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.