CEMS Performance Specification 1 For Opacity
| Text of CEMS Performance Specification 1 (PS-1) For Opacity |
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FREQUENTLY ASKED QUESTIONS (FAQS) for PS-1
Under PS-1, can I locate my continuous opacity
monitoring system (COMS) at a point in a duct or stack that is not
"at least 4 duct diameters downstream from all particulate control
equipment or flow disturbances and...at least 2 duct diameters
upstream of a flow disturbance..."?
Through an inadvertent omission of a phrase in the latest version of PS-1,
there appears to be conflicting language in paragraphs 8.1(2)(i) and 8.1(2)(ii).
In particular, paragraph 8.1(2)(i) should not limit the COMS locations to the
plus four and two diameter sites, but instead should refer to 8.1(2)(ii) for
additional options. Paragraph 8.1(2)(ii) is clear that you can install a COMS
in a location that is not at least 4 duct diameters downstream and 2 duct
diameters upstream of a flow disturbance as long as you meet the appropriate
requirements in the table of 8.1(2)(ii) and the associated figure (i.e., Figures 1-1
through 1-5). If the desired location does not meet the requirements of
paragraphs 8.1(2)(i) and 8.1(2)(ii), then you must demonstrate to the EPA
Administrator's satisfaction that the average opacity measured at the alternative
location is equivalent to the opacity measured at a location meeting the
requirements of paragraphs 8.1(2)(i) and 8.1(2)(ii), as described in 8.1(2)(iii).
We plan to clarify the language of Section 8.1 of PS-1 in a Federal Register
Corrections Notice or our next Methods Update Rulemaking Package.
Still have questions on this method? Contact the EMC
expert Lula Melton at
melton.lula@epa.gov .
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