      Guidance on Application of

Provincial Air Quality Objectives for SO2




     B.C. Ministry of Environment

           February 7, 2017
          Guidance on Application of Provincial Air Quality Objectives for SO2



1. Purpose
To provide guidance on the application of the interim provincial ambient SO2 air quality
objectives for stakeholders, and staff and statutory decision-makers of the Ministry of
Environment. Other statutory decision-makers, such as the BC Oil and Gas Commission,
are encouraged to consider this guidance when making statutory decisions under the
Environmental Management Act.

2. Background

Ambient air quality objectives (AQOs) are non-statutory limits used to assess air quality
and guide air management decisions, including those related to environmental
assessments and authorizations. They are not legal requirements unless referenced
directly in a regulation or authorization. Ambient air quality objectives applied in B.C.
include provincial and national objectives and standards developed for a number of
contaminants over various averaging periods.

A provincial interim ambient air quality objective (IAAQO) of 75 ppb (1 hour) was
adopted in 2014 to provide a health-based tool to help inform decisions regarding new
or significantly modified emissions of SO2 in B.C. In October 2016, the Canadian Council
of Ministers of the Environment endorsed new Canadian Ambient Air Quality Standards
(CAAQS) for 2020 and 2025 as summarized in Table 1.

                       Table 1. CAAQS for SO2 for 2020 and 2025.

  Averaging            2020               2025                       Metric
   Period
   1-hour             70 ppb             65 ppb        Annual 99th percentile of daily 1-
                                                        hour maximum, averaged over
                                                           three consecutive years
   Annual              5 ppb             4 ppb           Annual mean concentration


To facilitate the transition to the new CAAQS for 2020, the province replaced the 2014
IAAQO with new IAAQOs in December 2016 to provide a pathway to meeting the CAAQS
in 2020. The new IAAQO for SO2 are summarized in Table 2.




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Table 2. Summary of new provincial IAAQOs to support CAAQS implementation.

     Averaging             2017                 2018                 2019            2020 onwards
      Period                                                                            CAAQS
      1-hour             75 ppb               75 ppb               75 ppb               70 ppb
      Metric1        Annual 97th          Annual 97.5th        Annual 98th          Annual 99th
                     percentile,          percentile,          percentile,          percentile,
                     averaged over        averaged over        averaged over        averaged over
                     2015-2017            2016-2018            2017-2019            preceding
                                                                                    three years

Methodologies for comparing ambient data to the IAAQOs are provided in Appendix I.


3. Guiding Principles

The following principles were used to guide development of this implementation guide:
 Continuous improvement and keeping clean areas clean, to ensure ambient
   objectives are not “pollute up to” levels;
 Flexibility, recognizing that regulators require some latitude to manage the
   cumulative impacts of multiple emission sources, for the protection of human health
   and the environment;
 Science-based decision-making, using the most appropriate level of science to
   support decisions; and
 Airshed protection, striving to identify, understand and reduce cumulative
   environmental risk and impacts.

4. Application of Ambient Air Quality Criteria

4.1 Definition of Interim Ambient Air Quality Objectives
The “interim” status reflects the fact that the IAAQOs for SO2 will be in place to the end
of 2019, at which point the IAAQOs will be superseded by the CAAQS level and metric.

4.2 Scope of Application and Timing
Provincial air quality objectives apply to areas where there is public access, i.e. areas
beyond plant boundaries. As described in “Guidelines for Air Quality Dispersion
Modelling in British Columbia2, “plant boundaries” are defined as:
   the facility fenceline or the perimeter of disturbed area that defines where public
      access is restricted;

1
  One excursion above 75 ppb but no greater than 85 ppb is allowed over the three reporting years 2017
(based on 2015-2017 data), 2018 (based on 2016-2018 data) and 2019 (based on 2017-2019 data).
2
  Ibid



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       if a facility is located within another larger facility boundary, the plant boundary is
        the boundary of the encompassing facility; or
       if a public access road passes through the plant, the plant boundary is the
        perimeter along the road allowance.

The reporting of CAAQS achievement is focused on those monitoring sites that are
located beyond the industrial fenceline and in proximity to populated areas or other
sensitive receptors such as sensitive ecosystems.

IAAQOs for SO2 should be used to inform air management decisions prior to 2020, and
the CAAQS for SO2 from January 1, 2020 onwards. However, for new decisions on
authorizations made prior to January 1, 2020 and involving facilities that will be
operational beyond this date, the CAAQS should be applied.

4.3 Application to Authorized Emissions
The Environmental Management Act (EMA) sets out the responsibilities of the Minister
of Environment. It provides the ministry with overall responsibility for waste
management in the province and the underlying legislation to air-quality-related
regulations in B.C. It provides Metro Vancouver with delegated authority to manage air
discharges within the Greater Vancouver area. The Oil and Gas Commission (OGC),
under the Oil and Gas Activities Act (OGAA), makes permitting decisions for oil and gas
activities under EMA.3 OGC also administers the BC Oil and Gas Waste Regulation. The
authorization process used by OGC is similar to that used by the Ministry.

Under sections 6(2) and 6(3) of the EMA, waste must not be introduced into the
environment in the course of conducting a prescribed industry, trade or business unless
in accordance with:
     the Act,
     a site-specific authorization (e.g. permit, approval or order),
     a regulation (including code of practice), and
     a waste management plan approved by the Minister.

Schedules 1 and 2 of the Waste Discharge Regulation prescribe those industries, trades,
businesses operations and activities that must obtain ministry authorization to
discharge waste into the environment.

Prescribed industries, trades, businesses, operations and activities listed in Schedule 1
include those that will generally continue to be authorized through the use of site-
specific authorizations or regulations due to the complexity of their discharges, the
potential for significant environmental impacts, or the limited number of similar


3
 Exceptions include oil and gas activities falling under the jurisdiction of the National Energy Board, which
the Ministry of Environment has responsibility for administering.


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operations in the province. Schedule 1 also includes some industries, trades, businesses,
operations and activities that are not authorized by existing regulations.

Prescribed industries, trades, businesses, operations and activities listed in Schedule 2
are those that may be authorized by a minister’s code of practice or a regulation. Codes
of practice are legally enforceable standards. An authorization to discharge may be
obtained by registering under the code and complying with the requirements of the
code.

Those industries, trades, businesses, operations and activities not listed in either
Schedules 1 or 2 do not require a formal authorization to discharge waste. However, the
discharges must not cause pollution or present a risk to public health.

4.3.1 Application to Permits and Approvals
The issuance of a permit or approval under the EMA is based upon a multi-step process
described more fully in the ministry’s guidance document “Waste Discharge Regulation
Implementation Guide.” 4 Guidance specific to oil and gas activities can be found in
“Guidance For Applications to Discharge Air Contaminants From Oil and Gas Facilities in
British Columbia.”5

As part of the process to apply for a permit or approval, technical information must be
provided to the applicable regulatory body (e.g. ministry, OGC) that describes the source
and its potential impacts on the environment. For high risk or complex authorizations,
the applicant is required to prepare a detailed technical assessment report. The director
clarifies this requirement during a pre-application meeting. For lower risk or less
complex discharges, an environmental impact technical assessment report may not be
required. Instead, supporting technical information is provided directly in the
application form package.

Where a technical assessment is required, regulatory staff work with applicants in the
early stages to clarify regulatory expectations with respect to:
 ambient air quality objectives, including interim,
 ambient monitoring requirements,
 emission control technology requirements, and
 recommended approach to dispersion modelling , as appropriate and described in
    “Guidelines for Air Quality Dispersion Modelling in British Columbia” and related
    technical guidance by the Ministry. 6
This involves close collaboration between regulatory staff involved in source
management and ambient monitoring and protection to ensure a consistent and
coordinated approach.

4
  See: http://www.env.gov.bc.ca/epd/main/ema.htm#2
5
  See: https://www.bcogc.ca/node/5944/download
6
  See: http://www.bcairquality.ca/assessment/dispersion-modelling.html


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Once complete, regulatory staff conduct a review of the submitted impact assessment
and technical report. The director may then issue a permit subject to conditions
considered advisable for the protection of the environment. In determining what is
advisable, the director considers information provided by regulatory staff, the applicant,
concerned persons and other agencies.

The director may consider current or future economic growth and the associated
cumulative impacts of multiple emission sources in an airshed when determining an
applicant’s maximum allowable impact on that airshed. This extends to undeveloped
areas, to ensure that no single source “uses up” the entire capacity of an airshed, as
reflected in predicted concentrations approaching or exceeding the ambient air quality
objectives. The director may also require the application of additional ambient air
quality criteria beyond established provincial or national ambient air quality objectives
or standards, to assess site-specific concerns regarding potential health and
environmental impacts. This may include more stringent criteria than the current
IAAQOs.

Where exceedances of ambient air quality objectives are predicted, additional
consideration is typically given to the conditions related to the exceedances (e.g.
location of maxima relative to populated areas, timing, duration and magnitude of
exceedances), and the relative contribution and spatial variation of background levels.
The proponent may be asked to demonstrate that its project would not significantly
impact or increase the risk to human health or the environment. Following these
assessments, the director may require the proponent to develop strategies or options to
further mitigate emissions at the facility or within the affected airshed. For more
information on airshed management in B.C., see Section 4.4.

4.3.2 Application to Regulated Facilities
Regulations, including codes of practice, set enforceable standards that apply to
prescribed industries, trades, businesses, activities or operations. Section 138(2)(l) of
EMA gives the minister or director the authority to substitute a different requirement
than that contained in the regulations, including codes of practice, where deemed
necessary to protect the public or the environment, or where the intent of a code of
practice will be met by a substitution.

4.4 Application to Airshed Management
Airshed management is a process to coordinate activities affecting air quality in a
defined area or airshed. This approach recognizes that local air quality is influenced by a
number of activities and emission sources, stakeholders and overlapping jurisdictions.
Active airshed management plans are in place in a number of areas of the province,
including: Metro Vancouver, Fraser Valley Regional District, Sea-to-Sky Airshed, Merritt,
the Boundary Airshed, Central Okanagan Regional District, Williams Lake, Quesnel,
Prince George and Bulkley Valley-Lakes District.


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Under an airshed approach, the ministry manages authorized and regulated sources
under its jurisdiction, as described in Section 4.3, and coordinates monitoring across the
airshed. Where air quality levels approach or exceed ambient air quality objectives or
standards, the ministry considers a range of actions to improve air quality for the
affected communities, including: programs to reduce emissions from non-point sources;
more frequent permit reviews and compliance inspections; best achievable technology;
more stringent requirements for regulated sources; and detailed scientific studies to
better characterize and quantify the impacts of sources and other influences on air
quality. More information on these approaches can be found in “Provincial Framework
for Airshed Planning.”7

Expectations for affected industries under an airshed management approach may
include:
 Contributing to a robust monitoring network to ensure protection for the
    environment and human health;
 Considering the potential for future requirements in facility design; and
 Taking mitigative actions to reduce emissions if air quality approaches ambient air
    quality objectives, as indicated by air quality monitoring.


4.4.1 Air Zone Management
Jurisdictions across Canada are currently implementing the CCME-endorsed Air Quality
Management System (AQMS). Key components of this system include new CAAQS for
PM2.5, ozone and SO2; Base-Level Industrial Emission Requirements (BLIERS) for major
industry; a process to address emissions from mobile sources; and place-based
management in the form of air zones to encourage progressively more rigorous actions
in areas where air quality approaches or exceeds the CAAQS.8

B.C. is currently implementing the requirements for air zone management, and has
identified seven broad air zones to facilitate public reporting on CAAQS achievement.9
Existing airshed plans will be a fundamental part of broader air zone management. As
industrial facilities are the major sources of SO2 in B.C., the province has committed to
working with affected facilities and local government where the CAAQS level is
approached or exceeded.

4.5 Air Quality Advisories
Air quality advisories are issued by regional offices of the Ministry of Environment and
Metro Vancouver to inform the public of degraded air quality, and to trigger actions to

7
  http://www.bcairquality.ca/reports/pdfs/airshedplan_provframework.pdf . Note Canada-wide
Standards (CWS) referenced in framework have been replaced by CAAQS for PM 2.5 and ozone.
8
  For more information, see: http://www.ccme.ca/files/Resources/air/aqms/pn_1481_gdazm_e.pdf
9
  See: http://www.bcairquality.ca/plans/pdf/air_quality_man_system_fs.pdf


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reduce or avoid emissions. This may occur when measured air quality levels approach
or exceed “acceptable” levels, as defined by ambient air quality objectives or other
established criteria.

Historically, air quality advisories in the province have been triggered by elevated levels
of PM2.5, fugitive dust (PM10) or ground-level ozone. The spatial scale of these
advisories has ranged from community-specific to regional, depending on the
contaminant, the sources involved and the atmospheric dispersion conditions. To date,
no advisories have been issued for SO2. The ministry is working on a pilot project to
establish an SO2 public notification system in the Kitimat airshed that may form the
basis for future provincial application.

5. Monitoring and Reporting
All monitoring sites are required to meet minimum siting standards to ensure that a
representative measure of air quality is made.10 All sites are audited by the ministry
every 6 months to verify that monitors are operating properly to ensure the collection
of valid and complete data. Approved monitoring methods are as described in Appendix
II. It is expected that future ambient air quality reports will track achievement of the
IAAQOs (see Appendix I for recommended methodologies).

6. Summary
The province has adopted new interim 1-hour ambient air quality objectives for SO2 as
it transitions to the recently established CAAQS in 2020.. Guidance has been developed
to assist stakeholders, ministry staff and other statutory decision-makers in the
application of these criteria to various air management decisions, including those
related to authorizations and monitoring and reporting.




10
  “Quality Assurance Handbook for Air Pollution Measurement Systems, Volume IV: Meteorological
Measurements Version 1.0 (Draft).” EPA-454/D-06-001, U.S. Environmental Protection Agency, Office of
Air Quality Planning and Standards, October 2006.


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                                   Appendix I. Data Reporting


The following calculation methodologies should be used when comparing ambient data to
provincial IAAQOs for NO2 and SO2.

1. Daily Data Completeness
For the purpose of determining a daily 1-hour maximum concentration, a valid daily value is
calculated:
     where at least 18 hourly measurements are available in a day, or
     where <18 hourly measurements are available in a day but at least one hourly
        measurement exceeds the numeric limit of the IAAQO (i.e. 75 ppb for SO2).

2. Annual Data Completeness

2.1 Hourly Average IAAQO for SO2
The data set should be considered complete if there are available at least 60% of all daily
maximum 1-hour measurements in each quarter (i.e. Jan-Mar, Apr-Jun, Jul-Sep and Oct-Dec)
and 75% of all daily-maximum 1-hour measurements in each year. Years that do not meet data
availability criteria but which exceed the IAAQO should be flagged and retained for reporting.

3. Calculating the Daily 1-hour Maximum Concentration
The daily 1-hour maximum concentration refers to the maximum 1-hour value reported over a
24-hour period (midnight to midnight, local standard time). The value is to be reported to the
nearest 0.1 ppb.

4. Calculating the Percentile Values
Use of percentiles is a means of adjusting for differences in sample size and ensuring
that the values used for achievement determination are not unduly affected by extreme
events. For example, the 98th percentile is the daily 1-hour maximum value out of a year of
monitoring data for which 98 percent of all values at a given monitoring station are less than or
equal to this level. Percentiles are to be reported to the nearest integer.

The annual percentile value corresponds to the Kth highest value, which is obtained as follows:
 Sort all the daily 1-hour maximum concentration values for the given year into an array of
   numbers ordered from the highest to the lowest.
 Repeat equal values as many times as they occur.
 Determine number of valid days “N” of data for each year.
 Calculate the Kth highest value, where
      Kth highest value = N-truncated (N x p)
      p = p=.97, .975, .98 or .99 for the 97th, 97.5th, 98th or 99th percentile, respectively
 Data are reported to the nearest 1 ppb.




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Table I-1 describes the rank of the 97th, 97.5th, 98th and 99th percentile values for a given
number of days.

Table I-1. Rank equivalent to 97th, 97.5th, 98th and 99th percentile values over range of valid days
of reporting (data sorted in descending order).

                 Rank                           Rank                         Rank             Rank
  No. of                                                      No. of
             Equivalent to      No. of      Equivalent to                Equivalent to    equivalent to
  Valid                                                       Valid
              Annual 97th     Valid Days    Annual 97.5th                 Annual 98th      Annual 99th
  Days                                                        Days
               Percentile                    Percentile                    Percentile       Percentile
 1-33              1            1-39             1            10-50            1                1
 34-66             2            40-79            2            51-100           2                1
 67-99             3           80-119            3           101-150           3                2
100-133            4           120-159           4           151-200           4                2
134-166            5           160-199           5           201-250           5                3
167-199            6           200-239           6           251-300           6                3
200-233            7           240-279           7           301-350           7                4
234-266            8           280-319           8           351-366           8                4
267-299            9           320-359           9
300-333           10           360-366           10
334-366           11




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                    Appendix II. Approved Monitoring Methods for SO2.


The Ministry of Environment does not make specific recommendations regarding monitoring
methods. In general, methods approved by the U.S. Environmental Protection Agency (EPA) are
considered to be acceptable in B.C. Current EPA-approved monitors may be found at:
http://www.epa.gov/ttn/amtic/files/ambient/criteria/reference-equivalent-methods-list.pdf.
Ministry staff can provide advice to stakeholders regarding appropriate methods for specific
applications.




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