When sewage backs up in a Mukilteo property, the cleanup has to be done correctly from the first step. Incomplete containment, improper material disposal, or skipped sanitization steps leave biological contamination in the structural materials — creating an ongoing health risk long after the visible mess is gone.
📞 Call +1-844-499-0972 — Mukilteo Sewage ResponseThe four factors that make our Mukilteo Sewage Cleanup service different from a general water damage company handling a sewage call.
COS Water Damage Restoration's Mukilteo sewage cleanup crew operates under IICRC S520 standard — the industry's governing protocol for Category 3 contaminated water remediation. This covers the specific containment requirements, the PPE standards that protect our crew from pathogen exposure, the material removal requirements (what can be safely dried versus what must be removed and disposed of as a regulated waste stream), and the multi-application antimicrobial sanitization protocol that must be completed before any structural drying begins.
Sewage-contaminated materials removed from Mukilteo properties — carpet, pad, drywall, insulation, and any porous material that absorbed Category 3 water — require regulated waste handling and disposal. Our Mukilteo crew bags, labels, and disposes of all contaminated material to applicable WA 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 Mukilteo crew follows the sequence on every surface, every time.
Our Mukilteo claim coordinators handle the insurance piece. We can coordinate clearance testing when it's required.
Here's what our certified Mukilteo Sewage Cleanup crew handles on every job.
Containment is established before extraction begins. This is non-negotiable on every Mukilteo sewage job.
No material gets dried in place unless it passes decontamination protocol first.
After material removal, every remaining structural surface — framing, subfloor sheathing, masonry, concrete, and any hard surface that contacted sewage water in your Mukilteo 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 Mukilteo team follows is designed to address the pathogen load that Category 3 water deposits on structural surfaces.
Odor neutralization is a final treatment step, not a product sprayed at the end to cover incomplete remediation.
Our Mukilteo claim coordinators have processed Category 3 claims across WA carriers. We know what gets approved on first submission.
One company from sewage backup to finished reconstruction. No coordination gap, no separate contractor handoff.


Call +1-844-499-0972 and a live Mukilteo 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.
Containment before contact. Source identified and addressed before cleanup proceeds.
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.



"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 Mukilteo 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."
"The thing that stood out with COS Water Damage Restoration's Mukilteo 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 Mukilteo, 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 Mukilteo and surrounding communities throughout WA. 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 Mukilteo property. The health risk from incomplete remediation is real. Call +1-844-499-0972 — our certified Mukilteo team handles it correctly.
📞 Call +1-844-499-0972 — Mukilteo Sewage Response24/7 Response · IICRC S520 Certified · Category 3 Protocols · Mukilteo, WA