Projects Southwest


Project Details
CLIENT   HDR Engineering, Inc.
DATES  Jan. 2014 – July 2014
TASKS  Vadose zone well installation and testing

Matrix was contracted by HDR Engineering to provide professional services for the drilling and installation of a test vadose zone well at the City of Peoria’s Butler Water Reclamation Facility (WRF). The Butler WRF is located in the West Salt River sub-basin of the Phoenix Active Management Area. The purpose of the test well was to evaluate the subsurface conditions and provide a basis for location and design of future vadose zone recharge wells.

Matrix documented drilling of the test borehole which was drilled using a sonic drill rig to continuously core the vadose zone beneath the Butler WRF to approximately 227 feet below land surface (ft bls). Lithologic samples were extracted from a 6-inch core barrel and placed in plastic sleeves every 2.5-ft. Matrix inspected the sonic core samples for the presence of fine sediments, particularly silt and clay, which could potentially impede the infiltration of recharge water. Matrix prepared a lithologic log, designed, and oversaw construction of the test well which was completed in the vadose (unsaturated) zone to a depth of 180 ft bls using 6-inch Schedule 40 PVC casing.

Using potable water from a fire hydrant, a 13-day injection test was conducted in the test well. Matrix collected and analyzed the test data to evaluate the future potential of large diameter vadose zone recharge wells at the Butler WRF site.