EPA Methods Most environmental engineering companies and environmental testing labs are familiar with the environment of the states they operate in. Analytical testing is ruled by standardized EPA approved methods that are well defined and somewhat inflexible. Some examples: When an EPA method says that holding time is seven days, data is generally not considered valid if that time period is exceeded. Laboratories lose their state certification or get barred from future EPA and federal work if "time travel", (i.e. backdating of the time when samples were run to before the time of outdate) is discovered. Use of incorrect instrumentation and quality assurance (QA) procedures or testing not following the SOP (Standard Operating Procedure) will get a lab decertified or barred from future work.

The regulatory rules are so well known, and punishment for violations so severe, that it will probably be a surprise to many working in the environmental field that data not in conformance with the regulatory rules still may be legally defensible. The courts have their own rules, and they are more flexible than the regulatory framework.

PBMS (Performance-Based Measurement System) The federal government (i.e. the EPA) and with them the states, are slowly moving towards a performance-based measurement system. The current regulatory system based on EPA-approved testing methods does not permit modifications of existing methods or use of new, often cheaper and more precise testing methods.

In 1997, the EPA proposed their "streamlining rule" which was designed to allow flexibility in the use of currently approved methods. The laboratory modifying the method must demonstrate that the modifications do not adversely affect the quality of data by generating quality control results that meet the specifications contained in the method. Implementation of the "streamlining rule" is expected in the summer of 2000.

PBMS goes one step further than the "streamlining rule" and would permit the use of a new method after the user has validated and verified it. Currently there is no standard or guide available that can be used to demonstrate that a PBMS method is valid, but several groups are working on it.

The GEIS Report advocates a framework analogous to that set up in Daubert v. Merrell Dow Pharmaceuticals (see below.) The National Environmental Laboratory Accreditation Conference (NELAC), of which the EPA is a participant, has begun to standardize the implementation and verification of PBMS analytical methods. A draft of a PBMS checklist is available on the NELAC website. The EPA is expected to finalize procedures for the use of performance-based measuring procedures and guidance of their use in compliance monitoring by December 2000.

One question of great concern is whether data from a lab using PBMS methods has the same legal defensibility as the EPA-approved methods. This concern is unfounded, as the courts have implemented their own version of PBMS since the beginning of the 1920s. The courts have had to repeatedly evaluate extremely varied types of testing methods; they have developed their own system of procedures for evaluating legally defensibility, independent of what is acceptable under EPA-approved methods (see Frye v. United States and Daubert below).

The Consistency of Environmental Forensics The environmental forensics methods are derived from geochemistry and so specialized that they are not used often enough to have entered the routine regulatory arena. From a regulatory standpoint, they are considered non-approved methods. But these methods have been used extensively and successfully in litigation because they based on validated scientific principles.