Caption title. At head of title: Project summary. Distributed to depository libraries in microfiche. "Sept. 1990." "EPA/600-S4-90-013."

The sampling of soils in RCRA and Superfund monitoring programs requires associated quality assurance programs. One objective of any quality assurance program is to assess and document the quality of the study data to ensure that it satisfies the needs of the users. The purpose of this report is to describe the nature and function of certain quality assurance samples in the assessment and documentation of bias and precision in sampling studies of inorganic pollutant concentrations in soils. A foundation is provided for answering two basic questions: How many, and what type of, quality assurance (or, to be more specific, quality assessment) samples are required to assess the quality of data in a field sampling effort? How can the information from the quality assessment samples be used to identify and control the principal sources of error and uncertainty in the measurement process? This document has been developed to provide people who plan, implement, or oversee RCRA or Superfund soil sampling studies with information on quality assessment samples so that they will have a better basis for decisions concerning the employment of such samples in their quality assurance programs.