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School Siting Environmental Health and Safety Considerations J. Brad Peebles Ph.D.,C.E.P. Brad.Peebles@tetratech.com 813-504-0081. OVERVIEW. Current environmental due diligence methods do not fully evaluate the potential health and safety threat to the school based population
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School SitingEnvironmental Health and Safety ConsiderationsJ. Brad Peebles Ph.D.,C.E.P.Brad.Peebles@tetratech.com813-504-0081
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
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
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
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, freewaysand 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
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?
OVERVIEW • Using the expanded approach to due diligence in the planning process • New schools • School closings
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) .
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).
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
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
“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
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
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
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
Receptors School Based Population • Students • Teachers • Staff What are the differences in how these people may be exposed to airborne contaminants?
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 years • Teachers and Staff = 20 to 40 years • IR = inhalation rate (m3/day) • BW = body weight (kg)
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)
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
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)
Calculate chemical uptake Determine the Risk • Carcinogenic Chemical Risk • Dose times CPF • Non-carcinogenic Chemical Hazards • Dose divided by RfD
Calculate chemical uptake Determine the Risk • Dry Cleaner • Receptor 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
Calculate chemical uptake Determine the Risk • All 19 Sources Summed - Adults • Carcinogenic Chemical Risk • = 2.9E-06 • Non-carcinogenic Chemical Hazards • = 4.0E-02
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
“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)
“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
“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
“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
“Safety” portion of the “Health and Safety of School Based Population” • Example ALOHA Model from NOAA Web site
“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
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
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.
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
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
The Planning Process Expanded Approach to Due Diligence
Policy Implications • Using the expanded approach to due diligence in the planning process • New schools • School closings