April 14, 2014

Hazardous Waste Determination for an Unknown Waste

You find a drum of unknown waste in the back of your warehouse, or someone dumps a drum of unknown liquid at your facility. What now?

If the waste was not yours to begin with, there are rare cases where your local government may help you manage the abandoned waste. But in most situations, you are now the owner of a solid waste and need to determine if your newly acquired waste is hazardous.

It is usually difficult to determine if an unknown waste is hazardous based solely on visual inspection and the limited knowledge you have. So, a sample will often have to be analyzed. Remember the constituents of this waste are unknown, so make sure to wear the appropriate personal protective equipment (PPE).

Listed hazardous waste codes are assigned based on the sources of, or the processes that generated, the waste, rather than the concentrations of hazardous constituents. Therefore, analytical testing alone, without information on a waste’s source, will not produce information that will conclusively indicate whether a waste meets a listing description. If after making a good-faith effort, you are unable to determine the source of the waste, it can only be hazardous if it exhibits a characteristic. [RO 13181, 13586, 14291]

When it comes to determining whether the waste is characteristic, we have heard many different versions of what to ask the lab to test for, but the following is a consensus supplemented with limited EPA guidance.

Ignitability—This should include a flash point test if the unknown is a liquid; the flash point method should be one of the two specified in §261.21(a)(1). Oxidation potential per §261.21(a)(4) is sometimes screened by using potassium iodide (KI) paper, which is especially suited to detect strong oxidizers. Samples that screen positive can be tested using SW–846 Method 1040—Test Method for Oxidizing Solids if confirmation testing is deemed necessary.
Corrosivity—If the unknown waste is aqueous, pH paper is often used to screen the waste, and if this screening shows a pH close to the regulatory limits, Method 9040C should be used to confirm the result.
Reactivity—Talk to the lab about their recommendations on testing for this characteristic. Some people still ask (and some states require) that the rescinded HCN/H₂S release threshold tests be run to test for §261.23(a)(5) reactivity. Others just request total and amenable cyanides/sulfides analyses per Methods 9010C, 9012B, 9030B, 9031, and/or 9034.
Toxicity—Have the lab run the TCLP for all 40 constituents. According to EPA/530/R-94/024, once the TCLP is run, the extract obtained may be analyzed for the 40 constituents listed in §261.24 by any method, as long as that method has documented quality control and is sensitive enough to meet the regulatory limits. The agency noted that the following EPA test methods could be used in this step: Methods 3010 and 6010 for arsenic, barium, cadmium, chromium, lead, silver, and selenium; Method 7470 for mercury; Methods 3510 and 8081 for pesticides; Method 8151 for herbicides; Method 8260 for volatile organics; and Methods 3510 and 8270 for semivolatile organics.

As an alternative to running the TCLP (which can be expensive), some facilities will ask the lab to run totals for the 40 constituents in §261.24. Based on those results, the TCLP may then be requested only for those constituents with the potential to exceed regulatory levels.

PCBs—Although PCBs are regulated separately by the Toxic Substances Control Act (TSCA), unknowns should be tested for these constituents because 1) of how ubiquitous they are, and 2) the regulatory requirements associated with their management depend on the PCB concentration in the as-generated waste before treatment.
Asbestos—Regulated by the CAA, TSCA, and OSHA, not RCRA, asbestos is usually only tested where friable asbestos-containing material (ACM) may be present. ACM was commonly used in construction for thermal insulation systems, fireproofing, and acoustical insulation.

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Considerable care has been exercised in preparing this document; however, McCoy and Associates, Inc. makes no representation, warranty, or guarantee in connection with the publication of this information. McCoy and Associates, Inc. expressly disclaims any liability or responsibility for loss or damage resulting from its use or for the violation of any federal, state, or municipal law or regulation with which this information may conflict. McCoy and Associates, Inc. does not undertake any duty to ensure the continued accuracy of this information.

This document addresses issues of a general nature related to the federal environmental regulations. Persons evaluating specific circumstances dealing with the environmental regulations should review state and local laws and regulations, which may be more stringent than federal requirements. In addition, the assistance of a qualified professional should be enlisted to address any site-specific circumstances.