Sewage Clean-up
Sewage contamination is one of the most potentially dangerous water damage that we deal with. Black water contamination should be treated with caution. Call us for an on-site consultation.
BLACK WATER
Category 3 water is referred to as “black water”. It contains pathogenic agents and is grossly unsanitary. Black water includes sewage and other contaminated water sources entering or affecting the indoor envinronment. Water that originates from beyond a drainage trap is considered black water, regardless of the visible content, color or odor.
Mitigation of black water contamination is different from other types of flood and water damage restoration. It requires specific cleaning procedures by trained personnel. Surface sampling and clearance testing is critical to insure successful decontamination of the impacted materials.
MAIN LINE BACKFLOW
A main line backflow is defined as raw sewage from a municipal sanitary sewer system backing up into your home. This is typically one of the most dangerous situations you can face in terms of water damage. The reason for this is that residential, commercial and industrial users of that municipal sewer can legally dump some pretty nasty contaminants, not to mention what they dump illegally.
Great caution should be exercised when dealing with a mainline backflow. The very young (
<2 years old), the elderly and individuals with compromised immune systems are epecially susceptible to adverse health effects caused by black water exposure.
DRAIN OVERFLOW
A drain overflow differs from a Main Line Backflow in that it results from a restriction in the sewer line between the house (structure) and the main line sewer. This restriction results in waste water being discharged from the property backing up or “overflowing” a floor drain, shower drain, toilet or even a sink. Although still a serious condition, less risky than a Main Line Backflow.
SEWAGE BACKFLOWS
The single most long-term destructive substance indoors is water. It dissolves or weakens many materials, supports the growth of microorganisms on others, and can carry with it a wide variety of harmful pathogens and allergens. Immediate response to a water emergency not only saves time and money but protects property and health.
Quick response is even more critical when flood waters contain animal or human body fluids or wastes (e.g., raw sewage) or other organic contaminant’s, because sewage poses a significant threat to human health. How severe the threat depends on the content of the sewage and the degree and extent of penetration into the building environment. The degree of penetration is a factor of the porosity of contaminated materials, the quantity of sewage, and the amount of time the sewage remains in contact with materials.
The most severe form of sewage contamination: Waste originating in the built environment combines with other wastes from the main line of the sewage system and backs up into the immediate environment. The waste is widely dispersed and penetrates the structure and its furnishings. If flooding is from this kind of primary outside sewage system, evacuate occupants, and begin restoration immediately. Cleaning and restoration professionals should be protected by using respirators with high-efficiency particulate air (HEPA) cartridges, rubber boots, gloves, splash goggles, and protective garments. They must use extreme caution to avoid puncture wounds during the restoration process, and restoration staff who have cuts or open sores should not be allowed to work on the project.
Issues of Concern Associated with the Problem
Several Factors bear on the remediation of the problem: the nature of the contamination, the types of water-damaged materials (organic or synthetic, porous, semiporous, or nonporous)., the sewage microflora (pathogens and allergens), organic matter load, water volume, and the impact of ambient outdoor temperature and humidity on the indoor environment.
Of major concern are the survival of sewage-borne microflora (viral, bacterial, fungal, parasitic) and their potential transmission to humans. Some fungal and bacterial contaminants can establish and ecological niche and present a health risk from chronic exposure for some time after the event. You must assume that potential pathogens (including bacteria, fungi, viruses and parasites) are present in the contamination.
Health-Based Recommendations for Restoration
Begin remediation as soon as possible. The longer the contamination persists, the greater the potential for microbial growth and resultant damage.
Evacuate unprotected occupants and workers from the affected areas until sewage has been removed and disinfectants applied.
Equip technicians in the vicinity of the sewage during the initial stages of decontamination, cleaning and disinfection with organic vapor HEPA respirator, rubber gloves, splash goggles and boots. In the case of overhead contamination, also equip them with goggles, hard hats and protective suits. Make sure technicians report any wounds that occur during restoration and take care to avoid cross-contamination from affected to unaffected areas by foot traffic or material handling.
After water removal, decontaminate all affected materials by spraying with a disinfectant solution to initiate the reduction and containment of microorganisms. Evaluate all affected materials for porosity (permeance) and rate them as highly porous (saturated), semiporous, and nonporous. Some materials may exhibit varying degrees of porosity, depending on the exposed surfaces. For example, the surface of painted drywall has very low porosity, yet the base of the wall may be unpainted or have exposed gypsum or paper that is highly porous.
Remove highly porous (Permeance factor > 10) materials that have been exposed to sewage backflow and have a value that exceeds the cost of restoration (such as high-value rugs and carpet, upholstery, and other textiles), and restore them offsite. As soon as possible, remove and discard highly porous materials with low cost or replacement value, such as carpet cushion, carpet, cardboard, tackless strip, wicker and straw. Other materials, such as saturated mattresses and cloth upholstery, regardless of value, cannot be restored and should be discarded. Bag all materials you’re disposing of in plastic for removal to a proper disposal site.
Clean, disinfect, or replace semiporous (permeance factor of > 1 to 10) materials including items such as linoleum vinyl, all covering and upholstery, and hardboard furniture, along with construction materials such as wood, painted drywall and plaster as part of the initial restoration process.
Use a nonpenetration moisture meter to inspect nonporous materials (Permeance factor < 1) such as Formica, linoleum, vinyl and tile-finishing materials for subsurface contamination. Although these materials may be rated as nonporous, evaluate them carefully because contamination can migrate from the perimeter and become trapped below the surface. If migration of contamination below the surface has not occurred, these materials may be fully restored. Heavy orgainic matter, especially raw sewage and silt, must be physically removed by any safe means available (e.g., shovels, squeegees, septic pump trucks, wet vacuums and moisture extraction machines). Extract water from floor-covering fabrics such as carpets and rugs. Clean and disinfect all tools and machines, especially recovery tanks, wands and hoses after use.
Remove residual organic matter in cracks and crevices by pressure washing with a disinfectant solution. You must recover the solution with an extraction unit, immediately after application, to prevent further migration or saturation of contaminants into other porous materials.
After removing heavy organics, thoroughly clean affected materials, then apply a second application of disinfectants.
Chemicals classified as disinfectants are appropriate for use in areas exposed to sewage backlfow. These chemicals are defined as being capable of inactivating potential pathogenic microorganisms on inert substrates.
Fully evaluate all factors that affect the success of decontamination. These include the organic matter present, extent of pror cleaning, type and level of microbial contamination, concentration and time of exposure to the disinfectant, and the nature of the material to be decontaminated.
Implement procedure to increase the rate of drying. Reduce dampness and humidity as much as possible by using the existing ACS or HVAC system, auxiliary fans, carpet dryers and dehumidifiers. The indoor humidity in affected areas should be reduced to 40% RH as quickly as possible. Monitor the humidity with a hygrometer or a psychrometer.
Use moisture measurements, rather than surface or air sampling, to monitor the environment for the presence of viable microorganisms.