Permit Description: We will be performing twenty-one (21) geotechnical borings within the roadway of N 1st Ave from approximately 500ft north of the intersection of E River Rd (near 4980 N 1st Ave) and N 1st Ave to approximately 400ft north of the intersection of N 1st Ave and Grant Rd (near 2430 N 1st Ave). Asphalt coring will be conducted prior to drilling of soil borings. Cores will be obtained using an electric coring rig and will be approximately 10 inches in diameter. The soil borings will be advanced through the 10 inch asphalt core hole with 7 or 8 inch hollow stem auger to depths of approximately 5 to 150 feet below the ground surface (135 to 150ft borings will be performed near the 1st Avenue Bridge crossing the Rillito River. The borings will be backfilled with auger cuttings mixed with concrete (with concrete comprising between 20 to 50% of the soil-cement backfill). The exposed asphalt concrete at each boring location will be cleaned, wire-brushed, and patched with QPR brand asphalt cold path. (We understand the restoration of boring locations in the existing roadway as described above will be acceptable by the City of Tucson.) If groundwater is encountered during drilling, the boring will be backfilled with cement grout to the state minimum of the upper 20 feet, unless otherwise within the threshold distance of a WQARF, CERCLA, VRP, LUST, or DOD site, the boring(s) will be backfilled with cement grout to the full depth of the boring. See site plan for details on locations of planned boreholes and traffic control plans for anticipated one-lane closures along N 1st Ave. We do not anticipate performing any work within signalized intersections. Requesting no restrictions on work times. 135 to 150ft bridge borings will be performed as night work. Work performed for HDR Engineering for the City of Tucson, Contract No. 230193-01.