Question # 605

605. In calculating releases from incinerators, boilers, industrial furnaces and like units, is it sufficient to base the amount released on the efficiency of the unit?
Release calculations based solely on the efficiency of the unit may not be sufficient. Facilities must use the best readily available information. For example, the 99.99 percent efficiency of an incinerator may not refer to the destruction and removal of the chemical being reported on the Form R. If that is the case, the efficiency may have no relation to the release quantity of the chemical being reported. Even if the surrogate waste is the chemical being reported, the 99.99 percent efficiency may not only include the quantity of the chemical destroyed by combustion, but may also include the quantity of the chemical that is physically removed. The quantity of the chemical removed can include undestroyed chemical in the ash, and undestroyed chemical discharged from air pollution control devices like scrubbers, precipitators, baghouses, etc. Furthermore, releases of the chemical due to faulty equipment upstream from the feeding point of the combustion device can also be counted as quantity removed and included in the 99.99 percent efficiency calculation. As a result, release calculations based solely on the efficiency of the unit might count the chemical removed as destroyed. This will result in under-reporting of the quantity of the chemical released to the environment. The facility should also examine its operating records to account for chemical releases during upset conditions such as those released from an emergency dump stack.