Sewage backups and drain overflows in Unionville are among the most hazardous water damage events a property can experience. Category 3 black water — raw sewage, backed-up drain lines, toilet overflows — carries bacteria, viruses, and pathogens at concentrations that make any contact a serious health risk. COS Water Damage Restoration's Unionville sewage cleanup team is trained, equipped, and certified under IICRC S520 protocols for Category 3 biohazard remediation — from containment through full restoration.
📞 Call +1-844-499-0972 — Unionville Sewage ResponseThe four factors that make our Unionville Sewage Cleanup service different from a general water damage company handling a sewage call.
IICRC certification is the standard that defines whether a sewage cleanup was done correctly. Our Unionville team is certified. The difference is measurable.
Sewage-contaminated materials removed from Unionville properties — carpet, pad, drywall, insulation, and any porous material that absorbed Category 3 water — require regulated waste handling and disposal. Our Unionville crew bags, labels, and disposes of all contaminated material to applicable MO regulatory requirements. No dumping in standard refuse. No leaving contaminated materials in dumpsters that aren't rated for biohazard waste.
One application of sanitizer after a sewage event is not sufficient. Our protocol uses multiple applications with documented dwell times.
Sewage cleanup claims in Unionville typically proceed under homeowner's policy coverage for drain backup and water damage. Our Unionville coordinators are experienced with backup coverage riders and know how to document Category 3 events for claim approval. For commercial properties or clients requiring clearance testing, we coordinate third-party air quality and surface sampling after remediation to provide a written clearance certificate before reconstruction begins.
Here's what our certified Unionville Sewage Cleanup crew handles on every job.
The first action our Unionville sewage crew takes on any Category 3 event is establishing negative-pressure containment — critical plastic sheeting barriers that prevent sewage contamination from spreading into unaffected areas of the property through airborne particles, foot traffic, and air circulation. Containment also controls odor migration within the property while remediation is underway. Simultaneously, we identify and coordinate the correction of the blockage or failure that caused the backup — whether that's a main line obstruction, a failed cleanout, or a sump failure — so that remediation isn't interrupted by a secondary event.
Extracting Category 3 sewage water from a Unionville property requires specific PPE — full protective suits, respirators rated for biological hazard, and disposable boots — for every technician in the contamination zone. We use dedicated contaminated-water extraction equipment that is not shared with standard water damage jobs and is properly sanitized between uses. After extraction, all materials that contacted Category 3 water and cannot be decontaminated to a safe standard — carpet, pad, standard drywall, fiberglass insulation, and any non-cleanable surface materials — are removed as regulated waste, bagged in approved containers, and disposed of under MO biohazard material regulations.
After material removal, every remaining structural surface — framing, subfloor sheathing, masonry, concrete, and any hard surface that contacted sewage water in your Unionville property — receives a multi-phase sanitization treatment using EPA-registered, hospital-grade antimicrobial and antifungal agents. The sanitization sequence includes spray application, documented dwell time, surface contact, and at minimum one additional application after the first dwell cycle. This is not a one-spray process. The S520 protocol our Unionville team follows is designed to address the pathogen load that Category 3 water deposits on structural surfaces.
Category 3 sewage events leave odor-causing compounds embedded in structural materials, in the air space above the affected area, and — in HVAC systems — potentially distributed throughout the property. Our Unionville team uses hydroxyl generator technology and botanical-based counteractant treatments to neutralize sewage odor compounds in the air and on surfaces, not mask them. For properties where HVAC ductwork may have been exposed to Category 3 contamination, duct isolation and decontamination is included in our scope evaluation.
Our Unionville claim coordinators have processed Category 3 claims across MO carriers. We know what gets approved on first submission.
After Category 3 remediation is confirmed complete by instrument readings and — where required — by third-party clearance testing, our licensed Unionville reconstruction team rebuilds your property: new drywall, fresh insulation, flooring, paint, trim, and any affected cabinetry or millwork. All reconstruction is performed to the same documentation standard as the remediation phase, providing a complete recovery record from sewage event to finished property that your insurance carrier and any future property transaction will find clear and complete.


Call +1-844-499-0972 and a live Unionville dispatcher answers — not a recording. Describe the situation; our dispatcher confirms the sewage backup details, dispatches the nearest Category 3-equipped crew, and confirms estimated arrival. Evacuate the affected area and prevent household members and pets from entering while we're en route.
Our Unionville crew arrives in full Category 3 PPE with containment materials, dedicated contaminated-water extraction equipment, and sanitization products. Containment is established before extraction begins — no exceptions. After containment, we identify the source of the backup and coordinate correction if needed before the cleanup scope is assessed.
No extraction, no material removal before the written scope is reviewed and approved by you.
From sewage event to finished property — documented, guaranteed, and handled by one company.



"When our basement drain backed up in Unionville, I didn't realize I was dealing with a sewage event until the smell made it obvious. COS Water Damage Restoration arrived within the hour, set up containment before anyone entered the space, and explained the Category 3 protocols clearly — including why certain materials had to be removed and couldn't just be dried in place. They disposed of everything properly, treated all surfaces with a sanitization protocol I could actually track through each step, and filed the insurance claim the same day. The reconstruction brought the basement back completely. I feel good about the space now, and that was not a given after the event."
"The thing that stood out with COS Water Damage Restoration's Unionville sewage cleanup team was the containment setup — I've seen other companies skip it or do it loosely, and you can tell they don't understand why it matters. This team had proper negative-pressure containment up before they extracted a gallon of water. The two-phase sanitization after material removal, the hydroxyl generator running during drying, the final surface swab coordination — this was a Category 3 remediation done to the actual standard, not a watered-down version of it."
"I've used general contractors for water damage before with mixed results. After calling COS Water Damage Restoration for a sewage event in Unionville, I understand the difference between a certified Category 3 remediation team and a general restoration company that 'also does sewage.' The protocols aren't comparable."
COS Water Damage Restoration's certified Category 3 sewage cleanup team serves Unionville and surrounding communities throughout MO. Call +1-844-499-0972 to confirm same-day service at your address.
Don't let an uncertified company handle a Category 3 sewage event in your Unionville property. The health risk from incomplete remediation is real. Call +1-844-499-0972 — our certified Unionville team handles it correctly.
📞 Call +1-844-499-0972 — Unionville Sewage Response24/7 Response · IICRC S520 Certified · Category 3 Protocols · Unionville, MO