Water Intrusion Category 3

Category 3 Water

Category 3 water is grossly contaminated and can contain pathogenic, toxigenic or other harmful agents.  (i.e., sewage; toilet backflows that originate from beyond the toilet trap regardless of visible content or color; all forms of flooding from seawater; rising water from rivers or streams; and water entering or affecting the indoor environment, such as wind-driven rain from hurricanes, tropical storms, or other weather-related events that can carry contaminants (e.g., silt, organic matter, pesticides, heavy metals, regulated materials, or toxic organic substances).



Most household microorganisms (fungi, bacteria) typically require five conditions for germination, growth, amplification and dissemination. Generally, they include:

• organic food source, especially cellulose (e.g., paper, wood), which are found in abundance in construction materials
• moisture, even high humidity (67% RH plus)
• moderate temperature – 68-86°F/20-30°C
• stagnant air
• time – several hours to several days

Water Disposal

Category 3 water extracted from water-damaged
structures must be disposed in a sanitary sewer
system, Of, if not available or inoperable, collected
and hauled off-site for proper disposal using a septic
waste hauler. The removal and disposal of
contaminated materials must folloJ accepted
mitigation, removal, transport and disposal protocols
to reduce the risk of contamination to previously
unaffected environments. Follow special handling
and disposal procedures, in compliance with local,
state, provincial and federal laws, for the disposal of
asbestos, lead and other hazardous materials.


a) Begin at the point of water entry and trace the path of wetting, removing ceiling and wall components and insulation as you go.
b) Although it may be possible for professionals with specialized equipment to dry carpet, pad and subflooring materials, when damage is wholesale in an area, seldom will qualified contractors be available to respond for this work. Therefore, it is normally prudent to remove saturated carpet and pad.
c) It is highly recommended that solid or laminated wood flooring, or sheet vinyl be removed to expose pockets of saturation.

Porous Materials

a) Remove and dispose of drywall (Sheetrock®), paneling or other wall materials up to a point 15-24″ inches above the water line visible on the wall. If possible, stay within four feet of the floor to salvage as much wall material as possible, since drywall is usually installed horizontally in 4’x8’ or 4’x12’ panels.
b) Remove and dispose of wet insulation materials exposed during wall removal. Look for evidence of moisture wicking up insulation materials. Leave only wall framing components that are durable and minimally porous, and which can be cleaned and decontaminated with relative ease.
c) Remove and dispose of floor coverings; carpet, cushion, pad, felt and sheet vinyl, laminate, or tile flooring materials. Porous materials may absorb considerable quantities of water and contaminant, and non-porous materials may trap moisture to prolong drying. The inevitable result will be rapid microorganism growth, along with associated odor and health hazards. Hardwood flooring should be removed since contaminants and moisture will collect underneath in the flutes or hollow areas between the hardwood and the subfloor.

3rd Party Testing

In some water loss situations, where microbial
contamination was remediated, it may be specified
or necessary for a third-party to evaluate the
effectiveness of the remediation work. This must be
considered under the following circumstances:
where there is microbial contamination that can
adversely affect worker or occupant health;
Institute of Inspection, Cleaning and .Restoration Certification Standard
where there are high-risk occupants in the
structure; and
where there are public health issues (e.g.,
elderly care or child care facilities, medical care
facilities, public buildings).