A stationary source audit sample is a blind sample whose value is known only to the sample provider and is not revealed to the tested facility until after they report the measured value of the audit sample.  They are used as a quality assurance tool for compliance stack testing events. 

In September 2010, EPA took final action to promulgate amendments to the General Provisions to allow accredited audit sample providers (AASPs) to supply stationary source audit samples and to require sources to obtain and use these samples from the accredited providers instead of from EPA (through NJDEP in NJ), as was the prior practice.  In addition to allowing private AASPs to provide audit samples for the stationary source audit program, this action shifted the burden of obtaining an audit sample from the compliance authority (ie: NJDEP) to the source.  In the past, the EPA provided the samples to the compliance authorities at no cost, but this action required the source to purchase the samples from an accredited provider. 

The requirement to use an audit sample during a compliance test applies to all test methods for which a commercially available audit exists, once two providers are accredited for a particular method.  The purpose of this message is to inform you that one AASP now exists for many of the test methods.  Details on available audits can be found at:  http://nelac-institute.org/docs/comm/ssas/2012%20ERA%20SSAS%20Accreditation%20by%20Method%20Table%205-2012.pdf

Since only one AASP exists for these methods, facilities are not required to use these audits yet, but may choose to do so voluntarily to enhance the quality assurance of their test program.  Should you have any questions, please contact the Bureau of Technical Services at (609) 530-4041.