Field Validation of Pollutant Measurement Methods from Various Waste Media – USEPA Method 301

USEPA Method 301 is used whenever a source owner or operator proposes a test method to meet a U.S. Environmental Protection Agency (EPA) requirement in the absence of a validated method.  This method includes procedures for determining and documenting the quality, i.e., systematic error (bias) and random error (precision), of the measured concentrations from an effected source.  This method is applicable to various waste media (i.e., exhaust gas, wastewater, sludge, etc.). 
 
The purpose of these procedures is to determine bias and precision of a test method at the level of the applicable standard.  The procedures involve:

• introducing known concentrations of an analyte or comparing the test method against a validated test method to determine the method's bias;
• collecting multiple or collocated simultaneous samples to determine the method's precision.

Bias is established by comparing the method's results against a reference value and is eliminated by employing a correction factor established from the data obtained during the validation test.  An offset bias is handled accordingly.  Methods that have bias correction factors outside 0.7 to 1.3 are unacceptable.  Validated method to proposed method comparisons requires a more restrictive test of central tendency and a lower correction factor allowance of 0.90 to 1.10.
 
At the minimum, paired sampling systems are used to establish precision.  The precision of the method at the level of the standard is not greater than 50 percent relative standard deviation.  For a validated method to proposed method equivalency comparisons, the analyst must demonstrate that the precision of the proposed test method is as precise as the validated method for acceptance.
 
This method includes optional procedures that are used to expand the applicability of the proposed method.  These optional procedures include:

• ruggedness testing (Laboratory Evaluation), which demonstrates the sensitivity of the method to various parameters. 
• a procedure for including sample stability in bias and precision for assessing sample recovery and analysis times;
• a procedure for the determination of the practical limit of quantitation for determining the lower limit of the method.