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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.

How do Land Disposal Restrictions and the EPA Protect Groundwater?

You may not know this but a large portion of the hazardous waste management regulatory program (including Land Disposal Restrictions or LDR) deal with the protection of groundwater. These programs are put in place to protect us from having dangerous chemicals in the water we drink. The process by which hazardous waste can contaminate the groundwater is called leaching. Waste can be leached by water filtering down through the ground and drawing the contaminants out of buried wastes. As the water continues its trajectory those wastes can be carried and introduced into the groundwater.

Treatment of Wastes

In order to avoid this potentiality, Congress decided on two primary ways to circumvent this danger. The first is by reducing a waste’s toxicity by destroying or removing the harmful contaminants. The EPA provides the following example, “many of the chemicals capable of contaminating groundwater are organic compounds. Incineration or burning can destroy these organic compounds, usually breaking them down into less dangerous byproducts like carbon dioxide and water. Thus, incineration of organic-bearing hazardous wastes can protect groundwater by destroying organic contaminants before they have a chance to enter underground water supplies. The obvious advantage of such hazardous waste treatment is that it provides a more permanent and lasting form of groundwater protection than hazardous waste containment. Structural barriers separating hazardous contaminants from groundwater may eventually break down or leak. In contrast, treatment that destroys harmful contaminants or reduces a waste’s toxicity before it enters the environment is a permanent groundwater protection solution.”

Stabilization of Wastes

This leads us into the second way Congress saw to protect groundwater; immobilizing the hazardous contaminants. Due to the fact that not all hazardous wastes can be treated to remove toxicity, EPA determined another option. The EPA sites metal elements as common types of waste which cannot be broken down via combustion and provides the following explanation of how they can be handled; “treatment techniques other than incineration…can be used for such wastes. For example, through a process called stabilization or immobilization, metal contaminants can be chemically and physically bound into the wastes that contain them.  Although this treatment method does not reduce the overall concentration of toxic metals in a hazardous waste, it does immobilize these constituents, making them less likely to leach from the waste. Reducing the mobility or leachability of hazardous constituents in a waste is another means of achieving LDR’s groundwater protection goal.”

All this said, it is important to note that the LDR rules are not the only ones in place to protect groundwater. Actually, the EPA created a tiered approach to the protection of groundwater by attempting to prevent leachability of harmful constituents at three levels: LDR, LDUs, and groundwater monitoring. If you would like us to cover the other two tiers please let us know in the comments section!

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.