Grease Trap Cleaning 101: What Bronx Restaurant Owners Need to Know About NYC Compliance

The knock Bronx restaurant owners dread is not from a food critic, it is from an unannounced inspector asking to see the grease trap, the maintenance log, and the waste hauler manifests right in the middle of service. If that trap is overloaded, the paperwork is missing, or the sewer line is already starting to back up, the visit quickly turns from a quick check into a costly disruption.

At All County Sewer & Drain, we have been helping commercial kitchens in the Bronx and across NYC deal with that exact mix of plumbing and compliance pressure since 1987. We see what happens inside the traps, inside the lines under the floor, and down in the building sewer. That perspective matters, because grease trap cleaning for NYC restaurants is not just about passing inspection, it is about keeping your drains, floors, and dining room out of the mess.

What a Grease Trap Actually Does and When It Stops Working

A grease trap or interceptor is a separation tank in your drain line that uses gravity and time to pull fats, oils, and grease (FOG) out of wastewater before it hits the city sewer. As water from sinks, dishwashers, and floor drains enters the unit, heavier food particles settle to the bottom, FOG floats to the top, and relatively cleaner water exits from a middle layer through baffles to the sewer.

On day one after cleaning, that process works well. The problem is that a trap does not fail the moment it looks full, it fails once FOG and solids reach a specific threshold. Under 15 RCNY Section 19-11, the NYC DEP Bureau of Wastewater Treatment treats an interceptor as out of compliance once the combined FOG and solids layer exceeds 25 percent of the total liquid depth. At that point, the “clean” middle layer is gone and grease starts moving straight through into your downstream piping.

Once FOG escapes the trap, the issue stops being abstract compliance and becomes a drain emergency. Hot wastewater keeps grease soft long enough to travel into horizontal lines under the floor and out toward the building sewer. As it cools, it solidifies along pipe walls, narrowing the line. Add food solids, a bit of scale, and repeated cooling cycles, and you have the start of a blockage or even a local “fatberg,” a hardened grease mass that can choke a pipe.

We see this in Bronx kitchens as slow prep sink drains, floor sinks that bubble during dishwashing, and eventually raw sewage coming up through floor drains or cleanouts. By the time that happens, you are dealing with both a sanitary hazard in an inspected kitchen and the risk of a sanitary sewer overflow (SSO) affecting neighbors or common areas.

NYC DEP Requirements Every Bronx Restaurant Must Meet

Under 15 RCNY Section 19-11, any NYC food service establishment that sends FOG-bearing wastewater to the sewer must have and maintain a properly sized grease trap or interceptor. That includes full-service restaurants in the Bronx, fast food locations, cafeterias, delis, bakeries, butcher shops, and fish markets. If the operation cooks, fries, roasts, or handles meat, you are in the FOG business and the rules apply.

Installation is not a “do it yourself” decision. The rules require that a NYC Licensed Master Plumber design and install the system, including any hydromechanical grease interceptor under a sink or larger gravity grease interceptor in a pit or basement. Proper sizing uses DEP Tables I and II, which calculate required capacity from fixture volumes, flow rates, and the type of operation. A trap that is “there” but undersized can still put you out of compliance if it cannot handle your actual load.

One detail many Bronx restaurant owners miss is that food waste disposers, garbage disposals, are not permitted in NYC commercial establishments. Grinding food and sending it to the trap accelerates solids buildup, shortens cleaning intervals, and violates DEP guidance.

The rules also address what you cannot do in an attempt to cheat the system. Under 15 RCNY Section 19-11(u), the use of emulsifiers, enzymes, chemicals, microbial agents, or other additives in grease interceptors or automatic grease removal devices is prohibited. Those “miracle” bio-enzyme products that claim to dissolve grease inside the trap simply move FOG down the line into the sewer, where it re-solidifies and causes blockages. To an inspector, an additive bottle next to the trap is a red flag, not proof of good maintenance.

Cleaning Frequency: The 25% Rule in Practice

The DEP’s enforceable standard is simple on paper: FOG plus solids must not exceed 25 percent of the interceptor’s liquid depth. In the field, that translates into a cleaning schedule based on how fast your kitchen loads the trap. For many Bronx restaurants, that means service every one to three months. For high-volume, high-frying operations, it often means monthly or even a bit more often to stay comfortably below the 25 percent line.

The key is that frequency should be driven by your actual kitchen volume, not just a calendar reminder you inherited from a previous manager. A small Bronx deli that mostly makes cold sandwiches might comfortably stretch to a longer interval, as long as the trap is inspected and measured. A busy fried chicken or Latin restaurant pushing a lot of cooking oil and FOG-laden dishwater will reach that 25 percent threshold much faster, even if both locations have the same size interceptor.

Undersized traps complicate the picture. We often see change-of-use situations in the Bronx where the previous tenant had a low-grease operation and the existing trap was adequate. When a new tenant adds more cooking or frying, that inherited trap fills quickly. If you find yourself needing service every three to four weeks just to keep things flowing and compliant, you likely have a sizing problem, not only a scheduling issue. In those cases, it is worth having a Licensed Master Plumber review the system against current DEP sizing tables.

What Professional Cleaning Involves and What Records You Must Keep

A proper grease trap or interceptor service is more than dropping a hose in and pulling out some liquid. For NYC restaurants, a professional cycle typically includes:

• Full pump-out. Removing all contents from the unit, not just the top grease layer, so both FOG and settled solids are cleared.
• Physical cleaning. Scraping and washing trap walls, baffles, and the inlet and outlet areas to remove hardened deposits that restrict flow.
• Component check. Inspecting baffles, covers, gaskets, and inlet and outlet piping for cracks, corrosion, or missing parts that could lead to bypass or leaks.
• Water seal restore. Refilling the interceptor with clean water to the correct operating level so it can immediately separate FOG from incoming wastewater.
• Proper hauling. Transporting the removed waste to an approved facility using appropriate equipment and documentation.

If you have yellow grease (used cooking oil) picked up, the rules add another layer. Waste haulers collecting yellow grease in NYC must hold a valid trade waste removal license from the Business Integrity Commission (BIC). At every pickup, they must leave a written manifest or receipt documenting the collection. Under 15 RCNY Section 19-11, those yellow grease manifests must be kept on-site for at least one year.

For interceptor cleaning, there is no harm in keeping more documentation than the bare minimum. At a practical level, your records should include the date of service, volume removed, observed condition, any noted issues, and the name and contact information of the service provider. Because record-keeping requirements and inspector expectations can vary and missing paperwork alone can trigger a DEP violation, many operators choose to keep at least three years of maintenance logs and manifests as a buffer.

What DEP Inspectors Look For and How Violations Stack Up

NYC DEP inspectors make unannounced visits to food service establishments across the city, including the Bronx, to check grease interceptors. They verify that a properly sized unit is installed, that it has not been bypassed or altered, that FOG and solids are below the 25 percent threshold, and that maintenance records and manifests are available on-site. Inspections can also be triggered by complaints or by a sewer blockage or SSO that the city traces back to a particular stretch of businesses.

Grease mismanagement can draw attention from several agencies at once. The DEP can issue citations for violating sewer use rules and grease interceptor regulations. The Department of Health can cite unsanitary conditions if backups or odors affect food preparation areas. The Department of Buildings may get involved if the installation was not filed correctly or violates plumbing code. FDNY can raise concerns if grease buildup in ducts, interceptors, or connected systems contributes to fire or safety hazards. One neglected trap can turn into multiple separate tickets.

The maximum DEP penalty for non-compliance with grease interceptor rules is $10,000 per day per violation. Repeat violations can lead to escalating fines and more frequent monitoring. It is also important to understand that an inspector does not need to see a backup on the floor to cite your restaurant. An overloaded interceptor or missing documentation can be enough for a violation, even if the drains seem to be working that day.

Kitchen Practices That Reduce Trap Load Between Cleanings

Good kitchen habits make a big difference in how fast your trap loads and how your Bronx restaurant looks to an inspector or landlord. NYC DEP promotes a set of Best Management Practices as the first line of defense against grease problems, and they line up with what we see in the field.

• Dry wipe before washing. Staff should scrape and wipe pots, pans, and plates into the trash before placing them in the sink or dishwasher. Less FOG and food on dishes means less in the trap.
• Use drain screens. Strainers on all sink drains and floor sinks catch solids that would otherwise end up as sludge. Empty them into the garbage frequently during shifts.
• Contain used oil. Collect used cooking oil in sealed containers for pickup by a licensed yellow grease hauler, rather than pouring any into sinks, floor drains, or dumpsters.
• Avoid disposals. Since garbage disposals are not permitted in NYC commercial kitchens, remove or disconnect any legacy units left from previous tenants and adjust dishwashing procedures accordingly.
• Train and remind staff. Walk new hires through FOG do’s and don’ts, and post reminder signs near sinks and dish areas. DEP-provided posters and in-house reminders both signal to an inspector that management takes grease control seriously.

These steps do not replace interceptor cleaning, but they reduce how quickly you hit the 25 percent mark, help protect your lines from clogs, and demonstrate active management if an inspector visits during a busy service.

Landlord vs. Tenant: Who Owns the Grease Trap Problem?

Many Bronx restaurants lease their space, which raises a practical question: whose responsibility is the grease trap? Leases vary, but the city’s enforcement focus is simple. DEP and other agencies look to the food service establishment discharging FOG into the sewer, not just the property owner. If your kitchen creates the wastewater, you share responsibility for how it is managed.

In change-of-use situations, the trap that is “already in the ground” may not match your operation. A space that used to be a small deli might have a trap sized for light FOG, while your new concept adds fryers, grills, and higher volume dishwashing. Even if the landlord installed the original unit, you are the one an inspector will question if the interceptor is undersized or poorly maintained.

We often encourage tenants and landlords to address this together. A Licensed Master Plumber can compare the existing setup to DEP sizing tables based on the current or planned operation. If upgrades are required, lease language can address who pays for what, but from an enforcement perspective, “the landlord did it that way” is not a defense if a backup or violation occurs.

From Compliance to Drain Emergencies: How We Help Bronx Kitchens

You can follow DEP rules, train staff, and keep spotless records, and you still may wake up to a slow main line, a floor drain that starts to bubble during prep, or a full backup right before a busy weekend. Grease traps live at the intersection of compliance and plumbing reality, and they sit at the front of a drain system that can fail at the worst possible time.

That is where a sewer and drain team with commercial kitchen experience makes a difference. At All County Sewer & Drain, we have spent decades clearing lines and maintaining traps for restaurants, cafeterias, and food service operations throughout the Bronx and NYC. We understand how an overflowing interceptor, a partial blockage under the slab, and a looming DEP inspection all connect.

Whether you are trying to get ahead of DEP requirements with a consistent grease trap cleaning plan or dealing with a drain emergency that is already disrupting service, we can help you untangle both the plumbing and compliance sides. To talk through your restaurant’s situation or schedule service, reach out to All County Sewer & Drain at (718) 550-5956.