The Methods They Are’a Changing BY BART SIMMONS, PH.D. Better, Cheaper, Faster In June, US EPA adopted Update III to SW-846, Test Methods for Evaluating Solid Waste, Physical/Chemical Methods. The EPA Office of Solid Waste, which maintains SW-846, has consistently pointed out that, with a few specific exceptions like the Toxicity Characteristic Leaching Procedure (TCLP), use of SW-846 methods is not required, and that any reliable method may be used for most testing. Nevertheless, states and other federal agencies have come to rely on SW-846 methods for a variety of testing. Update III includes 40 revised methods, 8 revised chapters, and 62 new methods. In addition, Update III deletes 16 methods, such as 8010, 8020, 8080, and 8240, which are packed-column gas chromatography methods, that have been replaced by capillary column methods. SW-846, although originally written for testing under the Resource Conservation and Recovery Act (RCRA), is widely used for a variety of environmental measurements, including groundwater monitoring. Update III includes several changes to the collection and analysis of environmental samples, including a variety of immunoassays (4000 series), and a closed-system purge and trap technique for volatile organics in soil (5035). The transition to the new methods will have an impact on the whole environmental testing community. The elimination of some EPA methods poses a problem, since some methods are listed in Title 22 hazardous waste regulations, and because some permits and sampling and analysis plans have listed EPA methods which now technically no longer exist. Some of the calibration criteria have changed, which requires labs to change their standard operating procedures. The closed-system purge-and-trap system will require new sampling procedures for field staff. US EPA has encouraged some flexibility in the conversion to Update III, and it will certainly take some time for the conversion to Update III to be completed. In particular, some regulations will need updating, and some permits will need formal permit modifications to incorporate the new methods. Although the EPA Rule was effective immediately, it will take some time for conversion to the new methods. Enter the Performance-Based Measurement System The other solution to the methods problem is to eliminate the reliance on specific test methods. On October 6, US EPA published in the Federal Register a Notice of Intent to establish a Performance-Based Measurement System (PBMS) for all environmental media to the extent feasible. Although the exact details of a PBMS remain to be worked out, it would eliminate some of the prescriptive methods with a system which gives labs flexibility on methods so long as they meet criteria which are established by federal (and, presumably, state) programs. PBMS is also being considered for incorporation in the National Environmental Laboratory Accreditation Conference (NELAC) standards, which will be used for the new National Environmental Laboratory Accreditation Program (NELAP). The debate over PBMS versus prescriptive methods has been going for some time, and the resolution seems to be that in some cases, e.g., the TCLP, a prescriptive method is necessary, but for many needs a PBMS should work more efficiently than the current system. EPA plans to implement a PBMS as early as next fall, so we are likely headed for some significant changes in the way environmental testing is done. Elimination of the reliance on specific test methods could force regulatory agencies, consultants, and laboratories to think more about exactly what data quality objectives are needed for a specific project. The outcome is likely to be a more flexible and rational system for environmental measurements. Bart Simmons, Ph.D., is Chief of the Hazardous Material Laboratory, Department of Toxic Substances Control, Berkeley, CA.

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