How DiGiSci Environmental Helps Prepare EA Reports

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In Ontario, certain proposed facilities, largely government-backed or infrastructure facilities, require an Environmental Impact Assessment (or “EA”) of some type. This includes transportation (road, rail, etc.) and municipal infrastructure (sewage plants, garbage dumps, etc.). In rarer instances, private sector projects (e.g., controversial gravel pits) may be specially designated, by the Provincial government, for an individual EA. EAs also apply to federally-related projects, but technical requirements are similar to Provincial requirements, so for this article, we will concentrate on EAs in Ontario. DiGiSci Environmental is one of a number of Environmental Consulting Companies that can assist in providing the studies required to meet your EA obligations. Most of our comments will be with respect to air quality impact assessment component of an EA as that is our area of speciality.

Environmental Impact Assessment

An EA is meant to ensure that environmental impacts are not problematic but, at a higher level, also ensure that project planning has carefully considered (possibly less impactful) alternatives to a proposed project.

Provincial EAs can be “individual” full EA or “streamlined” EAs. Individual environmental assessments are prepared for large-scale, complex projects with the potential for significant environmental effects. They require Ministry of the Environment, Conservation, and Parks approval.

Streamlined environmental assessments can be used for routine projects that have predictable and manageable environmental effects. Proponents of these types of projects follow a self-assessment and decision-making process. Approval is not directly granted for each project. Streamlined self-assessment processes include:

  • Class Environmental Assessments
  • Electricity Projects Regulation
  • Waste Management Projects Regulation
  • Transit Projects

Unsurprisingly, the EA has to account for various factors including affects on air emissions, noise, water quality, traffic impacts, socio-economic impacts, and so forth.

Air Quality Assessments for EAs

Regardless of the type of EA, you are involved in there are various steps that your air quality experts must go through. In this article, we will provide a brief overview, but will take a deeper dive in later blogs. Most of this article will paraphrase a more detailed explanation provided in the International Association of Impact Assessment’s Guide on Air Quality Impact Assessment. DiGiSci Environmental is a leading environmental assessment company that specialises in air quality and can also provide expertise in other disciplines in EA.

The first step that your air quality experts must become involved in is in the setting of the Terms of Reference (ToR); this is essential a “list of things” you promise to do during the impact assessment. At this stage, you are defining the scope of the air quality assessment. It is important that the scope of the air quality impact assessment is sufficiently wide that you will ensure inclusion of all “on-site” sources or emissions of air pollutants, but also all off-site related activities that are within a reasonable distance of the subject site (and can thus accumulate greater impacts jointly). Since you need agreement from environmental assessment agencies, it is important to be thorough at this stage.

The next step is to develop an emissions inventory (EI) from all sources. The EI must be worst-case; different operating scenarios (if there are alternatives) must be tested to check which causes the greatest incremental air quality impact on the local surrounds. This check may need to be repeated for each of the separate contaminants emitted. We do this because the aim is to estimate the greatest impact on surrounding air quality that the facility can cause. Of course, a number of emissions scenario may need to be forwarded to the dispersion modelling stage in order to test which scenario is worst.

In developing the EI, fugitive dusts, especially their speciation, are often overlooked or not fully dealt with. For example, many “natural” dusts contain crystalline silica, the most common form being quartz. Exposure to sufficient levels for long enough periods of time can cause serious health effects. So, full speciation should be part of the plan for fugitive dust assessments.

The EI should also account for any variations in emissions rate or locations over time so that, again, the worst-case can be captured in the assessment.

Very often inputs, especially into emissions estimation calculations, must be estimated as there is no site-specific data (usually because the air quality assessment is forecast, and the facility is yet to be built and operate). In these cases, you must ensure that any estimates or substitute data errs on the cautious side, in other words, chosen “conservatively.” This can be a more difficult concept to get right; most practitioners that hold public safety as their highest priority will want to get this aspect right, and so this will be the subject of a “deep dive” blog at a later date. DiGiSci environmental consulting agency Senior Project Manager authored the IAIA Guide on Air Quality assessments, which is one of the first Guides to really provide extensive explanation of the Principle of Conservatism.

Once the EI has been completed, this information is fed into the dispersion model, along with appropriate terrain and meteorological data. The meteorological data should be of sufficient length to capture worst-case meteorological event (e.g., stable conditions at sunrise/sunset). This is used to estimate the worst-case incremental increase in air quality deterioration caused by the facility. The increment in air quality readings must also be added to pre-existing levels of air quality for the various contaminants emitted. In doing so spatial and temporal variations in baseline data must also be accounted (hot spot analysis).