Proposal to Modify the National Pollutant Release Inventory Reporting Requirements for Total Reduced Sulphur

Environment Canada (EC) proposed to change the National Pollutant Release Inventory (NPRI) reporting requirements for total reduced sulphur (TRS) with the 2014 reporting year. The revised requirements would restrict the requirement to report TRS released to air only. This change will resolve the double-counting of non-air release quantities and reflect the original intent of the proposal to add TRS to the NPRI. Consultations on this issue were conducted with the NPRI Multi-Stakeholder Work Group (WG) in February 2013. After considering the comments received, Environment Canada has decided to proceed with the change, and it is reflected in the 2014-2015 NPRI Canada Gazette notice.

A) Proposal (February 2013)

B) Summary of Stakeholder Comments and Environment Canada’s Response (July 2014)

A)  Proposal (February 2013)

1. Background

Total reduced sulphur was added to the list of Part 1A National Pollutant Release Inventory substances beginning with the 2007 reporting year, based on an Environment Canada proposal.Footnote 1 The rationale for the addition was harmonization with the Ontario Ministry of the Environment Airborne Contaminant Discharge – Monitoring and Reporting Regulation (O. Reg. 127/01). At the time, O. Reg. 127/01 required monitoring and reporting for air emissions of TRS, but TRS was not listed in the NPRI.

While not explicitly stated in the original proposal or in the subsequent reports of the NPRI Multi-Stakeholder Work Group on Substances,Footnote 2,Footnote 3the focus on air releases of TRS is quite clear in all three documents. The proposal and the two Work Group reports make no mention of disposals or transfers for recycling of TRS, nor do they refer to releases to surface waters or land. The focus of the addition of TRS to the NPRI was the concern over air releases, and harmonization with O. Reg. 127/01 reporting, which was for air releases only.

For the purposes of reporting to the NPRI, “total reduced sulphur” is defined as the total of six reduced sulphur compounds (see Table 1). The total of these compounds, expressed as hydrogen sulphide (H2S), is reported as TRS. Three of these sulphur compounds (hydrogen sulphide, carbon disulphide and carbonyl sulphide) are also listed individually in the NPRI and must be reported separately, if the reporting requirements are met for the individual substance.

Table 1. Total Reduced Sulphur Compounds
Substance nameChemical FormulaChemical Abstracts Services Registry Number
Hydrogen sulphideH2S7783-06-4
Carbon disulphideCS275-15-0
Carbonyl sulphideCOS463-58-1
Dimethyl sulphideC2H6S75-18-3
Methyl mercaptanCH4S74-93-1
Dimethyl disulphideC2H6S2624-92-0

The mass threshold for TRS, H2S, CS2 and COS is 10 tonnes and the concentration threshold is 1%, for quantities that are manufactured, processed or otherwise used. No concentration threshold applies to quantities of these substances that are by-products. If the reporting thresholds are met, facilities are required to report quantities of these substances that are released to air, surface waters and land; quantities that are disposed of; and quantities that are transferred off-site for recycling.

The total quantities of TRS, H2S, CS2 and COS releases, disposals and recycling that were reported for 2010 are shown in Table 2.Footnote 4 Table 3 shows the number of TRS, H2S, CS2 and COS reports that were received for 2010.Footnote 5 A total of 227 different facilities submitted 1,021 reports for TRS, H2S, CS2 and/or COS.

Table 2. Total Release, Disposal and Transfer Quantities of Total Reduced Sulphur, Hydrogen Sulphide, Carbon Disulphide and Carbonyl Sulphide Reported for 2010
 Reported Quantities (tonnes)
Air ReleasesWater ReleasesLand releasesOn-Site DisposalOff-Site DisposalOff-Site TreatmentRecycling
Total Reduced Sulphur (TRS)15,720208079,279172,71061
Hydrogen Sulphide (H2S)2,856920133,484479,650634
Carbon Disulphide (CS2)4,458000000
Carbonyl Sulphide (COS)5,160000000

 

Table 3. Number of Total Reduced Sulphur, Hydrogen Sulphide, Carbon Disulphide and Carbonyl Sulphide Reports Received for 2010
 Number of reports received
Air ReleasesWater ReleasesLand releasesOn-Site DisposalOff-Site DisposalOff-Site TreatmentRecycling
Total Reduced Sulphur (TRS)355210312164
Hydrogen Sulphide (H2S)371231382586
Carbon Disulphide (CS2)40000000
Carbonyl Sulphide (COS)71000000

2. Total Reduced Sulphur Reporting Issues

Since 2007, significant releases and disposals of TRS have been reported to the NPRI. Significant quantities of the individual TRS compounds that are also listed (hydrogen sulphide, carbon disulphide and carbonyl sulphide) have also been reported. The most common reporting scenario that occurs is where a facility reports quantities of H2S, CS2 and/or COS, and the quantity of TRS; and the TRS quantity includes the reported quantities of the individual substances.

Since H2S, CS2 and COS are part of TRS, the quantities of the three substances are being reported twice in most cases. This double-reporting occurs for H2S, CS2 and COS releases to air and for H2S reported as releases to water, disposed of and transferred for recycling. For example, a facility that reports a quantity of H2S disposed of by underground injection must also report that same quantity of H2S as TRS.

This double-reporting leads to complications when publishing and interpreting NPRI data. To avoid double-counting when EC publishes the annual Overview of Pollutant Releases, Disposals and Recycling Reported to the NPRI,Footnote 6 quantities of the three individual substances need to be excluded for the on-site release analysis, and quantities of TRS need to be excluded for the disposals and transfers for recycling analysis. Data users that are not aware of the potential that these quantities are reported twice may simply add up the values, leading to misleading results. These issues are especially visible because the quantities of disposals of TRS that are reported to the NPRI are quite large, relative to reported quantities of other substances, particularly when looking at disposals reported as underground injection.

For 2010, virtually all on-site and off-site disposals of TRS were reported as underground injection disposals. Small quantities of TRS were reported by a few facilities as disposed of to landfill, land treatment and storage (Table 4). Small quantities of H2S were reported as disposed of to landfill and land treatment, with the majority of the H2S disposals being reported as underground injection. No disposals of CS2and COS were reported in 2010.

Table 4. Total On-Site and Off-Site Disposal Quantities of Total Reduced Sulphur, Hydrogen Sulphide, Carbon Disulphide and Carbonyl Sulphide Reported for 2010
 Reported Quantities (tonnes)
LandfillLand TreatmentUnderground InjectionStorageTailings and Waste RockTOTAL
Total Reduced Sulphur (TRS)4.20.5251,984.00.80251,989.6
Hydrogen Sulphide (H2S)4.70.5613,128.50.80613,134.5
Carbon Disulphide (CS2)000000
Carbonyl Sulphide (COS)000000

Table 5 shows that the total quantity of all NPRI substances reported as disposed of by underground injection for 2010 was 941,590 tonnes. This total includes reported quantities of both TRS and H2S. However, each facility that reported underground injection of TRS reported an equal quantity of H2S disposed of by underground injection, i.e., the total 251,984 tonnes of TRS that were reported were also reported as H2S and make up part of the total 613,129 tonnes of H2S that were reported as disposed of by underground injection. Therefore, the quantity of TRS needs to be removed from the total to correct for the double-counting. This reduces the total of all NPRI substances disposed of by underground injection to 689,606 tonnes. The double-counted quantity of TRS accounts for 27% of the total quantity.

Table 5. Total On-Site and Off-Site Disposal by Underground Injection Quantities of All NPRI Substances Reported for 2010
 Underground Injection Reported Quantities (tonnes)
Total reported quantity of all NPRI substances941,590
Quantity of TRS251,984
Total of all NPRI substances (corrected for double-counting of TRS)689,606

Small quantities of TRS and H2S were also reported as transferred off-site for treatment prior to final disposal and for recycling in 2010 (see Tables 6 and 7). Each facility that reported a quantity of TRS as transferred off-site for treatment or recycling also reported an equal quantity of H2S as transferred off-site for treatment or recycling. Table 6 shows a total of 6.5 tonnes of H2S being transferred off-site for treatment. This 6.5 tonnes includes the 6.0 tonnes of TRS that were reported. The same is true for the quantities transferred off-site for recycling – the total of 34.33 tonnes of H2S reported in Table 7 includes the 0.64 tonnes reported for TRS. While the quantities reported as transferred for treatment and recycling are small relative to the reported disposal quantities, the double-counting still needs to be accounted for.

Table 6. Total Quantities of Total Reduced Sulphur, Hydrogen Sulphide, Carbon Disulphide and Carbonyl Sulphide Reported as Transferred Off-Site for Treatment for 2010
 Reported Quantities (tonnes)
Physical and Chemical TreatmentBiological TreatmentIncinerationTransfer to a Municipal Sewage Treatment PlantTOTAL
Total Reduced Sulphur (TRS)02.92.40.76.0
Hydrogen Sulphide (H2S)02.92.41.26.5
Carbon Disulphide (CS2)00000
Carbonyl Sulphide (COS)00000

 

Table 7. Total Quantities of Total Reduced Sulphur, Hydrogen Sulphide, Carbon Disulphide and Carbonyl Sulphide Reported as Transferred Off-Site for Recycling for 2010
 Reported Quantities (tonnes)
Energy, Solvent, Metal, Acid or Base, Catalyst, Pollution Abatement Residue and Used Oil RecoveryOrganic Compound RecoveryInorganic Compound RecoveryOtherTOTAL
Total Reduced Sulphur (TRS)00.6300.010.64
Hydrogen Sulphide (H2S)00.6326.607.1034.33
Carbon Disulphide (CS2)00"000
Carbonyl Sulphide (COS)00000

3. Proposed Change to the Reporting Requirements for Total Reduced Sulphur

It was originally intended that EC would address the possible double-counting issues for TRS, H2S, CS2 and COS when TRS was listed. However, a method to address these issues was not implemented in the requirements or the reporting system at that time. EC has addressed the issue by excluding TRS disposals and excluding H2S, CS2 and COS releases from analysis, as well as highlighting, in the published considerations for the use of NPRI data, that this issue should be taken into account when doing analysis.Footnote 7 However, it is preferable to introduce a change to the requirements and reporting system to minimize this issue prior to the analysis stage.

A simple solution that will resolve the double-counting of non-air release quantities (the issues that are especially visible because of the large quantities reported as underground injection) will also reflect the original intent of the proposal to add TRS to the NPRI. EC proposes to modify the existing reporting requirements for TRS starting with the 2014 reporting year. A clause would be added to the Canada Gazette notice indicating that TRS reporting is required for releases to air only. Facilities will no longer be required to report for TRS releases to surface waters or land, disposals of TRS and off-site transfers of TRS for recycling. No changes will be made to the mass and concentration thresholds for TRS (they will remain at 10 tonnes and 1%).

Other options for resolving the issues were explored. For example, requiring a report for TRS, followed by reports for speciated TRS compounds; or listing TRS as an air contaminant instead of a Part 1A substance (either as a Part 4 Criteria Air Contaminant, or in a new Part as an Air Contaminant), could also address the identified issues, but would lead to increased complexity in the requirements, reporting system and data publication. The solution proposed here is expected to address the issue while simultaneously minimizing complexity in reporting requirements.

4. Impacts of Proposed Change

This change will not result in a significant reduction in the information available through the NPRI. All disposals of TRS reported to the NPRI are also reported as disposals of H2S (every facility that reported a disposal of TRS, reported an identical disposal quantity of H2S). Since H2S disposals will still be reported to the NPRI, this information will still be available. A small amount of information will no longer be reported – TRS releases to surface waters. Not all releases to water of TRS are reported as H2S (in 2010, a total of 208 tonnes of TRS were reported as released to water and a total of only 92 tonnes of H2S were reported as released to water. No releases of CS2 and COS to water were reported). However, the proposed change reflects the original intent of adding TRS to the NPRI: to capture information on air releases, due to the health and environmental concerns with TRS releases to air.

In 2010, 198 facilities submitted reports for TRS, 68 of which reported non-air release quantities of TRS. Approximately the same number of facilities is expected to submit reports on TRS after the proposed change is implemented, since the 10-tonne/1% concentration threshold will still be based on quantities manufactured, processed or otherwise used. Facilities will no longer be required to report on quantities of TRS that are disposed of or transferred off-site for recycling, resulting in slightly less work required by about 70 facilities.

Table 8 shows that 227 facilities in 13 industrial sub-sectors reported for TRS, H2S, CS2 and/or COS in 2010. The majority of these facilities are in the oil and gas extraction, paper manufacturing and pipeline transportation sub-sectors. Approximately the same number of facilities in the same industrial sectors is expected to submit reports for the four substances after the proposed change is implemented.

Table 8. Industrial Sectors that Reported Reduced Sulphur, Hydrogen Sulphide, Carbon Disulphide and/or Carbonyl Sulphide for 2010
3-Digit NAICS CodeNAICS Sub-Sector NameNumber of Facilities
211Oil and Gas Extraction88
212Mining and Quarrying (except Oil and Gas)3
213Support Activities for Mining and Oil and Gas Extraction3
221Utilities11
311Food Manufacturing4
322Paper Manufacturing31
324Petroleum and Coal Product Manufacturing17
325Chemical Manufacturing13
327Non-Metallic Mineral Product Manufacturing3
331Primary Metal Manufacturing16
412Petroleum Product Wholesaler-Distributors4
486Pipeline Transportation27
562Waste Management and Remediation Services7
TOTAL227

B) Summary of Stakeholder Comments and Environment Canada's Response (July 2014)

The NPRI Multi-Stakeholder WG provided input on Environment Canada’s proposal to change the reporting requirements for TRS. After considering stakeholder input, Environment Canada (EC) has implemented the proposed change commencing with the 2014 reporting year.

The table below summarizes comments received from the Multi-Stakeholder WG and provides EC’s responses.

Comments were received from these the following stakeholders:

  • Assembly of First Nations
  • Chemistry Industry Association of Canada and Canadian Fuels Association (joint comment)
  • Great Lakes United
  • Canadian Vehicle Manufacturers’ Association
  • Canadian Association of Petroleum Producers
  • International Institute of Concern for Public Heath
  • Community Health Opposition to Known Emissions Dangers
Table 9. Summary of Stakeholder Comments and Environment Canada's Response
No./TopicStakeholder CommentEnvironment Canada Response
1. SupportThe proposed change to limit the reporting requirements for TRS to air releases only is warranted and is supported. The change will resolve data quality issues, reflect the original intent of the addition of TRS to the NPRI and reduce reporting burden on industry.Support for the change proposed by Environment Canada is acknowledged. No response is required.
2. TimingThe timing for the implementation of the proposed changes does not provide facilities with sufficient lead time to collect the required information. The proposed changes should be implemented for the 2015 reporting year at the earliest. NPRI notices should be published no later than December of the year prior to which the notices apply.

This change does not result in the requirement to report any additional data. As such, the timing is not an issue for the TRS change for 2014.

EC recognizes that the publication of notices for the NPRI should occur as early as possible. However, under CEPA 1999, NPRI reporting is based on information in the possession of the facility or that can be reasonably accessed. If a facility genuinely has little or no information on this substance, they would be required to report only the information that they do have for 2014, and should take reasonable steps to gather the full required information for future years.

Top of Page



Footnotes

Footnote 1

National Pollutant Release Inventory Submittal Form – Proposal for a Modification to the NPRI [Total Reduced Sulphur]. 2005.

Return to footnote 1

Footnote 2

Report of the National Pollutant Release Inventory Multi-Stakeholder Work Group on Substances. November 24, 2005.

Return to footnote 2

Footnote 3

Report of the 2006 National Pollutant Release Inventory Multi-stakeholder Work Group on Substances. September 30, 2006.

Return to footnote 3

Footnote 4

Six 2010 reports were excluded from the analysis for this proposal due to the probability of their being reporting errors (three TRS reports and three H2S reports). The facilities that submitted these reports are being contacted to resolve the issues as part of the NPRI quality control process.

Return to footnote 4

Footnote 5

These numbers include reports where the quantity was zero.

Return to footnote 5

Footnote 6

2010 NPRI Reviewed Facility Data Release – Overview of Pollutant Releases, Disposals and Recycling Reported to the NPRI for 2010.

Return to footnote 6

Footnote 7

Guide for Using and Interpreting National Pollutant Release Inventory (NPRI) Data.

Return to footnote7

Date modified: