Understanding Complex Remediation Waste Issues – Part 1

The Resource Conservation and Recovery Act (RCRA) has been in place for a number of years and it still creates many complex questions when relating to contaminated environmental media on remediation projects. Contaminated media can be generated through:

  • Excavation,
  • Investigations (with investigation derived wastes),
  • In-situ soil or groundwater treatment producing waste residuals, and
  • Other waste generating or construction activities.

Typical questions arise from complex issues relating to:

(1) Generator waste determinations for contaminated media,

(2) Unknown source wastes,

(3) Contained in listed wastes,

(4) Exempt/Excluded wastes, and

(5) Land Disposal Restriction (LDR) application.

*Sections 1 and 2 from above are discussed below and sections 3, 4, and 5 will be posted in next week’s blog.

Generator Contaminated Media Waste Determinations

First, be aware that the USEPA has indicated that environmental media contaminated with hazardous waste is itself not hazardous waste for waste determination purposes.  Only when the soil is exhumed, is it considered generated for the purposes of 40 CFR 261.

RCRA is a cradle to grave hazardous waste management system.  40 CFR 261 is RCRA’s heart because it establishes the thought process for determining if a solid waste is hazardous and if so it is subject to hazardous waste regulations. With this approach, generators (not their consultants, contractors, brokers or disposal facilities) are obligated to perform a waste characterization to determine if solid wastes are also hazardous waste.

This framework created mechanisms for solid waste to be considered hazardous wastes by their characteristics and by being listed alongside other inherently waste-like solid wastes. The language in 40 CFR 261 requires a generator to either:

(1) analyze the waste, or

(2) utilize generator knowledge to determine the applicable waste codes.

Why does this matter? USEPA has consistently indicated it is a generator’s responsibility to determine the generator status and all USEPA Hazardous Waste codes associated with the waste. Misapplication of codes can create issues with hazardous waste management, disposal (selecting a location permitted to accept the waste) and transportation.

USEPA regulations have long maintained that if testing is used, generators are required to analyze representative samples of the waste to determine if it is RCRA hazardous waste or not. Representative sampling requires that it be representative “of the whole” of the waste being managed. Industrial process waste generators have a reasonable opportunity to conduct sampling on waste streams that vary minimally in concentration, matrix, etc. Limited sampling can be done with in-plant generated wastes.  With soil remediation wastes, the waste concentrations vary at many points throughout a designated remediation area. For this reason, it becomes important to fully understand the remediation area and how the soil will be managed prior to analyzing samples per the Toxicity Characteristic Leaching Procedure (TCLP). Historically, some have thought that the existence of TCLP data from a single sample location mandates that all of the in place soil be managed according to that individual sample result. This may or may not be the case. A single in-place sample analyzed for TCLP characteristics does not necessarily mandate that the waste is managed as hazardous. TCLP information for in place soil is not completely consistent with the TCLP’s intent, because the soil in place (its designated use) is not yet a waste and therefore not yet a hazardous waste. TCLP requirements apply when a waste is generated. TCLP data for in place soil can be used to document the soil being hazardous waste, but is insufficient in determining Land Disposal Restriction (LDR) requirements as most LDR levels are either total concentrations or technology based. Knowledge regarding the likely TCLP levels and distribution (depth and radius from source) of contaminants throughout the media can be used to determine if site becomes a mass excavation, surgical excavation (based on waste code and LDR requirements) or if stockpiling is necessary to re-evaluate the waste following excavation or generation.

It is also important to understand the role that investigation data can play in media waste determination. Investigation data can often be biased from the fact that environmental investigation regulations or guidelines are typically looking for extent of any contamination, source area/hot-spots (elevated levels), and clean levels (to determine extent). Many times, if a source area is known, the investigation will be extremely limited within the source area. Additionally, sampling depths may completely ignore some intervals of decreasing or increasing concentrations. And lastly, those performing the investigation may be only analyzing for specific parameters that do not include parameters needed to document whether the waste is a characteristic hazardous waste (TCLP exceedance) or a listed hazardous waste.

Generator knowledge regarding contaminated media remediation projects is obviously difficult to document; especially if the generator is attempting to indicate that the waste meets certain LDR levels, indicate TCLP levels, or indicate other chemical data. Why do the actual concentrations matter? This information is critical in determining the disposal site selection and management techniques. An important factor in performing a waste determination using generator knowledge is that there may be more chemicals already existing in the environmental media than the generator has actual knowledge. For example, the removal of an underground storage tank and the associated diesel containing soil is regulated under 40 CFR 280 when soil removal is occurring. While the diesel impacted soil would be exempt from hazardous waste regulation, there could be mitigating factors such as a previous tank could have contained and released leaded fuels or a nearby dry cleaner could have previously contaminated the soil. In these situations, a “generator knowledge” based non-hazardous waste determination could be inaccurate.

Wastes from Unknown Sources

Many generators are confused when conducting waste determinations on waste where the source is unknown or undocumented. Determining a source is many times more difficult and typically requires more effort than obtaining TCLP sample results. An example would be a property owner conducting a contaminated soil removal at a dry cleaner site. The generator is required to make a waste determination and in so doing uncovers detectable levels of perchlorethylene in soil and groundwater. Perchloroethylene is a solvent stipulated in the USEPA listed waste codes F002 and U210 and it is also on the TCLP list as USEPA Waste Code D039. In “Management of Remediation Wastes Under RCRA”, USEPA indicated that a generator need not apply a hazardous waste listing if the source cannot be documented. The document has been perceived by many to be able to just say “I don’t know the source, so it’s not listed.”  This statement is inaccurate. The document still requires the generator make a good faith effort to determine the source and concentration of the chemicals identified in the contaminated media.  While industrial waste generators don’t generally have this issue with routine plant process wastes, it became a point of discussion in the contaminated media/remediation industry. The Proposed National Contingency Plan (NCP) preamble first indicated while the source is important information relevant to determining if wastes are listed, this information may not exist at CERCLA sites where USEPA was actively performing the clean-up. In an effort to maintain the clean-up progress and minimize potentially unnecessary costs, the determination could be limited to TCLP testing to determine only the characteristics (D codes). However, the document clearly references that a generator must make a good faith effort to determine the source of the waste.

It remains a compliance issue subject to enforcement. This becomes increasingly important as listed hazardous waste is typically more expensive to dispose than characteristic hazardous waste and disposal site selection can become more limited with listed wastes. While a generator is narrowly focused on his/her waste determination, keep in mind that a hazardous waste disposal site operates per its hazardous waste permit. As such, the disposal site may not agree with the generators waste determination and not accept the waste media for disposal. Waste misrepresentation has resulted in many landfills needing to remove improperly characterized and disposed hazardous waste. If a generator intends to utilize the unknown source claim to avoid applying listings (F, K, P, U Codes), the generator should have sufficient investigation information into facility history, chemical purchases, waste disposal, materials used, etc. to document the good faith effort.


One comment on “Understanding Complex Remediation Waste Issues – Part 1

  1. Hi envfield,

    I really like the article about waste and soil remediation services.

    i have used the Solidification and stabilization method for soil remediation. This method uses a binding agent to stop the flow of contaminants in soil. This method has a great track record but also has some environmental setbacks.

    Keep sharing.

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