If you've got corrosive hazardous waste (D002) that is only hazardous because of its pH, your waste stream may qualify for the elementary neutralization unit RCRA permit exemption! Depending on your generator status and how much corrosive waste you generate, this could be a HUGE DEAL for your facility! Check out the graphic below, as well as the resources and guidance linked underneath.
ADDITIONAL INFORMATION:
You might sometimes see this referred to as "elementary neutralization unit" exclusion, versus exemption. However, exemption is technically correct.
It important to note that this exemption is for the both the activity of neutralization AND for the waste inside - the waste is still considered solid waste, just not subject to hazardous waste regulations when utilizing the EMU permitting exemption. Generally, exclusions are for materials either excluded from the definition of solid waste or from the definition of hazardous waste (while still considered solid waste), while exemptions still consider the waste to be a solid waste that is hazardous, just regulated under a reduced set of regulations.
In this case, the regulations consider the D001 waste inside the EMU to still be solid waste, but as long as you fulfill the regulatory requirements of the exemption, it is not considered a hazardous waste to be counted towards your overall generator status. But don’t forget about any sludge or precipitation coming out of the EMU – if those waste streams are still hazardous upon removal, they are considered hazardous waste and are not included under the EMU exemption.
However, this web of varying terminology can get confusing when you have states like Washington that have the following on their regulatory guidance page – the exact opposite of how you’ll see EPA reference exempt vs excluded waste streams:
“Exempt wastes are not considered solid wastes, as long as they are used or managed under the requirements of WAC 137-303-016 or WAC 173-303-017. Excluded wastes remain solid wastes, but are not subject to most of the dangerous waste rules, including counting and Dangerous Waste Annual Reporting requirements.”
So, the best thing you can do is always reference back to (1) the EPA regulations, and then (2) your state-specific regulations, which may be more stringent than EPA regulations or have a more-specific interpretation or definition, to ensure you are meeting all of the regulatory requirements for any exemption or exclusion you are looking to utilize.
Here’s a few more regulatory citations for the EMU exemption:
40 CFR 262.13(c)(2)
When making the monthly quantity-based determinations required by this part, the generator must include all hazardous waste that it generates, except hazardous waste that:
(2) Is managed immediately upon generation only in on-site elementary neutralization units, wastewater treatment units, or totally enclosed treatment facilities as defined in 40 CFR 260.10.
40 CFR 264.1(g)(6)
The requirements of this part (i.e. owners and operators of all facilities which treat, store, or dispose of hazardous waste) do not apply to:
(6) The owner or operator of an elementary neutralization unit or a wastewater treatment unit as defined in § 260.10 of this chapter…to remove the characteristic before land disposal, the owner/operator must comply with the requirements set out in § 264.17(b).
30 TAC 335.2 (d)(3) (Texas-specific)
No permit shall be required for:
(3) the storage or processing of nonhazardous industrial solid waste, if the waste is processed in an elementary neutralization unit.
RESOURCES: