The 25% rule: what Ontario grease-trap compliance actually requires

Grease-trap compliance in Ontario comes down to one number most kitchen owners have never heard explained clearly: 25%. Your grease interceptor has to be pumped before the grease-and-solids layer inside it exceeds 25% of the interceptor's total liquid volume. Everything else in the rule exists to support that one threshold.

How the threshold is actually checked.

The check happens at the 4-week mark. If your interceptor is still under the 25% line at that point, you can go up to 8 weeks between pump-outs. If it isn't, pumping needs to happen sooner. Higher-volume kitchens, especially heavy fryers and 24-hour operations, hit 25% faster and land on a shorter interval by default.

The paperwork the rule requires.

Passing the 25% threshold check is only half the requirement. A compliance log has to stay on site and accessible for a minimum of two years, and every pump-out needs a licensed hauler's disposal manifest filed behind it: hauler name, MECP/ECA registration number, volume hauled, and disposal facility. An inspector who asks for proof is asking for this log, not just a verbal assurance that pumping happens regularly.

Toronto's version has a name and a number.

In Toronto specifically, this requirement sits inside Toronto Municipal Code Chapter 681, the Sewers By-law, and non-compliance carries real fine exposure: up to $50,000 for a first offence, up to $100,000 for a repeat one. Other GTA municipalities enforce the same kind of sewer-use by-law under their own separate rules, with their own separate penalty structures. What's constant everywhere is the underlying obligation. What varies is the specific by-law and fine attached to it.

Northfire handles the pumping schedule, the hauler manifest, and the compliance log as one service, not three separate things to track yourself. See what's included →