Illinois Administrative Code
Title 35 - ENVIRONMENTAL PROTECTION
Part 283 - GENERAL PROCEDURES FOR EMISSIONS TESTS AVERAGING
Subpart B - PROCEDURES FOR AVERAGING OF TEST RESULTS
Section 283.240 - Averaging Procedure

a) The average of the emissions tests results shall be determined by the arithmetic average of three valid test run results, as long as the test runs are conducted in conformance with either the provisions of an approved test plan or with a test plan that has been modified in accordance with Section 283.230 of this Part.

b) Notwithstanding subsection (a) of this Section, if the owner or operator of an emission unit elects to perform more than three test runs, then the average shall be calculated based upon the results of all valid test runs.

c) Notwithstanding subsection (a), in the event that a sample is accidentally lost or conditions occur in which one of the test runs must be discontinued because of forced shutdown, failure of an irreplaceable portion of the sample train, extreme meteorological conditions, malfunction or other dissimilar or non-representative circumstances, upon the owner's or operator's documentation of the existence of any of the circumstances set forth in this subsection (c) and verification by the Agency that the conditions existed, compliance may be determined by using the arithmetic average of the test results of all remaining valid test runs; however, a minimum of two valid test runs is required to determine compliance.