Identifying and dealing with Grey/Black water contamination from flooding Flooding inside of houses/buildings can occur due to rainwater leaks, groundwater intrusion, plumbing pipe bursts, sewage system back- ups, overflow of rising rivers and lakes, and ocean water due to storms or hurricanes. Some General Safety Considerations - Wash cooking, eating, and any other kitchen utensils that have been covered by floodwater in hot soapy water. Rinse thoroughly in safe water, then disinfect by immersing for 1 minute in a solution of 500 ml (about 2 cups) of plain, unperfumed household bleach in 10 litres of water. Rinse again in safe water. Alternatively, boil all utensils for 1 minute and let cool. - Discard wooden spoons and baby bottle teats and dummies if they have been covered by floodwater. There is no way to safely clean them. - A garden hose is useful for washing down. Do not use high-pressure hoses as they blast contaminated matter into the air. - Flood water can make the air in your home unhealthy. This is because when things get wet for more than 2 days they usually get mouldy. There may also be germs and bugs in your home after a flood. Mould may be more likely to make some people with asthma, allergies, or other breathing problems sick. Talk to your doctor if you have questions about cleaning or working in a home that has been flooded. - When cleaning protect yourself by wearing a certified respirator or mask, goggles, gloves, long pants, long-sleeved shirt, and boots or work shoes. - Avoid entering any building (home, business, or other) before local officials have said it is safe to do so. Buildings may have hidden damage that makes them unsafe. - Look for electrical system damage - if you see sparks or broken or frayed wires, turn off the electricity at the main fuse box or circuit breaker. If you have to step in water to get to the fuse box or circuit breaker, call an electrician for advice. - Look before You Step: after a flood, the ground and floors are covered with debris including broken bottles and nails. Floors and stairs that have been covered with mud can be very slippery. Wear long pants, a long-sleeved shirt, and sturdy shoes. The most common injury following a disaster is cut feet. - Keep children and pets out of the contaminated area Categories of Water Entering a Structure In considering what kind of remediation is required, evaluate the type of water that entered the building. Water causing a flooding situation is divided into three categories that require different remediation (clean-up) measures. These categories are clean, grey and black water. Clean water originates from a source that does not contain significant microbial content and does not pose substantial harm to humans. Examples are rainwater or melting snow from openings in the roof with no contamination, broken water supply lines, or tub or sink overflows with no contaminants. 1. Grey water contains a significant level of contamination and has the potential to cause discomfort or sickness if consumed by or exposed to humans. Grey water carries 2. microorganisms and nutrients for microorganisms. Examples may include sump pump failures, seepage due to hydrostatic pressure or floodwater, broken aquariums, or overflows from washing machines and dishwashers. Black water contains pathogenic agents and is grossly unsanitary. Black water contains sewage and other contaminated water sources entering or afflicting the indoor environment. Such water sources carry silt and organic matter into structures and create black water conditions. Toilet backflows that originate from beyond the toilet trap and contaminated floodwaters are often considered black water contamination, regardless of the physical content or color of the water. 3. Procedures for Grey or Black Water Remediation from Flooding Grey water or black water from flooding may contain pathogenic agents, including human or animal waste. This water may also be contaminated with chemicals such as pesticides, heavy metals, gasoline or other petroleum products. Where grey or black water intrusions have occurred in buildings, additional measures are needed to protect against pathogens. All floodwater from lakes, rivers or other bodies of water are considered black water, and should be treated as follows: Handle Black Water Flooding as though it Contains Infectious Organisms Those who perform remediation work after floods should wear impermeable, rubber gloves and a suitable respirator (at least an N-95 disposable dust mask) to avoid breathing spores and other contaminated particulate, and protective eyewear while handling contaminated material. They should wash their hands with soap and water after handling contaminated material and before eating, smoking, drinking or performing other hand to mouth actions. Handling Injuries Most cases of sickness associated with flood conditions are brought about by ingesting contaminated food or water. Tetanus, however, can be acquired from contaminated soil or water entering broken areas of the skin, such as cuts, abrasions or puncture wounds. If a cleanup worker experiences any of the signs or symptoms associated with tetanus, appropriate first-aid treatment and medical advice should be sought. If the skin is broken, particularly with a puncture wound or a wound in contact with potentially contaminated material, a tetanus vaccination may be needed if it has been five years or more since the individual’s last tetanus shot. If in any doubt, medical advice should be sought from a professional.