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2 An archaeological testing program consisting of six backhoe test units (BTU) and three auger bores (ATU) placed in the areas to be potentially affected by project subsurface construction has been approved to determine if prehistoric archaeological deposits could be adversely affected. Unit locations will be adjusted to avoid impacts to the underground infrastructure based on USA and other utility location information. Testing will not occur in areas that are not proposed for ground disturbing construction in order to minimize disturbance to the archaeological site. In addition, testing will not extend to depths below the proposed construction activities. The test locations will be field marked by Basin Research Associates (BASIN) with assistance from BKF Engineers. Prior to testing, USA will be alerted to determine the presence/absence of underground utilities and a private utility contractor may be employed to check and further determine the presence/absence of additional subsurface pipelines and conduits that could be damaged by the testing. BACKHOE TEST UNITS (BTU) The backhoe test unit(BTU) excavations will use a standard rubber tire backhoe outfitted with an 18-24-inch wide toothed bucket. The length, width, and depth of each BTU will vary slightly depending on field conditions including access and the presence of underground utilities. BASIN proposes to excavate six BTUs measuring approximately 5-8 feet long x 24-inches wide x 5 feet deep at selected improvement areas within the recorded site. The size of the BTUs will fit within the narrow project areas and be excavated to the potential depth of the proposed impact with a minimal buffer. The final location and size of each BTU will be at the discretion of the Project Archaeologist and selected based on the presence of underground utilities, extensive root systems, etc. which may affect unit location, depth, etc. It is anticipated that six-inch lifts will be used to remove the sediment to each unit's final depth. Each lift and the resulting spoils will be visually inspected by the Lead Archaeologist and Field Technicians. BTU testing will stop if, in the opinion of the Project Archaeologist and/or Lead Archaeologist, a substantially intact significant cultural deposit is exposed within the unit that suggests a potential for focused data recovery (see Data Recovery Program). A Shovel Test Unit (STU) may be excavated within the deposit to characterize it so that appropriate treatment can be planned. The Project Archaeologist will notify Caltrans to discuss the deposit and planned treatment. It is expected that if hand recovery cannot be undertaken immediately, the deposit will be covered with a steel plate or other suitable method until data recovery can begin. If no cultural materials are exposed that warrant a change in focus, the testing program will continue. Upon completion of the unit, the spoils and trench profiles will be visually inspected again for the presence/absence of cultural materials. Standard archaeological recordation, including a written description, stratigraphic sediment profile, and photographic documentation, will be completed for each unit (Note: Units deeper than 4.0 feet will not Scope and Cost Estimate-Archaeological Test Plan Encroachment Permit 0411-NMC0671 Mitigation Plan-CA-CA-ALA-574 June 2013(Revised November 2013)