scope:

EXECUTIVE SUMMARY

The petroleum industry has successfully used land treatment for over 25 years to treat and dispose of select wastes. Many of these petroleum industry land treatment facilities apply wastes which are classified as hazardous under 40 CFR Part 261 and, therefore, they are subject to the regulations specified under the Resource Conservation and Recovery Act (RCRA). These facilities, as well as any new facilities, must apply for an RCRA permit in order to operate. As part of the permit application, each individual facility must develop a treatment demonstration engineering report.

The treatment demonstration establishes which wastes can be applied to the facility and will provide the core information for (a) developing appropriate design and operating standards for the facility and (b) selecting appropriate constituents to be monitored in the unsaturated zone monitoring program.

This document provides background information for developing a treatment demonstration engineering report. Specifically the report summarizes available data on:

• hazardous constituents which may be present or are suspected to be present in significant concentrations in petroleum industry wastes which are land treated.

• the transformation, degradation, and immobilization of these constituents in the soil environment.

A detailed literature review of the Appendix VIII constituents which may be present in petroleum wastes indicates that all the constituents can be successfully immobilized and/or degraded by land treatment under appropriate environmental and operating conditions.

Available literature data can be used to estimate soil adsorption capacities and degradation rates for the Appendix VIII contituents evaluated in the report. A methodology is presented in this report which incorporates these data with site and waste specific factors to evaluate the relative treatability of any given waste at any given site. The methodology identifies those constituents present in the waste that are the most difficult to treat and require additional evaluation in an unsaturated zone monitoring progran. The methodology, therefore, can be used to:

• demonstrate the treatability of Appendix VIII constituents, and

• identify the principal hazardous constituents (PHCs) to be monitored in an unsaturated zone monitoring program.

Appendix VIII Waste Constituents Present in Petroleum Industry Wastes

Considerable variation exists among individual refineries as to the types of wastes generated as well as the physical/chemical composition of a specific waste type. This variation is a function of the wide variety of process operations and products produced at different refineries. Halogenation is not normally a refinery unit operation. Therefore, chlorinated Appendix VIII constituents were not included in the scope of this study.

The level of information available on specific constituents present in wastes which are land treated varies depending on the constituent. In general, detailed information is available on the Appendix VIII metals present in each major waste type. Limited information is available on specific organic constituents, although many refinery wastes have been well characterized in terms of broad hydrocarbon classes.

In order to distinguish the level of information available on a specific constituent, three general classes of constituents are identified in the following sections. These are:

• Appendix VIII Constituents Known to be Present--This group includes those constituents which have been identified as present in petroleum wastes through chemical analysis of the wastes or soils at land treatment facilities.

• Appendix VIII Constituents Suspected to be Present--This group includes those constituents which have been detected in (a) raw or treated wastewater from petroleum refineries or (b) crude oil or refined products. In addition, this group includes those constituents which would be suspected to be present based on an understanding of the petroleum chemistry and process operations.

• Appendix VIII Constituents Expected not to be Present--This group includes all other constituents not included in the preceeding two groups as well as chlorinated compounds, and suspected constituents of land treatment wastes, soils, or waste waters which were not detected by the analyses.

A comprehensive review of the literature resulted in the formulation of a list of Appendix VIII constituents which are known or suspected to be present in petroleum refining wastes which are land treated. These constituents are grouped according to similar physical/chemical characteristics, in the following categories:

• Inorganics--Metals and Cyanide

• Solvents--Benzene, Toluene and Pyridine

• Phenolics

• Polynuclear Aromatics

• Phthalate Esters

Treatability of Inorganics

Available data from petroleum industry land treatment sites indicate that the Appendix VIII inorganics can be immobilized or transformed within the treatment zone if they are within certain soil concentration limits. The factors which control the mobility of inorganics in the soil are site and waste specific. Therefore, acceptable upper soil concentration limits applicable to all petroleum industry sites cannot be defined. However, guidelines defining upper soil concentration limits which are acceptable for the growth of food-chain crops have been established for some of the Appendix VIII inorganics. Although growth of food-chain crops is not planned at most petroleum land treatment sites, these guidelines can be used in a first level screening effort to identify if additional site specific data are necessary to evaluate the migration potential of a specific constituent. Constituents which may potentially migrate beyond the treatment zone should be selected as PHCs, and appropriate operational changes should be incorporated to limit the constituents' mobilities.

Treatment of Organics

Available data on individual organic constituents indicate that all the Appendix VIII Constituents which may be present in land treated petroleum wastes can be degraded in the soil under proper environmental conditions. Furthermore, all the organics can be temporarily immobilized in the soil. The constituents with the longest biological half lives (i.e., those which are biodegraded slowly) are the least soluble and have the highest partition coefficient values (i.e., are not adsorbed very strongly in the soil). The converse of this statement applies to those constituents which have the shortest biological half lives.

The selection of an appropriate organic PHC is a function of the degradation rate and the adsorption rate for each constituent. In order to evaluate the relative importance of each process (i.e., immobilization rate vs. degradation rate), reported kinetic constants for each constituent can be used to predict:

• the time (td) to degrade an initial soil concentration of a constituent to a desired concentration.

• the time (tm) for a constituent to migrate beyond a specified soil depth.

If td is less than tm, the constituent is expected to degrade before it can migrate beyond the zone of incorporation. However, if the estimated td value is approximately equal to or greater than the tm value then the possibility exists that the constituent may migratebey ond the treatment zone before it is degraded to the desired concentration, and additional evaluation or monitoring of the constituent may be appropriate.

Analytical Considerations

Analytical limitations should be considered in selecting any constituent as a PHC. There are relatively few analytical limitations associated with monitoring the inorganics which may be present in petroleum wastes. Significant sampling, storage, and/or background interference problems exist for most of the organic compounds reviewed in this study. The data suggest, therefore, that gross indicator parameters such as total organic carbon or extractable hydrocarbons (oil and grease) may provide much more useful screening data than monitoring a single organic. If monitoring of these constituents indicates that additional monitoring data are necessary, then monitoring for the selected organic PHCs, or scans (such as GC/MS) for a large number of organics may be appropriate.