40 C.F.R. § 455.50
The pesticide active ingredients to which this section applies and for which effluent limitations guidelines and standards are specified in this part are named, together with the Chemical Abstracts Service (CAS) number (provided to assist in identifying the pesticide active ingredient only) and analytical method(s) designation(s) in Table IG at 40 CFR 136.3(a) . Except as provided in 40 CFR 136.5 , the discharge parameter values required under the Clean Water Act must be determined by one of the analytical methods cited and described in Table IG at 40 CFR 136.3(a) . Pesticide manufacturers may not use the analytical method cited in Table IB, Table IC, or Table ID of 40 CFR 136.3(a) to make these determinations (except where the method cited in those tables is identical to the method specified in Table IG at 40 CFR 136.3(a) ). The full texts of the analytical methods cited in Table IG at 40 CFR 136.3(a) are contained in the Methods For The Determination of Nonconventional Pesticides In Municipal and Industrial Wastewater, Volume I, EPA 821-R-93-010A (August 1993 Revision I) and Volume II, EPA 821-R-93-010B (August 1993) (the "Compendium"). Each pesticide chemical manufacturer that is required to determine discharge parameter values under this part using one of the analytical methods cited in Table IG at 40 CFR 136.3(a) must request in writing a copy of the Compendium from the permit authority or local control authority (as applicable) prior to determining such discharge parameter values, unless the manufacturer already has a copy.
40 C.F.R. §455.50