PM-2.5 FEM Requirements for
Met One BAM
Glenn Gehring, Technology Specialist
Tribal Air Monitoring Support (TAMS) Center
541-223-1402
glenn.gehring@nau.edu
To obtain a NAAQS designation
• FEM equipment must be operated in
accordance with FEM certification
• PM-2.5 network collocation and siting
requirements must be met
• You must follow your approved QAPP
(the QAPP must comply with all relevant CFRs)
Zero calibration at deployment
Collocation
Refer to: 40 CFR Part 58 Appendix A section 3.2.5
• 15% of PM-2.5 (FEM or FRM) sites must be
collocated (round up) – must have at least 1
• FRM collocation must be with same EPA FRM
method designation
• FEM collocation - 50% of the 15% required
collocations must be with FRMs and 50% with
FEMs of the same EPA FEM designation – The
first collocation MUST be with an FRM
• Must run FRM at least once every 12 days
[Most tribe will fall under the FEM (C) scenario where you have fewer than 7 sites and are
only required to have one collocated site for your PM-2.5 network. In this situation, if you
are using a FEM it must be collocated with a FRM. If your network needs two collocated sites
the second collocation must be with another FEM that has the same EPA FEM designation
number as the primary monitor. Basically, 50% of monitors used for collocation must be FRM
and 50% FEM (If FEMs are used in the network), with the FRM being first. If you need three
collocated sites the third monitor used for collocation must also be a FRM.]
PM-2.5 Probe Siting
Refer to: 40 CFR Part 58 Appendix E
• Overall probe height: 2–15 Meters above ground level (Microscale is 2-7
meters)
• Horizontal distance from obstacles: must be at least twice the height the
obstacle protrudes above the sampler inlet (two times the height
difference away) with at least 270 degrees unobstructed.
• Rooftop - horizontal distance from obstacles: at least 2-meters - should be
away from minor sources such as furnace, incineration or food service
exhausts flues – you should also avoid areas too close to residential areas
with wood burning stoves
• Horizontal distance from the dripline of a tree: must be at least 10meters and should be at least 20-meters.
• Collocated horizontal separation (for low vols): within 4-meters of each
other and at least 1-meter apart (you should also have a maximum of 1
meter vertical separation)
• Distance from road: 2-10 meters for microscale - see chart for other scales
PM probe distance from roads
Other PM-2.5 FEM Requirements
• Monthly flow verifications with NIST traceable
standards
40CFR58 Appendix A, Section 3.2.3
• Semi-annual flow audits (at least every 6-months)
40CFR58 Appendix A, Section 3.2.4
• PEP audits - 5 per year, minimum
40CFR58 Appendix A, section 3.2.7
• 75% data completeness
• Data Certification
• Maintained in accordance with manual
• QAPP compliance and appropriate documentation
http://ecfr.gpoaccess.gov/
Always check
with your EPA
Region’s Quality
Assurance folks
AND Refer to
the CFRs.