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Contaminated Soil Treatment Standards

Last week we wrote about Universal Treatment Standards, why they were created, and what they aimed to achieve. Today I’d like to cover a similar topic, treatment standards for contaminated soil. When hazardous waste sites go through remediation they often generate contaminated soil which must then be handled as a hazardous waste if it contains a listed hazardous waste or exhibits a hazardous waste characteristic. Because remediation wastes often have uncommon properties or are vast in volume treatment standards had to be reconsidered. The issue was resolved by designating contaminated soil as a “unique treatability group,” subject to alternate treatment standards (EPA).

It is important to note that as with any hazardous waste, RCRA prohibits land disposal of contaminated soils until they have come to meet LDR standards. What changed for contaminated soils was the ways in which they could treat the waste to meet the standards. According to the EPA, “a facility may treat contaminated soil to meet the waste-specific treatment standard in §268.40, (i.e., the same standard the waste would have to meet if it was newly generated rather than found in soil) or to meet the soil-specific standards in §268.49. The soil standards mandate reduction of hazardous constituents by 90 percent, capped at 10 times the UTS. This means that if a 90 percent reduction of a particular constituent would bring the constituent concentration to below 10 times the UTS level, treatment need only achieve the 10 times UTS level. If the 90 percent reduction is higher than 10 times UTS, treatment need only achieve the 90 percent reduction.”

Waste handlers can also treat contaminated soils that exhibit a characteristic of hazardous waste with the standards mentioned above. If after doing so the soil still exhibits a hazardous waste characteristic, however, it must be disposed of in a Subtitle C Facility. This can happen because 10 times the universal treatment standard is occasionally still above the hazardous waste characteristic level. If treatment drops the characteristic level far enough the soil can be disposed of in a Subtitle D facility. Since soils contaminated with listed wastes (like the listed wastes themselves) will carry that listing forever they must be disposed of in a Subtitle C facility even after meeting LDR treatment standards.

The EPA notes that, “the soil treatment standards are promulgated pursuant to HSWA. Because the soil treatment standards are generally less stringent than current federal requirements, they will not go into effect in authorized states until the states adopt and become authorized for them, even though the soil treatment standards are promulgated pursuant to HSWA.”

“If a state is authorized to implement the LDR treatment standards for any given waste or constituent, and that waste or constituent is contained in contaminated soil that is subject to LDR, then, generally, the more stringent treatment standard for the as-generated industrial waste or constituent applies to contaminated soil until the state adopts and becomes authorized for the soil treatment standards. This would not be the case if the state implements state waiver authorities or other state laws to allow compliance with the soil treatment standards in advance of adoption or authorization. Similarly, if a state has adopted, under state law, an authorization for the requirement, and that waste or constituent is contained in contaminated soil that is subject to LDR, the more stringent state requirement continues to apply until the state adopts, under state law, the soil treatment standards.”

All information for this blog post was gathered from the EPA document, “Introduction to Land Disposal Restrictions.” As always, this blog post is not intended to be comprehensive and it is always best to check with the EPA and local government for full, up-to-date, rules and regulations.

Why did the EPA Develop LDR Treatment Standards?

We’ve talked about LDR a few times in the past. If you missed the previous posts it might help you to check out the Intro to LDR post. For those who may not know, LDR stands for Land Disposal Restrictions. The primary focus of LDR is to protect the groundwater (we’ve written a bit about this topic in a previous post). The two ways the EPA decided on for the protection of groundwater are treatment and stabilization. Today we are going to focus on treatment, and in particular on treatment standards.

If hazardous wastes are going to be placed on the land LDR requires that waste handlers fundamentally change the threat the waste poses. Different waste types have different restrictions and thresholds for adequate treatment. These set thresholds are called treatment standards. Once the EPA restricts a waste and sets its treatment standard the waste is prohibited from being land disposed prior to meeting said set standard.

The EPA is required to create treatment standards that reduce toxicity or mobility of hazardous components in order to protect human health and the environment. To do this in the best manner the EPA decided to base treatment standards on technical practicability as opposed to risk assessment. In order to do this the EPA does research into available technologies in order to select the ones that work best to minimize mobility and/or toxicity of a material. These selected technologies are called the Best Demonstrated Available Technology (BDAT).

Once the BDAT has been determined for a waste stream the EPA develops waste-code specific treatment standards. These standards are based on the BDAT and incorporate any existing constituent treatment levels specified as universal treatment standards (UTS). We will discuss UTS’s in a later post. The finalized treatment standards are then expressed by the EPA as either concentration levels or required technologies.

When the EPA sets treatment standards as concentration levels generators and handlers are not limited to using only the BDAT to treat the waste. In these cases the BDAT is utilized to find the appropriate treatment level which can then be reached via other technologies assuming the technology would be impermissible dilution.

When the treatment standard is a required technology the generator or treatment facility must use that technology unless they can demonstrate a different method that will achieve an equivalent performance. Because allowing for different treatment processes leads to more innovation the EPA prefers to use numeric treatment standards whenever possible.

Physical and chemical composition of a waste has a major impact on the effectiveness of a given treatment technology. Because of this the EPA divides the treatment standards for each waste code into two categories, wastewaters and nonwastewaters.

According to the EPA, “ these two categories [are defined] based on the percentages of total organic carbon (TOC) and total suspended solids (TSS) present in a waste, since these factors commonly impact the effectiveness of treatment methods. Wastewaters contain less than one percent TOC by weight and less than one percent TSS by weight. Nonwastewaters include wastes that do not meet the definition of wastewater (§268.2).”

The EPA also developed alternative treatment standards for soil, debris, and lab pack wastes. Let us know in the comments section if you would like to see posts about these alternative methods in an upcoming post.

All information for this blog post was gathered from the EPA document, “Introduction to Land Disposal Restrictions.” As always, this blog post is not intended to be comprehensive and it is always best to check with the EPA and local government for full, up-to-date, rules and regulations.