Pollutants Reported by Source Industrial Classification (SIC) Code

Which air contaminants should you expect to report for your facility? The amount and type of air emissions depend on the product produced and the fuel burned to produce a product. We developed information that you can use to obtain a general idea on what pollutants should be reported under chapter NR 438, Wis. Adm. Code, based on our historical emission information and information from the United States Environmental Protection Agency (USEPA). If you know your four digit Source Industrial Classification (SIC) code, you can get an idea as to what pollutants should be reported for your facility. This information is a rough guide as to what pollutants can be expected and should not be viewed as a final determination.

Data Used

• In our emission inventory database, we collect SIC information for each reporting air facility. In order to calculate air emissions, an eight digit Source Classification Code (SCC) is assigned to each process. The computer retrieves a number associated with an air contaminant (e.g. carbon monoxide) based on that SCC. (This number is called the emission factor.) The computer then multiplies the amount of fuel burned or product produced (also known as an activity) by the emission factor to calculate an uncontrolled emission. The computer then adjusts the uncontrolled emission to a controlled emission if the effluent stream is processed by a control. For example, a boiler burns 100 gallons of fuel, the emission factor for the fuel is 10 lb particulate matter per gallon of fuel, and the effluent is processed through a control that is 98% efficient. The uncontrolled emission is 100 gallons x 10 lb particulate matter/gallon = 1,000 lbs particulate matter. The controlled emission is 1000 lbs particulate matter x (1.0-.98)=20 lbs particulate matter. For the information developed for the trables below, we used the SIC code and SCC information for companies reporting in 2004.
• USEPA publishes a document called AP 42, Fifth Edition Compilation of Air Pollutant Emission Factors, Volume 1: Stationary Point and Area Sources. This document contains generalized emission inventory information for a source category based on stack testing information obtained from local and state governments, companies, and trade associations across the United States. Each of the emission factors is linked to an eight digit code called the Source Classification Code (SCC) that links the emission factor to the piece of equipment generating the air emission. The electronic version of AP42 is named the Factor Information REtrieval (FIRE) Data System and lists the electronic versions of the same numbers shown in print in AP42. We chose uncontrolled emission factors for each SCC code in FIRE having uncontrolled emission factors where a number was supplied by USEPA. Some uncontrolled emission factors contain formulas for calculating emissions and this information was not used.

Calculation

All of the SCCs used under an SIC were identified. The emission factor information from FIRE was then obtained for each SCC. Only emission factors for air contaminants listed in chapter NR 438, Wis. Adm. Code, were chosen. The emission factor was divided by the chapter NR 438, Wis. Adm. Code, threshold for that pollutant. The resulting number was designated the "thruput". If the facility in total burns more fuel or produces more product than the "thruput" then the air contaminant listed in the table should be reported. [Note: This information should be used only as a guide. The "thruput" assumes an uncontrolled emission. If the air contaminant is controlled then the "thruput" would be higher before it exceeds the chapter NR 438, Wis. Adm. Code, threshold for the pollutant. If the air contaminant does not exceed its chapter NR 438, Wis. Adm. Code reporting threshold, the reporting of this pollutant amount is optional.]

Limitations

For some source categories, the emission factor information in FIRE is limited and therefore the "thruput" calculation may not be present in the table for your SIC. For example, emission factors for painting operations are extremely limited because emissions from painting operations is dependent on the formulation of the paint. Consequently, if you use these tables to determine what should be reported be mindful that an absence of a emission factor and the resulting "thruput" calculation does not mean the process does not emit reportable emissions under ch. NR 438, Wis. Adm. Code. Other source categories may also lack information because these emission factors are calculated using formulas based on variable parameters. For example, for some coal burning emission factors a representative sulfur content must be supplied to calculate sulfur dioxide emissions.

Because of these limitations, you will see a wealth of information regarding fuel burning emissions and limited information regarding emissions from production sources. We intend on improving this information by including more information, where possible, for production emission sources in the future if our users feel it is worthwhile.