# AGENCY:

 Environmental Protection Agency (EPA).

# ACTION:

 Notice of availability of two final documents and CD-ROM.

# SUMMARY:

 The U.S. Environmental Protection Agency (EPA) announces the availability of two final documents, The QTRACER Program for Tracer-Breakthrough Curve Analysis for Karst and Fractured-Rock Aquifers (EPA/600/R-98/156a, February 1999) and CD-ROM (EPA/600/R-98/156b, February 1999), and A Lexicon of Cave and Karst Terminology with Special Reference to Environmental Karst Hydrology (EPA/600/R-99/006, January 1999), prepared by the National Center for Environmental Assessment—Washington Office (NCEA-W), within the Office of Research and Development.

The QTRACER program was developed to provide a fast and easy method for evaluating tracer-breakthrough curves generated from tracing studies conducted in karst and fractured-rock aquifers. The results may then be applied in solute-transport modeling and risk assessment studies. The QTRACER document will serve as a technical guide to various groups who must address potential and/or existing ground-water contamination problems in karst and fractured-rock terranes. Tracing studies are always appropriate and probably necessary, but analyses can be difficult and tedious. This document and associated computer programs alleviate some of these problems.

A Lexicon of Cave and Karst Terminology with Special Reference to Environmental Karst Hydrology was prepared to satisfy the need to understand the terminology common to the field of karst. This document is a glossary of most terms that have some relationship to the field of environmental karst, as well as specific karst terms. It includes many foreign terms because much karst research is conducted in foreign countries and published using local terminology. In many instances common environmental terms are defined in such a way as to specifically reference karstic phenomena. This document will serve as a technical guide for those who must read the karst literature or hold discussion with karst researchers. It is intended to remove much of the confusion surrounding many karst terms.

# ADDRESSES:

 These documents are being made available electronically from the NCEA web site at http://www.epa.gov/​ncea. A limited number of copies of the printed and CD-ROM version of the QTRACER document is available from EPA's National Service Center for Environmental Publications (NSCEP) in Cincinnati, Ohio (telephone: 1-800-490-9198, or 513-489-8190; facsimile 513-489-8695). Please provide the title and EPA number when ordering from NSCEP. Paper copies of both documents also may be purchased from the National Technical Information Service (NTIS) in Springfield, VA (1-800-553-NTIS[6847] or 703-605-6000; facsimile 703-321-8547). Please provide the following PB numbers when ordering from NTIS: The QTRACER Program for Tracer-Breakthrough Curve Analysis for Karst and Fractured-Rock Aquifers (PB99-151904), and A Lexicon of Cave and Karst Terminology with Special Reference to Environmental Karst Hydrology (PB2000-101071).

# FOR FURTHER INFORMATION CONTACT:

 Malcolm Field, NCEA-W (8623D), U.S. Environmental Protection Agency, Washington, DC 20460; phone: 202-564-3279; facsimile: 202-565-0079; ­ e-mail: field.malcolm@epa.gov.

Dated: January 19, 2000.

George W. Alapas,

Acting Director, National Center for Environmental Assessment.

[FR Doc. 00-2480 Filed 2-3-00; 8:45 am]

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