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Sampling Plan Update
Current Situation:
Statistically valid sampling plans (e.g., ICMSF) were developed for
d f d h
ti f “ t i ti if
l
processe oo s, w ere assump on o con am na on un orm y
distributed” is likely to be valid
Published studies and industry testing has demonstrated that field
contamination, when it occurs, is most likely to be sporadic, not
uniformly distributed, so assumption is invalid
Most sporadic detections in field are inexplicable and
non-repeatable
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Sampling Plan Update
Current Situation:
Some operations using “Z-pattern”, some
using multiple Z-patterns, some using
serpentine, some using directional sampling,
some test upon receipt at the processing
facility
None are developed to be statistically valid
Currently no statistically valid field sampling protocol
A single “positive” condemns the whole field – no depth of analysis to
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indicate the degree of field contamination.
Negative test results are meaningless – a future “positive” invalidates the
field test results