In performing sewage cleanup work, the greatest risk is that of ingestion, which a full face respirator helps prevent. Attempts to salvage sewage contaminated semi-porous and highly porous materials such as wall to wall carpet can create a health risk by releasing infectious agents.
Carpet and cushions contaminated with Category 3 water should be removed and disposed of properly. Unless local regulations specify otherwise, recovered sewage and rinse water should be discharged into the sanitary sewer system or municipal waste water treatment facility.
Categories of Water Damage
Based on the source of the water, the length of time the Water has been allowed to dwell in the structure, the temperature, and pre-existing conditions, it is possible to assess the category and employ appropriate means of restoration. Restorers will diligently investigate structures for indications of contamination, assigning a category only after a thorough investigation.
There are three categories of water damage:
Category 1: Clean Water Source
Category 2: Moderately Unsanitary Source
Category 3: Grossly Unsanitary Source
Category 1 Water Damage
Water from a clean source with no substantial risk of causing sickness or discomfort is said to be Category 1 water, or “clean”. In order for a situation to remain category 1, water must not have been present for an excessive amount of time, and materials affected must be clean and well maintained. If odors are present in the structure, further investigation is necessary until the source of the odor is found. Odors indicate that the water is not Category 1.
Examples of Category 1 water include broken water supply lines, tub or sink overflows with no contaminants, shower pipe bursts, and appliance malfunctions involving water supply lines.
Category 2 Water Damage
Water that has a significant degree of chemical, biological and/or physical contamination is said to be Category 2. Water sources that can result in Category 2 damage include aquarium leaks, waterbed leaks, toilet bowl overflows (that contain urine), dishwasher or clothes washer discharges, and water that enters the structure from hydrostatic pressure (from below grade). In order to remain Category 2, water must not be allowed to dwell in the structure for an extended period of time.
When structures are affected by Category 2 water, special steps and procedures are necessary in order to return the structure to a pre-loss condition. Cleaning procedures must be employed before the drying process can continue. At a minimum, affected carpet underlay must be removed and disposed of, and carpet must be thoroughly cleaned using a hot water extraction method.
Restorers then employ appropriate anti-microbials to mitigate growth of microorganisms, especially when there are porous materials that are to be cleaned and restored. As with any water intrusion, once the affected materials have been completely cleaned, thorough and rapid drying is necessary to prevent further damage.
Category 3 Water Damage
When water intrusion results from a grossly unsanitary source or carries pathogenic (disease causing) agents, it is said to be Category 3. Examples of Category 3 water sources include discharge from toilets that originate from the sewer or septic system, and intrusion from the surface of ground water into the structure (flood waters). Many procedures are necessary to address cleanliness and safety when dealing with Category 3 water intrusions.
Very few exceptions exist to these rules when dealing with Category 3 water. If attempting to restore any highly porous item affected, such as a valuable oriental rug, restorers must thoroughly clean the item, properly apply an anti-microbial; perform intensive cleaning; dry; and employ third party testing. Additionally, restorers must apply an appropriate biocide during and after the demolition process to help control microorganisms and increase cleaning effectiveness.
The objective of Category 3 restoration is to remove the contaminants, while taking steps to not spread contamination either physically or through aerosolizing of particles. Contamination is removed as much as possible through the cleaning process.
Flood Water Contamination
Flooding occurs when rising water overflows the natural boundaries of bodies of water, such as rivers and streams, and flows across the ground picking up all kinds of contamination. The water can be contaminated with soil bacteria, decaying insects, animal droppings, oils and fluids from roadways, and fertilizers and pesticides from fields or gardens.
In locations where water has been used to extinguish fire, the water will migrate through the structure and wet building materials. During this process, the water becomes contaminated with innumerable materials.
Excess standing water should be extracted thoroughly. Some buildings are so full of water that special pumps are required to remove the standing water. Where possible, wet surfaces should be treated with a broad spectrum, government-registered disinfectant to control the growth of microorganisms.