PFAS guidance for reporting to the National Pollutant Release Inventory

Introduction

The National Pollutant Release Inventory (NPRI) is Canada’s legislated, publicly accessible inventory of pollutant releases to air, water and land, as well as disposals and transfers for recycling. Reporting facilities include manufacturing facilities, mines, oil and gas operations, power plants and sewage treatment plants. Every year, facilities that meet NPRI reporting requirements must report their releases, disposals and transfers of pollutants by the deadline. The NPRI is a key resource for identifying and monitoring sources of pollution in Canada. It helps set priorities, monitor environmental performance measures, contributes to the compilation of pollution patterns and trends, provides environmental information to the public, and fulfills international reporting obligations.

Per- and polyfluoroalkyl substances (PFAS) are a class of thousands of human-made substances. Some typical uses of PFAS include as surfactants, lubricants, and repellents (for dirt, water, and grease). PFAS can be found in many types of products, including certain firefighting foams, food packaging, drugs, cosmetics, sunscreens, pesticides, textiles (e.g., carpets, furniture, and clothing), non-stick cookware, vehicles, and electronics. Environment and Climate Change Canada (ECCC) has added reporting requirements for 163 individual PFAS to a new Part 1, Group C, of the NPRI substance list beginning with the 2025 reporting year. The list of PFAS added to the NPRI is provided in Table 1.  Reporting of releases, disposals and transfers for an individual PFAS will be required by any facility that meets the employee threshold and that manufactures, processes, or otherwise uses 1 kilogram or more of that individual PFAS at a concentration of ≥ 0.1%.

For each individual PFAS, the reporting threshold calculation should be based on the total quantity of a substance which is found by adding together the quantities:

• manufactured, processed or otherwise used at a concentration by weight greater than or equal to the concentration threshold (0.1%)
• incidentally manufactured, processed or otherwise used as a by-product at any concentration
• contained in tailings at any concentration
• contained in waste rock that is not clean or inert at any concentration

If facilities or users of this document have information that they would like to share that could help improve this guidance, or if they find that the recommendations are not suitable for their processes or situations, and that alternative approaches or information may be more accurate or better suited, the NPRI would greatly appreciate their input. Please contact the NPRI Helpdesk at inrp-npri@ec.gc.ca.

Should any inconsistencies be found between this guide and the Canada Gazette, Part I Notice with respect to substances in the National Pollutant Release Inventory, the Notice will prevail.

Purpose

PFAS have been utilized across a wide range of industries and applications. Due to their presence in numerous commercial products and industrial processes, this guidance is not exhaustive but provides a general overview of PFAS manufacture, process or otherwise use in certain sectors and activities. It aims as a start to assist facilities in:

1. examining the manufacture, processing or otherwise use thresholds that have been established in order to determine whether reporting to the NPRI is necessary
2. reporting releases, disposals, and transfers of PFAS to the NPRI

Although this guidance focuses on select sectors and applications, the general principles for determining NPRI reporting thresholds are applicable across various industries. Additionally, the chapter on firefighting foam use may be relevant to many sectors involved in such activities as well as the section on the method for estimating PFAS quantities in stormwater. 

To accurately perform threshold calculations for activities involving the 163 PFAS listed in the NPRI under Part 1C, it is important to understand the exemption for articles, as some PFAS may already be present in the manufactured articles used in many sectors.

An "article" is defined as a manufactured item that does not release an NPRI substance when it undergoes processing or any other use. When an article is processed and there are no releases, or the releases are recycled with due care, the NPRI substances in that article need not be included in the threshold calculation. Exercising due care means that the facility generated less than one kilogram of a Part 1A substance as waste during the year. There is no quantitative measure of due care in recycling Part 1C (PFAS). Therefore, if an article containing a Part 1C substance is processed or otherwise used and there are releases, the Part 1C substance in the article must be included in the threshold calculation.

When facility-specific data is not readily available, facilities are still required to make reasonable efforts to estimate the quantities of NPRI substances that are manufactured, processed, or otherwise used, as well as their potential releases, disposals, and off-site transfers.

For NPRI reporting purposes, if emissions are already monitored or measured under provincial or federal legislation or a municipal bylaw, those measurements must be used to report to the NPRI. However, all releases, disposals or transfers off site for recycling must be included in threshold calculations and reported, unless otherwise specified, not just those that are measured or monitored. An NPRI report is mandatory for any substances that meet the reporting thresholds, regardless of whether the substance is being measured or monitored for other jurisdictions. If emissions are not monitored or measured under provincial or federal legislation or a municipal bylaw, reasonable efforts must still be undertaken to gather information on releases, disposals and transfers of a substance. 

What is “reasonable” depends on individual circumstances but may include additional monitoring for NPRI substances. In deciding whether additional efforts should be undertaken to generate new information for the purposes of NPRI reporting, the following factors, among others, should be considered: 

• the health and environmental risks posed by a substance, including whether the substance has been declared toxic under CEPA
• the relative contribution of the industrial sector to releases, disposals and transfers for recycling of a substance in Canada
• the relative contribution of the facility to releases, disposals and transfers for recycling of a substance in Canada and 
• the cost of additional monitoring

General guidance has been provided on the following sectors/activities:

• firefighting foams
• textiles, upholstery, leather, apparel, and carpet manufacturing
• manufacturing of transportation vehicles
• oil and gas production
• mining
• recovered paper processing
• wastewater facilities
• non-hazardous and hazardous waste off-site landfill facilities 

Please note the references to fluoropolymers throughout the document is meant to offer additional information on how the use of PFAS could potentially be present within the identified sectors at the time of this document’s publication. Currently fluoropolymers are not included in the list of PFAS added to the NPRI. As knowledge regarding PFAS is ever-changing, this document will be updated as more information becomes available.

Firefighting foams

A firefighting foam is a stable mass of small air-filled bubbles, which has a lower density than oil, gasoline or water. According to General Foam Information - Chemguard (PDF), the foam is made up of three ingredients: 

• water
• foam concentrate
• air 

Based on the article Understanding Firefighting Foams, firefighting foams are divided into two classifications: 

• Class A 
• Class B 

According to the information in Types of Firefighting Foam Agents – Properties and Applications (PDF) Class A foam is specifically designed to combat fires involving ordinary combustible materials such as paper, tires, cloth, rubber, many plastics and wooden structures, as well as wildland fires. PFAS are not typically used in Class A foams.

According to the Fire Industry Association (PDF) and the American Chemistry Council, Class B foams are used to combat a fire of flammable and combustible liquids such as crude oil, gasoline, diesel, aviation fuel, kerosene, fuel oil, petroleum greases, tars, oil-based paints, solvents, lacquers and alcohols. Class B foams are used to principally form a cohesive floating blanket on flammable and combustible liquids. For more details, see the article Understanding Firefighting Foams. Unlike other extinguishing agents (e.g., water, dry chemical, CO₂, etc.) a stable aqueous foam can extinguish a flammable or combustible liquid fire by the combined mechanisms of cooling, separating the flame/ignition source from the product surface, suppressing vapours and smothering as reported in the article General Foam Information - Chemguard (PDF). It can also secure for extended periods of time against reflash or reignition. As a result of these characteristics, Class B foam is the primary fire-extinguishing agent for all potential hazards or areas where flammable liquids are transported, processed, stored or used as an energy source. PFAS are used in some, but not all, Class B foams. 

According to the Fire Industry Association (PDF), PFAS act as fluorosurfactants in many Class B firefighting foam concentrates. In this capacity, PFAS reduce surface tension by concentrating at the liquid-air interface which results in repelling hydrocarbons. Both characteristics positively impact the firefighting performance of Class B firefighting foams. Overall, there are six groups of Class B foams that contain PFAS and four groups of Class B foams that do not contain PFAS:

• fluorinated foams (contain PFAS and are synthetic):
  • aqueous film-forming foam (AFFF) 
    • legacy PFOS AFFF
    • legacy fluorotelomer AFFF
    • modern fluorotelomer AFFF
  • alcohol-resistant aqueous film-forming foam (AR-AFFF)
  • film-forming fluoroprotein foam (FFFP) 
  • alcohol-resistant film-forming fluoroprotein foam (AR-FFFP) 
  • fluoroprotein foam (FP) 
  • alcohol-resistant fluoroprotein foam (FPAR)
• fluorine-free foams (F3, do not contain PFAS):
  • protein foam 
  • alcohol-resistant protein foam (AR-P) 
  • synthetic fluorine-free foam (FFF)
  • synthetic alcohol-resistant fluorine-free foam (AR-FFF)

Brief summaries of the different types of Class B foams that contain PFAS follow.

Determine if NPRI reporting thresholds are met

The NPRI reporting threshold for each individual PFAS is 1 kg manufactured, processed or otherwise used (MPO) at ≥ 0.1% concentration. To determine if the facility meets this reporting threshold, calculations regarding the firefighting foam concentrate are required.

Step 1: determine if the firefighting foam concentrate manufactured, processed or otherwise used contains PFAS

Class A foam concentrates typically do not contain PFAS. Many Class B foam concentrates contain PFAS, while others do not. To determine if PFAS is contained in the Class B firefighting foam concentrates manufactured, processed or otherwise used at the facility, the following can be undertaken:

• identify the type of Class B foam concentrate manufactured, processed or otherwise used at the facility to determine if it is one of the six types of Class B foam concentrates that contain PFAS
  • the type of Class B foam concentrate is typically indicated on the container of the concentrate
• review the Safety Data Sheet and/or Technical Data Sheet for the Class B foam concentrate manufactured, processed or otherwise used at the facility to identify whether the concentrate contains PFAS or the type of Class B foam concentrate
• the supplier or the manufacturer of the Class B foam concentrate may be contacted

If the facility uses Class A foam concentrate and there is uncertainty whether it could contain PFAS, it is recommended that further reasonable efforts be conducted to determine whether PFAS are present in the foam. This may involve reviewing product documentation, contacting the supplier or manufacturer for chemical composition details, consulting published literature or performing analytical testing if necessary.  

Step 2: determine the individual PFAS and their concentrations in the Class B foam concentrates manufactured, processed or otherwise used

The NPRI reporting requirements are for individual PFAS. The Safety Data Sheet or the supplier/manufacturer of the Class B foam concentrate may be consulted to determine the concentration of individual PFAS in the concentrate. These individual PFAS need to be identified by Chemical Abstract Service Registry Number (CAS RN). 

The list of PFAS (by CAS RN) contained in the foam concentrate should be compared to the list of 163 PFAS that have been added to the NPRI. This list is provided in Table 1. 

Only individual PFAS (that have been added to the NPRI) in the Class B foam concentrate that are present at concentrations ≥ 0.1% may need to be reported to the NPRI. 

If the Class B foam concentrate that is being manufactured, processed or otherwise used at the facility does not contain any individual PFAS (that have been added to the NPRI) at concentrations ≥ 0.1%, then reporting to the NPRI is not required. 

If individual PFAS, that have been added to the NPRI, are determined to be present in the Class B foam concentrate that is manufactured, processed or otherwise used at the facility in concentrations ≥ 0.1%, then proceed onto Step 3. 

Step 3: calculate the quantity of Class B foam concentrate containing PFAS that was manufactured, processed or otherwise used for the NPRI reporting year

Determine the volume (in litres) of Class B foam concentrate manufactured, processed or otherwise used at the facility from available accounting records, equipment gauges or other means. 

If gauges are not available on equipment to determine how much Class B foam concentrate was used during firefighting events (or other events such as equipment malfunctions), then the quantity of Class B foam concentrate that was purchased or transferred from storage to in-service equipment to replace concentrate that was used during firefighting events can be used to estimate quantities consumed. 

It is important to note that the purchase of Class B foam concentrate is not considered “processed”. However, the transfer of Class B firefighting foam concentrate from storage to in-service equipment or the blending of firefighting foam concentrate is considered to be “processing”.

Once the volume of Class B foam concentrate that was manufactured, processed or otherwise used at the facility during the NPRI reporting year is determined, convert this amount in litres to kilograms using the density of the foam. Class B foam concentrate densities are typically in the range of 1.01-1.10 kg/L. (A total of 14 different product specification sheets were reviewed. All of these sheets showed densities in this range. The densities for these 14 products can be found in Appendix A). The following equation should be used:

Where:

• W_kg = quantity of Class B foam concentrate manufactured, processed or otherwise used during the NPRI reporting year, in kilograms
• V_L = volume of Class B foam concentrate manufactured, processed or otherwise used during the NPRI reporting year, in litres
• Density_kg/L = density of the Class B foam concentrate in kg/L

This calculation needs to be undertaken for each Class B foam concentrate (containing individual PFAS that have been added to the NPRI) that was manufactured, processed or otherwise used at the facility during the NPRI reporting year. 

It should be noted that the weight of Class B foam concentrate may already be available in product literature provided by the manufacturer/supplier. In these instances, the above calculation will not be necessary. 

Step 4: calculate the quantity of individual PFAS contained in the Class B foam concentrate manufactured, processed or otherwise used for the NPRI reporting year

From step 2, the concentration of individual PFAS in the Class B foam concentrate manufactured, processed or otherwise used at the facility and which have been added to the NPRI will have been determined. This concentration will typically be outlined in percentage (%) terms. Apply those percentages to the total quantity (in kg) of Class B foam concentrate (containing relevant PFAS) that was manufactured, processed or otherwise used at the facility during the NPRI reporting year. Use the following formula: 

Where:

• PFASⁱ_kg = quantity of PFAS chemical “i” contained in the Class B foam concentrate manufactured, processed or otherwise used at the facility during the NPRI reporting year, in kilograms
• Wⁱ_kg = quantity of Class B foam concentrate (containing PFAS chemical “i”) manufactured, processed or otherwise used during the NPRI reporting year, in kilograms
• Concentrationⁱ_% = concentration of PFAS chemical “i” contained in the Class B foam concentrate manufactured, processed or otherwise used at the facility during the NPRI reporting year, expressed in percentage terms

The above calculation needs to be repeated for all individual PFAS chemicals that have been added to the NPRI and that are contained in the Class B foam concentrate that was manufactured, processed or otherwise used at the facility during the NPRI reporting year. 

The above calculation also needs to be repeated for each different Class B foam concentrate that contains individual PFAS (that have been added to the NPRI) that was manufactured, processed or otherwise used at the facility during the NPRI reporting year.

Ensure to aggregate the quantity of individual PFAS (defined as having separate CAS RNs) present in different Class B foam concentrates that are manufactured, processed or otherwise used at the facility during the NPRI reporting year. For individual PFAS calculated to be present in Class B foam concentrates manufactured, processed or otherwise used at the facility in quantities ≥ 1 kg during the NPRI reporting year, reporting of releases, transfers and disposals to the NPRI is required (as long as those individual PFAS are contained in the Class B foam concentrate at concentrations greater than or equal to 0.1%). Please see the next section for guidance.

If there are no individual PFAS (that have been added to the NPRI) that are calculated to be present in Class B foam concentrates that were manufactured, processed or otherwise used in quantities ≥ 1 kg during the NPRI reporting year, then reporting of releases, transfers and disposals of PFAS to the NPRI is not required. 

Estimating releases, transfers and disposals

Releases of PFAS and generation of PFAS-containing waste from firefighting foam concentrate/foam can occur over several different lifecycle stages at a facility. Releases generally occur to: 

• surface water
• groundwater 
• stormwater and sewer systems 
• soil
• sediment 

Foam released to soils via spills/leaks or due to use of foam can further migrate and end up in groundwater or in runoff which reaches sewers or surface waters.

PFAS-containing waste could be generated due to: 

• firefighting foam use events
• spills/leaks/accidental discharges
• removal of unused concentrate 
• other handling

For those individual PFAS that met the threshold for reporting to the NPRI, all occurrences of those individual PFAS during manufacturing, processing or other use activities at the facility during the NPRI reporting year have to be taken into consideration when determining releases, transfers and disposals (e.g., even if that individual PFAS is contained in Class B firefighting foam concentrate at less than 0.1% concentration). 

Lifecycle process flow and PFAS release pathways for firefighting foams

The following process flow describes the lifecycle of foams used in firefighting operations and illustrates the points at which PFAS may be released into the environment: 

1. newly purchased AFFF concentrate is either: 
   • stored
   • added directly to firefighting systems
2. foam that is added to storage can be: 
   • disposed of if expired/unwanted/unused
   • disposed of from system decontamination
   • potentially released (leaks, spills, and accidental discharges)
     • a portion of accidental releases and waste materials may be collected for treatment and disposal
3. foam that is added directly to in-service equipment can be:
   • disposed of if expired/unwanted/unused
   • disposed of from system decontamination
   • potentially released (as leaks, spills, or accidental discharges)
     • a portion of accidental releases and waste materials may be collected for treatment and disposal 
   • used in the following situations which may result in intentional releases which may be partly collected for treatment and disposal: 
     • foam training (usually done with PFAS-free foams) 
     • foam equipment certification, testing and calibration (usually done with PFAS-free foams) 
     • firefighting events 
4. after use in firefighting events, contaminated oil and sediment may be removed for remediation and disposal

Note that PFAS-containing waste can be treated to reduce PFAS concentration before discharge or removal from the site.

Step 1: determine which activities/events during the NPRI reporting year resulted in PFAS releases, transfers and/or disposals

Firefighting foam concentrate and foam can be released into the environment, disposed of on-site or transferred off-site as a result of various activities and events, as described in the section on lifecycle process flow and PFAS release pathways for firefighting foams above. An assessment of these activities and events should be undertaken to determine which occurred during the NPRI reporting year and which involved PFAS. The key activities and events to consider are listed below – please note that other activities and events not listed may be appliable to your facility and should be considered, if relevant.

Use of firefighting foams during firefighting events

This can lead to PFAS releases to the environment and the collection of PFAS-containing waste materials (e.g., foam solution, fire wastewater and foam runoff, and rinse water/flushing from the cleaning of equipment at the scene). Releases to the environment may need to be reported to the NPRI when the event occurs at a facility and the threshold is met. In some instances, it is possible to contain and collect these waste streams in a contained area or tank through the use of ditching, dams, berms, booms, dikes or trenches as well as blocking storm drains, culverts or other surface inlets. In addition, collection of large volumes of the foam concentrate or the spent foam solution can be accomplished with pumps or vacuum trucks while absorbent material might suffice to clean up after a smaller release. Collected materials may trigger NPRI reporting even if the firefighting event occurs off the facility site and then the quantity disposed of or transferred for recycling or treatment before final disposal should be reported. For best practices, you may consult:

• Fire Fighting Foam Coalition: Best Practice Guidance for Use of Class B Firefighting Foams (PDF)
• Interstate Technology & Regulatory Council: PFAS Technical and Regulatory Guidance
• Ireland Environmental Protection Agency: The Changing Nature of Fire-Fighting Foams - Understanding the Risk Posed by PFAS (PDF)

Disposal of expired/unwanted/unused foam concentrate

Facilities which engage in firefighting operations sometimes have reason to remove PFAS-containing foam concentrates, for instance due to the expiry of the foam concentrate or the movement to fluorine-free foam concentrates. This concentrate could be removed from storage or from actual in-service equipment. There are a variety of initiatives that are used to remove foam concentrate from the facility, for instance through government sponsored initiatives to encourage disposal, programs operated by the manufacturer/supplier, removal by a hazardous waste management company at a cost, donation to fire-fighting training institutes, etc. If being disposed of, this foam concentrate is often transferred for treatment before final disposal to a hazardous waste incinerator or solidified and forwarded to a hazardous waste landfill. 

Unplanned releases

PFAS-containing concentrate or foam solution can be released from in-service equipment or from storage by spills, leaks and accidental discharges (e.g., due to faculty or malfunctioning equipment). Attempts are typically made to contain and capture these unplanned releases (e.g., drip-trays/bunds around the foam concentrate containers) in which case PFAS-containing waste will typically need to be removed from the facility site.  For more information, you may consult the Changing Nature of Fire-Fighting Foams - Understanding the Risk Posed by PFAS (PDF) from the Ireland Environmental Protection Agency.

System decontamination

Transitioning to fluorine-free foam concentrates can require the cleaning of system components (e.g., storage containers, stationary and mobile firefighting systems, piping) prior to the introduction of the new foam concentrate. These cleaning operations can involve triple-rinsing with water, hot water rinsing, rinsing with low- or high-temperature solvents or acids, etc. In these instances, PFAS-containing waste (e.g., flush/rinsing water) will be generated, collected and typically transferred for treatment prior to final disposal (e.g., high-temperature incineration, solidification) or disposed off site (e.g., downhole injection). For more information, you may consult the Firefighting Foam Transition Guidance - American Petroleum Institute (PDF).

Certification/testing/maintenance of firefighting systems

Fixed and mobile firefighting equipment requires inspection, calibration, and testing to ensure reliable performance during an actual fire event. For instance, testing typically occurs pursuant to the installation of the system and maintenance tests can be conducted annually. Surrogate liquids, fluorine-free foam or water that does not contain PFAS are typically used for this testing/maintenance with containment systems utilized (i.e., for complete containment, capture, and subsequent disposal). For more information, you may consult the Changing Nature of Fire-Fighting Foams - Understanding the Risk Posed by PFAS (PDF) from the Ireland Environmental Protection Agency.

Training 

Periodic training is conducted on fixed and mobile firefighting equipment. Typically, alternative fluids that do not contain PFAS (e.g., fluorine-free foams, training foams or water) are used during this training. This training is normally conducted under conditions conducive to the containment and collection (and subsequent treatment and disposal) of spent foam and wastewater. 

Remediation of contaminated soil/sediment

The use of PFAS-containing firefighting foam concentrate can lead to the contamination of soil/sediment at the facility site. Soil/sediment containing PFAS that is removed for remediation could include the immediate removal of a small amount of these materials after an event to prevent more widespread contamination as well as more extensive and longer-term remediation after an event. For more information, you may consult Operational Policy – Environmental Management of Firefighting Foam (PDF) from the Queensland Department of Environment and Heritage Protection.

Step 2: determine quantity of Class B foams released to the environment or transferred or disposed as waste materials for each relevant activity/event

It is necessary to determine the quantity (in litres) of Class B foam concentrate (containing PFAS) that was released to the environment, disposed of or transferred in waste materials for each category of activity/event listed in step 1 that occurred during the NPRI reporting year. If there was more than one instance of the activity/event that occurred during the NPRI reporting year, then all have to be taken into consideration. 

There are no release factors available to assist in this estimation as these activities/events are unique to each facility in terms of number, size and location of the activity/event. The volume of Class B foam concentrate (in litres) that was released directly to the environment, disposed of or transferred in waste materials may be calculated based upon accounting records, equipment gauges or other means. If gauges are not available on equipment to determine how much Class B foam concentrate was released, disposed of or transferred in waste materials, then the quantity of Class B foam concentrate that was purchased or transferred from storage to in-service equipment to replace concentrate that was released during the specific activity/event can be used to estimate quantities.

Once the volume of Class B foam concentrate that was released to the environment, disposed of or transferred as waste materials at the facility during the NPRI reporting year for each relevant activity/event is determined, convert this amount in liters to kilograms using the density of the foam. Class B foam concentrate densities are typically in the range of 1.01-1.10 kg/L. The following equation should be used:

Where:

• W_kg = quantity of Class B foam concentrate manufactured, processed or otherwise used during the NPRI reporting year, in kilograms
• V_L = volume of Class B foam concentrate manufactured, processed or otherwise used during the NPRI reporting year, in litres
• Density_kg/L = density of the Class B foam concentrate in kg/L

This calculation needs to be undertaken for each activity/event that resulted in discharges of Class B foam concentrate at the facility during the NPRI reporting year, whether directly to the environment (releases) or in waste materials (disposals or transfers). 

Step 3: calculate the quantity of individual PFAS contained in the Class B foam concentrate released during the NPRI reporting year

When determining if the NPRI reporting threshold was met, the concentration of individual PFAS in the Class B foam concentrate manufactured, processed or otherwise used at the facility and which have been added to the NPRI was determined. This concentration will typically be outlined in percentage (%) terms. Apply those percentages to the total quantity (in kg) of Class B foam concentrate that was released to the environment, disposed of or transferred in waste materials at the facility during the NPRI reporting year as determined in step 2. Use the following formula: 

Where:

• PFASⁱ_kg = quantity of PFAS chemical “i” contained in the Class B foam concentrate manufactured, processed or otherwise used at the facility during the NPRI reporting year, in kilograms
• Wⁱ_kg = quantity of Class B foam concentrate (containing PFAS chemical “i”) manufactured, processed or otherwise used during the NPRI reporting year, in kilograms
• Concentrationⁱ_% = concentration of PFAS chemical “i” contained in the Class B foam concentrate manufactured, processed or otherwise used at the facility during the NPRI reporting year, expressed in percentage terms

The above calculation needs to be undertaken for each category of activity/event that resulted in releases of Class B foam either directly to the environment or to disposals or transfers of waste materials during the NPRI reporting year. In addition, this calculation needs to be undertaken for each individual PFAS chemical (meeting the NPRI reporting threshold) that has been added to the NPRI and which is contained in the Class B foam concentrate that was released or disposed of at the facility or transferred off-site during the NPRI reporting year. 

Step 4: take into consideration any treatment technologies applied

It is important to take into consideration any on-site treatments applied that can reduce the PFAS content of releases/wastes prior to being actually released to the environment, disposed of on-site or removed off-site for treatment/disposal. For instance, finished PFAS-containing foam and runoff water can be treated with granular activated carbon (GAC) filtration (Spent GAC, which accumulates PFAS, can either be disposed of as a PFAS-containing waste or transferred for regeneration. In both cases, the PFAS must be considered respectively as disposed of or further transferred for treatment prior to final disposal) or other methods on-site to reduce PFAS concentrations. For more information, you may consult Firefighting Foam Use, Replacement and Disposal (PDF) from the Minnesota Pollution Control Agency. The treatment efficiencies, in terms of reducing PFAS concentration, of these technologies should be applied to the quantity of the individual PFAS chemicals that were calculated in step 3 above using the following formula:

Where:

• PFASⁱ_{kg-Controlled} = quantity of PFAS chemical “i” subsequent to the application of treatment technologies to reduce PFAS concentration, in kilograms
• PFASⁱ_{kg-Uncontrolled} = quantity of PFAS chemical “i” contained in the Class B foam concentrate released disposed of or transferred during the NPRI reporting year, in kilograms 
  • this quantity is prior to any PFAS treatment technology being applied to material or waste that is collected before releases, disposals or transfers occur 
• Treatment efficiency_% = reduction in PFAS content due to the utilization of treatment technologies, such as granular activated carbon, expressed in percentage terms 

Facilities are encouraged to access information on treatment efficiency from their technology suppliers, taking into account their site-specific conditions, the technologies employed, pretreatment methods utilized, and any other factors that may impact the treatment efficiencies of their systems.

Step 5:  allocate estimated releases, disposals and transfers of PFAS chemicals according to NPRI reporting categories

Step 4 will have estimated the quantity (in kilograms) of individual PFAS chemicals that were released (to the environment or waste materials) during the NPRI reporting year, subsequent to any treatment technologies applied to reduce PFAS concentration. It is then necessary to allocate this quantity to the NPRI reporting categories that have been established for on-site releases or to the on-site/off-site disposals and transfers of waste materials. These categories are as follows:

• air emissions: 
  • stack/point
  • storage tanks and related handling
  • fugitive
  • spills/other accidental releases
  • other releases to air
• water releases: 
  • direct discharges
  • spills 
  • leaks
• land releases: 
  • spills
  • leaks
  • other releases to land
• on-site disposal: 
  • landfill
  • land treatment
  • underground injection
  • tailings
  • waste rock
• off-site disposal: 
  • landfill
  • land treatment
  • underground injection
  • storage prior to final disposal
  • tailings
  • waste rock
• transfers for treatment prior to final disposal: 
  • physical treatment
  • chemical treatment
  • biological treatment
  • incineration or thermal
  • transfer to a municipal wastewater treatment plant
• transfers for recycling: 
  • energy recovery
  • recovery of solvents
  • recovery of organic substances (not solvents)
  • recovery of metals and metal compounds 
  • recovery of inorganic materials (not metals)
  • recovery of acids or bases
  • recovery of catalysts
  • recovery of pollution abatement residues
  • refining or reuse of used oil
  • other recovery, reuse or recycling activities

When assessing the environmental release of PFAS in firefighting activities, both fire training and fire intervention should be considered. The use of firefighting foam can lead to the release of PFAS, which may be released into the air, land, or water bodies. Spent firefighting foam can also be contained for disposal and/or transfer, for example, transferred to a municipal wastewater treatment facility, or other treatment options such as incineration. It is important to note that firefighting foam application can lead to air releases in the form of mist or aerosols. Facilities could consult with suppliers for any available information to help quantify these emissions. Site monitoring data, data from similar applications, expert judgment, and mass balance methods can be used to estimate the quantities of PFAS released, disposed, or transferred.

If no information is available, and there is no containment of the firefighting foam after discharge, air releases can be considered negligible. In this case, the release must be reported to land and/or water. Depending on the circumstances, it should be assumed that 50% of the release enters surface water without treatment or is transferred to a wastewater facility, while the remaining 50% is released to land as a spill (see Environmental Risk Evaluation Report: PERFLUOROOCTANESULPHONATE (PFOS) (PDF) and Pollution pathways and release estimation of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in central and eastern China). If this assumption does not apply, the entire release should be reported as a spill to land. The proposed partitioning approach may be considered by the reporting facility when site-specific data or expert advice is not available. However, it is important to clarify that each reporting facility should assess its own site conditions and consult subject matter experts to determine the most appropriate approach to estimate the environmental partitioning of used firefighting foams given that literature-based assumptions may not be generally applicable. 

Quantification of storm water releases is required if a facility has data on the concentration of NPRI-listed PFAS substances in its discharges. Determination of the amount of NPRI PFAS substances released in storm water run-off involves: 

1. calculating the total amount of volumetric run-off from the site
2. applying the measured or estimated concentration of PFAS (that have been added to the NPRI Substance List) to that volume

To calculate the total volume of run-off, the facility must determine the total area drained by each outfall, and the weighted average run-off coefficient for that area. Each coefficient is dependent on a specific area's soil structure, topography, usage and development. The coefficient represents the amount of rainfall that “runs off” the ground as storm water (i.e. does not soak into the ground). One way to calculate the flow rates from stormwater runoff is the Rational Method (Toxic Chemical Release Inventory Reporting Forms and Instructions [PDF]  -  page 63).

Once the volumetric flows are determined, the facility must apply the correct concentration (found through sampling during the event, average stormwater monitoring data or assumed based on available data) at each outfall, to each outfall’s flow. Prescribing stormwater sampling methodologies falls outside the scope of the NPRI. However, facilities may follow any applicable requirements related to stormwater sampling procedures as outlined in their operating permit, approval, authorization, license, certificate, or relevant provincial or territorial environmental programs. The following resources are provided for informational purposes only, as potential guidance on stormwater sampling procedures:

• Ontario Protocol for Conducting a Storm Water Control Study 
• USEPA Industrial Stormwater Monitoring and Sampling Guide (PDF)

Where:

• PFASⁱ_kg = quantity of PFAS substance i discharged during the year via surface runoff, kg/year
• A = land area of the facility covered by the stormwater, m²
• I = rainfall intensity, which is the average annual precipitation, m/year
• RC = runoff coefficient
• C_PFASⁱ = average surface water concentration, ng/L

Rainfall intensity can be obtained from an on-site weather station or from the nearest weather station from the Government of Canada. Canadian Climate Normals - Climate - Environment and Climate Change Canada offers normals and average climate information, presented in monthly and annual tables, including precipitation intensity for various locations across Canada. 

Averaged storm-water runoff coefficients can be obtained from Toxic Chemical Release Inventory Reporting Forms and Instructions (PDF) (see page 63). 

Textiles, upholstery, leather, apparel, and carpet manufacturing

According to the OECD's Synthesis paper on per and polyfluorinated chemicals, PFAS are used in textiles, upholstery, leather, apparel and carpets (TULAC) in two main applications: 

1. highly porous fabrics (e.g. Gore-Tex®) used in outdoor wear and camping accessories 
2. side-chain fluorinated polymers used as finishes to modify the surfaces of TULAC to impart water, oil, soil and staining resistance

The finishes/treatments are applied to materials in mills/tanneries and as aftermarket applications by professionals or consumers as aqueous dispersions. For more details, you may consult Annex A of the European Chemicals Agency (ECHA) Submitted restrictions under consideration for PFAS.

According to ECHA, the TULAC materials treated with PFAS exhibit the following:

• waterproof properties (lower water permeability and wettability)
• chemical resistance and inertness
• protection against exposure to liquids such as blood and other body fluids, but also chemicals and electrical discharge
• robust mechanical properties (e.g. resistance to abrasion) and the provision of low friction
• weatherability including UV protection and resistance to corrosion from salt water
• resistance to high temperatures (thermally stable)

Common TULAC product-types known to be treated with PFAS include:

• home textiles
  • carpets and rugs
  • curtains and blinds
  • textile-based coverings (fabrics for soft furnishings, tablecloths, bedding)
• home fabric treatments (sprays) for leather/textiles
• leather applications
  • leather based goods (wallets, belts, bags)
  • leather based apparel
  • shoes
• textile-based apparel
  • indoor and outdoor wear
  • footwear
  • sportswear
  • accessories (umbrellas, purses, wallets)
  • PPE for industrial and professional use (other than sportswear)
• technical textiles
  • outdoor technical textiles
    • canvas
    • awnings
    • tarps
    • tents
    • sails
    • rope
  • medical applications (surgical drapes, gowns, curtains)
  • high performance membranes such as those for automotive or medical applications

According to the ECHA, a variety of PFAS are used within TULAC applications, categorized into perfluoroalkyl acids (PFAAs) and PFAA precursors (including side-chain fluorinated polymers) and polymeric PFASs. Over 75% of the PFAS used in TULAC applications are fluoropolymers, almost half of which is PTFE. Other fluoropolymers used include PVDF, PFPE, FEP, PFA, and others. Polymeric PFAS are not amongst the individual PFAS that have been added to the NPRI.

Leather and textile manufacturing process flows and sources of wastewater

Leather processing and textile manufacturing are distinct. The leather production process includes three main phases: raw hide preparation, tanning and finishing. The steps are outlined below:  

1. raw hide processing
   • soaking
   • fleshing & trimming
   • liming
   • deliming and baiting 
   • picking and degreasing
2. tanning process
   • retanning 
   • dyeing 
   • fat liquoring
   • staking and buffing 
   • separation of wastewater from product
     • wastewater generated during processing is directed to wastewater treatment before the hides move to the finish coating process 
3. finish coating process
   • drying
   • embossing 
   • measuring and finishing

In textile processing, there are both dry processing stages and wet processing stages that interact differently depending upon the specific product being manufactured and the raw material being used to manufacture the product. As wastewater discharges potentially containing PFAS substances are the focus of this guidance, the dry processing steps are not described in the following process flow. 

For dry-processed textiles, substances can be sent to a wastewater treatment plant from multiple steps.  In general, dry-processed textiles undergo:

1. desizing
   • produces water, detergent, and dissolved size
2. scouring
   • produces water and scouring chemical(s)
3. any or all of:
   • bleaching
     • produces bleach water 
   • mercerizing
     •  produces water and chemicals 
   • dyeing
     • produces water and unfixed dye
   • printing
     • produces water and unfixed ink
4. finishing
   • produces any unfixed chemicals

The waste materials that are produced are sent to the wastewater treatment plant and treated prior to potentially being released. 

Determine if NPRI reporting thresholds are met

The NPRI reporting threshold for individual PFAS is 1 kg manufactured, processed or otherwise used (MPO) at ≥ 0.1% concentration. To determine if the facility meets this reporting threshold, inventory tracking for PFAS-containing products is recommended.

Step 1: identify products containing relevant PFAS manufactured, processed, or otherwise used at the facility and the concentration of individual PFAS in those products

Facilities should conduct research to determine which products they MPO that contain any of the 163 PFAS listed in the NPRI. The types of products used within the TULAC sector that contain PFAS were described in the Introduction to this chapter. The research to identify the presence of individual PFAS can involve reviewing the Safety Data Sheet and/or Technical Data Sheet for the products that the facility MPOs that have the potential of containing PFAS. Contacting the manufacturer or supplier of these products could also be a source to obtain relevant/necessary information. 

Through this research, a determination of the concentration (typically expressed in percentage terms) of each individual PFAS (using a CAS RN) within the products being used can be made. Individual PFAS that have been added to the NPRI must be present in the products manufactured, processed or otherwise used at a concentration of at least 0.1% in order to meet reporting thresholds. If there are no such products manufactured, processed or otherwise used at the facility, then NPRI reporting is not required. If products were identified that contain individual PFAS (that have been added to the NPRI) at a concentration ≥ 0.1%, then it is necessary to proceed to step 2.

Step 2: calculate the weight of individual PFAS contained in products manufactured, processed or otherwise used for the NPRI reporting year

For those products identified as containing individual PFAS (that have been added to the NPRI) at concentrations ≥ 0.1%, facilities should utilize information on inventory changes (e.g., purchasing records, transfers, amount of product remaining in storage) to quantify the amount of each relevant product manufactured, processed or otherwise used at the facility over the NPRI reporting year. 

With the concentration of individual PFAS in the products and the quantity of the product manufactured, processed or otherwise used over the course of the NPRI reporting year available, the following formula can be used to calculate the total quantity of individual PFAS manufactured, processed or otherwise used:

Where:

• PFASⁱ_kg = weight of PFAS chemical “i” contained in the product manufactured, processed or otherwise used at the facility during the NPRI reporting year, in kilograms
• Wⁱ_kg = weight of the product (containing PFAS chemical “i”) manufactured, processed or otherwise used during the NPRI reporting year, in kilograms
• Concentrationⁱ_% = concentration of PFAS chemical “i” contained in the product manufactured, processed or otherwise used at the facility during the NPRI reporting year, expressed in percentage terms

The above calculation needs to be repeated for all individual PFAS chemicals that have been added to the NPRI and that are contained in products (at ≥ 0.1% concentration) that were manufactured, processed or otherwise used at the facility during the NPRI reporting year. 

The above calculation also needs to be repeated for each different product that contains individual PFAS (that have been added to the NPRI) that were manufactured, processed or otherwise used at the facility during the NPRI reporting year.

Aggregate the quantity of individual PFAS (defined as having separate CAS RNs) present in different products that are manufactured, processed or otherwise used at the facility during the NPRI reporting year. For individual PFAS calculated to be present in products manufactured, processed or otherwise used at the facility in quantities ≥1 kg during the NPRI reporting year, reporting of releases, transfers and disposals to the NPRI is required. Please see the next section for guidance.

If there are no individual PFAS (that have been added to the NPRI) that are calculated to be present in products that were manufactured, processed or otherwise used in quantities ≥1 kg during the NPRI reporting year, then reporting of releases, transfers and disposals of PFAS to the NPRI is not required.

Estimating releases, transfers and disposals

For those individual PFAS that met the threshold for reporting to the NPRI (as determined in the preceding section), all occurrences of those individual PFAS during manufacturing, processing or use activities at the facility during the NPRI reporting year have to be taken into consideration when determining releases, transfers and disposals (e.g., even if that individual PFAS is contained in products at less than 0.1% concentration). 

Two main categories of releases, transfers or disposals generated at TULAC manufacturing facilities could potentially contain PFAS: 

1. solid waste from the disposal of off-cuts or other waste textiles/leather treated with PFAS
2. industrial wastewater from emptying industrial baths 

However, depending on the physicochemical properties of the PFAS used, they may also be released into the air during textile manufacturing as reported in Emissions of Per- and Polyfluoroalkyl Substances in a Textile Manufacturing Plant in China and Their Relevance for Workers’ Exposure. It is also plausible to assume that PFAS could be emitted into the air during leather processing, particularly when thermal treatments are involved, as leather finishing has been identified by the USEPA NESHAP as a source of certain hazardous air pollutants (USEPA NESHAP For Leather Finishing Operations, AP-42: Compilation of Air Pollutant Emissions Factors from Stationary Sources: 9.15 Leather Tanning [PDF]).

According to PFAS in the textile and leather industries (PDF) from the Minnesota Pollution Control Agency, industrial wastewater is likely the dominant path for PFAS release from TULAC facilities. PFAS are applied to industrial baths to perform dyeing, bleaching, waterproofing, coating, and for leather, tanning and related steps. When these baths are emptied, PFAS contained in the process water is discharged to wastewater facilities.

Meanwhile, industrial solid waste contaminated with PFAS is most likely relatively minor, for instance off-cuts or other product wastage represent costs and are avoided whenever possible. These solid wastes could potentially be recycled internally, sent to textile recyclers in Canada, or be disposed of.

Very limited data was identified on techniques that could be used to estimate releases, transfers, or disposals of PFAS from TULAC operations. The ECHA's Submitted restrictions under consideration for PFAS cited another EU document from 2020 on the use of PFAS and fluorine-free alternatives in textiles, upholstery, carpets, leather and apparel. This document did not contain original research on estimating releases of PFAS from textile or leather manufacturing/finishing facilities, but instead slightly modified the OECD emission scenario document (ESD) methodologies on leather finishing (PDF) and textile finishing (PDF). The emission estimation techniques below were taken from this OECD documentation.

Two estimation techniques for PFAS releases from TULAC facilities were identified - one for leather manufacturing/finishing facilities and the other textile manufacturing/finishing facilities. These are described below. 

Leather Finishing

The leather finishing estimation methodology relies upon a number of facility-specific datapoints. The estimation methodology is therefore divided into three steps: 

1. gathering facility-specific information to support PFAS release estimates
2. estimating PFAS releases and 
3. applying the impacts of potential mitigation techniques

Step 1: gather facility-specific information to support PFAS release estimates

The following facility-specific information is required to estimate releases of PFAS to water from leather finishing operations:

• quantity of rawhides processed per day in tonnes at the facility*
• fraction of the mass of leather remaining from the rawhide at the chemical application stage of the process*
• the consumption of the chemical formulation containing the PFAS substance per tonne of leather production*
• the fraction of the specific PFAS substance that is contained in the mixture (this should already be known by the reporter as it was required information for determining if the facility met the reporting threshold, and should be known for each individual PFAS substance that meets reporting thresholds)
• the degree of fixation to the leather for the product being applied (not for the individual PFAS substance but for the product as a whole)
• the fraction of daily production treated with the product containing the PFAS substance(s)*
• the fraction of each individual PFAS substance that would be eliminated due to any on-site wastewater treatment*
• the number of operating days for the facility during the NPRI reporting year

Note: asterisks (*) represent those values for which recommended values (from the OECD Emission Scenario Document (ESD) on leather finishing [PDF]) are available if facility-specific information is unavailable. 

The data above will need to be known for each individual PFAS substance that meets NPRI reporting thresholds, so that the calculation shown in Step 2 can be applied for each individual PFAS substance that must be reported.

Step 2: estimate PFAS releases to water from leather finishing operations

Utilizing the data identified in Step 1, complete the following equation for each PFAS that meets the reporting thresholds. This will provide an estimate of releases for each PFAS substance per day from the facility. Multiply the daily release figure by the number of operating days for your facility as follows:

Where:

• E_water = initial release to water (kg/day)
• Q_rawhide = quantity of raw hides processed per day 
  • the OECD ESD recommends a value of 15 tonnes per day
• F_{remaining mass} = fraction of mass of leather remaining from raw hide at the application stage
  • OECD ESD recommends a value of 0.2 for leather finishing
• Q_{chemical formulation} = consumption of chemical formulation containing the substance (mass of substance use per tonne of production)
  • OECD ESD recommends a value of 15 kg/tonne
• F_chemical = fraction of chemical “i” contained in the formulation applied to the leather
• F_fixation = degree of fixation to leather
• F_{daily production} = fraction of daily production that is treated with the specific chemical
  • OECD ESD recommends a default value of 1
• F_{on-site treatment} = fraction of chemical elimination by on-site wastewater treatment prior to discharge to a municipal sewage treatment plant
  • a default value of 0 could be used if there is no onsite treatment

European Union documentation indicates that the median number of operating days for a leather finishing site is 225 days per year, but no similar Canadian-specific information was identified. The fixation on leather factor is given as a default value of 0 by the OECD ESD on leather processing (PDF), but this may not accurately reflect the degree of fixation for PFAS substances that are specifically meant to remain on the treated leather. No PFAS-specific factors for this variable were identified according to The use of PFAS and fluorine-free alternatives in textiles, upholstry, carpets, leather and apparel from the European Commission.

For potential PFAS air emissions from open top vessel sources, the evaporation model from section 3.7 of Methods for Estimating Air Emissions from Chemical Manufacturing Facilities (PDF) could be used. Facilities are encouraged to prioritize facility-specific data, such as source testing with mass balance, site-specific emission factors, or engineering estimates and process simulator models, when reporting to the NPRI. Additionally, other estimation methods, such as data from similar facilities or emission factors developed from comparable operations or surrogate substances, may also be used for NPRI reporting.

Step 3: apply the impacts of mitigation techniques to release estimates

Leather finishing facilities generate wastewater and may apply mitigation techniques to limit the release of certain substances within their wastewater. The efficacy of wastewater treatment systems varies by technology type, flow rate, the specific substance under consideration, and many other factors. If facilities apply mitigation techniques to their wastewater stream that will impact the release of any PFAS quantified under steps 1 and 2 above, they may choose to estimate how these mitigation techniques may impact their releases should the required information be available. Facilities may utilize engineering estimates, available release factors, etc. to quantify the impact of their mitigation techniques.

Textile Finishing

One textile finishing estimation methodology was identified. It relies upon a number of facility-specific datapoints. The estimation methodology is therefore divided into three steps: 

1. gathering facility-specific information to support PFAS release estimates
2. estimating PFAS releases
3. applying the impacts of potential mitigation techniques 

The methodology below is based on an OECD emission scenario document for textile finishing (PDF).

Step 1: gather facility-specific information to support PFAS release estimates

The following facility-specific information is required to estimate releases of PFAS to water from textile finishing operations:

• daily amount of textiles treated (in tonnes)*
• application amount (kg of the product per tonne of textiles produced)*
• the fraction of daily production that is treated with the product containing PFAS
• the fraction of residual liquor that could be released from the process*
• degree of fixation of the product containing PFAS to the textiles being produced
• the number of operating days for the facility per year

Note: asterisks (*) represent those values for which recommended values are available if facility-specific information is unavailable.

Step 2: estimate PFAS releases to water and air from textile finishing operations

Utilizing the data identified in Step 1, complete the following equation for each PFAS that meets reporting thresholds. This will provide an emissions estimate for each PFAS substance per day from the facility. Multiply the daily release figure by the number of operating days for your facility.

Where:

• E_water = initial release to water (kg/day)
• E_air = initial release to air (kg/day)
• Q_textile = daily amount of textile treated (tonnes/day)
  • the OECD ESD recommends a value of 13 tonnes/day
• Q_product = application amount (mass of substance use per mass of fabric)
  • in the absence of specific data, the OECD ESD recommends a value of 20 kg/tonne
• F_product = fraction of textile that is treated with the product containing the substance
  • this is to account for the fact that not all textiles manufactured on a given day will be treated with the same substance
• F_{residual liquor} = fraction of the residual liquor that could be released from the process
  • a value of 0.1 is recommended as a first estimation in the OECD (ESD) for padding processes
• F_fixation = degree of fixation
  • a value of 1 is recommended as a first estimation in the OECD ESD for padding processes
• F_s = Emission factor to air for the substance (g/g)

The OECD ESD on textile finishing (PDF) describes the application of functional finishes to all kinds of textiles. Typical application methods include padding (covered via the equation above) and spraying (which the equations above do not cover). Releases to water from spraying operations are likely to occur from overspray. The variables detailed in the equation above rely on default values (in the absence of more specific information), but no default value was identified for the emission factor to air. The Use of PFAS and Fluorine-Free Alternatives in Textiles, Upholstery, Carpets, Leather and Apparel indicates that the median number of operating days for a textile finishing site is 225 days per year, but no similar Canadian-specific information was identified.

For potential PFAS air emissions from open top vessel sources, the evaporation model from section 3.7 of Methods for Estimating Air Emissions from Chemical Manufacturing Facilities (PDF) could be used. Facilities are encouraged to prioritize facility-specific data, such as source testing with mass balance, site-specific emission factors, or engineering estimates and process simulator models, when reporting to the NPRI. Additionally, other estimation methods, such as data from similar facilities or emission factors developed from comparable operations or surrogate substances, may also be used for NPRI reporting.

Step 3: apply the impacts of mitigation techniques to release estimates

Textile finishing facilities generate wastewater and may apply mitigation techniques to limit the release of certain substances within their wastewater. The efficacy of wastewater treatment systems varies by technology type, flow rate, the specific substance under consideration, and many other factors. If facilities apply mitigation techniques to their wastewater stream that will impact the release of any PFAS quantified under steps 1 and 2 above, they may choose to estimate how these mitigation techniques may impact their releases should the required information be available. Facilities may utilize engineering estimates, available release factors, etc. to quantity the impact of their mitigation techniques.

Manufacturing of transportation vehicles

This section provides guidance on the reporting of PFAS to the NPRI for facilities involved in the manufacturing of transportation vehicles. The manufacturing of transportation vehicles not only encompasses the production of automobiles, but also that of aerospace, marine and rail transportation vehicles. In addition, the guidance can be used for niche transportation vehicle manufacturers, for instance the production of off-road vehicles for the mining, forestry, oil and gas and other sectors. The guidance encompassed in this chapter can be used by assembly plants for these different vehicles as well as the component manufacturers that supply these assembly plants with a wide range of parts. 

Because of their vast range of properties, PFAS are widely used in the manufacturing of transportation vehicles. According to Annex A of ECHA Submitted restrictions under consideration for PFAS, PFAS may be used in:

• body, hull and fuselage construction
• sealing applications and lubricants
• fuel engine systems
• hydraulic fluids
• electrical engineering and information technology
• coatings and finishes
• heating, ventilation, air conditioning and refrigeration (HVACR)-systems
• lifesaving and fire protection

It appears that a limited set of PFAS may be used in the manufacture of transportation vehicles that may be potentially relevant for NPRI reporting.

Determine if NPRI reporting thresholds are met

The NPRI reporting threshold for individual PFAS is 1 kg of manufacturing, processing or otherwise use (MPO) at ≥ 0.1% concentration. To determine if the facility meets this reporting threshold, inventory tracking for PFAS-containing products is recommended.

Step 1: identify products containing relevant PFAS manufactured, processed, or otherwise used at the facility and the concentration of individual PFAS in those products

Facilities should review and identify which products they manufacture, process or otherwise use that contain any of the 163 PFAS listed in the NPRI. 

To accurately perform threshold calculations for activities involving the 163 PFAS listed in the NPRI under Part 1C, it is important to understand the exemption for articles, as some PFAS may already be present in the manufactured articles used in assembly facilities.

An "article" is defined as a manufactured item that does not release an NPRI substance when it undergoes processing or any other use. When an article is processed and there are no releases, or the releases are recycled with due care, the NPRI substances in that article need not be included in the threshold calculation. Exercising due care means that the facility generated less than one kilogram of a Part 1A substance as waste during the year. There is no quantitative measure of due care in recycling Part 1C (PFAS). Therefore, if an article containing a Part 1C substance is processed or otherwise used and there are releases, the Part 1C substance in the article must be included in the threshold calculation.

Identifying the presence of individual PFAS in key products manufactured, processed or otherwise used by the facility can involve reviewing the Safety Data Sheet and/or Technical Data Sheet for the relevant products that have the potential of containing PFAS. Contacting the manufacturer or supplier of these products could also be a source to obtain relevant/necessary information.

Through this review, a determination of the concentration (typically expressed in percentage terms) of each individual PFAS (using a CAS RN) within the products being manufactured, processed or otherwise used can be made. Individual PFAS that have been added to the NPRI must be present in the products that are manufactured, processed or otherwise used at a concentration of at least 0.1% in order to meet reporting thresholds. If there are no such products used at the facility, then NPRI reporting of PFAS is not required. If products were identified that contained individual PFAS (that have been added to the NPRI) at a concentration ≥ 0.1%, then it is necessary to proceed to step 2. Please note that the concentration threshold is not applicable if the substances qualify as a 'by-product' under the NPRI definition.

Step 2: calculate the weight of individual PFAS contained in products manufactured, processed or otherwise used for the NPRI reporting year

For those products identified as containing individual PFAS (that have been added to the NPRI) at concentrations ≥ 0.1%, facilities should utilize information on inventory changes (e.g., purchasing records, transfers, amount of product remaining in storage) to quantify the amount of each relevant product used at the facility over the NPRI reporting year.

With the concentration of individual PFAS in the products and the quantity of the product used over the course of the NPRI reporting year available, the following formula can be used to calculate the total quantity of individual PFAS consumed:

Where:

• PFASⁱ_kg = weight of PFAS chemical “i” contained in the product manufactured, processed or otherwise used at the facility during the NPRI reporting year, in kilograms
• Wⁱ_kg = weight of the product containing PFAS chemical “i” that was manufactured, processed or otherwise used during the NPRI reporting year, in kilograms
• Concentrationⁱ_% = concentration of PFAS chemical “i” contained in the product manufactured, processed or otherwise used at the facility during the NPRI reporting year, expressed in percentage terms

The above calculation needs to be repeated for all individual PFAS chemicals that have been added to the NPRI and that are contained in products (at ≥ 0.1% concentration) that were manufactured, processed or otherwise used at the facility during the NPRI reporting year. 

The above calculation also needs to be repeated for each different product that contains individual PFAS (that have been added to the NPRI) that were manufactured, processed or otherwise used at the facility during the NPRI reporting year.

Aggregate the quantity of individual PFAS (defined as having separate CAS RNs) present in different products that are manufactured, processed or otherwise used at the facility during the NPRI reporting year. For individual PFAS calculated to be present in products manufactured, processed or otherwise used at the facility in quantities ≥1 kg during the NPRI reporting year, reporting of all releases, transfers and disposals to the NPRI is required (as long as those individual PFAS are contained in the relevant products at concentrations greater than or equal to 0.1%). Please see the next section for guidance.

If there are no individual PFAS (that have been added to the NPRI) that are calculated to be present in quantities ≥ 1 kg in products that were manufactured, processed or otherwise used during the NPRI reporting year, then reporting of releases, transfers and disposals of PFAS to the NPRI is not required. 

Estimating releases, transfers and disposals

Before estimating releases, transfers, and disposals, it is important to note that if PFAS (that have been added to the NPRI) are present in the components used in manufacturing transportation vehicles, and these components retain their article status, the NPRI-listed PFAS within them are exempt from threshold calculations and reporting obligations.

Step 1: quantify the amount of individual PFAS contained in relevant products/processes manufactured, processed or otherwise used during the NPRI reporting year

For those individual PFAS that met the threshold for reporting to the NPRI, all occurrences of those individual PFAS during manufacturing, processing or use activities at the facility during the NPRI reporting year have to be taken into consideration when determining releases, transfers and disposals (e.g., even if that individual PFAS is contained in products at less than 0.1% concentration). Step 2 in the preceding section in this chapter provides guidance on how to quantify the amount of individual PFAS that are manufactured, processed or otherwise used at your facility during the NPRI reporting year.  

Step 2: apply available default release factors to estimate releases to air, water and land during the NPRI reporting year

For NPRI reporting, facilities are encouraged to prioritize facility-specific data, such as source testing with mass balance, site-specific emission factors, or engineering estimates, when reporting to the NPRI. Additionally, other estimation methods, such as data from similar facilities or emission factors developed from comparable operations or surrogate substances, may also be used for NPRI reporting. 

If facilities do not have access to facility-specific data or other estimation methods, they could consider using the approach applied in Annex A of Submitted restrictions under consideration for PFAS to estimate releases of PFAS in the transport sector for fluorinated gases and polymeric PFAS. This method involves applying default (worst-case) release factors to specific Environmental Release Categories (ERCs) developed by the European Chemicals Agency (ECHA). However, these are the individual PFAS that have not been added to the NPRI and furthermore, it is important to note that ERCs and pollutant release inventory reporting systems like the NPRI serve distinct functions. ERCs are designed to provide conservative overestimates for environmental exposure and should be used with caution when applied to NPRI reporting. Facilities should use ERCs only as an initial reference for identifying potential release sources or estimating releases, and always with careful consideration alongside more specific input from facility experts.

Step 3: account for PFAS disposed of or sent for recycling

It is likely that PFAS-containing waste/recyclable materials are generated by facilities involved in the manufacturing of transportation vehicles, for instance rubber/textile/plastic trimmings, waste materials associated with the application of coatings, adhesives and sealants, wastewater treatment sludge, etc. Individual PFAS (that have been added to the NPRI) that are contained in these waste/recyclable materials need to be accounted for. Due to the wide variety of waste materials that could be generated containing PFAS among facilities in this sector, it is difficult to provide guidance on how to estimate the quantities of individual PFAS that are contained in this material.

It is recommended that, where possible, estimates are made of the content of individual PFAS (that have been added to the NPRI and met the reporting threshold) that are contained in materials that are forwarded for recycling or disposal during the NPRI reporting year. The following equation can be used:

Where:

• PFASⁱ_kg = weight of PFAS chemical “i” contained in waste or recyclable materials generated during the NPRI reporting year, in kilograms
• PFASⁱ_Waste% = content of PFAS chemical “i” contained in materials that are forwarded for disposal or recycling during the NPRI reporting year, expressed in percentage terms
• Waste or Recyclable Materialsⁱ_kg = quantity of materials containing PFAS chemical “i” that are forwarded for disposal or recycling during the NPRI reporting year, in kilograms

Facility-specific knowledge can then be used to properly account for the quantity of PFAS chemical “i” in terms of whether it was disposed on-site, disposed of off-site, removed from the facility for recycling, etc.

The above equation would need to be applied to the different waste or recyclable materials, containing PFAS chemical “i” that were disposed of or recycled during the NPRI reporting year. In addition, the above equation would need to be applied to the range of individual PFAS that met the NPRI reporting threshold and that are contained in materials that were disposed of or recycled during the NPRI reporting year.

Oil and gas production

Both non-polymeric PFAS and polymeric PFAS (like fluoropolymers) are used in a variety of applications within the oil and gas production sector.

According to PFAS in mining and petroleum industry – use, emissions and alternatives (PDF) from the Norwegian Environment Agency, the main non-polymeric uses of PFAS in the oil and gas sector are as anti-foaming agents or as tracers.

Determine if NPRI reporting thresholds are met

The NPRI reporting threshold for individual PFAS is 1 kg manufactured, processed or otherwise used (MPO) at ≥ 0.1% concentration. To determine if the facility meets this reporting threshold, inventory tracking for PFAS-containing products is recommended.

It is important to note that the exploration for oil or gas, or the drilling of oil or gas wells are activities that are exempt from NPRI reporting (Legal requirements: Canada Gazette notices). This exemption should be taken into consideration when determining if the activities at your facility during the NPRI reporting year (that manufacture, process or otherwise use PFAS that have been added to the NPRI) meet the NPRI reporting threshold.  

Step 1: identify products containing relevant PFAS manufactured, processed, or otherwise used at the facility and the concentration of individual PFAS in those products

Facilities should conduct research to determine which products that they consume contain any of the 163 PFAS listed in the NPRI. The types of products used within the oil and gas sector that contain PFAS were described in the Introduction to this chapter.

Below are some specific PFAS that have been identified as being used in the oil and gas production sector and which have been added to the NPRI. There may be other PFAS used in your operations that have also been added to the NPRI. Research is necessary to determine their existence within your operations. This simply provides some assistance in identifying specific PFAS (i.e., with distinct CAS RNs) that may be manufactured, processed or otherwise used at your facility, and which have been added to the NPRI. 

PFAS added to the NPRI identified as being used in oil and gas production and their functions

• heavy crude oil well polymer blocking remover:
  • CAS RN 1691-99-2
  • CAS RN 56773-42-3
  • CAS RN 754-91-6
• enhanced oil recovery:
  • CAS RN 1652-63-7
    • hydrocarbon foaming agent
    • fluorinated surfactants to enhance gas production
  • CAS RN 335-67-1
    • renders surfaces of the oil-bearing reservoirs oleophobic
  • CAS RN 678-39-7
    • hydrocarbon foaming agent
• oil containment:
  • CAS RN 29117-08-6
• surface active agent in oil and gas drilling, extraction and support activities:
  • CAS RN 65545-80-4 (contained in hydraulic fracturing fluid)
• use identified but with an unknown function:
  • CAS RN 68187-47-3
  • CAS RN 70969-47-0

Research to identify the presence of individual PFAS in key products manufactured, processed or otherwise used by the facility can involve reviewing the Safety Data Sheet and/or Technical Data Sheet for the relevant products that have the potential of containing PFAS. Contacting the manufacturer or supplier of these products could also be a source to obtain relevant/necessary information. It is important to identify the CAS RN of PFAS contained in the products that the facility manufactures, processes or otherwise uses so that it can be compared to the list of PFAS (by CAS RN) that have been added to the NPRI.

Through this research, a determination of the concentration (typically expressed in percentage terms) of each individual PFAS (using a CAS RN) within the products being manufactured, processed or otherwise used can be made. Individual PFAS that have been added to the NPRI must be present in the products consumed at a concentration of at least 0.1% in order to meet NPRI reporting thresholds. If there are no such products consumed at the facility, then NPRI reporting is not required. If products were identified that contained individual PFAS (that have been added to the NPRI) at a concentration ≥ 0.1%, then it is necessary to proceed to step 2. 

Step 2: calculate the weight of individual PFAS contained in products manufactured, processed or otherwise used for the NPRI reporting year

For those products identified as containing individual PFAS (that have been added to the NPRI) at concentrations ≥ 0.1%, facilities should utilize information on inventory changes (e.g., purchasing records, transfers, amount of product remaining in storage) to quantify the amount of each relevant product consumed at the facility over the NPRI reporting year. 

With the concentration of individual PFAS in the products and the quantity of the product consumed over the course of the NPRI reporting year available, the following formula can be used to calculate the total quantity of individual PFAS manufactured, processed or otherwise used:

Where:

• PFASⁱ_kg = weight of PFAS chemical “i” contained in the product manufactured, processed or otherwise used at the facility during the NPRI reporting year, in kilograms
• Wⁱ_kg = weight of the product containing PFAS chemical “i” that was manufactured, processed or otherwise used during the NPRI reporting year, in kilograms
• Concentrationⁱ_% = concentration of PFAS chemical “i” contained in the product manufactured, processed or otherwise used at the facility during the NPRI reporting year, expressed in percentage terms

The above calculation needs to be repeated for all individual PFAS chemicals that have been added to the NPRI and that are contained in products (at ≥ 0.1% concentration) that were manufactured, processed or otherwise used at the facility during the NPRI reporting year. 

The above calculation also needs to be repeated for each different product that contains individual PFAS (that have been added to the NPRI) that was manufactured, processed or otherwise used at the facility during the NPRI reporting year.

Aggregate the quantity of individual PFAS (defined as having separate CAS RNs) present in different products that are manufactured, processed or otherwise used at the facility during the NPRI reporting year. For individual PFAS calculated to be present in products manufactured, processed or otherwise used at the facility in quantities ≥ 1 kg during the NPRI reporting year, reporting of releases, transfers and disposals to the NPRI is required (as long as those individual PFAS are contained in the relevant products at concentrations greater than or equal to 0.1%). Please see the next section for guidance.

If there are no individual PFAS (that have been added to the NPRI) that are calculated to be present in products that were manufactured, processed or otherwise used in quantities ≥1 kilogram during the NPRI reporting year, then reporting of releases, transfers and disposals to the NPRI is not required. 

Estimating releases, transfers and disposals

It is expected that the PFAS products (e.g., tracers, antifoaming agents) are released into the oil/gas stream as part of their active use, with some PFAS in these products having direct releases to the environment and some PFAS in these products being contained in produced water.

Due to the diverse number of operations within the oil and gas production sector, each reporting facility should review the products that they consume that could contain PFAS (see the first section in this chapter) to determine if there are any relevant non-polymeric PFAS contained in products outside of tracers, antifoaming agents and additives in hydraulic fracturing fluids. 

When reporting to the NPRI, facilities are encouraged to prioritize facility-specific data, such as source testing with mass balance, site-specific emission factors, or engineering estimates and process simulator models. Additionally, other estimation methods, such as data from similar facilities or emission factors developed from comparable operations or surrogate substances, may also be used for NPRI reporting. Please note, releases, transfers and disposals could be also generated from the use of firefighting foams like AFFFs or stormwater runoff which are covered under Firefighting Foams. 

PFAS movements in oil and gas production and potential for releases/disposals/transfers 

In oil and gas drilling operations, PFAS can be found in anti-foaming agents used in drilling fluids and in tracers. The use of these products can result in releases to air, water and land. Some of the products may also end up as part of the oil and gas stream or can be contained in recovered water. Recovered water may be: 

• injected for enhanced oil recovery
• injected for disposal (on-site or off-site) 
• transferred off-site (after treatment) for reuse (e.g. ag. applications)
• evaporated in impoundments 
• released to water or land

PFAS can also be found in hydraulic fracturing fluids used in oil and gas fracturing operations. The use of these fluids can result in releases to air, water and land. A large portion of the fluid used remains underground (and should be reported accordingly). A much smaller portion of the fluid is recovered during flowback operations where it is then: 

• reused in nearby fracturing operations
• stored awaiting disposal (on-site or off-site)
• disposed of in deep injection wells

Step 1: quantify the amount of individual PFAS contained in relevant products manufactured, processed or otherwise used during the NPRI reporting year

For those individual PFAS that met the threshold for reporting to the NPRI, all occurrences of those individual PFAS during manufacturing, processing or use activities at the facility during the NPRI reporting year have to be taken into consideration when determining releases, transfer and disposals (e.g., even if that individual PFAS is contained in products at less than 0.1% concentration). Step 2 provides guidance on how to quantify the amount of individual PFAS that are manufactured, processed or used at your facility during the NPRI reporting year.

PFAS in mining and petroleum industry – use, emissions and alternatives (PDF) assumed that the PFAS content in tracers was 100% while the PFAS content in anti-foaming agents was 2-5%. Meanwhile the majority of hydraulic fracturing fluid (up to 97%) is water with the next largest component of hydraulic fracturing fluid being the proppant. Therefore, PFAS concentrations in hydraulic fracturing fluid are likely less than 1%. 

It is recommended that facilities develop more accurate percentages based on a review of the Safety Data Sheet, Technical Data Sheet. Contacting the manufacturer or supplier of these products could also be a source to obtain relevant/necessary information. If more accurate data cannot be obtained through these avenues, then the PFAS concentrations identified above can be applied to the relevant quantity of tracers, anti-foaming agents and hydraulic fracturing fluids that were manufactured, processed or otherwise used during the NPRI reporting year.  

Step 2: apply available mass balance factors to PFAS quantities manufactured, processed or otherwise used for tracers and antifoaming agents

The most relevant existing estimation of releases, transfers and disposals of PFAS from the oil and gas sector applied various different scenarios (including worst-case European Chemical Agency release factors) to the PFAS content in the amount of tracers and anti-foaming agents consumed in Europe. This publication did not analyze hydraulic fracturing fluids, potentially due to the fact the hydraulic fracturing is much less prevalent in the European Union than in North America. Please see Step 3 below for guidance on estimating the release, transfer and disposal of PFAS in hydraulic fracturing fluids. 

Based upon information contained in the European document, the table below presents a mass balance of PFAS contained in tracers and anti-foaming agents. Release/mass balance factors are presented for two separate activities:

1. formulation of the tracers and anti-foaming agents into a mixture
2. use of functional fluids at an industrial site
   • tracers
   • anti-foaming agents

If facility-specific information is available, it should be used instead of the default factors provided in Table 3.

Should oil and gas facilities purchase already formulated products, then the release factors/mass balance factors for this formulation activity are not relevant to their operations. Alternatively, if oil and gas facilities formulate these products on-site from purchased raw materials, then the release factors/mass balance factors for this formulation activity need to be applied. 

Unless more detailed specific data are available to the facility on the use or release patterns of these products, an estimate of releases to air, water, land and waste should be made using the mass balance estimates in the table below. There is a significant uncertainty range associated with these mass balance estimates. This is largely due to lack of data on the precise environmental release and behaviour of chemical products (e.g., anti-foaming agents and tracers) that are applied within oil and gas facilities.

Note: Modified based on information contained in PFAS in Mining and Petroleum Industry – Use, Emissions and Alternatives (PDF), prepared for the Norwegian Environment Agency.

Tracers and antifoaming agents are expected to be released into the oil/gas stream as part of their active use. For the use of anti-foaming agents, it is expected that the PFAS-containing products will be contained in the injection fluids but, due to the lipophilic nature of the PFAS compounds, they will tend to be retained in the oil/gas stream. Based on PFAS in mining and petroleum industry – use, emissions and alternatives (PDF), a conservative estimate is applied, assuming 80% is retained in the petroleum stream and 20% remains in the recovered/produced water (these percentages are applied after releases to air, water and land occur). In terms of tracers, there is limited specific data available on the precise release patterns or exactly how these substances will behave when released to the environment. In particular, the use phase is extremely challenging to characterize accurately and this is subject to considerable uncertainty. The same assumption (80% retained in petroleum stream, 20% in recovered water) has also been applied for tracers.

According to PFAS in mining and petroleum industry – use, emissions and alternatives (PDF), PFAS contained in antifoaming agents also partially partitions to recovered water. Oil and gas recovered water, also known as produced water, is a non-potable by-product of oil and gas production. It's a mixture of water that was already in the reservoir and water that was injected to extract oil and gas. In addition, a portion of the chemicals added during processing of reservoir fluids may partition to the produced water. For more details, see the National Energy Board's Offshore Waste Treatment Guidelines. As reported in U.S. Produced Water Volumes and Management Practices in 2021 (PDF) and Process water treatment in Canada’s oil sands industry: I. Target pollutants and treatment objectives, there are various different fates for recovered water/produced water, including:

• enhaced recovery:
  • injecting water into conventional hydrocarbon bearing formations to produce additional oil and gas beyond what would be produced using only primary recovery
• in-situ operations:
  • use of process water to create steam that heats bitumen, then recovers and recycles the water
• operator disposal:
  • injection of produced water into disposal wells by the operator who generated the water
• commercial disposal:
  • injection of produced water into disposal wells by a third-party being paid to dispose of the water
• surface discharge:
  • includes offshore discharges to surface water as well as onshore discharges to surface waters and land surfaces typically after treatment and when the water meets certain water quality standards
• evaporation:
  • evaporation ponds are large impoundments that require a relatively large space to efficiently evaporate water by sunlight
  • the extent that this technique is used in Canada may be quite limited to non-existent
• beneficial reuse:
  • this can include the incorporation of produced water to augment fresh water in hydraulic fracturing fluids or drilling operations in order to complete new wells
  • uses outside the oil and gas sector can include agricultural irrigation and dust and ice control on roads
  • the extent to which these reuse applications are used in Canada is unknown
• on-site containment:
  • for instance, the storage of process water on-site in setting basins and tailing ponds
• reintegration in the landscape:

  • process water (and tailings) can be reintegrated into the landscape to restore aquatic and terrestrial ecosystems through various reclamation scenarios

Each facility will need to utilize their own internal records on the fate of recovered water that they generated during the NPRI reporting year in order to determine the fate of the PFAS that partitioned to that recovered water. 

Aggregated national data on the fate of produced water generated by the oil and gas sector in Canada was not located. For information purposes, the fate of produced water in U.S. Produced Water Volumes and Management Practices in 2021 (PDF) was as follows: 

• 48.3% was injected for enhanced oil recovery
• 37.3% was injected for disposal by the operator
• 10.1% was injected for disposal by commercial operations
• 1.2% was discharged to waterbodies or land surfaces (over 95% of these discharges were to water bodies)
• 0.2% was evaporated in either lined or unlined impoundments
• 2.6% was used beneficially within or outside the oil and gas sector
• 0.4% was categorized as “other”: 
  • spilled
  • unaccounted for
  • record errors 
  • differences in produced versus management

Step 3: estimate fate of PFAS contained in hydraulic fracturing fluids

There was no identified equivalent mass balance accounting for PFAS contained in hydraulic fracturing fluid which was available for anti-foaming solutions and tracers. In the absence of more precise information or facility-specific data, the assumptions used for the fate of PFAS used in anti-foaming solutions and tracers can be applied for PFAS contained in hydraulic fracturing fluids. However, the default factors for releases to air, water and land presented above for anti-foaming solutions and tracers have been modified based on an understanding of the generation of recovered water from hydraulic fracturing operations and the percentage of fluid that remains underground. To be more specific, a large percentage of the hydraulic fracturing fluid (containing PFAS) remains underground and therefore there is not as much PFAS available to be released to surface air, water and land as indicated in the default factors presented earlier for anti-foaming solutions and tracers.

During hydraulic fracturing, produced saline water (called flowback water) is returned to the surface. As reported in Understanding the Fate of Non-recovered Fracturing Water and the Source of Produced Salts for Optimizing Fracking Operations and Water Resource Reporting and Water Footprint from Marcellus Shale Development in West Virginia and Pennsylvania (PDF), field observations show that as little as (or less than) 10% of the injected fracturing fluid may be recovered during flowback. Imbibition (or leak-off) of fracturing water into the rock matrix may be the main mechanism by which fracturing water is lost. From Understanding the Fate of Non-recovered Fracturing Water and the Source of Produced Salts for Optimizing Fracking Operations, it has been suggested that up to 30% of water injected during hydraulic fracturing can be recovered to the surface after flowback operations, however field observations to date indicate approximately 10%. This information was utilized to establish default fates for PFAS contained in hydraulic fracturing fluids that are injected into the well in terms of what percentage of the PFAS contained in hydraulic fracturing fluids remains underground, what percentage returns to the surface contained in flowback fluid and what percentage remains to result in potential releases to surface air, water and land.

Note: Modified based on information contained in PFAS in Mining and Petroleum Industry – Use, Emissions and Alternatives (PDF), prepared for the Norwegian Environment Agency.

Surface discharge of flowback fluid is not permitted in Canada, which means it is not released into surface waters, such as lakes and streams. Flowback fluid may be recycled for further hydraulic fracturing, stored or disposed of by injection into deep sub-surface formations, through a licensed disposal well. Additional details on these fates are as follows:

Mining

PFAS substances can be used in the mining sector as follows:

• in firefighting foams (e.g. aqueous firefighting foams (AFFFs)) for training or actual use
• extraction of minerals from ores
• in acid mist suppressing agents (leaching and electrowinning processes)
• in wetting agents (leaching processes)
• in hydrocarbon foaming agents (ore flotation processes)
• in fluorinated surfactants (ore flotation processes)

The use of firefighting foams is covered under Firefighting foams; that chapter also includes a section outlining the method that could be used to estimate PFAS quantities in stormwater runoff. The guidance within this section will therefore cover the manufacturing, processing, or otherwise use of products containing PFAS in the extraction of minerals from ores. Overall, three processes in the mining sector utilize products that can contain PFAS substances: 

1. leaching
2. ore flotation
3. electrowinning processes

Brief descriptions of these processes follow.

Leaching

Leaching involves dissolving metals from ore using a chemical solution, creating a “leachate” that contains the dissolved metals at higher concentrations than existed within the ore. According to PFAS—emerging constituents of concern for mine closure studies, PFAS substances are used to increase the wetting of sulfuric acid or cyanide that can be used to leach the ore, or as an ingredient in acid mist suppressant. As reported by An overview of the uses of per- and polyfluoroalkyl substances (PFAS) PFAS can be found as ingredients in leaching products or mist suppressants due to their ability to lower surface tension.

Two types of leaching processes have been identified in Canada: 

1. heap leaching
2. in-situ leaching

According to the article A Review of In Situ Leaching (ISL) for Uranium Mining (published in 2024 in Mining Journal),  in-situ leaching processes are currently limited in Canada and the first Canadian in-situ leaching project was started at the Pheonix Uranium Deposit in 2023. Facilities practicing in-situ leaching processes while utilizing solutions containing PFAS are encouraged to undertake their own mass-balance calculations to estimate potential releases. Due to variables in site specific geology, technology, hydrology, design, etc., the provision of a single estimation methodology is not advisable. The following diagram provides an indication of how heap leaching is typically practiced.

Heap leaching is typically practiced by spraying a chemical solution (dilute sulphuric acid) over a heap of crushed ore which has been placed on a pad of impermeable material. The solution percolates through the ore heap and leaches the metals into a leach solution which is collected at the toe of the ore heap, in a collection pool. The pregnant leach solution in the pool contains 60-70% pure copper in solution. This solution is sent to solvent extraction where the copper in solvent is separated from the acid. The acid solution from the process is typically recycled or moves through solvent extraction and on to the electrowinning process (described below). The quantity of each individual PFAS (of the 163 that must be reported to the NPRI) that may partition from the acid solution and into the ore waste is unknown. Literature regarding the fate and transport of PFAS in different environmental media was reviewed, but no specific literature on how PFAS within sulfuric acid or cyanide solutions interact with waste ores was identified. Waste ore that has undergone leaching is typically disposed of on-site in tailings areas.

Electrowinning

Electrowinning (also referred to as electroextraction) is a further concentration step that typically follows leaching. Electrowinning “is the electrodeposition of metals from their ores that have been put in solution via a process commonly referred to as leaching. The process involves passing an electric current through a solution containing metal ions, causing the metal to plate out onto an electrode". For more information, see Electrowinning: A Complete Guide.

Floatation

Similar to leaching, flotation is used to separate valuable minerals from ore. Typically, crushed ore is mixed with water and chemical additives to make slurry wherein the target minerals are made hydrophobic. Air is then injected into the slurry to form bubbles and the hydrophobic minerals attach to the bubbles and rise to the surface as a froth layer, which is then separated from the remaining unwanted material that did not float.

Leaching and froth flotation may not be used within the same concentration processes, and electrowinning is only utilized near the end of hydrometallurgical concentration processes (that utilize leaching). More information can be found in Mining - Flotation.

Determine if NPRI reporting thresholds are met

The NPRI reporting threshold for individual PFAS is 1 kg of manufacturing, processing or otherwise use at ≥ 0.1% concentration. To determine if your facility meets this reporting threshold, calculations regarding all of the products that your facility has purchased containing PFAS substances are required.

Step 1: identify products containing relevant PFAS manufactured, processed, or otherwise used at the facility and quantify the scale of their use

Research to identify the presence of individual PFAS in key products manufactured, processed or otherwise used by the facility can involve reviewing the Safety Data Sheet and/or Technical Data Sheet for the relevant products that have the potential of containing PFAS. Contacting the manufacturer or supplier of these products could also be a source to obtain relevant/necessary information. If readily available data can not be obtained, reasonable efforts should be taken to estimate the manufactured, processed or otherwise used. Substances present in these mixtures at concentration of at least 0.1% must be considered in the calculation of whether reporting thresholds were met.

Step 2: calculate the weight of individual PFAS contained in products manufactured, processed or otherwise used for the NPRI reporting year

After all products used at the facility containing PFAS have been identified, and the volume of their use has been established, the concentrations of the individual PFAS substances within the products will need to be determined in order to estimate the weight of each individual PFAS substance utilized over the course of the reporting year. This information could be available from product manufacturers. This concentration will typically be outlined in percentage (%) terms. Apply those percentages to the total quantity (in kg) of product that was manufactured, processed or otherwise used at the facility during the NPRI reporting year. Use the following formula: 

Where:

• PFASⁱ_kg = weight of PFAS chemical “i” contained in the product manufactured, processed or otherwise used at the facility during the NPRI reporting year, in kilograms
• Wⁱ_kg = weight of the product containing PFAS chemical “i” that was manufactured, processed or otherwise used during the NPRI reporting year, in kilograms
• Concentrationⁱ_% = concentration of PFAS chemical “i” contained in the product manufactured, processed or otherwise used at the facility during the NPRI reporting year, expressed in percentage terms

The above calculation needs to be repeated for all individual PFAS chemicals that have been added to the NPRI and that are contained in products that were manufactured, processed or otherwise used at the facility during the NPRI reporting year. 

The above calculation also needs to be repeated for each different product that contains individual PFAS (that have been added to the NPRI) that were manufactured, processed or otherwise used at the facility during the NPRI reporting year.

Aggregate the quantity of individual PFAS (defined as having separate CAS RNs) present in different products that are manufactured, processed or otherwise used at the facility during the NPRI reporting year. For individual PFAS calculated to be present in products manufactured, processed or otherwise used at the facility in quantities ≥1 kg during the NPRI reporting year, reporting of releases, transfers and disposals to the NPRI is required (as long as those individual PFAS are MPO at concentrations greater than or equal to 0.1%.). Please see Estimating releases, transfers and disposals for guidance.

If there are no individual PFAS (that have been added to the NPRI) that are calculated to be present in products that were manufactured, processed or otherwise used in quantities ≥1 kilogram during the NPRI reporting year, then reporting of releases, transfers and disposals to the NPRI is not required. 

Estimating releases, transfers and disposals

There are three different processes from which releases or disposals of material streams containing PFAS substances may be generated from mining operations:

1. leaching
2. ore flotation
3. electrowinning processes

Electrowinning processes typically follow leaching processes, and therefore these two processes are described together. Ore flotation is described separately. Facilities are encouraged to prioritize facility-specific data, such as source testing with mass balance, site-specific emission factors, or engineering estimates and process simulator models, when reporting to the NPRI. Additionally, other estimation methods, such as data from similar facilities or emission factors developed from comparable operations or surrogate substances, may also be used for NPRI reporting.

For those individual PFAS that met the threshold for reporting to the NPRI, all occurrences of those individual PFAS during manufacturing, processing or use activities at the facility during the NPRI reporting year have to be taken into consideration when determining releases, transfers and disposals (e.g., even if that individual PFAS is contained in a product at less than 0.1% concentration).

Leaching and electrowinning

PFAS added to a leaching solution will either partition to tailings that are disposed of, or partition to pregnant leachate and eventually be released with effluent from the electrowinning process.

Tailings from leaching processes may get leached again but will eventually be disposed of in a tailings area. No publicly available information on how each of the 163 PFAS that must be reported to the NPRI might partition to either tailings or pregnant leachate (from a cyanide or sulfuric acid solution used in a leaching process) was identified. Therefore, facilities may utilize testing processes that analyze site-specific/process-specific concentrations of PFAS within tailings in order to estimate the total quantity of each of the 163 PFAS that must be reported to the NPRI contained within tailings disposed of during the course of the NPRI reporting year. If no testing data is available, facilities could make reasonable estimates using the best readily available information.

Pregnant leach solution from the leaching process will typically flow through to solvent extraction and electrowinning processes and is not released or disposed of during leaching. Instead, effluent from the electrowinning process (typically acidic in nature and requiring treatment before release) may be recycled back into the process but will eventually undergo treatment before being released. The specific type of treatment the effluent will undergo will depend upon the specific mine site. Facilities may choose to undertake testing of their electrowinning effluent to estimate the total quantity of each of the 163 PFAS that must be reported to the NPRI contained within effluent released during the NPRI reporting year. Effluent should be tested at the point of release as opposed to before treatment in order to ensure that the potential impact of effluent treatment is applied. 

For both electrowinning effluent and tailings, calculate annual disposals or releases using the following calculation: 

Where:

• PFASⁱ_kg = weight of PFAS chemical “i” contained in the tailings from leaching (kg for disposal) or effluent from electrowinning (litres for releases) at the facility during the NPRI reporting year
• Wⁱ_kg = weight of the tailings generated while using PFAS containing leaching solution in kg, or volume of the electrowinning effluent generated while using PFAS containing leaching solution, in litres
• Concentrationⁱ_% = concentration of PFAS chemical “i” contained in the tailings (kg/kg) or electrowinning effluent (kg/l) during the NPRI reporting year, expressed in percentage terms determined through testing

The above calculation needs to be repeated for all individual PFAS chemicals that have been added to the NPRI and that are contained in tailings or electrowinning effluent that were utilized in the leaching/electrowinning processes during the NPRI reporting year.

Ore flotation

Ore flotation generates a tailing stream that may contain PFAS. The minerals that are harvested via flotation are typically sent to smelting processes, where they are smelted at temperatures over 1,200°C. These temperatures are sufficient to destroy PFAS substances. For more information, see Guidance on Landfill Gas Flaring (PDF) (published by the Scottish Environmental Protection Agency in 2002). Therefore, all PFAS substances utilized within the ore flotation process are either disposed of (on-site or off-site) with tailings or destroyed. No information on how each of the 163 PFAS that operators must report to the NPRI might partition through a flotation process was identified. Operators may choose to conduct testing on the tailings exiting flotation processes to establish the quantities of waste PFAS contained within their tailings. If this testing is conducted, the results of this testing can be used to estimate total PFAS contained in tailings generated annually at the facility for reporting purposes. Use the following calculation: 

Where:

• PFASⁱ_kg = weight of PFAS chemical “i” contained in the tailings from flotation at the facility during the NPRI reporting year, in kg
• Wⁱ_kg = weight of the tailings generated from flotation while using PFAS containing products, in kg
• Concentrationⁱ_% = concentration of PFAS chemical “i” contained in the tailings from flotation generated during the NPRI reporting year, expressed in percentage terms determined through testing

The above calculation needs to be repeated for all individual PFAS chemicals that have been added to the NPRI and that are used in the flotation process during the NPRI reporting year. Aggregate the quantity of individual PFAS (defined as having separate CAS RNs) used in the flotation process during the NPRI reporting year.

If no testing data is available, facilities could make reasonable estimates using the best readily available information about the PFAS utilized in a flotation process that partitions to tailings for disposal. To estimate the quantity of PFAS present in tailings from flotation processes, utilize the following steps.

Step 1: identify products containing relevant PFAS used in flotation processes at the facility and quantify the scale of their use

Facilities should identify whether any products used in the flotation process contain one or more of the 163 PFAS substances listed in the NPRI. This could be done by reviewing the product's Safety Data Sheet (SDS), Technical Data Sheet (TDS), or by contacting the manufacturer or supplier. Using readily available information such as inventory changes, purchasing records, product transfers, or storage amounts or applying reasonable estimates when data is limited, facilities should quantify the amount of each PFAS-containing product used in the flotation process over the NPRI reporting year. 

Step 2: calculate the weight of individual PFAS contained in products used in flotation processes for the NPRI reporting year

After all products used in the flotation process containing PFAS have been identified, and the volume of their use has been established, the concentrations of the individual PFAS substances within the products will need to be determined in order to estimate the weight of each individual PFAS substance utilized in the flotation process over the course of the reporting year. This information should be available from product manufacturers. This concentration will typically be outlined in percentage (%) terms. Apply those percentages to the total quantity (in kg) of product utilized in the flotation process during the NPRI reporting year. Use the following formula:

Where:

• PFASⁱ_kg = weight of PFAS chemical “i” contained in the product used in the flotation process during the NPRI reporting year, in kilograms
• Wⁱ_kg = weight of the product used in the flotation process during the NPRI reporting year, in kilograms
• Concentrationⁱ_% = concentration of PFAS chemical “i” contained in the product used in the flotation process at the facility during the NPRI reporting year, expressed in percentage terms

The above calculation needs to be repeated for all individual PFAS chemicals that have been added to the NPRI and that are used in the flotation process during the NPRI reporting year. Aggregate the quantity of individual PFAS (defined as having separate CAS RNs) used in the flotation process during the NPRI reporting year.

Step 3: apply the impacts of mitigation techniques to release estimate

Ore flotation generates tailings, and facilities may apply mitigation techniques to limit the release of certain substances within their tailings. The efficacy of tailings treatment systems varies by technology type, flow rate, the specific substance under consideration, and many other factors. If facilities apply mitigation techniques to their tailings stream that will impact the release of any PFAS quantified under Step 1 and Step 2 above, they may choose to estimate how these mitigation techniques may impact their releases should the required information be available. Facilities may utilize engineering estimates, available release factors, etc. to quantity the impact of their mitigation techniques.

Recovered paper processing

According to the article Recycling of paper, cardboard and its PFAS in Norway, PFAS have been used in paper and paperboard products since the 1960s, most notably in food contact materials. When paper products – including food contact materials treated with PFAS – enter a recovered paper processing facility, the PFAS substances will flow through the paper recovering process and into facility wastewater and newly manufactured paper products (as non-intentionally added substances or by-products). Please note that releases, transfers, and disposals may also result from the use of firefighting foams like AFFF or from stormwater runoff, both of which are addressed in the section on Firefighting foams.

The scope of this section is limited to the recovered paper processing facilities that break down the waste products for the manufacture of new products as opposed to collection or sortation activities that typically take place in separate facilities. Any potential releases of PFAS-containing paper products from collection or sortation processes (typically undertaken at material recovery facilities that handle many different products as opposed to just paper) are not described within this section. 

PFAS exiting paper recovered paper processing facilities within new product as non-intentionally added substances are also not considered to be within scope, as these are not releases or transfers, but instead unintentional PFAS within a product. Finally, no suitable information was identified on: 

• potential PFAS releases to air from recovered paper processing facilities
• concentrations of specific PFAS analytes in sludge generated by wastewater treatment at recovered paper processing facilities
• how to quantify potential PFAS transfers to landfills within rejected paper products containing PFAS

Therefore, this chapter provides guidance on how to estimate the quantity of PFAS contained within treated wastewater that is released from recovered paper processing facilities. The following section describes fresh water use and recycling within the paper recovering process as well as how water is treated via a wastewater treatment plant within the facility before it is released to the environment.

Description of recovered paper processing and potential sources of PFAS

The steps in a typical recovered paper processing flow are as follows: 

1. recovered paper storage 
   • storage of received bales of recovered paper from household and/or commercial sources
2. mixture preparation
3. pulping
   • additional inputs: 
     • steam
     • water (fresh water and recycled from water treatment)
     • sludge from water treatment 
     • fibres from future sorting steps
   • outputs: 
     • scraps sent to scraps press
4. HD (High Density) cleaning (requires water) 
5. mechanical sorting
   • outputs: 
     • fibres recycled back to pulping step
     • scraps to scraps press
6. screening (stage i and stage ii)
7. screening (stage iii) 
   • some material goes to this stage
   • outputs:
     • materials returned to screening (stage i & ii)
     • scraps to scrap press
8. thickening
   • output: 
     • water to water treatment
9. (optional) refining
10. cyclones
    • output: 
      • water to water treatment
11. paper machine
    • inputs: 
      • water (fresh water and recycled from water treatment) 
      • steam
      • chemicals
    • outputs:
      • steam
      • water to water treatment 
12. product
    • output: 
      • final paper product

Additional processes which occur alongside the main material flow: 

1. scraps press
   • inputs received from:
     • pulping
     • mechanical sorting
     • screening (stage iii) 
   • outputs: 
     • scraps removed from system
     • water sent to water treatment
2. water treatment: 
   • inputs:
     • defoamers
     • wastewater received from: 
       • scraps press
       • thickening 
       • cyclones
       • paper machine
       • rainwater
   • outputs: 
     • provides recycled water to many process steps 
     • excess water is discharged

Limited data on the concentrations of specific PFAS substances that flow through recovered paper processing facilities were identified. Two main sources of information on PFAS concentrations in recovered paper processing facilities were found:

US EPA data

USEPA presented some limited effluent PFAS data from pulp, paper, and paperboard facilities in the United States in Multi-Industry Per- and Polyfluoroalkyl Substances (PFAS) Study – 2021 Preliminary Report. Since then, it has been updated with additional data collected on PFAS use and discharge from other pulp, paper, and paperboard facilities and presented in the subsequent 2023 Final Effluent Guidelines Program Plan 15 (EPA-821-R-22-004) [PDF]. This updated report contains a table that shows concentration ranges and average concentrations for 34 PFAS substances in the wastewater of paper mills based on 4,664 samples (not specifically recovered paper processing facilities). Monitoring data from the 52 facilities showed detectable but generally low PFAS levels. As per the 2022 PPEC Recycled Content Survey (PDF) (published by The Paper and Paperboard Packaging Environmental Council [PPEC]) As many paper mills utilize post-consumer paper as a feedstock. Consequently, it can be assumed that some of these mills that are involved in recovered paper processing likely have PFAS within their wastewater due to post-consumer feedstock contaminated with PFAS. No information about the 52 facilities is available, however: 

1. only a small subset of paper mills in the U.S. use PFAS substances and therefore products for which PFAS substances are added intentionally make up a very small percentage of overall production
2. the EPA did not identify any paper mills utilizing wastewater treatment technologies known to reduce PFAS, and therefore these figures likely provide a good indication of PFAS concentrations in facility wastewater

Given the fact that these facilities were located in North America, this data has been chosen for use within this guidance.

Recycling of paper, cardboard, and its PFAS in Norway

Langberg et al., (2024), Recycling of Paper, Cardboard, and its PFAS in Norway is a study is for a single pulp mill in Norway but is specific to a paper recycling facility. It analyzes 37 PFAS within the facility at 8 different sampling points as follows:

• (1) reject paper from the initial sorting
• (2) pulp of the paper sorted for recycling
• (3 and 4) wastewater filtered to separate the dissolved, and particulate phases
• (5 and 6) reject from the paper machines PM5 and PM6
• (7 and 8) recycled paper from PM5 and PM6

This study gathered results from only one facility in Norway, and it is unknown if the samples taken from this single facility are representative of average concentrations at paper recycling facilities in North America. Additionally, the study only found 6 PFAS analytes in the pulping stage of the process (sampling point 2) – some of which are not on the NPRI list. A Similar number of analytes were identified at other stages of the process – leaving the data of limited utility for the purposes of this guidance.

Determine if NPRI reporting thresholds are met

The NPRI reporting threshold for individual PFAS is 1 kg of manufacturing, processing or otherwise use at ≥ 0.1% concentration. For recovered paper processing facilities, all substances collected in the waste paper feedstock or produced during wastewater treatment are considered to be “by-products”, and as a result, the concentration threshold does not apply (recovered paper processing facilities do not manufacture PFAS, and they do not use PFAS). In order to determine if NPRI reporting thresholds are met, it must be determined if more than 1 kg of any specific PFAS substance entered the facility within waste paper during the reporting year. Given that any individual piece of paper may have no PFAS in it, or may have high concentrations of PFAS, the most sensible place (given currently available data) to conduct testing for PFAS in a recovered paper processing facility would be within wastewater. The following estimation methodology can be used to determine if the facility meets the reporting threshold for any individual PFAS.

Step 1: determine if individual PFAS concentrations in the pulping step at your facility during the NPRI reporting year would result in exceeding the 1 kg threshold

Whether a substance has the potential to reach the 1 kg reporting threshold level in a year will depend, in part, on the concentration of the substance in the paper entering the facility and the annual average throughput of the facility. The facility should review information available in order to identify the NPRI substances present at concentrations sufficient to trigger a reporting requirement. Based on the facility’s throughput rate, the following equation can be used to ascertain the concentrations of substances required to exceed the reporting thresholds for the particular facility:

Where:

• C_PFASⁱ = concentration of a PFAS substance in the wastewater that will trigger a reporting requirement, ng/l, or ppb
• Q_facility = average daily flow rate of discharge from the facility’s wastewater treatment system, m³/day

The results of these calculations can be compared to concentrations from monitoring data, literature values and other information sources to determine which substances may be reported.  Facilities are encouraged to prioritize facility-specific data, such as source testing with mass balance, site-specific emission factors, or engineering estimates, when evaluating reporting to the NPRI. Additionally, data from similar facilities, comparable operations, or surrogate substances may also be considered. If there has been no testing for the concentration of individual PFAS in a facility or if relevant estimate data is unavailable, then Table 5 provides available testing data from the U.S. EPA study described in the introduction to this chapter. However, due to limited information on the sampled facilities and the treatment of non-detect data, this dataset may not accurately represent wastewater effluents from recovered paper processing. Reporting facilities should evaluate with the help of facility experts whether the data in Table 5 could be used to estimate possible water releases from their sites.

Step 2: if possible, determine the quantity of individual PFAS created within the paper recycling facility

As a general rule, reporting for individual PFAS is triggered by the amount of the individual PFAS initially present in the raw feedstock entering the facility. However, exceptions to the general rule for triggering PFAS reporting on the basis of raw feedstock exist and include:

• PFAS produced as a result of the process
  • in this case, the quantity of the individual PFAS produced should be used to determine whether the threshold was exceeded
• PFAS present in the raw feedstock and produced by any processes at the facility
  • in this case, the quantity of substance in the raw feedstock plus that produced should be used to determine whether the threshold was exceeded

In the above exceptions, available concentration data from biosolids/sludges and/or effluent could be used to determine if the threshold is met. However, this would require an understanding of whether individual PFAS are generated within the paper recycling facility (and not just contained in the feedstock) and/or what percentage of individual PFAS in the recovered paper processing facility are a result of the feedstock and what percentage were generated within the facility. If this understanding/knowledge of the partitioning/generation of PFAS within a recovered paper processing facility is not available, then the calculations that only rely on the feedstock (as described in step 1 above) should be relied upon to determine if the 1 kg NPRI reporting threshold for individual PFAS has been met. At the time this guidance was written, no information on PFAS concentrations within the sludges generated in wastewater treatment processes employed at recovered paper processing facilities was identified. If this information becomes available in future, it could be utilized in the absence of on-site testing to help determine if thresholds are met.

Estimating releases, transfers and disposals

For those individual PFAS that met the thresholds for reporting to the NPRI, the following steps need to be undertaken:

Step 1: determine individual PFAS quantities in wastewater effluent

Should you have testing available for the concentration of individual PFAS in the effluent (typically expressed in ng/L) from your recovered paper processing facility, then these concentrations should be used. 

If there has been no testing for the concentration of individual PFAS in your effluent, reasonable estimates may be used based on data from similar facilities, comparable operations, or surrogate substances. Table 5 provides available testing data from the U.S. EPA study described in the introduction to this chapter, but this should be applied cautiously, in conjunction with more specific input from facility experts and may not be representative of actual operations of the facility.

Once the individual PFAS concentrations have been identified, the following formula should be used to calculate the quantity of individual PFAS that were contained in effluent released from your paper recycling facility during the NPRI reporting year:

Where:

• PFASⁱ_kg = quantity of PFAS chemical “i” contained in effluent released from the paper recycling facility during the NPRI reporting year, in kilograms
• Volume_L = total volume of effluent released from the paper recycling facility during the NPRI reporting year, in litres
• Concentrationⁱ_ng/L = concentration of PFAS chemical “i” contained in effluent released from the paper recycling facility during the NPRI reporting year, expressed in ng/L
• 10^-12_kg/ng = conversion factor for nanograms to kilograms (1 kg = 10¹² ng)

Step 2: determine individual PFAS quantities in sludge/biosolids

In determining whether reporting to the NPRI is required for individual PFAS (see previous section Step 2), a calculation was made of the quantity of individual PFAS that were contained in the sludge/biosolids that were generated at the facility during the NPRI reporting year. The fate of this quantity of individual PFAS needs to be reported. The fate will typically be either to: 

• off-site disposal – land treatment 
•  transfers for treatment – incineration
• off-site disposal – landfill

However, the full set of release/transfer/disposal categories should be reviewed to determine the most appropriate category for the individual PFAS contained in sludge/biosolids. No data on PFAS concentrations within the sludge generated by wastewater treatment systems at recovered paper processing facilities was identified; onsite testing could be used, and further data to support this analysis may be identified in future.

Table of PFAS concentrations in recovered paper processing wastewater 

Two studies were identified that provided information on PFAS concentrations at recovered paper processing facilities, as described in the introduction to this chapter. As noted previously, the U.S. EPA study has been selected for use due to its significantly higher number of samples and the fact that it surveyed 52 facilities instead of one and therefore may have generated more representative average concentration figures. The table below shows the different PFAS analytes that were detected in pulp, paper and paperboard wastewater within these 52 facilities, including the range of concentrations detected and the average concentrations of the samples. The facility may utilize the average concentrations within the samples for any calculation steps described in the sections above if site-specific testing data is unavailable. As previously mentioned, this table is intended only as an indication of the potential presence of PFAS in paper recovery processes and should be used with caution. It should be complemented by more specific input from facility experts, as it may not accurately reflect the actual operations of a given facility.

Abbreviations: 

• ND – non-detection
• ppt – parts-per-trillion (equivalent to nanograms per litre)

Data published in the USEPA Effluent Guidelines Program Plan 15 (PDF).

Wastewater facilities

This chapter applies to the wastewater treatment sector which refers to wastewater facilities serving communities, and includes, but is not limited to, wastewater facilities owned and/or operated by municipalities, wastewater facilities on federal lands serving communities (such as military bases) and wastewater facilities serving indigenous communities. These wastewater facilities may also be owned and/or operated by private individuals or corporations in public-private partnership situations. This chapter applies to wastewater facilities classified under the North American Industry Classification System (NAICS) code 221320 (sewage treatment facilities) and does not apply to industrial wastewater treatment facilities.

For NPRI purposes, a wastewater facility is defined as a wastewater collection/treatment system that discharges treated or untreated wastewater into surface waters with an annual average flow rate of 10,000 cubic metres per day or more. For NPRI reporting, a wastewater facility includes both treatment and collection systems. For general details about reporting requirements for wastewater facilities under the NPRI and to determine whether a report is required for your facility, consult the Reporting Guidance for the Wastewater Sector to the National Pollutant Release Inventory. Wastewater facilities with annual average discharge of < 10,000 m³ per day are exempt from reporting for NPRI.  If a facility is not under the above definition (i.e. it is not primarily a wastewater facility but instead meets the definition of a contiguous facility where the minimum employee hours are met), then the annual average flow rate of 10,000 cubic metres per day or more is not relevant and any wastewater treatment plant activities should be regarded as part of the facility’s operations.

As further context, the wastewater addressed in this guidance refers to used water from homes, businesses, industries, and institutions that drains into sewers. It contains sanitary sewage and is sometimes combined with stormwater from rain or melting snow draining off rooftops, lawns, parking lots and roads. Treating wastewater before it is released into lakes and rivers reduces the risks posed to human health and the environment. According to Canadian environmental sustainability indicators : municipal wastewater treatment, the treatment processes applied can be summarized as follows:

According to the article Occurrence, fate, and persistence of per- and poly-fluoroalkyl substances (PFASs) during municipal sludge treatment, the various  treatment processes employed at municipal wastewater facilities results in the generation of two major streams released to the environment, specifically treated effluent and a concentrated stream of solids called sludge (or biosolids).

Wastewater facilities provide a critical link between producers and users of PFAS-containing products and the environment. Effluent discharge from wastewater facilities is regarded as an important pathway of PFAS pollution to the aquatic environment, while biosolids produced by wastewater facilities may be land applied for beneficial uses. For more information, see the article Occurrence, fate, and persistence of per- and poly-fluoroalkyl substances (PFASs) during municipal sludge treatment. Air emissions from wastewater facilities may represent an additional source of PFAS and should be considered when monitoring data from the facility are available, or when estimates can be obtained from literature sources or drawn from similar facilities or processes. 

According to the article Poly- and Perfluoroalkyl Substances in Municipal Wastewater Treatment Plants in the United States: Seasonal Patterns and Meta-Analysis of Long-Term Trends and Average Concentrations, PFAS are ubiquitous in municipal wastewater effluent and biosolids. PFAS concentrations in wastewater vary widely, reflecting the diversity of sources. Major point sources include PFAS producing or using industrial sites, such as papermaking, textile mills, and electroplating. The use of consumer products can also be a significant contributor to the overall PFAS load to municipal wastewater treatment plants. For instance, PFAS stemming from apparel during the washing cycle can contribute to the overall PFAS load to wastewater facilities. Other consumer products that can lead to increased PFAS loading to wastewater facilities include the washing of floors, the use of a wide variety of personal care products, residue from food packaging (e.g. microwave popcorn), automobile washing/cleaning products, etc. More information can be found in the article A source-based framework to estimate the annual load of PFAS in municipal wastewater. Also, according to Global patterns and temporal trends of perfluoroalkyl substances in municipal wastewater: A meta-analysis, landfill leachate is often directed to wastewater facilities thereby providing another potential significant source of PFAS. Finally, as reported in A source-based framework to estimate the annual load of PFAS in municipal wastewater, environmental recirculation events such as stormwater runoff and groundwater leakage into the sewer system can contribute to PFAS entering wastewater. For instance, PFAS contained in coatings, paints and varnishes, as well as other outdoor protective coverings can be washed away during rain events, in addition to PFAS already being present in rainwater.

Due to the chemical, thermal, and biological stability imparted by their C-F bonds, PFAS are not effectively removed by conventional wastewater treatment processes and are commonly detected in influent, effluent, and biosolids. Furthermore, some PFAS such as fluorotelomer alcohols and perfluorooctane sulfonamides (precursor compounds) can biodegrade to other PFAS including PFAAs during treatment resulting in measured concentrations increasing from influent to effluent (and biosolids). For more details, see the article A source-based framework to estimate the annual load of PFAS in municipal wastewater.

According to this article and Occurrence, fate, and remediation for per-and polyfluoroalkyl substances (PFAS) in sewage sludge: A comprehensive review, the main mechanism of removal of PFAS within liquids streams in conventional wastewater processes is adsorption to sludge and suspended particulate matter. Collected sludge is considered biosolids after undergoing appropriate treatments such as digestion, lime stabilization, composting, or heat treatment, to meet regulatory requirements. More information about reporting of NPRI substances in biosolids can be found in the NPRI page Biosolids: Guide to Reporting.

Determine if the NPRI reporting threshold is met for individual PFAS

In general, the NPRI reporting threshold for individual PFAS is 1 kg of manufacturing, processing or otherwise use at ≥ 0.1% concentration. For wastewater facilities, all PFAS collected in the influent from industrial, commercial, institutional or residential sources, or produced during wastewater treatment are considered to be “by-products”, and as a result, the above-noted concentration threshold does not apply. 

Given the large number and diverse classes of PFAS substances included in the NPRI, along with their distinct chemical properties, many are likely to be present in both effluents and biosolids—potentially at elevated concentrations due to the transformation of PFAS precursors. Considering the complexity of the wastewater matrix and the variety of biological and physicochemical processes that can affect these PFAS substances fate, it is more appropriate to base the NPRI reporting threshold on estimated quantities in effluents and biosolids, rather than on influent data. This approach provides a more practical and balanced method, offering both flexibility and comprehensive coverage. 

There are a limited number of available data sources for individual PFAS to Canadian wastewater facilities. ECCC has conducted extensive testing of wastewater. Wastewater samples were analyzed for PFAS over the 2009-2024 time-period, but not every year. ECCC may continue to periodically analyze PFAS in wastewater samples in the future. A summary of the data collected between 2018 and 2024 are provided in the series of tables of PFAS concentrations in wastewater effluent, and biosolids on about 40 individual PFAS that have been added to the NPRI. The data collected between 2018 and 2024 are considered approximately representative of current levels of PFAS in wastewater. ECCC used U.S. EPA Method 1633 for measurement of PFAS in aqueous, solid and biosolid samples. 

According to the article Global patterns and temporal trends of perfluoroalkyl substances in municipal wastewater: A meta-analysis, there remains significant variability in data across countries related to PFAS concentrations in wastewater influent, effluent and sludge/biosolids, possibly due to regional variability (e.g., due to variations of GDP per capita). Therefore, only Canadian wastewater effluent and biosolids concentrations are provided in the tables of PFAS concentrations to assist in determining whether NPRI reporting thresholds are met. Whether an individual PFAS has the potential to reach the 1 kg reporting threshold level during the NPRI reporting year will depend on its presence in the treated final effluent and biosolids. The steps to follow to make this determination are as follows:

Step 1: determine the quantity of PFAS in effluent during the NPRI reporting year

Should you have testing available for the concentration of individual PFAS (that have been added to the NPRI) in the effluent (typically expressed in ng/L) from your wastewater facility, then these concentrations should be used. If there has been no testing for the concentration of individual PFAS in your effluent, then Table 7 provides available testing data (at Canadian wastewater treatment plants) from ECCC on about 40 of the individual PFAS that have been added to the NPRI. In addition to the Canadian-specific information, Table 6 provides information on the average concentration of individual PFAS (that have been added to the NPRI, however were not tested for by ECCC) from wastewater treatment facilities in the U.S. Since these are average concentrations across many wastewater facilities in the U.S., they are considered applicable to Canada. 

Once the individual PFAS concentrations have been identified, the following formula should be used to calculate the quantity of individual PFAS that were contained in effluent released from your wastewater facility during the NPRI reporting year:

Where:

• PFASⁱ_kg = quantity of PFAS chemical “i” contained in effluent released from the wastewater treatment plant during the NPRI reporting year, in kilograms
• Volume_L = total volume of effluent released from the wastewater treatment plant during the NPRI reporting year, in litres
• Concentrationⁱ_ng/L = concentration of PFAS chemical “i” contained in effluent released from the wastewater treatment plant during the NPRI reporting year, expressed in ng/L
• 10^-12_kg/ng = conversion factor for nanograms to kilograms (1 kg = 10¹² ng)

Step 2: determine the quantity of PFAS in biosolids during the NPRI reporting year

Should you have testing available for the concentration of individual PFAS in the biosolids (typically expressed in ng/g, dry weight basis) generated at your wastewater facility, then these concentrations should be used. 

If there has been no testing for the concentration of individual PFAS in your biosolids, then Table 8 provides available testing data (at Canadian wastewater treatment plants) from ECCC on about 40 of the individual PFAS that have been added to the NPRI

Once the individual PFAS concentrations have been identified, the following formula should be used to calculate the quantity of individual PFAS that were contained in the biosolids generated at the wastewater facility during the NPRI reporting year: 

Where:

• PFASⁱ_kg = quantity of PFAS chemical “i” contained in biosolids generated at the wastewater treatment plant during the NPRI reporting year, in kilograms
• W_tonnes = the total quantity of biosolids generated at the wastewater treatment plant during the NPRI reporting year, in tonnes
• Concentrationⁱ_ng/L = concentration of PFAS chemical “i” contained in biosolids generated at the wastewater treatment plant during the NPRI reporting year, expressed in ng/g, dry weight
• 10^-12_kg/ng = conversion factor for nanograms to kilograms (1 kg = 10¹² ng)

Step 3: determine which PFAS need to be reported to the NPRI

Based on the quantity calculated in step 1 and 2, calculate the total quantity from effluent and biosolids at the wastewater facility and compare it to the mass reporting threshold. Each individual NPRI PFAS with a quantity ≥1 kg must be considered for reporting to the NPRI:

Please note, when available, any estimated releases to air should be added to the total quantity determined to be in effluent and/or biosolids in order to establish if the reporting threshold is met. 

Estimating releases, transfers and disposals 

For those individual PFAS that met the 1 kg threshold for reporting to the NPRI, the following steps need to be undertaken to estimate releases, transfers and disposals (additional details available in the Reporting Guidance for the Wastewater Sector to the National Pollutant Release Inventory):  

Step 1: determine individual PFAS quantities in wastewater effluent

Should you have testing available for the concentration of individual PFAS (that have been added to the NPRI) in the effluent (typically expressed in ng/L) from your wastewater facility, then these concentrations should be used. 

If there has been no testing for the concentration of individual PFAS in your effluent, then Table 7 provides available testing data (at Canadian wastewater treatment plants) from ECCC on about 40 of the individual PFAS that have been added to the NPRI. 

In addition to the Canadian-specific information, Table 6 provides information on the average concentration of individual PFAS (that have been added to the NPRI, however were not tested for by ECCC) from wastewater treatment facilities in the U.S. Since these are average concentrations across many wastewater facilities in the U.S., they are considered applicable to Canada.

Source: Poly- and Perfluoroalkyl Substances in Municipal Wastewater Treatment Plants in the United States: Seasonal Patterns and Meta-Analysis of Long-Term Trends and Average Concentrations, ACS ES&T Water (published in 2022).

Once the individual PFAS concentrations have been identified, the following formula should be used to calculate the quantity of individual PFAS that were contained in effluent released from your wastewater facility during the NPRI reporting year:

Where:

• PFASⁱ_kg = quantity of PFAS chemical “i” contained in effluent released from the wastewater treatment plant during the NPRI reporting year, in kilograms
• Volume_L = total volume of wastewater effluent released from the wastewater treatment plant during the NPRI reporting year, in litres
• Concentrationⁱ_ng/L = concentration of PFAS chemical “i” contained in wastewater effluent released from the wastewater treatment plant during the NPRI reporting year, expressed in ng/L
• 10^-12_kg/ng = conversion factor for nanograms to kilograms (1 kg = 10¹² ng)

The above formula needs to be applied to each individual PFAS that was determined to have met the 1 kg reporting threshold for the NPRI.

Step 2: determine individual PFAS quantities in biosolids

Should you have testing available for the concentration of individual PFAS in the biosolids (typically expressed in ng/g, dry weight basis) generated at your wastewater facility, then these concentrations should be used. 

If there has been no testing for the concentration of individual PFAS in your biosolids, then Table 8 provides available testing data (at Canadian wastewater treatment plants) from ECCC on about 40 of the individual PFAS that have been added to the NPRI. 

Once the individual PFAS concentrations have been identified, the following formula should be used to calculate the quantity of individual PFAS that were contained in the biosolids generated at the wastewater facility during the NPRI reporting year:

Where:

• PFASⁱ_kg = quantity of PFAS chemical “i” contained in biosolids generated at the wastewater treatment plant during the NPRI reporting year, in kilograms
• Quantity_g = the total quantity of biosolids generated at the wastewater treatment plant during the NPRI reporting year, in grams
• Concentrationⁱ_ng/L = concentration of PFAS chemical “i” contained in biosolids generated at the wastewater treatment plant during the NPRI reporting year, expressed in ng/g, dry weight
• 10^-12_kg/ng = conversion factor for nanograms to kilograms (1 kg = 10¹² ng)

The above calculation needs to be completed for each individual PFAS (that meets NPRI reporting thresholds) for which concentration data in biosolids is available. These calculations will aid in the reporting of any PFAS disposals or transfers. 

The fate of this quantity of individual PFAS in biosolids needs to be reported. The fate will typically be either to:

• off-site disposal – land treatment
• transfers for treatment – incineration
• off-site disposal – landfill

However, the full set of release/transfer/disposal categories should be reviewed to determine the most appropriate category for the individual PFAS contained in biosolids. 

Tables of PFAS concentrations in wastewater effluent, and biosolids

The tables below provide the average concentrations of various individual PFAS in effluents and biosolids from wastewater treatment facilities in Canada, based on measurements conducted by ECCC. They are also available in Excel format (email the NPRI to request a copy at inrp-npri@ec.gc.ca).

• the average was calculated for detectable PFAS only
• when not detected, the maximum detection limit is indicated (For NPRI reporting, the half detection method should be used)

• the average was calculated for detectable PFAS only
• when not detected, the maximum detection limit is indicated (For NPRI reporting, the half detection method should be used)

Non-hazardous and hazardous waste off-site landfill facilities

Canadians utilize and dispose of products and materials (e.g., consumer products, contaminated soils and biosolids) that contains PFAS substances every day, and many of these products are eventually sent to landfill. Landfills “can become an indirect pathway of release to the environment. PFAS may leach out of these products and materials and accumulate in landfill leachate and eventually be released to the environment, even if that leachate is sent to a wastewater treatment system".  For more information, see State of per- and polyfluoroalkyl substances (PFAS) report. Not all landfills treat leachate which may lead to untreated leachate entering the environment. Moreover, not all on-site or off-site leachate treatment systems, nor the wastewater treatment facilities that may receive this leachate, are equipped with the necessary technology to effectively remove PFAS.  According to the article Wastewater Treatment Plant and Landfills as Sources of Polyfluoroalkyl Compounds to the Atmosphere, PFAS can also be released from landfills to air, as studies have found higher levels of PFAS in the air near landfills than reference levels.

Please note that this chapter applies to off-site landfill facilities classified under NAICS Code 562210 – Waste Treatment and Disposal. It is important to distinguish between Municipal Solid Waste (MSW) Landfills (see Figure 1) and Hazardous Waste Landfills, as they differ in design, operation, maintenance, and regulatory requirements. This distinction significantly influences both the types and quantities of PFAS they receive, as well as the environmental fate of PFAS within each landfill type.

For NPRI purposes, a landfill located on the same site, on contiguous sites, or on adjacent sites with the operating facility—provided they are owned or operated by the same entity and function as a single integrated site—meets the definition of a contiguous facility and should be considered as part of the operating facility, as on-site disposal – landfill. However, if a facility disposes of its waste at a landfill owned by a different entity and/or at a landfill owned by the same company but located at a separate, non-contiguous site, this landfill is considered an off-site disposal facility.

Figure 1: Diagram of MSW landfill components and potential PFAS release pathways

It should be noted that some MSW landfills may not have leachate and/or landfill gas collection systems. Moreover, not all landfills are equipped to capture landfill gas, and among those that do, some may choose to flare the gas rather than use it for energy recovery.

Determine if NPRI reporting thresholds are met

The NPRI reporting threshold for individual PFAS is 1 kg of manufacturing, processing or otherwise use (MPO). Since landfills do not intentionally manufacture, process or otherwise use PFAS, these substances are considered by-products for NPRI reporting. Consequently, the 0.1% concentration threshold will not apply and the landfill facility is  expected to report the NPRI PFAS substance once it exceeds MPO threshold of 1 kg, regardless of the concentration. In order to determine if NPRI reporting thresholds are met, three different processing operations need to be considered: 

• acceptance and landfilling of waste
• generation of landfill leachate
• generation of landfill gas

Acceptance and landfilling of waste

There is little data available on the concentration of individual PFAS in municipal solid waste. At the time of publishing this guidance, direct measurements of PFAS concentrations within the solid waste matrix of landfill cells are not readily available in publicly available literature and the majority of studies of PFAS in landfills focus on municipal solid waste (MSW) landfill leachate, with comparatively fewer studies, in the waste material received by the landfill facility. 

As most studies focus on leachate and in some cases, on gas emissions as indicators of PFAS presence in landfills. Therefore, information on landfill leachate and landfill gas emissions generated at your landfill facility could be the focus of determining whether your facility needs to report to the NPRI. The total quantity of the NPRI PFAS substance generated from landfill leachate and landfill gas emissions could be used to assess if the facility meets the NPRI threshold of 1 kg.

If information for a specific PFAS in the waste received for disposal is known or could be obtained from the below quantity calculation within the landfill facility, it could be combined or compared with data from leachate and gas emissions to assess whether the MPO threshold for this specific PFAS at the landfill facility is exceeded. 

If the quantity or concentration for a specific PFAS in the waste received for disposal is known, it could be used to estimate this PFAS MPO threshold. Another approach (reported in the article Evaluation of per- and polyfluoroalkyl substances (PFAS) released from two Florida landfills based on mass balance analyses) could be used which is to approximately estimate the quantity of a specific PFAS within the landfill facility based on:

• the volume of waste within the landfill facility (V)
• the density of waste (ρ)
• the specific PFAS concentration (C_i) in the waste material,
• the fraction (WT_k) of different types of waste material (e.g. paper products, textiles, etc.) within the landfill

Where:

• “k” is the type of waste material
• “m” is the total number of waste materials like paper and paper board, food, plastics, metals, wood, textile, rubber

For MSW landfill facilities, the V could be estimated from basic geometry considerations using the height, area, and slopes of solid waste disposal area within the evaluated landfills. The ρ of solid waste could be extrapolated as 350 to 500 kg/m³. The C_k and WT_k could be obtained from literature review or reasonable estimates maybe used based on data from similar facilities, comparable operations, or surrogate substances. If no specific data or comparable facility data can be obtained, WT_k could be retrieved from Environment and Climate Change Canada (2024) Canadian Environmental Sustainability Indicators: Solid waste diversion and disposal and the National waste characterization report : the composition of Canadian residual municipal solid waste.

The tables below present the concentrations of selected PFAS substances found in certain types of materials that end in the MSW. The listing is not exhaustive and other PFAS maybe present.

Sources:

• Table 9:
  • Per- and polyfluoroalkyl substances (PFAS) in consumer products: Current knowledge and research gaps
  • Characterization of Per- and Polyfluoroalkyl Substances (PFAS) in Broad Solid Waste Streams. University of Florida, Gainesville, Fla. 2022.
• Tables 10-14:
  • Per- and polyfluoroalkyl substances (PFAS) in consumer products: Current knowledge and research gaps

Generation of landfill leachate

One of the two streams containing PFAS at landfills which can be used to account for the total quantity generated from the landfill facility that trigger NPRI reporting thresholds is landfill leachate. The following steps should be followed to estimate the quantity generated from landfill leachate:

Step 1: determine the quantity of landfill leachate generated by your landfill during the NPRI reporting year

From available metering systems and accounting records, the quantity of landfill leachate generated by your landfill could be tabulated. All landfill leachate that is generated at your landfill should be taken into consideration including leachate that was transferred off-site for treatment, leachate that was treated on-site and untreated leachate that was generated by your facility. All leachates should be aggregated so that the total is available as one number, ideally in litres. Hydrological models commonly recommended or used to meet regulatory agencies’ requirements, such as the model HELP (Hydrologic Evaluation of Landfill Performance (HELP) Model | US EPA) may also be used to estimate the leachate generation and other water pathways that could be sources of PFAS substances from landfill facilities.

Step 2: determine the concentration of individual PFAS in landfill leachate generated at your facility during the NPRI reporting year

Should you have testing available for the concentration of individual PFAS in the landfill leachate (typically expressed in ng/L) generated at your landfill, then these concentrations should be used. 

If there has been no testing for the concentration of individual PFAS in your leachate, reasonable estimates may be used based on data from similar facilities, comparable operations, or surrogate substances or from publicly available data sources such as peer-reviewed literature combined with expert judgment and knowledge of the design and operations of the facility.  Table 15 provides some available sampling results conducted by ECCC of landfill leachate for 40 of the individual PFAS that have been added to the NPRI, which may be used as a substitute in the absence of site-specific data for MSW landfill facilities. 

Beyond Canada, in the article Poly- and Perfluoroalkyl Substances (PFAS) in Landfills: Occurrence, Transformation and Treatment, Zhang et al. studied data from more than 10 countries (250+ landfills) and provided ranges for 7 PFAS in these landfills - all of which are already present in the Canadian dataset. A review of other studies on landfill leachates indicated that the ECCC data had captured the major PFAS that has been found to be present in landfill leachate. Therefore, the Canadian-specific data could be used in determining if the NPRI reporting threshold is met and if necessary, in calculating the quantity of individual PFAS transfers/disposals/releases.

Step 3: calculate the quantity of individual PFAS in the landfill leachate generated during the NPRI reporting year

Once the individual PFAS concentrations have been identified, the following formula should be used to calculate the quantity of individual PFAS that were contained in landfill leachate generated at your landfill during the NPRI reporting year:

Where:

• PFASⁱ_kg = quantity of PFAS chemical “i” contained in landfill leachate generated at the landfill during the NPRI reporting year, in kilograms
• Volume_L = total volume of landfill leachate generated at the landfill during the NPRI reporting year, in liters
• Concentrationⁱ_ng/L = concentration of PFAS chemical “i” contained in landfill leachate generated at the landfill during the NPRI reporting year, expressed in ng/L
• 10^-12_kg/ng = conversion factor for nanograms to kilograms (1 kg = 10¹² ng)

The above calculation needs to be completed for each individual PFAS for which concentration data in the landfill leachate is available.

Generation of landfill gas

The second stream containing PFAS from landfills which can be used to account for the total quantity generated from the landfill facility that trigger NPRI reporting thresholds is landfill gas. Landfill gas has been found to contain PFAS substances – typically in pg/m³. The following steps should be followed to estimate the quantity generated from landfill gas:

Step 1: access the quantity of landfill gas generated annually at the landfill site

It is assumed that the total quantity of landfill gas generated annually at the landfill facility is known. Total landfill gas generated per year will be used in the next step of the calculation below, expressed in m³. The Landfill Gas Emissions Model (LandGEM) | US EPA can be used to estimate the total landfill gas production and associated emission rates for the facility.

Step 2: determine the concentration of individual PFAS within landfill gas generated during the NPRI reporting year

Should you have testing available for the concentration of individual PFAS in the landfill gas (typically expressed in pg/m³) generated at your landfill, then these concentrations should be used. 

If there has been no testing for the concentration of individual PFAS in your landfill gas, reasonable estimates may be used based on data from similar facilities, comparable operations, or surrogate substances or from publicly available data sources such as peer-reviewed literature combined with expert judgment and knowledge of the design and operations of the facility. Table 16 provides available testing data from Canadian landfills on landfill gas for 16 of the individual PFAS that have been added to the NPRI that may be used in the absence of site-specific data for MSW landfill facilities (Note that data has been retrieved for both on-site concentrations of PFAS and upwind concentrations of PFAS and the on-site concentrations of PFAS have been utilized for the purpose of this methodology). Additional data on similar PFAS substances found in landfill gas are also reported by Zhang et al. (2023) and Lin et al. (2024) from studies conducted in other countries.

Step 3: calculate the quantity of individual PFAS in the landfill gas generated during the NPRI reporting year

Once the individual PFAS concentrations have been identified, the following formula should be used to calculate the quantity of individual PFAS that were contained in landfill gas generated at your landfill during the NPRI reporting year:

Where:

• PFASⁱ_kg = quantity of PFAS chemical “i” contained in landfill gas generated at the landfill during the NPRI reporting year, in kilograms
• Volume_m3 = total volume of landfill gas generated at the landfill during the NPRI reporting year, in m³
• Concentrationⁱ_pg/m3 = concentration of PFAS chemical “i” contained in landfill leachate generated at the landfill during the NPRI reporting year, expressed in pg/m³
• 10^-15_kg/ng = conversion factor for nanograms to kilograms (1 kg = 10¹⁵ pg)

The above calculation needs to be completed for each individual PFAS for which concentration data in the landfill gas is available. 

Step 4: which PFAS need to be reported to the NPRI

Based on the quantity calculated in Step 3 for leachate and for landfill gas, calculate the total quantity generated at the landfill facility and compare it with the mass reporting threshold. Each individual NPRI PFAS substance generated with a quantity ≥1 kg must be considered for reporting to the NPRI if the employee threshold is met.

Estimating releases, transfers and disposals

Landfills typically transfer treated or untreated leachate to wastewater treatment plants for treatment. However, landfills may release PFAS to surrounding water (e.g. groundwater, surface water) and/or soil depending upon the permeability (or presence) of an adequate liner and leachate collection system. Landfills may also release PFAS to air depending upon the presence of a landfill gas collection and treatment (i.e. flaring) system.

Information to support the estimation of PFAS release, transfer and disposal contained in both landfill leachate and landfill gas are provided in this section. 

Landfill leachate

For those individual PFAS that met the thresholds for reporting to the NPRI, the following steps need to be undertaken:

Step 1: determine individual PFAS quantities in landfill leachate

In determining whether reporting to the NPRI is required for individual PFAS (see previous section), a calculation was made of the quantity of individual PFAS that were contained in the landfill leachate generated at the facility during the NPRI reporting year. The fate of this quantity of individual PFAS needs to be reported for those individual PFAS that met the NPRI reporting requirements. Leachate generated at MSW landfill is typically treated either on-site or off-site at a wastewater treatment facility or it may be released into the environment. There wouldn’t be any “disposal of leachate”. Although hazardous waste landfills usually do not produce leachate, if they do, it would likely be transferred for treatment prior to final disposal. The typical fate of leachate will be transfers for treatment prior to final disposal – transfer to a wastewater treatment facility. However, the full set of release/transfer/disposal categories should be reviewed to determine the most appropriate category for the individual PFAS contained in landfill leachate. 

Landfill gas

Step 1: determine individual PFAS quantities in landfill gas

In determining whether reporting to the NPRI is required for individual PFAS (see previous section), a calculation was made of the quantity of individual PFAS that were contained in the landfill gas generated at the facility during the NPRI reporting year. The fate of this quantity of individual PFAS needs to be reported for those individual PFAS that met the NPRI reporting requirements. The fate will typically be releases to air. 

In cases where the landfill in question has a landfill gas capture system that either combusts (for energy generation) or flares PFAS (According to Review of per- and poly-fluoroalkyl treatment in combustion-based thermal waste systems in the United States, PFAS can be destroyed (~99.99%) in thermal treatment systems operating at >850°C ), the following additional step must be undertaken.

Step 2: estimate PFAS releases after application of thermal treatment

Many landfills in Canada undertake thermal treatment of landfill gas, either to generate energy or to reduce emissions of methane and other pollutants. If the landfill gas combustion system is operating correctly, it should provide sufficient heat and residence time to destroy PFAS substances.

To estimate the quantity of PFAS released to atmosphere after thermal treatment, utilize the following calculation:

Where:

• PFASRⁱ_kg = quantity of PFAS chemical “i” in landfill gas released from the landfill during the NPRI reporting year after landfill gas capture and combustion, in kilograms
• PFASⁱ_kg = quantity of PFAS chemical “i” in total landfill gas generated at the landfill during the NPRI reporting year, in kilograms
• UnCapRate_% = the amount of landfill gas that is not captured by the landfill gas capture system, expressed in % of total landfill gas generated

Controlled releases must be reported under the stack or point releases source category. However, there may also be uncontrolled fugitive emissions, and if data is available, the quantity should be considered for reporting under the fugitive releases source category.

Table of PFAS concentrations in landfill leachate

Provided in the table below are the average concentrations of various individual PFAS measured in landfill leachate, as determined by ECCC. 

Table of PFAS concentrations  in landfill gas

Provided in the table below are the average concentrations of various individual PFAS measured in landfill gas, as determined by Ahrens et al. (2011). 

Appendix A