A Biohazard Event, Not a Cleaning Problem
A property manager in North Las Vegas called me after a tenant's toilet had backed up through a first-floor drain. The tenant had already mopped it up. The carpets were wet but looked clean. The manager wanted to know if they still needed professional cleanup.
They did. What looked clean on the surface was Category 3 contamination: raw sewage mixed with greywater, soaked into carpet padding, subfloor, and the base of drywall along the perimeter. Without proper remediation, that property would have had active bacteria and mold growth in every porous material the sewage touched within 48 hours. The tenant was still living there.
Sewage contamination is classified as Category 3 water damage under the IICRC S500 Standard. That means the water contains human pathogens including bacteria such as E. coli and Salmonella, viruses, and sometimes parasites. For context on how biological contamination affects indoor health, ask us directly when you call we will walk you through what Category 3 exposure means for your property. Mopping does not address Category 3 contamination. Neither does air drying. Porous materials that have been in contact with Category 3 water must be physically removed.
Why Las Vegas Has More Sewage Backup Calls Than You Would Expect
Clark County has significant aging sewer infrastructure concentrated in the older residential corridors. Many neighborhoods built in the 1960s through 1980s have clay and cast iron sewer lateral lines connecting properties to the main that have cracked, filled with roots, or collapsed over the decades. North Las Vegas, Paradise, and Spring Valley all have documented aging sewer systems that contribute to backup rates.
Municipal sewer overflows during heavy monsoon events push sewage backward through drain lines into properties on low-lying lots. This happens every monsoon season in parts of the valley. We get calls the day of and the day after every significant rain event.
Grease buildup in kitchen drain lines is another common cause, especially in rental properties and older homes where drain maintenance has been neglected. The backup can happen without warning and release significant volume before anyone realizes what is happening. Sewage events also introduce sewer gas into the living space, which contains hydrogen sulfide and methane. Both are hazardous at elevated concentrations. That is another reason the building needs to be ventilated and assessed before occupants return.
How We Handle Sewage Cleanup
Every sewage job starts with Category 3 containment. We isolate the affected area and use negative air pressure with HEPA filtration before any material removal begins. This keeps contamination from spreading to clean areas.
All porous materials that contacted Category 3 water come out: carpet and padding, contaminated drywall, saturated subfloor sections, and insulation. All removed material goes into sealed disposal bags. After removal, remaining structural surfaces are treated with EPA-registered hospital-grade disinfectants. We verify surface decontamination with ATP testing before clearance. ATP testing measures biological residue at the surface level and confirms the disinfection was effective. We also verify moisture content across all remaining materials. If the sewage event involved significant water volume, structural drying of wall assemblies and subfloor cavities is part of the same job. Documentation of the Category 3 protocol is provided in a format that satisfies insurance carrier requirements for sewage claims. If sewer gas odor persists after cleanup, that is a separate drain or vent issue. Read our odor removal page for how we locate and treat odor sources that remain after the primary remediation is complete.
We respond within one hour, 24 hours a day. Want to know how sewage cleanup works in Las Vegas or whether your insurance covers it? Read our guide to what homeowners insurance typically covers for water and sewage events.