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Soil Protection and Contaminated Sites Rehabilitation Policy
Please note that the 1998
Soil Protection and
Contaminated Sites
Rehabilitation Policy is
being revised.
If required, you may contact
the Ministère’s Service des
lieux contaminés et des
matières dangereuses (Contaminated
sites and hazardous
materials department) at
418-521-3950.
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6. Rehabilitation
6.1 Strategy
6.1.1 Priority Situations
6.1.2 Stages in the Approach
6.1.2.1 Knowledge
6.1.2.2 Impact and Risk Assessment
6.1.2.3 Impact and Risk Management
6.1.2.4 Owner Commitments
Figure 2: Risk Management in the Case of Sites
Subject to the Risk Assessment Procedure
Table 1: Undertakings, Obligations and Compatibility
Certificates Related to Selected Risk Management Measures
Limitations
Governing Recourse To Certain Risk Management Measures
6. Rehabilitation
A site that is contaminated or presumed contaminated, even if it has no
impact or does not constitute a significant risk in its actual condition and at
the present moment, bears a handicap nevertheless. On the one hand, the presence
of contamination, even suspected, corrodes the urban fabric, constitutes a brake
to redevelopment, and reduces the municipal tax base. This problem can become
acute in some areas of cities with an industrial history. On the other hand,
poorly planned decisions or works on or around contaminated sites that do not
take into account the presence of contamination can alter the balance attained,
have negative repercussions, or increase the level of risk to human health,
wildlife, flora or the environment.
For these reasons, contaminated sites cannot be left to themselves. A
strategy must make it possible, in the short term, to end the impacts that they
cause and, in the longer term, to rehabilitate the sites so as to allow them to
be reintegrated into the sustainable development cycle.
6.1 Strategy
The "rehabilitation" aspect of the policy is centred around a
strategy for various priority situations that fundamentally allow a four-stage
approach: knowledge, impact and risk assessment, impact and risk management,
owner commitments.
6.1.1 Priority Situations
In theory, all contaminated sites may have an impact on the environment or
adjacent property or constitute a significant risk to human health, wildlife or
flora. Most often, however, it is only after completing the characterization of
a site that we are able to determine whether it is having an impact on the
environment and whether it constitutes a significant risk. As well, in the case
of plans to reuse a contaminated site, impact and risk depend on the
characteristics of the reutilization project under consideration.
Because of the magnitude of the task, it is impossible in the short term to
characterize all contaminated sites to determine the associated impacts and
risks. In order to optimize the use of available resources, protect users’
health and maximize environmental gain, the MEF gives priority to the following
sites:
- potentially contaminated sites for which there is a reutilization project;
- contaminated sites that have an obvious impact on human health, wildlife,
flora, the environment or property;
- sites most likely to have an impact or constitute a significant risk to
human health, wildlife, flora, the environment or property
6.1.2 Stages in the Approach
The four stages in the approach are: knowledge, impact and risk assessment,
impact and risk management and commitment by the owner. For each of the three
priority situations, trigger components make it possible to initiate the
approach. Each stage is described below.
6.1.2.1 Knowledge
This stage aims at establishing the characteristics of the contamination on
the site, the environment, the users and, where appropriate, the project being
considered. The data collected must make it possible to determine if it is
necessary to extend the assessment.
The presence of contamination on a site must also be registered with the
Registry Office so as to make this information available to future buyers and
users (see Section 7).
Finally, if the characterization reveals the presence of contamination at
the boundary of the site, the owner must also notify neighbouring owners (see
Section 11.1). In some cases, action involving adjacent sites may be necessary
if they have been damaged. This action may then be undertaken after agreement
with and with the consent of the owner(s) of the neighbouring sites in
question.
6.1.2.2 Impact and Risk Assessment
Impact and risk assessment is carried out, first, applying the generic
criteria for soils and groundwater found in Appendix 2 to the policy.
Then, the owner may generally assess the particular danger that a site
poses, so as to confirm or deny the existence of an impact or significant risk
(except for the cases described in the box entitled "Limitations
Governing Recourse To Certain Risk Management Measures"). To do
this, the risk assessment procedure described in Appendix
3, which takes into
account toxicological risk, ecotoxicological risk and impact on the
groundwater of the site, must be followed. To ensure the uniformity and
validity of the studies carried out, they must be submitted to the assessment
group set up by the MEF and its endorsement obtained (see Section
11.7).
Depending on the existing chemical species, not all
forms of metals or metalloids measured in a soil are necessarily available to
human or ecological receptors. In that particular context, an evaluation of
bioavailability may refine the assessment of impacts and risks. This
bioavailability analysis aims at establishing the portions of metals or
metalloids measured in the soil that can have negative impacts on human or
environmental receptors. This type of analysis implies the identification of
the chemical species in the soil and the completion of bio-assays directly in
the soil matrix and its leachate.
6.1.2.3 Impact and Risk Management
Sites that have an impact or that constitute a significant risk must be
subject to risk management measures. The objective of these measures is to
guarantee that the targeted sites will no longer have an impact on the
environment or property and do not or no longer constitute significant risks
to human health, wildlife and flora, in the short or long term.
To do this, the owner of the site, in addition to taking action, where
appropriate, on the sources of the contamination (defective equipment,
inadequate storage, etc.), may generally have recourse (except in the cases
described in the box entitled "Limitations Governing Recourse To Certain
Risk Management Measures") to any one of or a combination of the
four management measures identified by the MEF:
- decontamination to the use-based generic criteria;
- decontamination to specific criteria determined using the risk
assessment procedure as defined in Appendix 3;1
- the introduction of active or passive confinement, control and
monitoring (CCM) measures as defined in Appendix
4;1
- the introduction of restrictive measures.1
1These options are possible only for
sites that have been subject to the risk assessment procedure.
If the owner of the site opts for risk management measures other than
decontamination to the use-based generic criteria, the management measures
proposed must be harmonized with the character of the contaminants found on
the site, their behaviour in the environment, and the sensitivity of human,
animal or vegetable populations that may be exposed. The proposed measures
must be submitted to the assessment group set up by the MEF and its
endorsement obtained (see Section 11. 7).
The approach to be followed in selecting a mode of risk management for
sites that have already undergone a risk assessment procedure is illustrated
in Figure 2.
6.1.2.4 Owner Commitments
An owner who opts to manage the risk constituted by his site other than by
using the generic criteria shall, to obtain authorization to carry out the
required work, ratify a Restrictive Use Covenant with the MEF and register it
with the Registry Office (see Table 1).
When the work is completed, the owner of the site on which work has been
carried out shall forward to the MEF a work completion report signed by the
owner and certified by a recognized professional. This standardized document
will indicate the type of management measures carried out on the site,
(application of active or passive CCM measures, restrictive measures,
decontamination in excess of the specific or generic criteria) and will
confirm that the site no longer constitutes a significant risk for the planned
use, since the soils have been decontaminated to the generic criteria or the
commitments and work agreed to in the Restrictive Use Covenant have been
carried out.
Table 1: Undertakings, Obligations and Compatibility
Certificates Related to Selected Risk Management Measures
|
Cat. |
Condition of the site
|
Land Ownership Registration to be carried out by owner |
Obligation to obtain MEF authorization to carry out work |
Information to be provided to the MEF to have the Compatibility
Certificate issued on application |
Information to be provided to the MEF to have the Conditional
Compatibility Certificate1 issued on application |
|
1.1 |
The site is contaminated but has been subject to active CCM measures. |
Restrictive Use Covenant
|
Yes |
N/A |
Proof of registration of the Restrictive Use Covenant
Monitoring plan
Work Completion Report
(5 year term) |
|
1.2 |
The site is contaminated but has been subject to passive CCM measures. |
Restrictive Use Covenant |
Yes |
N/A |
Proof of registration of the Restrictive Use Covenant
Monitoring Plan
Work Completion Report 2 |
|
2.1 |
The site is contaminated but subject to restrictive measures. |
Restrictive Use Covenant |
No |
N/A |
Proof of registration of the Restrictive Use Covenant
|
|
3.1 |
The site has been decontaminated according to specific criteria. |
Restrictive Use Covenant (where appropriate) |
Yes (where appropriate) |
N/A |
Proof of registration of the Restrictive Use Covenant
(where appropriate)
Work Completion Report 2 |
|
3.2 |
The site has been decontaminated in excess of the use-based generic
criteria provided. |
None |
Only if the mode of soils treatment or disposal so requires |
Work Completion Report |
N/A |
| 1 |
Issued
only in case of reuse. |
| 2 |
On demand, the characterization study, impact and risk assessment study and
restoration report must also be provided. |
| 3 |
If
there is an associated usage restriction, if a contamination level remains
in excess of the customary generic criterion or if the soil treatment or
elimination mode so requires. |
| 4 |
On demand,
the characterization study and restoration report must also be provided. |
Limitations governing recourse to certain risk
management measures
For certain sites and in certain situations, recourse to risk
management measures that would have the effect of leaving contamination
in place in excess of the use-based generic criteria is
counter-indicated. Consequently, in these cases, application of the
use-based generic criteria is advocated. These cases are described below.
The reuse of contaminated sites for residential purposes, when the
users have access to individual plots of land
With respect to residential use, the two first metres of soil on the
sites where residences are to be constructed whose future users will
have access to individual plots of land (single family development,
duplex, etc.) must comply with the generic criteria for residential use
(B Criteria). In such developments, without this buffer layer, the
monitoring needed to ensure the safety of users would be impossible to
guarantee. As well, if the underlying soils are not decontaminated to
the generic criteria for usage but managed through risk management
measures other than decontamination to the generic criteria, this shall
to be done according to the procedure described in Section 6.1.2.3.
However, residential developments involving larger-scale buildings,
where vacant lots are common property and used for utilitarian purposes
(parking, etc.) or landscaping, may be subject to risk management
measures other than decontamination to generic criteria (see Appendix
4). for any depth of the soil layer
Contamination of soils by petroleum products
The generic criteria must be applied for cases of contamination
related to the presence of underground and above-ground storage
equipment subject to the Ministère des Ressources Naturelles (MRN)’s
Petroleum Products Regulation since:
- In 1991, the MRN initiated an underground tank replacement program
whose requirements are defined by the Petroleum Products Regulation
and which will end in 2001. This program is already more than 50%
completed and, for reasons of fairness, must continue as it began;
- This regulation stipulates that, in the case of replacement and
dismantling of underground storage systems, dismantling of surface
storage systems or, more generally, any leak or spill occurring at a
petroleum products establishment, the owner shall replace or
decontaminate the contaminated materials or decontaminate the site.
- Article 9 of the MEF’s Hazardous Materials Regulation in
effect on December 1, 1997 stipulates that "Any person who
accidentally releases a hazardous material into the environment shall
immediately ... recover the hazardous material and remove all
contaminated material that is not cleaned or treated on site."
Petroleum products are hazardous materials within the meaning of this
regulation.
As well, the vast underground tank replacement operation that began
with the adoption of the Petroleum Products Regulation in 1991
permitted the development of effective treatment technologies for these
products and the setting up of some twenty treatment centres distributed
throughout the territory of Québec. Easy access to these treatment
centres, the demonstrated efficiency of technologies applied in situ
and ex situ, and the competitive costs incurred by users of this
equipment are all factors that militate in favour of the decontamination
of sites and soils contaminated by petroleum products.
Many petroleum products storage sites are located on small lots and for
these, recourse to the use-based generic criteria is strongly encouraged,
whatever the nature of the contamination. Thus:
- Petroleum products are found in more than 32,000 underground tanks
and nearly 49,000 surface tanks distributed throughout the territory
of Québec (MRN, 1997). To date, the program to replace underground
tanks containing hydrocarbons implemented by the MRN has made it
possible to establish that more than a third of the underground tanks
replaced leaked. It would be very difficult to ensure monitoring of
this hidden contamination if it were to remain in place after the
installations are dismantled. Located on small lots in city centres,
often close to residences, a large number of these sites lack the
buffer zones that would make it possible to reduce the damage or
impact related to the presence of contamination. Systematic recourse
to CCM measures to manage all these cases would have the consequence
of raising the level of risk to the territory.
As well, the large number of cases to be dealt with constitutes a
short and medium term administrative problem, since clearly, neither the
private nor the public sector would be able to handle such a large
demand in terms of risk assessment.
More generally, recourse to the use-based generic criteria in cases of
soils contaminated by hydrocarbons is made necessary by the fact that:
- Petroleum products are made up of a blend of hundreds of substances
whose nature and quantity vary according to the source of the product,
the treatment it has undergone and the time it has spent in the soil.
Several of these substances are very volatile or soluble, and some are
proven carcinogens. A study to identify and quantify the risk of each
of these substances would be very onerous and difficult to carry out.
Although research has begun to define methodologies or indicative
parameters representing all contaminants likely to be found in
petroleum products, they are still not sufficiently conclusive.
- Independently of their toxicity, petroleum products can be detected
by odour or taste in very small amounts. They thus constitute, even in
small concentrations, a potential harm to users of former contaminated
sites and may have, even in very small concentrations, an impact on
reserves of groundwater used as drinking water. Decontamination of the
site using the use-based generic criteria has the advantage, in
addition to greatly reducing the source of contamination, of allowing
soils to be aerated to a certain extent, which has the effect of
minimizing residual odours. CCM measures that leave contamination in
place do not have this effect.
However, recourse to risk management measures other than the
application of the use-based generic criteria is acceptable in cases where
the excavation or in situ treatment of contaminated soils found
under the infrastructures is technically impracticable.
Small Areas
The extent of the contamination is a determining factor in selecting
the proper mode of management to reduce the risk constituted by the site
to an insignificant level and maintain it there. For small areas, the
difficulty of guaranteeing the maintenance of CCM measures through time,
together with the delays and cost of characterization and research
associated with carrying out the risk assessment procedure, means that
this approach is viable only in the case of larger areas. The
decontamination of small and average-sized sites is quicker and often less
expensive in the long term if the work is guided by the use-based generic
criteria. |
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