TM01-05 Establishment of Long-Term Method Detection Levels for the Analysis of Oil and Grease

The National Water Quality Laboratory (NWQL) analyzes water samples for Oil and Grease, Parameter Code 00556, method code B, labcode 2125. The NWQL Minimum Reporting Level (MRL) for this analysis has been 1 mg/L. A Long-Term Method Detection Level (LT-MDL) has been established at 3 mg/L and the Laboratory Reporting Level (LRL) has been set at 7 mg/L (Childress and others, 1999). The purpose of this memo is to announce the establishment of the LTMDL and discuss the implications on data reported for samples taken prior to Oct. 1, 2001, the effective date of the LT-MDL.