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RE-EVALUATION OF APPLICABILITY OF AGENCY SAMPLE HOLDING TIMES
Citation:
Schumacher, B A. RE-EVALUATION OF APPLICABILITY OF AGENCY SAMPLE HOLDING TIMES. Presented at EPA Regional Laboratory Directors Spring Meeting, Kansas City, KN, April 27, 2004.
Impact/Purpose:
The overall objective of this task is to provide the Agency (i.e., Regions and Program Offices) with independent scientific data on contaminant concentrational changes through time to allow for the reevaluation of the current holding times presented in the current regulations.
Description:
Purpose and Rationale:
1) To assess the validity of currently recognized holding times and to provide a scientific basis for changes that may be necessary to the current regulations.
2) While holding times may appear adequate to protect sample integrity and provide sufficient time for laboratory analysis, relevant data is sparse on individually defined holding times and, thus, some of the holding times appear to be arbitrary and/or politically driven.
3) When holding times are exceeded, even if only by 1 day, the data must be flagged and are often declared invalid or are reported as "estimated", and the data are then called into question, especially if the data are to be used in a court of law.