This action under the Clean Water Act (CWA) section 304(h) amends 40 CFR Part 136 to add clarifying footnotes to the lists of approved test procedures, to update method citations in Tables IA, IB, IC, and ID, to amend the incorporation by reference section of the regulation accordingly, and to correct certain typographical errors and omissions in the Technical Amendments appearing in the Federal Register of January 31, 1994.