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Selection of Remediation Technologies and Risk Management on Typical Service Stations |
| Tool: | Assists stakeholders understand various remediation and risk management options for typical service stations. Not meant as a substitute for expert opinion. For property specific decisions, engage a Qualified Person. List of abbreviations provided at end of the Tool. See Glossary for definitions of terms. Click here for a printable PDF version of the tool. |
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Remediation Type |
Examples |
Relative Chance of Success1 |
Approx. Time
(months)1 |
Approx. Cost |
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Other Considerations |
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A. REMEDIATION TO GENERIC
STANDARDS |
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A1. SOIL |
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Excavation
and Off-site Disposal |
· Dig and haul to landfill for
garbage cover ("dig and dump") · Dig and treat for surface land
spreading |
High |
2-4 |
100 - 300 |
Licensed
hauler, licensed disposal facility (May require
PTTW and/or CofA (Sewage) if dewatering required) |
o
Problem
removed from site o
Relatively
simple to design and implement o
Shipping
costs may be high depending on location of off-site disposal. Landfill tipping fees vary - market driven o
May
not be feasible for deep or difficult to access contamination o
Fugitive
emissions may be a problem |
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Ex-Situ
On-site Treatment |
· Bioremediation · Allu Bucket · Composting · Thermal desorption |
Medium to |
4-36 |
100 - 200 |
CofA
(Waste), CofA (Air) (May
require PTTW and/or CofA (Sewage) if dewatering required) |
o
Requires
space to operate treatment facility o
Generally
most effective for organic compounds o
May
not be feasible for deep or difficult to access contamination o
Effectiveness
may be limited by concentrations o
Time
varies depending on technology; biopile may take up to 2-3 years. Allu bucket may take only 4 months o
Fugitive
emissions may be a problem |
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In-Situ
On-site Treatment |
· Vapour Extraction · Multiphase extraction · In-Situ enhanced bioremediation · Bioventing · Chemical oxidation |
Medium |
24-48 |
200 - 400 |
CofA (Air
/ Groundwater) |
o
Generally
creates minimal site disturbance o
Degree
of success variable o
Geological
complexity and/or shallow water table may limit applicability o
Fugitive
emissions and vapour migration may be problems o
Vapour
collection system may be required o
Significant
site characterization and significant operational and post-confirmatory
monitoring required o
Cold
temperatures may slow process |
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Remediation Type |
Examples |
Relative Chance of Success1 |
Approx. Time
(months)1 |
Approx. Cost |
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Other Considerations |
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A2. GROUNDWATER |
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In-Situ
On-site Treatment |
· Oxygen injection · Oxygen releasing compounds · Air sparging · Vapour extraction |
Medium |
24-48 |
100 - 300 |
CofA (Air
/ Groundwater) |
o
Generally
creates minimal site disturbance o
Degree
of success variable o
Geological
complexity and/or shallow water table may limit applicability o
Fugitive
emissions and vapour migration may be problems o
Vapour
collection system may be required o
Cold
temperatures may slow process Significant
site characterization and operational and post-remediation (2 4 years)
confirmatory monitoring required |
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Monitored
Natural Attenuation (MNA) |
· Monitoring low level contamination
or small source that is not expected to have an off-site impact |
Medium to |
36+ |
50 - 100 |
|
o
Long
term groundwater monitoring and management (likely 10+ years) o
May
not be well received by the public because it is perceived as doing nothing o
Minimal
site disturbance o
Less
effective where PHC concentrations in soil are high (i.e. continuing source).
May require source removal with MNA o
Not
suitable if receptors are being impacted o
Significant
site characterization required to establish plume stability and document
evidence to support MNA o
Attenuation
may not proceed as predicted contingency planning required |
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Pump and
Ex-Situ On-site Treatment |
· Pumping with biological treatment · Pumping with carbon adsorption · Pumping with air stripping |
Low |
100+ |
300+ |
PTTW, CofA
(Sewage), licensed haulage & disposal of solids |
o
Requires
significant site characterization, long term operation, maintenance and
monitoring o
Residual
saturation of the contaminants in the soil pores and sorbed to in the soil
matrix is not easily removed by ground water pumping o
Generally
considered a containment technology rather than a treatment method |
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Remediation Type |
Examples |
Relative Chance of Success1 |
Approx. Time
(months)1 |
Approx. Cost |
|
Other Considerations |
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B. REMEDIATION TO PROPERTY
SPECIFIC STANDARDS |
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Remediation
to Property Specific Standards (PSS) derived from Risk Assessment (RA) |
Same
technologies as in Section A for both soil and groundwater |
Chance of success may be greater
using more appropriate PSS through a RA |
Time required may be less, due to use
of more appropriate PSS |
Costs may be less, due to more
appropriate PSS |
As per |
o
As
per Section A o
PSS,
based on a RA, are mandatory for sensitive sites |
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Similar to
the step for Remediation to Property Specific Standards (PSS), a Risk
Assessment (RA) is required to develop a Risk Management Plan (RMP) and
implement Risk Management Measures (RMM). |
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Remediation Type |
Examples |
Relative Chance of Success2 |
Approx. Time
(months)2 |
Approx. Cost |
|
Other Considerations |
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C. RISK MANAGEMENT |
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Containment
of Soil, Groundwater, or Vapour |
· Impermeable barriers or liners · Caps · Permeable reactive barriers · Protective membrane to inhibit
vapour intrusion · Passive/active sub slab vapour
movement |
High |
6 |
100 |
May
require CofA (Air) and or PTTW. RSC
requires supporting RA and RMM. CPU may be registered on title |
o
Practical
for large volumes or sites where other treatment is impractical o
Applicable
to the complete range of contaminant groups o
Cost
relatively low for large volumes of soil o
Does
not lessen toxicity, mobility or volume of impacted material o
Most
effective where the majority of the underlying impacted material is above the
water table o
Cannot
prevent the horizontal flow of groundwater, only the vertical entry of water
into the impacted material o
May
require long-term maintenance and monitoring or containment mechanisms such
as capping |
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Pump and
Ex-Situ On-site Treatment of Groundwater |
· Pumping with biological treatment · Pumping with carbon adsorption · Pumping with air stripping |
High |
6 |
100 |
PTTW, CofA
(Sewage), Licensed haulage & disposal of solids. |
o
Requires
significant site characterization, long term operation, maintenance and
monitoring o
May
require financial assurance as part of the CPU |
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LEGEND: (1) Sections
A and B pertain to meeting soil and groundwater condition standards. Time and costs exclude up-front demolition
and assessment work, but include all remediation-related activities and
verification. Time and costs are based
on a typical
service station having 2000 tonnes of soil requiring remediation. (2) Section C pertains to installation activities only. Operational timeframe is very long and life
cycle costs cannot be generalized (3) PTTW and CofA (Sewage) may be required if dewatering is
involved. CofA (Air) required for
permeable reactive barrier (4) Abbreviations:
References: -
Redevelopment Framework for Former
Service Stations ( |
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