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HWTR Pollution Prevention

My Watershed

On-Site Treatment by Generator

The Washington State Department of Ecology is working with schools and laboratories to find safer alternatives to reduce, or even eliminate the use of substances.

Under certain conditions generators may treat their own wastes on site without a permit. When generators choose to treat their own waste, it is called treatment by generator or TBG. Treatment is done to make wastes less hazardous, non-hazardous, or easier and safer to transport.

All facilities that conduct on-site treatment by generator (TBG) activities involving dangerous wastes must have a site identification (ID) number and notify Ecology in advance of conducting TBG activities involving dangerous wastes. Ecology expects businesses to follow best management practices, ensuring workplace safety as they accumulate and treat dangerous waste as identified in the Treatment by Generator technical information memorandum. These requirements also apply to small quantity generators of dangerous waste.

Laboratories are uniquely qualified to treat some of their wastes to eliminate the hazards or reduce the amount of waste needing disposal, thereby cutting costs. Ecology recommends that individual departments within a college or university setting that want to conduct TBG activities, contact their Environmental, Safety, and Health Coordinator to inquire about regulatory requirements.

For more information about treatment by generator, go to Ecology’s TBG Web page. For assistance, contact your Ecology Regional Office.

Most Common Laboratory TBG Activities Best Management Practices for TBG Activities References
Elementary Neutralization:
This treatment can only be used on wastes that are regulated solely because they exhibit the characteristic of corrosivity from having a pH of less than or equal to 2.0, or greater than or equal to 12.5.

If the aqueous waste carries any additional listed, process, or characteristic hazardous waste codes other than "characteristic corrosive," it cannot be neutralized and disposed of to the sanitary sewer. Instead, it must be managed as a hazardous waste.

This treatment is only used for inorganic waste mixed with water. Use secondary containment for the evaporator to contain potential spills. Designate and dispose of remaining sludge properly.
Regulatory requirements:
Within a college/university setting, individual labs that want to conduct TBG activities should contact their Environmental, Safety, and Health Coordinator to inquire about regulatory requirements.

Tracking of TBG activities
Written logs must be kept of all dangerous waste treated on site, including the date of treatment and the amount of each dangerous waste treated.

Disposal of treated solutions:
Check with your local publicly owned treatment works (POTW) to determine if treated waste can be disposed of in the sanitary sewer system, and if so, at what concentration. Do not discard treated wastes into septic systems.

Treatment by Generator online

Treatment by Generator technical information memorandum, Ecology publication, #96-412 (revised August 2012) provides guidance for treating wastes on site.

Use this form to request a site ID number or notify Ecology of TBG or other dangerous waste activities.

Hazardous Waste: More common than you think, (revised March 2004), is a quick checklist of dangerous waste requirements for regulated generators.

This page last updated September 2015