The United States Environmental Protection Agency (EPA) recently published a significant rule under the Resource Conservation and Recovery Act (RCRA) concerning the disposal of hazardous waste on land. Known as the Phase IV land disposal restrictions (LDR), the rule establishes new treatment standards for hazardous metal-bearing wastes, wastes derived from mineral processing, and soil contaminated with hazardous wastes. These treatment standards must be met prior to land disposal. The new rule is the latest in a series of EPA rules that implement the 1984 Hazardous and Solid Waste Amendments to RCRA, which generally prohibits the land disposal of hazardous waste unless it first meets treatment standards established by EPA or is disposed of in units that will not allow any migration of the hazardous constituents into the environment. The rule becomes effective on August 24, 1998.
The Phase IV LDR Rule imposes disposal restrictions on a group of 8 wastes known as "toxicity characteristic" (TC) metal wastes, which were previously not subject to LDRs. These wastes are identified as hazardous due to toxic concentrations, as determined by a laboratory test known as the toxicity characteristic leaching procedure (TCLP), of the following metals: arsenic, barium, cadmium, chromium, lead, mercury, selenium, and silver. Previously, these wastes were not prohibited from land disposal unless they were also identified as hazardous under the analytical test known as the extraction procedure (EP), which predates the TCLP. Further, wastes that were identified as both hazardous under the EP and the TCLP were only required to be treated to reduce the metal concentrations to levels below the characteristic level prior to land disposal. Under the Phase IV LDR Rule, however, all wastes that exceed the TC for these 8 metals must be treated to the amended "universal treatment standards" (UTS) established in the rule. UTSs are constituent-specific standards that apply generally to all wastes, rather than waste-specific standards that apply only to a specific waste stream. The amended UTSs for TC metal wastes established in the rule are generally more stringent than the TC levels. In addition, any underlying metal or organic hazardous constituents contained in these wastes must also be treated to meet the applicable LDR standard, regardless of whether the concentration exceeds a TC threshold.
The Phase IV LDR Rule also expressly applies the new UTSs to certain mineral processing wastes. Under the "Bevill Amendment" to RCRA, EPA was required to study the hazardous characteristics of mineral processing wastes before imposing RCRA's regulatory requirements on those materials. In 1991, EPA identified certain mineral processing wastes that are not exempt from hazardous waste regulation under the Bevill Amendment because the wastes exhibit corrosivity, reactivity, or toxicity characteristics. In addition to setting treatment standards for these non-Bevill mineral processing wastes, EPA also established storage restrictions for other mineral processing materials that are subject to the Bevill Amendment and that are being stored prior to reclamation or reuse. The Phase IV LDR Rule generally requires that these materials be stored in tanks or containers and prohibits any storage on land, unless the materials are placed on a state or EPA-approved pad.
Finally, the Phase IV LDR rule establishes new LDRs for soil that is contaminated with a listed hazardous waste or that exhibits a hazardous characteristic. Previously, contaminated soil was subject to the same LDR treatment standards that apply to the underlying hazardous waste contained in the soil or the hazardous waste characteristic exhibited by the soil. EPA determined that these treatment standards, which were based on the treatability of pure industrial waste, were often not achievable or were impracticable when applied to contaminated soil. As a result, EPA found that the remedies selected for soil cleanup projects often involved capping or treating the soil in place, rather than excavating the soil and triggering the LDR treatment standards. Accordingly, EPA established soil LDR treatment standards as a performance goal capped by specific treatment levels rather than specific numerical standards, such the UTSs established for TC metal waste. The new soil LDR treatment standards require that contaminated soil be treated until the concentrations of hazardous constituents in the soil are reduced by 90% or are below 10 times the applicable UTS, which ever is greater. EPA concluded that the technology-based soil treatment levels "are achievable using a variety of common remedial technologies which destroy, remove or immobilize substantial amounts of hazardous constituents." The Phase IV LDR Rule also provides for a risk-based, site-specific variance to the soil treatment standards. Such a variance is available, however, only after public notice and an opportunity for public comment.
63 Fed. Reg. 28556 (May 26, 1998)
This article was prepared by Jeffrey L. Woolstrum, a partner in our Environmental Department, and previously appeared in the July, 1998 edition of the Michigan Environmental Compliance Update, a monthly newsletter prepared by the Environmental Department and published by M. Lee Smith Publishers.