Collecting accurate air emissions data is crucial for regulatory compliance (such as air emission permits) and for identifying opportunities to reduce carbon emissions in industrial operations. Whether for air emission permits or carbon reduction strategies, the process involves understanding and quantifying emissions from different sources in your facility and in the case of carbon reduction, taking steps to reduce those emissions over time.

Key Steps for Collecting Air Emissions Data

Here’s a structured approach for collecting air emissions data for both regulatory compliance and carbon reduction efforts:

1. Understand the Regulatory Requirements for Air Emissions Permitting

Different regulations and agencies may require specific emissions data collection for air quality permits, typically through the Clean Air Act in the U.S. or equivalent country specific regulations. If your facility has, or is planning to have air emission sources, equipment, or processes that directly or indirectly emit regulated air pollutants, you first need to evaluate the need for air emission permits to either install and/or operate those air emission sources. As part of this evaluation, you may need to calculate the quantity of both actual and potential emissions for a variety of pollutants, including:

• Nitrogen oxides (NOx)
• Sulfur oxides (SOx)
• Particulate matter (PM)
• VOCs (volatile organic compounds)
• HAPs (hazardous air pollutants)
• Greenhouse gases (GHGs) such as carbon dioxide (CO₂) or hydrofluorocarbons (HFCs).

Potential emissions are based on the maximum physical and operational design capacity of the emission source to emit regulated pollutants. Applicability to the air emission permit regulations must be evaluated for new construction, modifications, or routine operations.

The type of emission source, and possibly the quantity of both actual and/or potential emissions emitted from the source, along with the site operator’s need for operational flexibility, will dictate the type of air emission permit required. Types of air emission permits arranged from most to least rigorous, include Title V Operating Permits (large facilities having the potential to emit significant quantities of pollutants); New Source Review (NSR) Permits (For facilities with new or modified emissions sources); and State-Level Permits (for facilities having lower actual emissions or the ability to take limits on potential emissions). Some geographical state regions have additional or more specific permitting requirements.

Air emission sources, whether air permits are required or not, may need to report emission inventories annually to regulatory bodies. These inventories help track emissions sources, monitor compliance, and identify potential emission reduction opportunities.

2. Identify Emission Sources in Your Facility

The next step in collecting air emissions data for both regulatory compliance and carbon reduction efforts begins by identifying all potential emission sources in your facility. Common sources of emissions include but are not limited to:

• Combustion Processes (boilers, furnaces, ovens, dryers, reciprocating internal combustion engines)
• Chemical Processes (chemical processes that either manufacture, process, or use chemicals that emit VOCs, PM, CO2, or other regulated pollutants)
• Manufacturing Processes (including metal, wood, and plastic fabrication operations including painting and coating operations that emit VOCs, PM, other regulated pollutants or NF3)
• Metallurgical Processes (including mining, metal production and processing operations that emit PM, HAPs, and air toxics)
• Waste Handling (Waste treatment, incineration, landfilling, and wastewater treatment processes that can emit regulated pollutants and/or methane, another potent GHG).

A secondary activity related to air emission source identification would be those emission sources, that while not necessarily owned and operated by your business entity, would have significant impact on your sustainability and carbon reduction efforts. These emission sources include but are not limited to:

• Energy Use (purchase of electricity, steam, heat, and cooling which have indirect GHG emissions)
• Raw Material Use (purchase of raw materials and production support materials which have indirect GHG emissions)
• Transportation (fuel use and associated GHG emissions for transport vehicles including trucks, trains, and ships both on-site and off-site).

3. Select the Right Data Collection Methodology

To collect reliable air emissions data, you will need to select an appropriate methodology. Common methods include Direct Emission Measurement using emissions testing or monitoring equipment to directly measure the emission rate or concentration of pollutants. Continuous Emissions Monitoring Systems (CEMS) are sometimes required conditions of an air emission permit for large combustion sources like boilers or thermal oxidizers. They provide real-time emissions data for pollutants such as NOx, SOx, and PM. Permit conditions or emission standard compliance may also prompt emission source testing (analytical and/or electronic instrumentation) on some specified frequency to verify compliance with set emission rates for regulated pollutants.

A second methodology for estimating air emissions is the use of emission factors. Using emission factors is the most common method for calculating emissions, mainly because of its low cost in comparison to direct emission measurement or stack testing. An emission factor is a multiplier that correlates a unit of activity (e.g., fuel consumption) with a quantity of pollutant emitted. The U.S. Environmental Protection Agency (EPA) provides an Emission Factor Database (AP-42) that offers emission factors for a variety of industries and pollutants. Additionally, the Intergovernmental Panel on Climate Change (IPCC) provides a methodology used for GHG inventories, including industrial processes, transportation, and energy use.

A third methodology for estimating emissions is referred to as the Mass Balance approach. This methodology is based on inputs and outputs of materials and energy. This is used when emissions are related to specific chemical reactions (e.g., combustion processes or production of chemicals) and is sometimes used in combination with the “Ideal Gas Law” where only minimal losses of volatiles (VOC emissions) are expected. For more complex situations, such as dispersion of pollutants or chemical reactions in large areas, pollutant concentrations can be estimated using air quality modeling software.

4. Data Collection for Greenhouse Gases (GHGs)

For carbon reduction and GHG emissions reporting, accurate data on GHGs is key. These emissions are organized into Scope 1, Scope 2, and Scope 3 categories. Scope 1, or direct emissions, are emissions that are the result of onsite activities such as the combustion of fossil fuels in boilers or furnaces, or in the engine of owned and operated vehicles. Scope 2, or indirect emissions, are those emissions that are associated with the generation of electricity, steam, heating, and cooling that your site purchases. Scope 3, or other indirect emissions, are all other indirect emissions in the value chain, such as from employee commuting, transportation, waste management, and product use.

Key data points for GHG emissions calculation include type and quantity of fuel used (e.g., natural gas, diesel, gasoline, coal), energy consumption data (electricity, steam, cooling), materials used in the manufacturing process (e.g., raw materials with associated emissions), and waste disposal methods.

The tools and protocols commonly used include the Greenhouse Gas Protocol, a widely used corporate standard for calculating and reporting GHG emissions, and the International Organization for Standardization (ISO) 14064, which is a standard for quantifying and verifying GHG emissions at organizational and project levels.

5. Use of Emissions Data

Once emissions data is collected, it can be used in many ways. First and foremost, the emissions data can be used to document day-to-day compliance with air emission permits and standards. Any legal compliance is of course a baseline operational expectation of high-performing companies and encourages them to actively set budgets necessary to continue the collection and analysis of their emission data. Emission data is also shown to be not only useful but also necessary in other environmental regulatory compliance such as Emergency Planning and Community Right to Know Reporting.

Emissions data can be used by regulatory agencies to identify high emitting activities or sources. This could include energy-intensive equipment or processes, excessive fuel consumption, or waste generation. Many companies use their GHG emissions data to set achievable carbon reduction targets (e.g., reducing annual GHG emissions by X% from a given baseline year), and to implement far ranging reduction strategies in the following:

• Energy Efficiency (by investing in energy-efficient technologies, switching to cleaner fuels, or upgrading older less efficient equipment)
• Renewable Energy (by switching to renewable energy sources)
• Carbon Capture and Storage (in some industry sectors typically with high-purity emissions sources)
• Transportation Optimizations (by improving fuel efficiency of vehicles or transitioning to electric vehicles)
• Waste Minimization and Recycling (by reducing the amount of waste sent to landfills and improving recycling and reuse efforts).

6. Ensure Ongoing Monitoring and Reporting

Just like any other information gathering process, Emissions Data Collection requires quality control and begs for management system concepts. The use of continuous emission monitoring systems to track emissions in real-time, such as CEMS, requires calibrations, software updates, and manufacturer-specified maintenance. Compliance calendars and written reporting procedures, including a quality review of acquired data, are also necessary practices to ensure that emissions data is accurate and based on credible sources or calculations to avoid penalties.

Additionally, many companies are required to report emissions to regulatory bodies on a regular basis (e.g., quarterly, annually) or in response to requests by investors or customers. Reporting may also be voluntary, as part of sustainability initiatives or corporate social responsibility (CSR) goals.

7. Align with Sustainability Goals and Industry Standards

Many companies are aligning their carbon reduction efforts with global initiatives like the Paris Agreement and science-based targets (SBTi). Your emissions reporting should support these efforts to reduce carbon footprints. Additionally, companies are looking to participate in voluntary programs like CDP (formerly the Carbon Disclosure Project), which provides a framework for companies to disclose their emissions and reduction progress.

Conclusion 

Collecting and using air emissions data is a key component of both air emission regulatory compliance and carbon reduction efforts. To ensure you meet permitting requirements, it's essential to understand the regulatory framework in your region, identify emissions sources, and employ accurate data collection methods (e.g., emissions factors, direct measurements). For carbon reduction, using this data to set targets, implement reduction strategies, and monitor progress will help reduce your environmental impact and align with sustainability goals. By integrating accurate emissions data into decision-making processes, companies can both comply with regulations and work toward a more sustainable future.

Do you have any questions? Our Air Emissions Management team and our Climate Change Advisory team are here to help get you answers, so reach out today!