Every business that treats hazardous waste onsite within the Yolo County area is required to notify the CUPA Program through Yolo County's Environmental Health Services. Onsite hazardous waste treatment can range from simple, low-risk processes to complex operations that pose significant risks to public health, safety, and the environment. With limited exceptions, facilities that treat hazardous waste onsite are required to notify the Yolo County Environmental Health Division, the Certified Unified Program Agency (CUPA). The CUPA reviews required treatment notifications and documentation and inspects these facilities at least once every three years to ensure compliance with applicable regulations.

Hazardous waste treatment is any physical or chemical process performed on a waste stream before disposal. Treatment may make waste non-hazardous, enable recycling, reduce disposal volume, or prepare waste for discharge to air or water. Some low-risk activities, such as silver recovery from photographic waste, are exempt from treatment requirements.

Processes that may require notification include pH adjustment, filtration, centrifugation, gravity separation, drying, distillation, and other methods used to alter or manage hazardous waste. If you modify a waste stream after it has been generated and are unsure whether the activity is considered treatment, contact Environmental Health for guidance.