Deana Crumbling

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The Need for Change EPA's Office of Solid Waste and Emergency Response (OSWER) manages the Superfund, RCRA Corrective Action, Federal Facilities, Underground Storage Tank, and Brownfields programs, all dealing with issues related to the management of wastes, hazardous materials, and site contamination. Within OSWER, the Technology Innovation Office (TIO) is charged with advocating for more effective, less costly approaches by government and industry to assess and clean up contaminated waste sites through federal, state, and local programs. TIO disseminates technical and market information in an effort to remove policy and institutional impediments to adopting "smarter solutions" for investigating and remediating contaminated sites. "Smarter solutions" may take two major forms. One is through the adoption of new tools; the other is to revolutionize the strategy by which tools are deployed. Both are connected in a feedback loop, since strategy shifts are both f...

The Purpose of the Triad Approach Experienced practitioners from the public and private sectors have pooled their efforts to create the Triad approach. This scientific effort is supported by EPA to foster modernization of technical practices for characterizing and remediating chemically contaminated sites. The goal of the Triad approach is to manage decision uncertainty, that is, to increase confidence that project decisions (about contaminant presence, location, fate, exposure, and risk reduction choices and design) are made correctly and cost-effectively. ("Correct" decisions are here defined as the decisions that would be made if fully completely accurate knowledge of contamination nature and extent and receptor exposure were available to decision-makers.) The foundation for site-related decisions that are both correct and optimized (from a cost-benefit standpoint) is the conceptual site model (CSM). A CSM uses all available historical and current information to estimat...

The terminal differentiation of Schwann cells is dependent on contact with basement membrane. The present study was undertaken to investigate the role of cell surface heparan sulfate proteoglycans (HSPGs) in mediating Schwann cell responses to extracellular matrix contact. Phosphatidylinositol-specific phospholipase C-releasable cell surface HSPGs purified from cultures of neonatal rat Schwann cells were subjected to affinity chromatography on immobilized laminin and fibronectin. Binding of the HSPG to both affinity matrices was observed. The strength of the association, however, was sensitive to the ionic strength of the buffer. In 0.1 M Tris-HCl, HSPG binding was essentially irreversible whereas in physiological ionic strength buffer (e.g. 0.142 M NaCl, 10 mM Tris), weaker binding was detected as a delay in elution of the HSPG from the affinity columns. Further studies of HSPG-laminin binding suggested that the binding was mediated by the glycosaminoglycan chains of the proteoglyc...

This fact sheet discusses concepts and techniques for processing soil samples submitted to laboratories for chemical analysis in order to ensure the analytical results are representative with respect to the decisions that are to be made using the data. Specifically, this fact sheet recommends application of incremental-composite sampling (ICS) as a subsampling technique in the laboratory when processing soil samples in order to minimize the influence of within-sample variability. Appropriate sample processing is particularly important when analyzing for trace concentrations (parts per million and lower) of organic and inorganic contaminants. If appropriate sample processing techniques are not used when subsampling soil samples for chemical analysis, the results cannot be considered representative of the sample or, therefore, of the area or volume of soil the sample is intended to represent. Effective soil sampling for any contaminant requires consideration of the factors that can af...

Environmental regulatory policy states a goal of "sound science." The practice of good science is founded on the systematic identification and management of uncertainties; i.e., knowledge gaps that compromise our ability to make accurate predictions. Predicting the consequences of decisions about risk and risk reduction at contaminated sites requires an accurate model of the nature and extent of site contamination, which in turn requires measuring contaminant concentrations in complex environmental matrices. Perfecting analytical tests to perform those measurements has consumed tremendous regulatory attention for the past 20-30 years. Yet, despite great improvements in environmental analytical capability, complaints about inadequate data quality still abound. This paper argues that the first generation data quality model that equated environmental data quality with analytical quality was a useful starting point, but it is insufficient because it is blind to the repercussio...