ESTIMATION OF DIOXIN AND DIOXIN-LIKE COMPOUND EMISSIONS FOR THE TRI DUE JULY 1, 2001
 

On October 29, 1999, the Environmental Protection Agency (EPA) promulgated a final rule to address Persistent Bio-accumulative Toxic (PBT) chemicals as part of the Emergency Planning and Community Right-to Know Act (EPCRA) Section 313 Toxic Release Inventory (TRI)¹. EPA added seven chemicals and two chemical compound categories to the list of toxic chemicals subject to reporting under EPCRA section 313. One of the new chemical compound categories is dioxin and dioxin-like compounds. The dioxin and dioxin-like compounds are the seven 2,3,7,8-substituted poly-chlorinated dibenzo-p-dioxin congeners and ten 2,3,7,8-substituted poly-chlorinated dibenzofuran congeners that have toxic equivalency factors. The TRI reports for these PBT chemicals and chemical categories for the 2000 reporting year are due on July 1, 2001.

WHO HAS TO REPORT
Before July 1, 2001 many facilities, primarily manufacturing facilities in SIC Codes 20 through 39, will have to determine if combustion devices and other processes at their facilities manufacture more than 0.1 grams per year of dioxin and dioxin-like compounds. If a facility does manufacture more than 0.1 grams per year of dioxin and dioxin-like compounds, this will have to be reported to the EPA for the TRI.

DIOXIN EMISSION SOURCES
The most likely sources of dioxin and dioxin-like compound emissions are the combustion devices that are typically used at manufacturing facilities; hazardous waste incinerators, fume incinerators, solid waste incinerators, sludge incinerators, hazardous and process waste-fired boilers, fossil-fired boilers and process heaters.

TRI GUIDANCE DOCUMENT
In a final TRI Guidance Document released by the EPA in January 2001, the EPA supported the use of the following three different approaches for estimating annual releases of dioxin and dioxin-like compounds from facilities subject to reporting²:

  · Actual facility-specific monitoring data
  · Facility-specific emission factors
  · EPA default emission factors

If a facility has actual data for dioxin and dioxin-like compound emissions, the data must be used for the estimation of the reporting threshold. If no data is available, estimates can be made using facility-specific emission factors from similar devices from other facilities or by using the EPA's default emission factors.

FACILITY-SPECIFIC EMISSION FACTORS
In this estimation approach, facility-specific emission factors should be used that were developed from actual dioxin sampling data from similar facilities. The guidance document states that the selection of a similar facility should be based on "…similarity of design, operations, feed stocks, end products, SIC code, manufacturing process, combustion process and air pollution control systems." For a combustion device, Focus Environmental feels that the most important parameters that influence the estimate are similar wastes and/or fuels, a similar combustion device and similar temperatures and residence times for the combustion device, the boiler (if applicable) and the air pollution control system. Engineering judgment and combustion experience are the keys to determining whether a combustion device is similar or not.

EPA DEFAULT EMISSION FACTORS
If unable to use actual data or facility-specific emission factors, the EPA recommends that facilities should estimate their annual dioxin releases through the use of default emission factors published by the EPA in the guidance document. The guidance document includes thirteen tables with emission factors for ten sources for the dioxin and dioxin-like compounds. The EPA default emission factors are very conservative and will typically result in high end dioxin estimates.

LEAST-COST SCREENING APPROACH
Focus recommends a least-cost screening approach to our clients. The EPA default emission factors should be used first for estimation of dioxin and dioxin-like compound emissions at your facility. If you are using these default factors and your dioxin and dioxin-like compound emissions are below the 0.1 gram per year reporting threshold, then your facility does not have to report to the TRI. However, if the emissions estimate of dioxin and dioxin-like compounds is above 0.1 gram per year, then the facility-specific estimation approach should be used to estimate emissions of dioxin and dioxin-like compounds.

FOCUS ENVIRONMENTAL FACILITY-SPECIFIC DIOXIN EMISSIONS DATABASE
Focus Environmental, Inc. (Focus) can help your facility estimate the amount of dioxin and dioxin-like compounds that are manufactured by the combustion devices at your facility. Since the early 1980s, Focus has been involved in many projects for the estimation, measurement and control of dioxin and dioxin-like compounds from industrial combustion devices. Over the years, Focus has developed an extensive database of dioxin and dioxin-like compound emissions from over 70 different combustion devices. This database can be used to help your facility personnel estimate the amount of dioxin and dioxin-like compounds that are manufactured and emitted at your facility.

As an example, consider a facility owned by ABC Chemical that utilizes a 50 MM Btu per hour fire-tube boiler to burn an organic liquid process waste containing about 1.0 weight per cent organic chlorine at 1800°F with a wet scrubber as an air pollution control device. In order to estimate the dioxin and dioxin-like compound emissions from this facility, Focus would use the information shown in Table 1 from the Focus facility-specific dioxin emissions database. In this case, the information used by Focus would be for a "similar facility" that utilizes a 32 MM Btu per hour fire-tube boiler to burn an organic liquid process waste containing about 0.6 weight per cent organic chlorine at 1896°F with a wet scrubber as an air pollution control device. As shown in Table 1, the dioxin and dioxin-like compound emission factor for this boiler is 7.1 nanogram (ng) per kilogram (kg) of waste feed. Based on an annual waste feed of 10,000,000 kg per year at the ABC Chemical facility and using the 7.1 ng per kg of waste feed emission factor, the estimated emissions of dioxin and dioxin-like compounds is estimated to be 0.0710 grams per year. Using the EPA default factor for Boilers and Industrial Furnaces of 12.2 ng per kg of waste feed results in an estimate of 0.1220 grams of dioxin and dioxin-like compounds per year. In this example, if ABC Chemical uses the EPA default emission factor, the company would need to report their dioxin and dioxin-like compound emissions to the TRI. If, however, ABC Chemical uses the facility-specific emission factor from the Focus database, the company would not have to report their dioxin and dioxin-like compound emissions to the TRI.

FOCUS EXPERIENCE
Focus Environmental has already performed preliminary dioxin and dioxin-like compound emissions estimates for two Fortune 500 manufacturing companies and a wood burning facility in support of their year 2000 TRI reporting. This same dioxin and dioxin-like compound emission estimating methodology can be applied at your facility. A recent article in Chemical Engineering describes the new TRI-PBT regulations in more detail.³ Call Jim Cudahy or Mark Walker at (865) 694-7517 or email to focus@focusenv.com to discuss your dioxin and dioxin-like compound TRI needs with our experienced staff.

REFERENCES

1. "Persistent, Bioaccumulative Toxic (PBT) Chemicals; Final Rule", Federal Register, October, 29, 1999, pp 58666-58753.

2. Emergency Planning and Community Right-to-Know Act - Section 313:Guidance for Reporting Toxic  Chemicals within the Dioxin and Dioxin-like Compounds Category, EPA-745-B-00-021, December 2000.

3. Cudahy, J.J. and T.L. Schomer, "Estimating Emissions of Dioxin and Dioxin-like Compounds", Chemical Engineering, November 2000, pp 111-115.