Environmental Remediation Program fact sheet
Division of Environmental Quality Director: Kyra Moore

Generator Categories

Businesses producing hazardous waste must follow certain federal and state laws and regulations. The laws and regulations applying to those businesses depend on the amount and type of hazardous waste generated. There are three waste generator categories:

  1. Conditionally Exempt Small Quantity Generators (CESQGs) do all of the following:
    • Generate 100 kilograms (kg) (approximately 220 pounds) or less of hazardous waste in one calendar month
    • Generate 1 kg (approximately 2.2 pounds) or less of acutely hazardous waste in one calendar month
    • Accumulate100 kg or less of hazardous waste at any one time
    • Accumulate less than 1 kg of acute hazardous waste and less than 100 kg of residue or contaminated soil from cleanup of an acute waste spill at any one time
  2. Small Quantity Generators (SQGs) do any of the following:
    • Generate more than 100 kg (approximately 220 pounds) but less than 1,000 kg (approximately 2,200 pounds) of hazardous waste in one calendar month
    • Generate 1 kg (approximately 2.2 pounds) or less of acutely hazardous waste in one calendar month
    • Accumulate less than 1 kg of acute hazardous waste at any one time
    • Accumulate less than 6,000 kg (approximately 13,200 pounds) of hazardous waste. Note: SQGs that accumulate 6,000 kg or more of hazardous waste must obtain a hazardous waste storage permit
  3. Large Quantity Generators (LQGs) do any of the following:
    • Generate 1,000 kg (approximately 2,200 pounds) or more of hazardous waste in one calendar month
    • Generate more than 1 kg (approximately 2.2 pounds) of acutely hazardous waste or more than 100 kilograms per month of residue or contaminated soil from cleanup of an acute hazardous waste spill

A business’ acute hazardous waste cannot be managed separately from other hazardous wastes. For example: LQG status cannot be maintained for acute waste and then maintain SQG status for all other hazardous wastes. Failing to meet any single criteria noted in a generator category above will cause the facility to fall into one of the larger generation categories. For example: even if a facility generates less than 100 kg in a calendar month, if an amount greater than that is accumulated on site this facility is no longer considered CESQG.

Change in Generator Status

Businesses generating or accumulating greater than100 kg of hazardous waste, or 1 kg or more of acutely hazardous waste, are required to register with the Missouri Department of Natural Resources. According to 10 CSR 25-5.262 (2)(A)3.B., those businesses are also required to complete and file an updated Notification of Regulated Waste Activity (NORWA) form whenever there is any change in:

  1. Contact person
  2. Mailing address or billing address
  3. Phone number or area code
  4. Business name
  5. Ownership
  6. Waste stream(s)
  7. Generator status, including Episodic Events
  8. Proper street address
  9. Satellite accumulation option choice

As a convenience to the generator for items 1-3 in the list above, the generator may inform the department of these changes by email or by indicating them in section B of the Generator’s Hazardous Waste Summary Report MO 780-1097. All other changes require completing the NORWA in its entirety.

For a change in ownership, businesses must pay the usual registration fee. If the proper street address changes, such as when a town renames a street or alters numbering on a block, the business will keep its original generator identification number. If a business changes locations, it will need to register the new location and request a new generator identification number using the NORWA. The old generator identification number is not transferable.

Episodic Generators

Many businesses experience a one-time hazardous waste generation event where they produce more hazardous waste than their current generator status. This event could be caused by a change in product line, production error, product recall, spill cleanup, inventory clean-out or similar event. When this occurs and a CESQG either generates or stores over 100 kg (approx. 220 pounds) of hazardous waste, then its generator status changes. The business is required to register as either a SQG or LQG, depending on how much hazardous waste was generated or stored. The business must also follow the regulations for that generator category including submitting the Generator’s Hazardous Waste Summary Report form. After the one time generation event, the business can choose to return to their CESQG status, as long as they no longer generate or accumulate at the higher level; however, hazardous waste fees will apply to the waste generated during the event.

When this type of event occurs at a SQG, the event can be considered an episodic event if it occurs only once in 12 months and the business does not store the extra waste for more than 30 days. Because the situation is temporary, the Department considers the business to be in episodic generator status. There are three things to keep in mind when trying to decide if your business qualifies as an episodic generator:

  1. Amount of hazardous waste currently at the business
  2. Amount of hazardous waste the business has produced in the past
  3. Amount of hazardous waste the business plans to produce in the foreseeable future

Send notification by submitting an updated NORWA, checking and dating the episodic generation Section VII.A.1.e. on the second page of the form and submitting it by mail to:

Missouri Department of Natural Resources
Waste Management Program
PO Box 176
Jefferson City, MO 65102-0176.

Be sure to include all of the following additional information in the comment section of the NORWA or in a cover letter accompanying the form:

  • An updated NORWA
  • Reason for the extra hazardous waste
  • Estimated amount of extra waste
  • Anticipated time period for the event
  • A statement saying at the end of the period the business will return to Small Quantity Generator status

If a business notifies the Department of its episodic event immediately, it may continue to provide an annual Generator Summary Report. However, it is required to submit a biennial report to the U.S. Environmental Protection Agency if the event occurs in an odd numbered calendar year. For more information on biennial reporting, contact the Department’s Waste Management Program at 573-751-3176.

Inspectors may check hazardous waste records to make sure a business is classified in the correct hazardous waste generator category and is following the regulations for that category. Business operations can be simplified by remaining classified as a LQG if the business believes it will repeatedly cross the limit between SQG and LQG.

Example Episodic Generator

A CESQG performs a one-time clean out of its maintenance shed. One hundred kg of hazardous waste is produced as a result of the clean out. The business must register as a SQG with the department, provide the required hazardous waste reporting and pay the associated fees. The business must follow all SQG requirements while the waste remains on site. The business can return to CESQG status after the waste is transported and as long as they do not produce 100 kg or more in any one calendar month during the next 12 months or accumulate this amount at any one time. The CESQG must also notify the department of its desire to return to CESQG status. This request may be included in a cover letter when submitting their summary report.

Additional Information

Nothing in this document may be used to implement any enforcement action or levy any penalty unless promulgated by rule under chapter 536 or authorized by statute.