role of the environmental professional
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Role of the Environmental Professional. GFOA PS3260 Contaminated Sites Workshop Thursday, November 14, 2013 Whitehorse, YT. Outline. Role of the Environmental Professional Process – from screening to determining financial liability. Page 2. Role – To Participate in All Or Part Of:. - PowerPoint PPT PresentationTRANSCRIPT
Role of the Environmental Professional
GFOA PS3260 Contaminated Sites WorkshopThursday, November 14, 2013
Whitehorse, YT
Role of the Environmental Professional
Process – from screening to determining financial liability
Outline
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Role – To Participate in All Or Part Of:
Screening of sites Initial Assessment
◦ Ranking? Confirming contamination Determining extent Evaluating remediation strategies Opinion of cost of remediation
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Screening of Sites Inventory all properties
◦ By government body◦ Screen to select sites that are no longer
productive Non-productive property list
◦ Is it, or might it, be contaminated?◦ Initial screening to select potential contaminated
sites Owner knowledge of site and adjacent sites
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Phase I Investigation An assessment of current and historic site
uses and conditions◦ Historic records:
Air photographs City directories Land use maps Fire insurance maps Topographic & geological maps MOE records (Site Registry) Local government archives Fire department records Newspapers
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Phase I Investigation◦ Interviews:
Persons knowledgeable about current and past property uses and activities
Current and former employees◦ Site reconnaissance:
Visual or olfactory evidence of possible contamination: Staining Distressed vegetation Aboveground storage tanks Underground storage tanks - fill or vent pipes “Patches” in pavement Oil water separators Waste material or other storage or disposal Soil disposal Etc.
Phase 1 Investigation– Internal or External Process or Split
Can you do part or all of the assessment? Can the Environmental Professional provide
a template that can be used to enable staff to undertake?
How much does it cost?
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If a large number, may rank for further action:◦ By potential risk:
Known contamination Type of contaminant What “media” is suspect to be contaminated Potential consequence Financial constraints
Phase I Investigation – What Do You Do With The Results?
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Phase I identifies only potential for contamination
Phase II includes collection and analysis of samples (soil, groundwater, and/or surface water)
Results compared to standards Contaminated if exceed standards
Phase II Site Assessment
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Soil:◦ Land use dependent◦ Current land use or future land use
Groundwater:◦ What is current and expected future use
Surface Water – aquatic and other uses
What Standards Should You Use?
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Create a risk profile?◦ Set priority for further assessment
Consider: Likelihood of adverse effect Consequence of adverse effect Receptors affected (human vs. ecological)
Duty to Act – imminent threat
Phase II Assessment Complete – Now What?
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To determine the extent of contamination in all affected media◦ Vertical and horizontal extent (three dimensions)
Conceptual Site Model (CSM)◦ Shows conceptually where contamination may be
Phase II Assessment continued
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Soil and Groundwater Investigation
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Remediation can be an expensive process and where there are multiple properties, there may be a need to rank them
◦ Is there an imminent threat to human health or the environment?
◦ Is there current or likely contamination migration to other properties or sensitive environments?
◦ Is there a “business” priority?
Rank Sites Following Phase II
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There are dozens of ways to remediate a site
As a rule of thumb, the faster the process, the more expensive it will be
Costs tend to be higher if the Phase II is not rigorous
Remediation Methods (Plan of Restoration)
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Client considerations:◦ Schedule◦ Cost – capital vs. operating and maintenance or long timeframe◦ Public considerations – transparency◦ Future land use
Technical considerations:◦ Contaminant type:
Metals Organic Easy to treat/difficult to treat Mobility
◦ Media contaminated◦ Geology and hydrogeology◦ Access constraints
Remediation Planning
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Remediation Options
SOIL
Remove and dispose Excavate and treat onsite Excavate and treat offsite Treat in-situ Manage in-situ
GROUNDWATER
Pump and treat Pump, treat and reinject Natural attenuation Modify groundwater
movement characteristics In-situ biological
treatment In-situ chemical
treatment (oxidize, reduce, immobilize)
SEDIMENT
Dredge and dispose Dredge and cap Cap
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In-Situ Remediation Options
Physical
Soil vapour extraction Sparging
Biological
Biological ◦ Amendment with
nutrients◦ Amendment with new
carbon source (food)◦ Modify groundwater
flow conditions (direction, mounding)
Chemical
Oxidizing chemicals Reducing chemicals Oxygen enhancing Chemicals to immobilize
metals
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Does the contamination present an unacceptable risk to human health and/or the environment
Can that risk be reduced by engineered controls or administrative controls
Contamination remains Conditions on use based on
controls/assumptions about use in risk assessment
Remediation by Risk Management
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Preliminary Site Investigations◦ Stage 1 about $2,500 or lower when multiple sites◦ Stage 2 Minimum $10,000 for simple site.
Complex sites can reach many tens of thousands Detail Site Investigation
◦ Suggest budget minimum $25,000 per site if simple
◦ Can be several hundreds of thousands of dollars for complex multiple contaminant sources and multiple media
Costs - Investigations
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Simple site budget $10,000 Complex sites with multiple contaminants
and media – planning a preliminary engineering can be several hundred thousand dollars
Required to determine opinion of cost of remediation
Remediation Planning
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Underground Storage Tank - $10,000 - $50,000
Works Yard◦ Vehicle maintenance - $25,000 - >$100,000◦ Fueling station $50,000 - >$250,000
Depends on complexity, extent and media affected
Remediation Costs
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Thank YouFor further information contact