WEF Discussion Forums
Laboratory Management and Technical Issues
Is the 22nd Edition of SM an "Editorial" revision?
EPA published a letter stating that the 22nd edition of SM is merely an editorial version of the approved method and issued a national ATP approval. Since PDF files cannot be attached to these posts, please send me an e-mail if you want a copy of the letter.
However, some have noticed differences in method practices such as the inclusion of MS/MSDs in the BOD method and the incorporation of a change in the incubator temperature reading schedule found in 9020B.
It is becoming apparent that the 22nd edition is not a mere correction of spelling, but potentially significant changes in practice. It would appear that SM is incorporating the 12 QC elements that EPA first proposed then subsequently eliminated as required in the final Methods Update Rule (the 12 were relegated to option 3 for when a method lacks QC).
From a legal standpoint the letter is merely an ATP approval of the 22nd edition and is an option to the approved method cited in 40CFR part 136.3. The selection of methods is your choice so be sure you know what you are obligating yourself to do if you select the 22nd edition.
The question - after all of the expose - is what other changes have been made? Have any of you noticed a difference in method or QC requirements between the approved method and the 22nd edtion version?