Guide for reporting to National Pollutant Release Inventory 2001: appendix 6

Appendix 6: examples of estimating releases of alternate-threshold substances

This appendix provides examples of various reporting scenarios for alternate-threshold substances. With the exception of wood-preservation processes, polycyclic aromatic hydrocarbons (PAHs), dioxins/furans and hexachlorobenzene (HCB) are typically by-products formed during certain manufacturing and combustion processes, and as such the quantities released as a result of incidental manufacture cannot be determined using engineering calculations or a mass balance. Instead, direct measurements or emission factors must be used. Environment Canada has prepared a database with emission factors for all alternate-threshold substances, called the National Pollutant Release Inventory (NPRI) emission factor database for alternate-threshold substances (see Appendix 11).

Example 1: reporting for a hospital waste incinerator using stack testing data

At this facility, 200 tonnes of biomedical waste were incinerated during the year, with a waste feed rate of 100 kg/hr. The facility has stack testing data for dioxins/furans. The measured stack gas concentration of dioxins/furans in air was 2.1 ng toxicity equivalent (TEQ)/m³. The stack flow rate was 1.2 m³/s. The facility produced 20 tonnes of incineration ash in the year and has measured an average dioxin/furan concentration of 1.52 mg TEQ/tonne of ash. The ash was shipped off site for disposal in a landfill.

Step 1. Determine if the facility must report to the NPRI for any alternate-threshold substances

Reporting is required by facilities used for the "biomedical or hospital waste incineration of 100 tonnes or more of waste per year", regardless of the number of hours worked by employees. This facility incinerated 200 tonnes of biomedical waste, so a report is required for any substance that met the reporting criterion.

Step 2. Determine which substances and information must be reported

Dioxins/furans

1. Determine if the measured concentration of dioxin/furan releases to air (2.1 ng TEQ/m³ was greater than the level of quantification (LoQ) of 32 pg TEQ/m³.

This facility is required to report releases of dioxins/furans to air since the measured concentration of 2100 pg TEQ/m³ was greater than the LoQ of 32 pg TEQ/m³.

Calculate the hours of operation.

Calculate the quantity of dioxins/furans released to the air.

The substance report for dioxin/furan releases to air would indicate: basis of estimate code - monitoring or direct measurement (Code M); detail code - at or above LoQ (Code AL); Quantity - 0.018 g TEQ. The quantity is rounded to the nearest thousandth (that is, 0.018 g TEQ), since the smallest unit that the NPRI reporting software will accept for dioxins/furans is 0.001 g TEQ.

2. Determine if the measured concentration of dioxins/furans in the incineration ash (1.52 mg TEQ/tonne ash) was greater than the LoQ of 22 pg TEQ/g ash.

The measured concentration of 1520 pg TEQ/g ash was greater than the LoQ for dioxins/furans in ash of 22 pg TEQ/g ash, therefore the quantity of dioxins/furans in ash transferred off site for disposal must be reported.

3. Calculate the quantity of dioxins/furans contained in the incineration ash that was transferred off site for disposal.

Quantity of dioxins/furans transferred off site = (ash produced) × (concentration of dioxins/furans in ash)

The substance report for dioxin/furan transfers off site would indicate: basis of estimate code - monitoring or direct measurement (Code M); detail code - at or above LoQ (Code AL); Quantity - 0.030 g TEQ. The quantity is rounded to the nearest thousandth (that is, 0.030 g TEQ), since the smallest unit that the NPRI reporting software will accept for dioxins/furans is 0.001 g TEQ.

4. Based on process operations, it is known that there were no on-site releases of dioxins/furans to land, water or underground injection resulting from the incineration process. The substance report for dioxin/furan releases to land, water and underground injection would indicate: basis of estimate code - not applicable (Code NA); detail code - not applicable; quantity - not applicable.

HCB

1. There were no direct measurements performed for HCB at this facility. Use the emission factors provided in the NPRI emission factor database for alternate-threshold substances (Environment Canada) to estimate the HCB releases to air.

The substance report for HCB releases to air would indicate: basis of estimate code - emission factors (Code E); detail code - not applicable; quantity - 171.4 g.

2. There was no information available on the concentration of HCB in incineration ash transferred off site for disposal. The substance report for HCB transferred off site for disposal would indicate: basis of estimate code - No information available (Code NI); Detail Code - not applicable; Quantity - not applicable.

3. Based on unit operations, it is known that there were no on-site releases of HCB to land, water or underground injection resulting from the incineration process. The substance report for HCB releases to land, water and underground injection would indicate: basis of estimate code - Not applicable (Code NA); detail code - not applicable; quantity - not applicable.

Example 2: reporting for a cement kiln

A facility operated a cement kiln and employed 25 full-time employees. Process throughput amounted to 2 500 000 tonnes of clinker produced during the year. The facility incidentally processed and released 9.4 kg of mercury to air from trace mercury contamination in the limestone processed in the kiln and from fossil fuels combusted. The concentration of dioxins/furans released to air was measured at 0.051 ng TEQ/m³, and the total quantity of dioxins/furans released to air from the stack was calculated to be 0.025 g TEQ. The average concentration of HCB released to air over the year was measured at 30.0 ng/m³, and the total quantity of HCB released to air from the stack was calculated to be 9 g.

Step 1. Determine if the facility must report to the NPRI for any alternate-threshold substances

The facility met the 20,000-hour employee threshold and, as such, is required to report to the NPRI for substances which met the NPRI reporting criteria.

Step 2. Determine which substances and information must be reported

Mercury (and its compounds)

The facility incidentally processed and released 9.4 kg of mercury to air. This quantity exceeded the 5-kg manufacture, process or other-use threshold for mercury, so the facility must report for mercury (and its compounds).

PAHs

1. Determine if the facility met the NPRI reporting criteria for PAHs. PAHs are reported if the facility incidentally manufactured these substances and the quantity of the PAHs released on site or transferred off site totalled 50 kg or more.

In this example, the facility uses the emission factors provided in the emission factor database for alternate-threshold substances (Environment Canada), to calculate the quantities of the individual PAHs that were incidentally manufactured and released or transferred. The quantity of each individual PAH released is added to determine whether the total of the PAHs listed in Schedule 1, Part 3, of the 2000 Canada Gazette notice met or exceeded the 50-kg threshold for total PAHs incidentally manufactured and released or transferred. For a throughput of 2,500,000 tonnes of clinker, the following quantities of individual PAHs are released to air.

The quantity of the individual PAHs resulting from incidental manufacture totalled more than 50 kg, so the facility has met the reporting threshold for PAHs, and must report these substances.

3. The facility must submit a substance report to the NPRI for each of the three PAH substances for which there are data. The substance reports and quantity reported for on-site releases to air are: 6.05 kg of fluoranthene, 42.25 kg of phenanthrene and 3.65 kg of pyrene. No report is required for the individual PAHs for which there are no emission factors (that is, benzo(a)anthracene, benzo(a)phenanthrene, etc.). The releases are not reported under the listing "PAHs, total Schedule 1, Part 3" because the facility has information for some of the individual PAHs listed in Schedule 1, Part 3.

4. There were no releases to water, land or underground injection of any incidentally manufactured PAHs, so the facility reports no releases to these media.

5. There is no knowledge of the quantity of incidentally manufactured PAHs in the residue from the pollution control devices (for example, electrostatic precipitator), so the facility reports no transfers of the three PAHs.

Dioxins/furans

1. A direct measurement was used to determine the quantity of dioxins/furans released to air. Compare the measured concentration value to the LoQ for air. The LoQ for releases to air is 32 pg TEQ/m³.

The concentration of 51 pg TEQ/m³ was above the LoQ for dioxins/furans for air of 32 pg TEQ/m³, therefore the facility is required to report the quantity of dioxins/furans released. The substance report for dioxins/furans released to air would indicate: basis of estimate code - monitoring or direct measurement (Code M); detail code - at or above LoQ (Code AL); quantity - 0.025 g TEQ.

2. There were no releases of dioxins/furans to water, land or underground injection, nor any transfers off site for disposal. The substance report for dioxin/furan releases to land, water and underground injection would indicate: basis of estimate code - not applicable (Code NA); detail code - not applicable; quantity - not applicable.

HCB

1. Direct measurement was used to determine releases to air. Compare the measured concentration value to the LoQ for air. The measured concentration of 30 ng/m³ was larger than the LoQ for HCB for air of 6 ng/m³, so the facility is required to report the quantity released. The substance report for HCB released to air would indicate: basis of estimate code- monitoring or direct measurement (Code M); detail code - at or above LoQ (Code AL); quantity - 9 g.

2. There were no on-site releases of HCB to water, land or underground injection, nor any transfers off site, so the facility reports no releases to these media or transfers. The substance report for HCB releases to land, water and underground injection would indicate: basis of estimate code - not applicable (Code NA); detail code - not applicable; quantity- not applicable.

Example 3: using the manufacture, process or other-use threshold for reporting mercury (and its compounds)

The following example illustrates the calculation of the 5-kg manufacture, process or other-use reporting threshold applicable to mercury (and its compounds). This facility used several processes in which mercury (and its compounds) were manufactured, processed or otherwise used. There is no 1% concentration exemption for mercury (and its compounds). Mercury (and its compounds), at any concentration, must be considered when calculating the reporting threshold and subsequently when reporting.

The facility met the 20,000-hour employee threshold and the processes used were:

1. In the first process, mercury was present in a mixture at a 1% concentration.

2. The facility received a raw material which contained 0.005% mercury, which was processed in stream 2.

3. In process stream 3, mercury was present at a concentration of 0.01%.

In this example, the facility would be required to submit a report to the NPRI for mercury (and its compounds) because the total quantity manufactured, processed or otherwise used at the facility exceeded the 5-kg reporting threshold. The facility must report the quantity released on site and transferred off site.