Toronto Municipal Code § 681 · Environmental Code of Practice
The 8-week grease trap rule
Toronto's default is a pump-out every four weeks. The by-law also allows up to eight — but only with documentation most kitchens have never been asked to produce. This page is the rule in plain language, and what it takes to qualify.
Combined grease and solids, measured against the interceptor's liquid volume. Hit it and service is due immediately.
The maximum interval the City may permit, on evidence — never automatic, and never granted retroactively.
How long servicing and disposal records must be kept and available for inspection.
What the by-law actually says
Two requirements run at the same time, and it's the second one that catches people out.
The interval: service every four weeks. The condition: or before combined grease and solids reach 25% of the interceptor's liquid volume — whichever comes first. A busy kitchen can breach the 25% condition in three weeks and still be inside its four-week schedule. It is still out of compliance.
Service is required every four weeks, or before the grease and solids (combined) reach 25 per cent of the interceptor's liquid volume. City of Toronto — Grease Interceptor Maintenance
The relationship runs the other way too. A low-volume kitchen with a correctly sized interceptor may sit well under 25% after four weeks, and pump anyway, because nobody told them there was an alternative.
The eight-week extension
The City may permit a longer interval — up to eight weeks — where records demonstrate that combined grease and solids reach less than 25% of liquid volume within the first four weeks.
Three things about that sentence matter more than they look:
- "May permit." This is a decision the City makes, not a threshold you cross. Staying under 25% makes you eligible, not approved.
- "Where records demonstrate." The evidence has to exist before you apply. There is no way to build it retroactively, which is why the work starts a few cycles ahead of the application.
- "Within the first four weeks." The measurement is taken at the four-week mark, on your current schedule. You do not stretch to eight weeks and then measure.
The records you need
Servicing records must be kept at the establishment and produced on request. Service contracts, receipts and invoices all count — but a receipt that only shows a date and a price does very little for you. A useful carrier record documents:
- The date and the work performed
- An estimate of the grease and solids percentage
- An estimate of the appropriate servicing frequency
- The condition of the interceptor
- Where the waste was disposed
Disposal records are separate and also required: the company name, the disposal date, the type of waste, and the measured quantity. If you service the interceptor manually rather than using a carrier, you must keep maintenance logs on site at all times.
All of it is held for a minimum of seven years.
Why this is worth the trouble
Moving from four weeks to eight halves the number of service visits in a year — thirteen becomes seven. For a kitchen that qualifies, that is a permanent reduction in a mandatory recurring cost, achieved with paperwork rather than by cutting anything.
The same records are also the ones that answer an inspection. Kitchens rarely fail because the trap was dirty. They fail because nobody can produce the last two years of receipts.
The process
Getting to eight weeks
Numbered because the order is the whole point — the evidence has to exist before the application does.
Stay on four weeks
Keep the standard cycle while you gather evidence. Stretching the interval before you have records is the one move that can't be undone.
Measure before every pump-out
Combined grease and solids, as a percentage of liquid volume, recorded at the four-week mark on every visit.
Establish the pattern
Several consecutive cycles under 25%. One reading is an anecdote; a run of them is a case.
Apply with the history
The service record goes to the City as supporting documentation for an extended interval, up to the eight-week maximum.
Keep filing for seven years
Approval doesn't end the record-keeping. Servicing and disposal records stay on site and available for inspection.
Questions
Common misreadings
Is eight weeks automatic if I stay under 25%?
No. Eight weeks is a maximum the City may permit, not an entitlement you claim. Staying under 25% makes you eligible; the documented service history is what makes the case.
Can I just start pumping every eight weeks?
No — and it's the most expensive mistake available here. Without an approved extension you're in breach from the fifth week, and you've also destroyed the four-week measurements the application depends on.
What counts as 25% — just the grease?
Grease and solids combined, against liquid volume. They sit at opposite ends of the tank, which is why a surface that looks manageable can still add up past the limit once the settled sludge is counted.
What if my interceptor is undersized?
Then it will keep hitting 25% early and no amount of documentation will get you to eight weeks. In that case the honest answer is that the unit is wrong for the kitchen's volume, and a longer interval isn't the problem worth solving.
Does this apply outside Toronto?
The 25% threshold and the eight-week maximum are Toronto's. Other municipalities in the GTA set their own sewer-use requirements, and several are less prescriptive. Check the rule that applies to your address — our Toronto page covers the city's requirements in full.
Find out where you stand
Is your kitchen a candidate?
Send us the basics and we'll tell you honestly whether your interceptor is likely to hold under 25% at four weeks — and quote scheduled service either way. If it won't qualify, we'll say so rather than sell you a process that ends in a refusal.