It is the area, or areas, at the facility of a hazardous waste generator where hazardous waste accumulates if it meets the conditions for the accumulation of hazardous waste.

It is defined at 40 CFR 260.10 in the regulations of the US Environmental Protection Agency (EPA):

Central accumulation area means any on-site hazardous waste accumulation area with hazardous waste accumulating in units subject to either §262.16 (for small quantity generators) or §262.17 of this chapter (for large quantity generators). A central accumulation area at an eligible academic entity that chooses to operate under 40 CFR part 262 subpart K is also subject to §262.211 when accumulating unwanted material and/or hazardous waste.

Please note the following about this term:

• Its place in §260.10 is relatively new, only since May 30, 2017 when the Generator Improvements Rule went into effect.
• The term was defined by EPA only as a matter of convenience.
• The addition of the term does not establish any new regulatory standards or burden on generators.
• Terms used in the past to refer to hazardous waste accumulation areas include:
  • “Generator accumulation area”
  • “Less-than-180-day area” for a small quantity generator (SQG)
  • “Less-than-90-day area” for large quantity generator (LQG)
• The term “central accumulation area” was first defined at 40 CFR part 262, subpart K in December 0f 2008 to differentiate CAAs from satellite accumulation areas and laboratories in those regulations only.  Since that time it has become more widely used leading EPA to include it with its general definitions.
• The definition of “central accumulation area” was removed from 40 CFR 262, subpart K by the Generator Improvements Rule.
• A generator may have more than one central accumulation area (CAA) at their site.
• The use of the word “central” does not denote a physical location nor indicate the generator must establish the CAA in a centrally located area within the site.
• The CAA(s) can be in any location at the facility of either an SQG or LQG.