Bolsa Quartzite - Acid-Base Accounting Properties and Humidity Cell Testing Results

One focus of the geochemical testing program for the proposed Rosemont Copper Project in Pima County, Arizona has been the characterize the acid-base accounting (ABA) properties of the expected waste rock materials. Of the expected waste rock materials, the Bolsa Quartzite (Bolsa) is anticipated to comprise a small percentage (1.9%) of the total waste rock mass. Based on this percentage, only a single sample of Bolsa Quartzite was tested during initial 2007 geochemical testing program. The ABA results from this sample (VABH0608-01) indicated that the Bolsa could be classified as inert according to Arizona Department of Environmental Quality (ADEQ) criteria and therefore would not require additional testing (ADEQ, 1999; Tetra Tech, 2007).