Sewage Cleanup Situations
Q: Is there ever a time when you would use different procedures to clean up sewage based upon the type of building you're working in?
A: I am not clear on what you mean by "type of building." So I will assume that you are referring to how the building is used (e.g., home, office, school or hospital) opposed to the type of construction (e.g., wood frame, concrete tilt-up or masonry). Ultimately the same procedures are used in all cases; however, the way the building is used may have an impact on the level of concern about containment and exposure to workers and occupants.
The procedures that you would want to follow are found in the "IICRC S500 Standard and Reference Guide for Professional Water Damage Restoration." (The Standard is now in it second edition; the IICRC will soon be releasing a third edition.) The reason I bring up the S500 is that it was preceded by an article in the Journal of Environmental Health in 1994 titled "Suggested Guidelines for Remediation of Sewage Backflow into Buildings." The article made reference to three situations. Each situation was progressively more serious and required a slightly different response. The situations that were listed were:
Situation 1. A very limited quantity of waste that originates in the built environment is deposited or flows slightly beyond the confines of the sewage system. In this situation, the waste is found in one specific location, is contained, and does not penetrate the building structure. A limited amount of contact time has passed. An example of this situation might be waste that overflows in a bathroom and is deposited on and confined to a tile floor. In this situation, there is a limited quantity of waste, which is contained and does not contact absorbent materials. Decontamination, which includes water extraction, cleaning and disinfection, can be effective in reducing this particular potential health risk.
Situation 2. Waste that originates in the built environment is deposited or flows beyond the confines of the building's disposal system. In this case, there is limited or confined flooding, but water and waste penetrates the structure and furnishings of the building. For example, flooding occurs in a men's room of an office building, water flows under a wall, and into the carpet of an adjacent hallway. In this case, there is a limited amount of waste that is confined to a relatively small area of the building, but it penetrates regions of the environment that have complex surfaces and are difficult to restore. Effective restoration involves decontamination (as in Situation 1) and drying all surfaces that have been in contact with the sewage. In the case of stretch-in carpet, lifting and cleaning the contaminated carpet, disposing of the cushion, and treating both sides of the carpet thoroughly with a disinfectant are all necessary. Affected porous wall materials need to be treated with a disinfectant and evaluated for replacement. Because of the confinement of the sewage spill, aggressive, comprehensive treatment can be effective.
Situation 3. Waste that originates in the built environment, along with other wastes from the main line of the sewage system, is backed up into the immediate environment, where the waste is widely dispersed and penetrates both the structure and its furnishings. In this situation, there is extensive risk because humans can be exposed to pathogenic raw wastes that have penetrated and become contained by the building and its furnishings. If flooding is from this kind of primary outside sewage system, occupants should be evacuated, and restoration should begin immediately. In this situation, cleaning and restoration professionals should be protected with respirators with high-efficiency particulate air (HEPA) cartridges, rubber boots, gloves, splash goggles, and protective garments. Extreme care should be taken to avoid puncture wounds during the restoration process. Restoration staff who have cuts or open sores should not be allowed to work on this kind of restoration project. The principles of restoration of this situation are outlined in the last section of this paper, which contains specific recommendations for techniques.
There is a distinction made between sewage that was generated within the built environment and sewage that was generated from the main line. While portions of the above referenced article were adopted by the original S500, this concept of situations was not. Recognizing that there are degrees of concern based upon the source of the sewage might require a modification of the procedures. I would like to take this thought another step forward and propose my own scenario, Situation 4.
Waste that originates in the built environment that is from a hospital, along with other wastes from the main line of the sewage system, is backed up into the immediate environment, where the waste is widely dispersed and penetrates both the structure and its furnishings. In this case, the potential for infectious disease is greatly increased over the potential in Situation 3. If Situation 3 places occupants and workers at extensive risk, then Situation 4 would put workers and occupants at extreme risk of exposure to pathogenic wastes. Extra precaution in the last two cases is necessary as a result of the source of the sewage.
While there may be other situations that could also be addressed, it is important that anyone performing sewage-damage remediation consider the guidance provided in the S500. Because it is not always possible to determine the source of sewage, remediators are well advised to treat all sewage as if it were from a Situation 3 or 4. Worker and occupant safety should be of paramount concern.
I would like to point out that the suggestion in the original JEH article was that sewage-saturated carpets be cleaned. Since that time the standard of care, along with anecdotal and empirical evidence, suggests that it should not be cleaned but replaced. In the case of high-value area rugs, cleaning may take place, but its effectiveness should be verified by an indoor environmental professional.
As you can see, the way the building is used may have an impact on the level of concern about containment and exposure to workers and occupants. In this case, consider making adjustments in some of your procedures.