ICS Magazine

Sewage Backflows - Essential Steps for Proper Remediation

March 2, 2007


Remediators are constantly confronted by uneducated parties who want to simplify procedures for restoring their sewage saturated homes and furnishings. As has been demonstrated in a number of studies, sewage represents an exposure that can have severe and long-term health effects.

For example, if someone even mentions mold in a building, everyone wants to evacuate immediately, whether justified or not. But even if a sensitive person has a reaction to mold, typically, if they leave the building, within a few hours, most symptoms will disappear.

But if a sensitive person has a sewage exposure, there is the possibility that they could die or contract a chronic disease, such as hepatitis, which could affect them for months or years.

So just what are necessary and justifiable remediation procedures in response to a significant sewage backflow? They include but are not necessarily limited to:
  1. Inspection and evaluation by protected sewage remediators. This may include advising occupants to evacuate the premises, depending on the extent of contamination. Questions regarding health effects should be referred to qualified public health professionals.
  2. Depending on the scope and complexity of the sewage backflow, it may be prudent for the property owners to hire an independent indoor environmental professional (IEP) or other specialized expert to perform an assessment and conduct pre-remediation sampling, and to write a remediation protocol, if appropriate.
  3. Typically, affected areas should be contained with critical barriers or polyethylene plastic sheeting.
  4. Remediators should establish negative pressure using HEPA-rated, air filtration devices (AFDs), which are exhausted outside affected areas, to prevent cross-contamination.
  5. Unsalvable porous furnishings and contents materials (e.g., carpet, pad, upholstery, bedding) that are contacted by the sewage should be properly packaged and removed for disposal.
  6. Structural materials and furnishings (e.g., base molding, lower wall materials, built-in cabinets or bookcases, fixtures, appliances, even vinyl or solid wood flooring materials) should be removed to expose pockets of saturation for direct-access cleaning and disinfecting.


  • Unsalvable materials and furnishings should be packaged and properly disposed of.
  • Durable, salvable structural materials should be thoroughly cleaned, possibly using low-pressure washing to flush contaminates from cracks and crevices.
  • Wastewater from cleaning operations should be collected and disposed in a sanitary sewer system.
  • Antimicrobials or disinfectants should be applied to clean surfaces as an extra measure of protection.
  • Tools and equipment should be cleaned and disinfected before being loaded for transport to another location to avoid contaminating vehicles or other buildings.
  • Salvable materials should be dried to acceptable standards to prevent on-going microbial growth and amplification.
  • Post-remediation verification by an independent IEP usually is required to ensure that the building is safe to re-occupy.
  • Affected areas can be reconstructed or materials can be replaced, as appropriate.


  • It should be obvious that sewage remediation procedures often will be complicated and involved. However, the alternatives, in terms of potential health effects for occupants and increased liability, are simply unacceptable.