Performance assessment of high-level nuclear waste containment feasibility requires representative values of parameters as input, including parameter moments, distributional characteristics, and covariance structures between parameters. To meet this need, characterization methods and data sets for interstitial, hydraulic, pneumatic and thermal parameters for a slightly welded fractured tuff at the Apache Leap Tuff Site situated in central Arizona are reported in this document. The data sets include the influence of matric suction on measured parameters. Spatial variability is investigated by sampling along nine boreholes at regular distances. Laboratory parameter estimates for 105 core segments are provided, as well as field estimates centered on the intervals where the core segments were collected. Measurement uncertainty is estimated by repetitively testing control samples. 31 refs., 10 figs., 21 tabs.

This book is written in a simple, straightforward manner without complicated mathematical derivatives. Compiled by experienced practitioners, this guide covers topics such as basic principles of vadose zone hydrology and prevalent monitoring techniques. Case studies present actual field experiences for the benefit of the reader. The Handbook provides practitioners with the information they need to fully understand the principles, advantages, and limitations of the monitoring techniques that are available. The Handbook of Vadose Zone Characterization & Monitoring expands and consolidates the useful and succint information contained in various ASTM documents, EPA manuals, and other similar texts on the subject, making it an invaluable aid to new practioners and a useful reference for seasoned veterans in the field.

Fluid flow and solute transport within the vadose zone, the unsaturated zone between the land surface and the water table, can be the cause of expanded plumes arising from localized contaminant sources. An understanding of vadose zone processes is, therefore, an essential prerequisite for cost-effective contaminant remediation efforts. In addition, because such features are potential avenues for rapid transport of chemicals from contamination sources to the water table, the presence of fractures and other channel-like openings in the vadose zone poses a particularly significant problem, Conceptual Models of Flow and Transport in the Fractured Vadose Zone is based on the work of a panel established under the auspices of the U.S. National Committee for Rock Mechanics. It emphasizes the importance of conceptual models and goes on to review the conceptual model development, testing, and refinement processes. The book examines fluid flow and transport mechanisms, noting the difficulty of modeling solute transport, and identifies geochemical and environmental tracer data as important components of the modeling process. Finally, the book recommends several areas for continued research.

Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 42. This monograph is an update and revision of the first edition, Geophysical Monograph 42, on ground-water flow and transport through unsaturated, fractured rock, published by AGU in 1987. The first edition evolved from a special symposium held during the American Geophysical Union fall meetings in San Francisco in December 1986. Invited and contributed papers at that AGU session, as well as panel presentations, focused on conceptualizing, measuring and modeling flow and transport through unsaturated fractured rock. As noted in the preface to the first edition, "the expanded interest in the topic (water flow and contaminant transport through unsaturated fractured rock) was initiated when the U.S. Geological Survey proposed that deep unsaturated zones in arid regions be considered in the site selection for the first high-level, commercially generated radioactive waste repository." Much of the research reported in that first edition was motivated by the U.S. Department of Energy's program to investigate Yucca Mountain at the Nevada Test Site as a possible geologic repository for commercially generated, high-level radioactive waste. As noted in the overview paper of the first edition, "characterization methods and modeling are in their developmental stage with the greatest lack of knowledge being the interaction between fracture and matrix flow and transport properties." Although the first edition of this monograph reflected the state-of-the science, laboratory and field experimental programs were novel and limited and, in general, followed from the principles and methods developed in the soil science community.