Restaurant Kitchen Water Loss with Grease Contamination

Why this matters

A line cook leaves a prep sink running, a triple-basin DSP backs up, or the grease trap inlet overflows during a Saturday rush, and by Sunday morning the kitchen floor, the dry storage one door over, and the dining room cove base are sitting in water that is not just water. Cooking grease aerosolizes during normal operations and coats every horizontal and vertical surface in a working kitchen with a thin polymerized film; the moment that surface gets wet, the film mobilizes into the water and you have an organic-load contaminated event that classifies as Category 3 under IICRC S500 Section 12. Treating this as a Category 1 clean-water loss skips required source removal of the contaminated film, leaves grease-saturated gyp board behind walls, and produces a rancid-smelling kitchen 30 days later that the health department will close. This SOP is the field protocol for restaurant kitchen water losses where grease contamination is in play.

Initial assessment and categorization

S500 Section 10 governs scope. In a restaurant kitchen any water loss meets the Category 3 definition by default because the environment is grossly unsanitary even before the loss event. Triggers that confirm Cat 3:

1. Grease trap backflow or overflow (always Cat 3, contains rendered fat, food solids, biofilm).
2. Three-compartment sink or dish-machine backflow (food solids, detergent residue, bacterial load).
3. Clean-water source running across grease-coated floor for more than 15 minutes; the film mobilizes, transitions per S500 Section 10.5.4.

The claims rep may push for Cat 2 because the source is potable water. Document environmental conditions photographically, note grease film on equipment legs and walls, write Cat 3 in the scope. S500 Section 10 is explicit that source water class does not override environmental conditions.

Personal protective equipment

Cat 3 in a restaurant: Type 5/6 coverall, nitrile gloves, full-face APR with P100 cartridges (organic vapor cartridges if protein load is decomposing), boot covers over slip-resistant boots, sodium hypochlorite footbath at egress. OSHA 29 CFR 1910.134 fit testing applies. A two-bag decon outside the work area satisfies S500.

Source removal sequence

Step 1: stop the source. Isolate the failed plumbing fixture and confirm with the customer's licensed mechanical contractor; restoration does not own plumbing repair. Get the building manager or franchise FM to schedule a plumber the same day.

Step 2: extract free water. Truck-mount extraction with hard-floor tools first; the grease load fouls portable extractor filters fast and you will burn through cartridges. Use a debris-tolerant truck mount (Sapphire Scientific 870SS or equivalent) and dispose of recovery tank contents as oily wastewater per the local POTW pretreatment program. Most municipalities prohibit grease-laden water discharge into the sanitary system without a hauled-waste manifest.

Step 3: degrease horizontal and vertical surfaces inside the affected zone. EPA-registered alkaline degreaser at label dilution (Benefect Atomic Degreaser, Aramsco Degreaser-D, Spartan Pro-tek Heavy Duty Degreaser). Two-bucket method: degreaser solution, clean water rinse. Vertical surfaces wiped top-down. The cleaning step is non-negotiable; you cannot apply antimicrobial to a grease-coated surface and expect contact-kill. S500 Section 12.5 sequencing: clean before treat.

Step 4: remove and dispose of porous materials per S500 Section 12.2.3. Wet gyp board, wet rigid insulation, wet ceiling tile, wet wood casework not fabricated of solid hardwood: all bagged and disposed. Cove base is removed as a matter of routine in a restaurant Cat 3 to inspect and degrease the wall behind. Quarry tile or sealed concrete floor: degrease, do not remove.

Drying environment

After source removal and cleaning, build the drying chamber per S500 Section 13. Restaurant-specific:

1. Ventilation. Type I hood exhaust runs during off-hours; coordinate with the operator. Hood-on accelerates air change but draws conditioned air across the zone; hood-off lets you control the drying environment with temporary exhaust. Most jobs run hood-off with temporary HEPA exhaust outside.
2. Equipment. Refrigerant LGR (Drieaz LGR 7000XLi, Phoenix R250); one axial fan per 14 to 16 linear feet of wall. Verify ambient stays below 90 F or LGR efficiency drops.
3. Walk-in coolers. If affected, the operator decides on contents disposition before drying; FDA Food Code 2022 Section 3-202.11 prohibits return-to-service of TCS food in a contaminated environment.
4. Hood and duct. Greasehood interior was likely affected by splash. NFPA 96 Section 11 governs hood and duct cleaning; coordinate with the operator's NFPA 96-certified vendor for work inside the hood enclosure.

Post-remediation verification

Restaurant Cat 3 PRV is two-track:

1. Restoration PRV per S500 Section 14. Visual inspection clean, dry materials at target moisture content (gyp board less than 12%, framing less than 16%), surface ATP swab on representative non-food-contact surfaces less than 200 RLU as a cleaning verification metric, no marker fungal genera if microbial sampling is performed.
2. Health Department re-opening inspection. Local jurisdiction; typical scope is FDA Food Code 2022 Sections 4 (equipment), 5 (water, plumbing, waste), 6 (physical facilities). The operator schedules this; restoration provides the cleaning verification documentation.

Document the Cat 3 designation, source elimination, degrease sequence, antimicrobial application (EPA reg number, SDS, dilution log), and final moisture readings. The franchise FM and the operator both sign release.

References

1. IICRC S500-2021, Sections 10 (water categorization), 12 (cleaning), 13 (drying environment), 14 (PRV).
2. FDA Food Code 2022, Chapters 4 (Equipment, Utensils, and Linens), 5 (Water, Plumbing, and Waste), 6 (Physical Facilities).
3. 21 CFR 178.1010, Sanitizing solutions (food-contact surface approval).
4. NFPA 96-2024, Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations, Chapter 11 (cleaning).
5. OSHA 29 CFR 1910.134, Respiratory Protection.
6. Sapphire Scientific 870SS Truckmount Specification (debris-tolerant extraction).
7. EPA Pretreatment Program guidance, 40 CFR 403 (industrial discharges to POTW including grease-laden water).