PM2.5 Equivalence Program

When the variation to the Ambient Air Quality NEPM was made in 2003 to incorporate advisory reporting standards for PM_2.5, provision was made for a program to determine whether manual gravimetric methods of monitoring PM_2.5 and continuous methods (such as the TEOM) can be considered equivalent. The reference method for monitoring PM_2.5 is the manual gravimetric method. The TEOM does not have reference or equivalence status through the USEPA designations for monitoring of PM_2.5 due to issues related with loss of volatiles.

All jurisdictions are now monitoring PM_2.5 using the designated reference method for sampling.

The findings of these collocation studies will be used to determine the appropriate method(s) for PM_2.5 monitoring under the NEPM.