Estimation of contamination volume at Seaway Area A, New York.

The purpose of this analysis was to estimate the volume of soil with a radioactive contaminant activity level above the cleanup Guideline at Seaway Area A, Tonawanda, New York. A site-specific cleanup guideline of 40 pCi/g thorium-230 was derived for Seaway, as well as for the nearby Ashland 1 and Ashland 2 sites. All three are Formerly Utilized Sites Remedial Action Program (FUSRAP) properties. The level was developed to ensure protection of human health and the environment and compliance with applicable or relevant and appropriate requirements. The available data included historical discrete soil samples taken at the surface and at depth and results of a surficial gamma walkover with a sodium iodide (NaI) 2x2 sensor. The balance of this document provides background information about the site and discusses the available data sets, the methodology used, and the results and conclusions from the analysis