winds from the southwest

Low elevations sources have higher impact to the northwest because of lower velocity winds from the southeast

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Conclusions - 2

Significant process changes since 1995 has changed the ABTP air emission profile

Removal of incineration eliminated• arsenic, • cadmium, • lead,• PCBs, and • Dioxins/Furans

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Conclusions - 3

Compared to Toronto Ambient Air While Incinerator Operating Predicted maximum levels below

Toronto measured ambient levels

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Conclusions - 4

15 chemicals were unequivocally detected at ABTP

All detected chemicals below MOE air quality criteria/standards for all time scales

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Conclusions - 5

Most detected chemicals below health benchmarks except Hydrogen Sulphide above the lower chronic

limit (2 ug/m3) for some scenarios Cadmium exceeds only during incineration

By 2010, all detected chemicals meet health benchmarks

All detected chemicals below Toronto measured levels during incineration

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Conclusions - 5

Benzo[a]pyrene/PAHs less than detection limits

At B[a]P detection limits, Health benchmark exceeded for all scenarios MOE air quality criteria will be met by 2010

Maximum predicted impact was greater than measured

Impact over estimated