The answer is “yes.” Many environmental professionals believe land application isn’t acceptable for hazardous secondary materials like coproducts, byproducts, or used chemicals. However, this isn’t always true. While the Resource Conservation and Recovery Act (RCRA) and state regulations ban land application as “use constituting disposal” for many materials, some hazardous secondary materials are allowed under certain conditions.
When is Land Application Permissible?
Specifically, if a hazardous secondary material has a corresponding prime chemical that’s normally used in land applications, its use might be permissible. This approach can apply to various industries, such as agriculture, mining, and construction. These industries often use chemicals as soil conditioners, fertilizers, or dust suppressants. The prime chemical serves as a benchmark, meaning that if the secondary material behaves similarly and meets certain purity standards, it may be suitable for land application.
The Importance of “No Toxics Along for the Ride”
The key to successful land application is ensuring the material contains no additional toxic contaminants. These are impurities that might pose environmental or health risks if applied to the land. For example, heavy metals like lead, mercury, or arsenic, if present in the secondary material, could leach into the soil or groundwater, causing contamination. Therefore, it’s crucial to perform a detailed analysis to confirm that these unwanted substances are absent or below regulatory limits.
Avoiding Listed Wastes
It’s also essential to verify that the material is not classified as a “listed waste” by the EPA. Listed wastes are those specifically identified by the EPA based on their source or hazardous properties. Some examples include toxicity, ignitability, corrosivity, or reactivity. Using listed waste in land applications is strictly prohibited, as it could lead to environmental damage or legal penalties.
Conducting a Risk Assessment
Before considering land application, a thorough risk assessment should be conducted. This evaluation involves examining the chemical properties of the secondary material, potential exposure pathways, and the impact on soil, water, and air quality. By comparing these factors with the risks associated with using the prime product, you can determine whether the secondary material poses any additional hazards. Monitoring and testing during the application process ensure the material remains within safe limits.
Benefits of Proper Land Application
When done correctly, land application of hazardous secondary materials can offer significant benefits. It reduces waste disposal costs, conserves natural resources, and promotes sustainability by recycling valuable materials. This practice can improve soil quality, providing nutrients and enhancing the land’s productivity, especially in agricultural settings.
Final Considerations
If the hazardous secondary material meets the criteria of having no added toxic elements and isn’t a listed waste, it may be viable for land application. However, always perform a thorough evaluation of each potentially hazardous constituent. Ensure the risks are no different than those of using the prime product. This careful approach helps maintain compliance with environmental regulations while contributing to sustainable waste management practices.
For a specific example of this type of land application of hazardous secondary materials, please see our blog entitled “Can my former sulfuric acid waste be used to make fertilizer?”