A key point in the National Science Foundation's (NSF) funding of EMMA is its connection to the new National Environmental Methods Index (NEMI). Although any source of method information could be used as input to EMMA's decision criteria, NEMI's report format is especially convenient because it presents all the information you need to compare multiple methods to each other (i.e., detection levels, accuracy, precision, instrumentation, relative cost, method source, etc.). This relationship was developed by design and Dr. Keith, the author of EMMA, is also the chairman of the committee that is developing and updating NEMI. Over four years in the making, this database is perfect for providing method selection input data into this expert system.
Thus the National Environmental Methods Index (NEMI) is the primary source of information for environmental analytical methods used in conjunction with this expert system. NEMI is a new Internet-searchable database of environmental method summaries available at http://www.nemi.gov since May 2002.
NEMI is not a database of analytical methods. Rather it is a database of method summaries that include all available information, including literature citations, from which to make a scientific comparison of one method versus another, in terms of their ability to meet project-specific requirements. It is a database that is easily searchable on the Internet and, as such, does not require sophisticated software to run it - only a modern browser and an Internet connection. However, links to the full methods (if they are public domain) or to their commercial sources (if they are copyrighted) are provided, so that once a decision is made as to which method is likely to meet a user's needs, it can be obtained.
NEMI's Content and Features
Method summaries currently include those involving laboratory methods and sample preparation for organic and inorganic analytes, nutrients, radiochemicals, and microbiological "analytes" in water. Later versions of NEMI will include biological and field analytical methods for water, soils and solids, air, and other matrices. There are over 30 fields of information for each method summary. These are designed to provide information useful for methods comparison, but not for using a method.
Many of the methods, especially the older ones, do not have information available for all of the fields; however, when information is available, it is included in the database. In fact, the absence of critical information is, in itself, useful for methods comparison. If, for example, among several methods available for consideration for a particular analyte, some are missing important QA/QC metadata information and others have this data, the methods having this information will tend to be the methods of choice, all other criteria having been met.
Method summaries are being contributed by government agencies and private sector organizations and companies. Current contributions by government agencies include the U.S. Environmental Protection Agency, the U.S. Geological Survey, and the Department of Energy. Current private sources of method summaries include the American Society for Testing and Materials, Standard Methods for the Examination of Water and Wastewater, Syngenta, Hach, and others.
U.S. EPA methods are further sub categorized to include those from the Office of Research and Development -- National Exposure Research Lab (formerly EMSL), the Office of Water -- Office of Science and Technology (Engineering and Analysis Division), Office of Ground Water and Drinking Water -- and the Office of Solid Waste.
NEMI already contains information from over six hundred methods and it is expected to grow rapidly as its utility is discovered. The only requirement for submitting method summary information to NEMI is that the method be published and available to the public. Availability of the methods referenced in NEMI may be free, as with public domain methods, or purchased, as with copyrighted methods from some non-profit organizations and also private for-profit companies. Methods may be submitted using an on-line form. In all cases, submitted methods information is carefully peer reviewed for technical content and consistency with respect to units of measurement, database business rules, and meta data prior to its entry into the database.