Compliance with California Title 23 and SWAT in an Arid Environment: Use of Oil-Well Data to Minimize On-Site Investigations

SHEPPARD, MARC A., and KENNETH S. KNIGHT, Uribe & Associates, Bakersfield, CA

California Title 23 and the Solid Waste Assessment Test (SWAT) program, as administered by the Regional Water Quality Control Boards (RWQCB), require extensive characterization and monitoring of waste disposal sites. Typical SWAT/Title 23 investigations require multiple characterization boreholes in addition to groundwater and unsaturated zone monitoring. In an arid environment such as the southwestern San Joaquin Valley, many of these requirements become impracticable. Regions such as these are often characterized by extreme depths to groundwater, non-potable groundwater, and moisture deficient and hydrocompacted soils.

Through the use of oil-field data, an accurate portrayal of subsurface conditions at a SWAT-ranked site was possible. Because of the extensive background material available and the relatively benign nature of the site, a single borehold was deemed by the REQCB to be an acceptable characterization of the site. As predicted from the background data review, this borehole was drilled to 1000 ft in depth without encountering a water-saturated interval capable of yielding a sample. In addition, oil-saturated intervals were encountered beneath the site as predicted.

AAPG Search and Discovery Article #91009©1991 AAPG-SEPM-SEG-SPWLA Pacific Section Annual Meeting, Bakersfield, California, March 6-8, 1991 (2009)