GFOA PS3260 Contaminated Sites Workshop Thursday, November 14, 2013 Whitehorse, YT.

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Role of the Environmental Professional GFOA PS3260 Contaminated Sites Workshop Thursday, November 14, 2013 Whitehorse, YT

Transcript of GFOA PS3260 Contaminated Sites Workshop Thursday, November 14, 2013 Whitehorse, YT.

Page 1: GFOA PS3260 Contaminated Sites Workshop Thursday, November 14, 2013 Whitehorse, YT.

Role of the Environmental Professional

GFOA PS3260 Contaminated Sites WorkshopThursday, November 14, 2013

Whitehorse, YT

Page 2: GFOA PS3260 Contaminated Sites Workshop Thursday, November 14, 2013 Whitehorse, YT.

Role of the Environmental Professional

Process – from screening to determining financial liability

Outline

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Page 3: GFOA PS3260 Contaminated Sites Workshop Thursday, November 14, 2013 Whitehorse, YT.

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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Page 4: GFOA PS3260 Contaminated Sites Workshop Thursday, November 14, 2013 Whitehorse, YT.

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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Page 5: GFOA PS3260 Contaminated Sites Workshop Thursday, November 14, 2013 Whitehorse, YT.

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.

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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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Page 8: GFOA PS3260 Contaminated Sites Workshop Thursday, November 14, 2013 Whitehorse, YT.

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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Page 9: GFOA PS3260 Contaminated Sites Workshop Thursday, November 14, 2013 Whitehorse, YT.

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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Page 10: GFOA PS3260 Contaminated Sites Workshop Thursday, November 14, 2013 Whitehorse, YT.

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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Page 11: GFOA PS3260 Contaminated Sites Workshop Thursday, November 14, 2013 Whitehorse, YT.

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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Page 12: GFOA PS3260 Contaminated Sites Workshop Thursday, November 14, 2013 Whitehorse, YT.

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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Page 13: GFOA PS3260 Contaminated Sites Workshop Thursday, November 14, 2013 Whitehorse, YT.

Soil and Groundwater Investigation

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Page 14: GFOA PS3260 Contaminated Sites Workshop Thursday, November 14, 2013 Whitehorse, YT.

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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Page 15: GFOA PS3260 Contaminated Sites Workshop Thursday, November 14, 2013 Whitehorse, YT.

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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Page 16: GFOA PS3260 Contaminated Sites Workshop Thursday, November 14, 2013 Whitehorse, YT.

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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Page 17: GFOA PS3260 Contaminated Sites Workshop Thursday, November 14, 2013 Whitehorse, YT.

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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Page 18: GFOA PS3260 Contaminated Sites Workshop Thursday, November 14, 2013 Whitehorse, YT.

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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Page 20: GFOA PS3260 Contaminated Sites Workshop Thursday, November 14, 2013 Whitehorse, YT.

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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Page 21: GFOA PS3260 Contaminated Sites Workshop Thursday, November 14, 2013 Whitehorse, YT.

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