Sewage backups and drain overflows in Chelsea 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 Chelsea 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 — Chelsea Sewage ResponseThe four factors that make our Chelsea 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 Chelsea team is certified. The difference is measurable.
Sewage-contaminated materials removed from Chelsea properties — carpet, pad, drywall, insulation, and any porous material that absorbed Category 3 water — require regulated waste handling and disposal. Our Chelsea crew bags, labels, and disposes of all contaminated material to applicable MI regulatory requirements. No dumping in standard refuse. No leaving contaminated materials in dumpsters that aren't rated for biohazard waste.
After contaminated material is removed and Category 3 extraction is complete, every structural surface that contacted sewage water receives multiple applications of EPA-registered, hospital-grade antimicrobial and antifungal treatments. The sanitization sequence — spray application, dwell time, surface wipe-down, second application — is protocol-driven, not judgment-call driven. Our Chelsea crew follows the sequence on every surface, every time.
Our Chelsea claim coordinators handle the insurance piece. We can coordinate clearance testing when it's required.
COS Water Damage Restoration handles the complete scope of Sewage Cleanup in Chelsea — from containment and extraction through material removal, sanitization, structural drying, and rebuild. Category 3 protocols, start to finish.
Containment is established before extraction begins. This is non-negotiable on every Chelsea sewage job.
No material gets dried in place unless it passes decontamination protocol first.
Sanitization happens before drying equipment is staged. This sequence matters.
Odor neutralization is a final treatment step, not a product sprayed at the end to cover incomplete remediation.
Our Chelsea claim coordinators have processed Category 3 claims across MI 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 Chelsea 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 Chelsea 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 Chelsea 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.
Extraction, material removal, multi-phase sanitization, structural drying, and reconstruction proceed under your approved scope. Daily progress updates keep you informed. Clearance testing is coordinated where required or requested. Final sign-off at a walkthrough with your project manager. Written satisfaction guarantee on every Chelsea job.



"We have a young child and a dog and the moment the sewage smell hit I knew this was something I couldn't handle myself. COS Water Damage Restoration's Chelsea team was there in under 60 minutes, contained the area so our family could stay in the upper floors, and handled every part of the cleanup in a way I trusted. The clearance testing they coordinated at the end gave me documented proof that the remediation was complete."
"Three years later, no odor, no mold, no recurring issues. COS Water Damage Restoration did the Chelsea sewage cleanup right the first time. I'm telling every neighbor I know to call them first."
"Managing a rental property in Chelsea means sewage backups occasionally happen, and the response you choose matters enormously because you have tenant health and habitability on the line. COS Water Damage Restoration handled a Category 3 event at one of our properties with complete transparency — documented scope before work started, clear removal decisions explained in writing, and a clearance certificate at the end that we could show our tenant as proof the property was properly remediated. The insurance claim was settled without any dispute."
COS Water Damage Restoration's certified Category 3 sewage cleanup team serves Chelsea and surrounding communities throughout MI. Call +1-844-499-0972 to confirm same-day service at your address.
Sewage contamination requires certified remediation — not a general cleanup crew. Call +1-844-499-0972 and our Chelsea Category 3 team responds fast, contains the event, and remediates to the standard that protects your household.
📞 Call +1-844-499-0972 — Chelsea Sewage Response24/7 Response · IICRC S520 Certified · Category 3 Protocols · Chelsea, MI