Land treatment is categorized in the Resource Conservation and Recovery Act of 1976 (RCRA) as one of the land disposal options for managing hazardous wastes. Land treatment relies on detoxification, degradation, and immobilization of hazardous waste constituents within the defined treatment zone to ensure protection of surface water, groundwater, and air. Under the authority of Subtitle C of RCRA, the U.S. Environmental Protection Agency has promulgated regulations governing the treatment of hazardous wastes in land treatment units (40 CRF, Part 264, Subpart M, July, 1982).

This paper describes the land treatment practices used by petroleum waste land treatment facilities in the U.S. Information obtained for thirteen full-scale land treatment facilities included types of waste land treated, characterization of land treated wastes, waste application rates (loading rates), waste application frequencies, and management practices used at the treatment units. Engineering design matrices which illustrate the relationships among waste application rate, application frequency, and waste degradation rate, and the effect of these parameters on stabilized concentrations during the active life a unit were developed. Waste degradation half-life and waste application frequency were observed to have greater influence in determining the stabilized weight percentage of oil in the treatment soil than waste application rate. A three-dimensional graph was developed as an example of how design matrices can be used as engineering/management aids for petroleum land treatment site design and operation.