11

School SitingSchool SitingEnvironmental Health and Safety Environmental Health and Safety

ConsiderationsConsiderations

J. Brad Peebles Ph.D.,C.E.P.J. Brad Peebles Ph.D.,C.E.P.

Brad.Peebles@tetratech.comBrad.Peebles@tetratech.com813-504-0081813-504-0081

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OVERVIEW

• Current environmental due diligence methods do not fully evaluate the potential health and safety threat to the school based population

• Over-reliance on Phase I and Phase II Environmental Site Assessments

• Poor evaluation of

• Off-site air emission sources

• Sudden Offsite Accidental Releases

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OVERVIEW Expanded Approach to Due Diligence

Health and Safety of School Based Population

Modeled After:

• California Public Resources Code Section 21151.8

• California Education Code Section 17213

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OVERVIEW

• California Public Resources Code Section 21151.8

• expanded approach to due diligence in an environmental impact report shall not be certified or a negative declaration shall not be approved for a project involving the purchase of a school site or the construction of a new elementary or secondary school by a school district unless all of the following occur……

• A site that is within 500 feet of the edge of the closest traffic lane of a freeway or other busy traffic corridor.

• http://law.onecle.com/california/public-resources/21151.8.html

55

OVERVIEW

• California Education Code Section 17213

• The governing board of a school district may not approve a project involving the acquisition of a school site by a school district, unless all of the following occur ….

• ….both permitted and non-permitted facilities within that district's authority, including, but not limited to, freeways and other busy traffic corridors, large agricultural operations, and railyards, within one-fourth of a mile of the proposed schoolsite, that might reasonably be anticipated to emit hazardous air emissions, or to handle hazardous or extremely hazardous materials, substances, or waste.

•http://law.onecle.com/california/education/17213.html

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OVERVIEW

Health and Safety of School Based Population

• What are the sources of off-site air emission sources?

• How is the school-based population exposed?

• Who is exposed?

• How are the risk characterized?

• How to evaluate the potential for sudden offsite accidental releases?

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OVERVIEW

• Using the expanded approach to due diligence in the planning process

• New schools

• School closings

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Phase I and Phase II Environmental Site Assessments

• CERCLA defense

• buyer (prospective purchaser)

• innocent landowner

• hazardous substance in the soils or groundwater

• A hazardous substance is any one of 600 chemicals defined under CERCLA 101(14) .

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Phase I and Phase II Environmental Site Assessments

• CERCLA defense

• “Standards and Practices for All Appropriate Inquiries” (see 40 CFR 312)

• “Standard Practice for Environmental Site Assessments: Phase I Environmental Site Assessment Process” (ASTM E1527 – 05).

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Phase I and Phase II Environmental Site Assessments

• CERCLA defense

• hazardous substance in the soils or groundwater

• Mostly on-site

• soils

• Upgradient off-site

• groundwater

1111

Phase I and Phase II Environmental Site Assessments

• CERCLA defense

• buyer has reasonable assurance

• chain-of-title CERCLA liability issues

• little assurance

• health and safety of school based population is addressed

1212

“Health” portion of the

“Health and Safety of School Based Population”

• “Conceptual Exposure Model”• Source of contaminants• Release Mechanism• Pathway and route of exposure• Receptors

1313

Sources of Off-site Air Emission Sources

• permitted and non permitted facilities located within a 1/4 mile radius • a freeway traffic lane or busy traffic corridor within 500 feet• large agricultural operations, and rail yards, within one-fourth of a mile of the proposed school site

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Sources and Rates of Air Emissions

1515

Sources and Rates of Air Emissions

1616

Sources and Rates of Air Emissions

1717

Sources and Rates of Air EmissionsOperation: Dry Cleaning

System: Open

    hrs/day days/wk weeks/year

Temporal Profile:   11.5 5 52

  9.5 1 52

Materials:

Perchloroethylene (gal/mo) 8.5

Product Density (lbs/gal) 13.55

Emission Factor:

Pound emitted/Pound Used 0.95

Emissions

 

0.380 Lbs/Hour

0.048 Grm/Sec

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Air Modeling – Source to Receptor

Determine which air emissions model to use.

• Estimate ground level impacts from point and fugitive sources in simple and complex terrain

• SCREEN3 • AERMOD

• Collect area-specific meteorological data

1919

Air Modeling – Source to Receptor

Dry Cleaner• Source emission rate

= 0.048 Grm/Sec• Receptor Concentration

= 1.1E-04 mg/m3

Or

= 0.00011262 mg/m3

2020

ReceptorsSchool Based Population

• Students

• Teachers

• Staff

What are the differences in how these people may be exposed to airborne contaminants?

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Calculate chemical uptake Determine the Risk

EF = exposure frequency (days/year) Students = 180 days

Teachers = up to 250 days Staff = 240 days

ED = exposure duration (years)

Students = 6 years; 2 years; 4 yearsTeachers and Staff = 20 to 40 years

IR = inhalation rate (m3/day) BW = body weight (kg)

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Calculate chemical uptake Determine the Risk

Dose calculated as: CDI = (Cair × EF × ED × IR) / (BW × AT)

Where: CDI = chronic daily intake (mg/kg/day)

Note: CDI is the daily “dose”

Cair = concentration of contaminant in air (mg/m3) Note: this is the modeled

value EF = exposure frequency (days/year)

ED = exposure duration (years) IR = inhalation rate (m3/day) BW = body weight (kg) AT = averaging time (days)

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Calculate chemical uptake Determine the Risk

• For each chemical • Carcinogenic Chemical Risk• Non-carcinogenic Chemical Hazards

• Develop a sum of the • Carcinogenic Chemical Risk • Non-carcinogenic Chemical Hazards

• Compare the sums against established criteria

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Calculate chemical uptake Determine the Risk

Risk = a function of exposure and toxicity• exposure = dose• toxicity … cancer and/or non-cancer

“Toxicity factor”• cancer potency factor (CPF) • reference dose (RfD)

2525

Calculate chemical uptake Determine the Risk

• Carcinogenic Chemical Risk

• Dose times CPF

• Non-carcinogenic Chemical Hazards• Dose divided by RfD

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Calculate chemical uptake Determine the Risk

Dry CleanerReceptor Concentration = 1.1E-04 mg/m3

Cair or “dose”= 1.1E-04 mg/m3

Carcinogenic Chemical Risk

• Dose times CPF= 2.0E-07

•Non-carcinogenic Chemical Hazards• Dose divided by RfD

= 1.7E-03

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Calculate chemical uptake Determine the Risk

All 19 Sources Summed - Adults

Carcinogenic Chemical Risk

= 2.9E-06

Non-carcinogenic Chemical Hazards = 4.0E-02

2828

Compare the calculated risk against the criteria

All 19 Sources Summed - Adults

• Carcinogenic Chemical Risk = 2.9E-06• Florida Criterion = 1.0E-06 • Almost three times the Florida limit• Largest contributor?

• Nearby freeway• Diesel Exhaust Particulate

• Risk = 1.7E-06

• Non-carcinogenic = 4.0E-02• Florida Criterion = 1.0• Well below the Florida limit

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“Safety” portion of the

“Health and Safety of School Based Population”

• An opportunity for an accidental release of regulated substances from:

• propane storage facilities• waste water treatment plants• facilities with a “threshold quantity” of “listed” or “regulated” substances

• Accidental Release Prevention program • (Title 40, Code of Federal Regulations, Part 68)

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“Safety” portion of the

“Health and Safety of School Based Population”

• Facilities with a “threshold quantity” of “listed” or “regulated” substances

• Risk Management Plan • RMP*Comp model

• screening model• http://www.epa.gov/oem/content/rmp/rmp_comp.htm

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“Safety” portion of the

“Health and Safety of School Based Population”

• RMP*Comp model• Steel Pickling Company

• located less than 0.1 mile from school• 500-gallon tank of ammonia • leak/rupture

• release its contents over 10 minutes

• ammonia toxic endpoint• less than 0.1 miles

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“Safety” portion of the

“Health and Safety of School Based Population”

• ALOHA Model• Areal Locations of Hazardous Atmospheres

• models key hazards• toxicity, • flammability, • thermal radiation (heat), and • overpressure (explosion blast force)

• URL…very long

3333

“Safety” portion of the

“Health and Safety of School Based Population”

• Example ALOHA Model from NOAA Web site

3434

“Safety” portion of the

“Health and Safety of School Based Population”

• Industrial Accident Consequence Analysis•Accidental release scenario

• School occupants traveling to the school would likely be affected

• Explosion hazard scenario • Explosion footprint would impact a portion of the school site

• Boiling Liquid Expanding Vapor Explosion (BLEVE)

• Impact the entire school site

•

3535

The Planning Process Expanded Approach to Due Diligence

• Tier I Hazards and Risks Evaluation

• Tier II Hazards and Risks Evaluation

• Tier III Hazards and Risks Evaluation

3636

Tier I Hazards and Risks Evaluation• There are no volatile chemicals in the soil or groundwater or the depth to groundwater was greater than 15 feet below land surface; and• The major highways and rail lines are greater than 500 feet from the future school property boundary, and• There were no pipelines located within a quarter-mile of the future school boundary that carry explosive gases or liquids, and• There are no businesses currently located within a quarter-mile of the future school boundary that emitted chemicals to the atmosphere, and• There were no businesses currently located within a quarter-mile of the future school property boundary that present an opportunity for an accidental release of regulated substances, and,• There was no past use of the future school site by the Department of Defense.

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Tier II Hazards and Risks Evaluation

• The Tier I criteria are not met - Mitigate risks or conduct Tier II

• Tier II

• SCREEN3 air model• RMP*Comp• Evaluate results against

• Applicable criteria • Appropriate criteria

3838

Tier III Hazards and Risks Evaluation

• The Tier II criteria are not met - Mitigate risks or conduct Tier III

• Tier III

• AERMOD air model• ALOHA• Evaluate results against

• Applicable criteria • Appropriate criteria

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The Planning Process Expanded Approach to Due Diligence

Hazards and Risks Evaluation – Information on Costs

Level Lower Cost Higher Cost

Tier I $5000 $15,000

Tier II $10,000 $20,000

Tier III $20,000 $40,000

Note: Phase I ESA and the Phase II ESA costs are not included.

4040

Policy Implications

• Using the expanded approach to due diligence in the planning process

• New schools

• School closings