Prepared by GreaseTrapLocator · Fact review: October 16, 2026
Why cold weather matters
FOG can solidify and obstruct flow as conditions change. The real risk depends on the wastewater, piping, location, burial, covers, exposure, equipment, and actual service history. That is why this guide does not publish a universal temperature threshold or automatic winter service increase.
Pre-season review
- Review the previous cold season's service, blockage, and repair records.
- Confirm the local minimum service rule and emergency contacts.
- Have a qualified person inspect covers, access, piping, vents, alarms, and any installed heat or insulation system.
- Use the exact current manufacturer instructions for installed heaters, controls, insulation, and monitoring.
- Keep exterior access secure, identifiable, and reachable for authorized service without creating a trip or traffic hazard.
- Brief managers on the early-warning and emergency response.
Do not improvise thawing
Do not aim a heat gun or space heater at unknown equipment, open a vault, enter a pit, or push grease downstream with hot water or chemicals. These actions can create fire, electrical, gas, cover, confined-space, and sewer risks. Isolate affected fixtures and use qualified service.
If drainage changes
Slow flow, gurgling, rising levels, or recurring odor are warning signs, not a diagnosis. Stop using affected fixtures and call a qualified person before a backup occurs. If sewage backs up into food, prep or customer areas, close the food establishment immediately as a precaution and contact the health authority for instructions on cleanup and reopening; then follow the emergency response guide.
Official sources used
U.S. Environmental Protection Agency
FOG can solidify, reduce sewer capacity, and block flow; 40 CFR 403.5(b)(3) prohibits solid or viscous pollutants in amounts that obstruct flow and result in interference; local programs establish controls.
Controlling Fats, Oils, and Grease Discharges from Food Service Establishments · reviewed August 8, 2026
Erie County, New York
Warm kitchen wastewater cools quickly once it reaches the sewer, and grease that congeals at room temperature sticks to pipe walls; grease traps are to be installed in strict accordance with the manufacturer's instructions, and additives have not been found effective.
Guidelines for Oil and Grease Separators · reviewed October 16, 2026
Connecticut Department of Energy and Environmental Protection
For covered outdoor, in-ground passive grease interceptors and for super-capacity grease interceptors (indoor or outdoor), the cited permit requires pumping whenever 25 percent of the operating depth is occupied, and in any case at least every three months. Only the three-month interval can be extended: the authorized agent may approve a longer interval in writing after a year of quarterly inspections showing less than 25 percent. The permit also requires specified records for five years, and prohibits intentionally using hot water, steam, physical means, chemicals, or biological additives that will cause the release of FOG into the sewer.
General Permit for the Discharge of Wastewater Associated with Food Establishments (effective October 5, 2025) · source updated October 16, 2026
U.S. Occupational Safety and Health Administration
Smell is not a reliable warning. Evaluate hydrogen-sulfide and confined-space hazards and apply the monitoring, training, entry controls and respiratory protection required by the applicable standards and site assessment.
Hydrogen Sulfide: Evaluating and Controlling Exposure · reviewed August 8, 2026
Frequently asked questions
At what temperature will a grease trap freeze?
There is no universal threshold for every device and site. Follow the manufacturer instructions and a qualified site-specific assessment.
Should we pump more often in winter?
Use the local rule and the facility's actual inspection and service records. Do not apply an unsupported percentage increase.
Can hot water thaw a grease interceptor?
Do not use hot water to push FOG downstream. Isolate affected fixtures and follow qualified service and manufacturer instructions.
Can staff use a heat gun or space heater?
Do not improvise heating around wastewater, unknown atmospheres, covers, wiring, or combustible material. Use qualified service.
Author: Grease Trap Locator Editorial Team
The Grease Trap Locator editorial team covers FOG compliance, grease trap maintenance, and commercial kitchen regulations across the US and Canada. Our guides are written for restaurant owners, facility managers, and food service operators who need practical, accurate information without the fluff.
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