Gossman Consulting, Inc.
July 1992

The EPA Proposed Hazardous Waste Identification Rule Potential Impact on Cement Kiln Dust

The EPA is proposing two approaches for amending regulations under the RCRA for hazardous waste identification. The proposed rule is called the Hazardous Waste Identification Rule (HWIR). The first approach would establish concentration-based exemption criteria (CBEC) for listed hazardous wastes, wastes mixtures, derivatives, and media contaminated with certain listed hazardous wastes for exiting RCRA Subtitle C management requirements. The second approach proposed would establish "characteristic" levels for listed hazardous wastes, wastes mixtures, derivatives, and media contaminated with certain listed hazardous wastes for both entering and exiting RCRA Subtitle C via an expansion of the number of toxic constituents in the Toxicity Characteristics (TC) rule. This approach is referred to as the Expanded Characteristics Option (ECHO).

Differences between these two options as well as differences with existing regulations including BIF could have a significant impact on future CKD management options particularly if the Bevill exemption for CKD is eventually removed. (The preamble briefly discusses removing certain waste exemptions.) Even if this does not occur, the proposed rule provides insight regarding eventual likely changes to the BIF health based trigger levels on inorganic leachates for CKD. Table 1 provides a comparison of existing TCLP characteristic leachate limits, BIF health based leachate limits and proposed HWIR leachate limits under both the CBEL and ECHO options.


Inorganic Parameter 40CFR Part 261

Inorganic Keachate


BIF Appendix VII

Health Based Inorganic

Leachate Limits


(Unconditional Exemption)

Leachate Limits

CBEC Tier 2

(Conditional Exemption)

Leachate Limits

ECHO Proposed

Part 261 Inorganic

Leachate Limits

Antimony _____ 1 0.1 1 1
Arsenic 5 5 0.5 5 5
Barium 100 100 20 200 200
Beryllium _____ .007 0.01 0.1 0.1
Cadmium 1 1 0.05 0.5 0.5
Chromium 5 5 1 10 10
Lead 5 5 0.15 1.5 1.5
Mercury 0.2 0.2 0.02 0.2 0.2
Nickel _____ 70 1 10 10
Selenium 1 1 0.5 5 5
Silver 5 5 2 20 20
Thallium _____ 7 0.02 0.2 0.2
Vanadium _____ _____ 2 20 20
Zinc _____ _____ 70 700 700

Note: Tier 2 (conditional) Exemptions would require management of wastes in a Part 258 (municipal waste) landfill or a facility meeting those standards, including liners.

Some notable aspects of these proposals are:

1. The Pb TCLP limit is lowered from 5 to 1.5 ppm.

2. The proposed Tl limit of 0.2 ppm compares with the BIF limit of 7 ppm. Tl concentrates in CKD and is quite leachable. As little as 4 ppm total Tl in CKD will produce 0.2 ppm leachable Tl. Cement plants using coal flyash as a raw material and/or wasting very little dust may be particularly vulnerable to this limit.

3. Be, Cr, Se and Ag have all had their TCLP limits raised.

4. The Cd TCLP limit has been lowered.

5. When compared with BIF TCLP health based limits, Ni and Tl are much lower and Be is much higher.

6. V and Zn have been added to the TCLP list.

Clearly the EPA is proposing radical changes to existing TCLP limits without discussion or justification in the preamble. Our first impression is that the CBEC approach is a kludge on top of an overly complex set of existing regulations. ECHO, on the other hand, is a fresh approach that seems much more technically sound as well as easier to implement from a logistical perspective. Nevertheless, EPA should provide comprehensive rational when making changes which appear to conflict with previously established limits.

Special Note

Analysis of CKD for Organic Compounds

The BIF requirement to analyze CKD for selected Appendix VIII compounds and PICs has caused some laboratories difficulty with selected compounds. If 2-butanone (methyl ethyl ketone) has shown up in any of your analyses, tell the lab to switch from methanol to water as the extraction solvent (both are SW-846 approved procedures). CKD has been shown to catayze the reaction of alcohols to form ketones at ppm levels.