TM98-03 Changes in Reporting Levels and Data Qualifiers for Selected Pesticides and Degradation Products in Schedules 2050 and 2051

This memorandum replaces NWQL Technical Memorandum 98.03 and portions of 96.06A. This technical memorandum announces changes, effective December 15, 1997, in the following data reporting practices for NWQL schedules 2050 and 2051 (Werner and others, 1996): (1) Reporting levels for nondetections will be raised for 14 constituents. (2) An "E" code (estimated value) data qualifier will be added for all values of aldicarb, aldicarb sulfoxide, and aldicarb sulfone. (3) Esfenvalerate and 1-naphthol are deleted from the method. These changes are based on analysis of performance data for schedule 2050 from the Organic Blind Sample Program by the NWQL's Quality Assurance Unit and from routine laboratory reagent spike recovery data. This memorandum also clarifies approaches previously used to derive reporting levels for all constituents in schedules 2050 and 2051.