Plumbing Africa October 2020 | Page 39

HEALTH AND SANITATION 37 • The following equipment will be needed: ○ A high-quality digital chlorine meter/ test kit ○ A digital thermometer for measuring water temperature ○ Anti-vandal tools for removing aerators and supply stop covers (check with the appropriate manufacturers) • Important – Sewer gases, floor drains and traps: If an overwhelming smell of sewer gas is detected in the building or when entering bathrooms that have been unused for long periods of time, it is likely that floor traps or fixture traps have run dry. It may be possible, while very rare and only in extreme instances, that turning on exhaust fans under such conditions could cause an explosion. Play it safe! If high concentrations of sewer gases are suspected in the building, evacuate the building and contact the local fire department to assess the condition. • Ensuring that there are no dry traps in the plumbing system is a critically important first step. Building sanitary systems harbour many waterborne microorganisms, and dry traps and floor drains can provide a pathway for those pathogens to enter the building. Go through the building and slowly pour clean water into floor drains and sinks to make sure that traps are fully restored. Remember, sanitary systems have been implicated in the spread of the coronavirus, so any dry trap provides a potential pathway for exposure to the virus and other harmful microorganisms. • Know which products are installed in the building: It will be important to know which specific plumbing products, fixtures and fittings are installed in the building prior to beginning. Look for markings on plumbing fixtures and fittings that detail manufacturer and the flush volumes per flush on toilets and urinals, and the flow rate. (Flush volumes are typically shown in close proximity to the manufacturer’s logo, and faucet flow rates are typically found embossed on faucet aerators.) Contact the manufacturer of those products to seek guidance regarding their specific flushing recommendations. Always follow manufacturer instructions. Be careful not to overlook features such as break rooms, kitchen sinks, coffee makers, ice machines, carbonated drink dispensers, dishwashers, executive bathrooms, hair washing stations and church baptistries. • Exhaust fans and water heating systems: After verifying that all floor drains and fixture traps have been restored, go through the building and turn on available exhaust fans in rooms that have plumbing fixtures and fixture fittings (toilets, urinals, showers, faucets). Turn all water heaters and boilers off and allow the water to start to cool. If the building has a hot water circulation system, allow it to continue to circulate water. • Potential for sanitary system blockages: It is possible that solid waste in the sanitary building drain has dried out and solidified. This can result in blockages during the flushing process or after the building reopens. Never leave a room unattended while the flushing process is ongoing. • Tips for reducing splashing and reducing aerosols: When flushing toilets, always close the toilet seat lid. If the toilet does not have a seat lid, utilise a non-porous, rigid, flat device such as a piece of rigid plastic that covers the toilet bowl. This will help reduce aerosols resulting from flushing the toilet. A plastic trash can lid may work well for this purpose. Do not attempt to make the cover airtight, as some air will be required to get into the toilet bowl to allow the toilet to flush. Clean the flat device with a disinfecting cleaner after each use. • When flushing urinals, consider covering the urinal with a plastic trash bag to trap aerosols if numerous, repetitive flush activations are required. For sinks and showers, consider using a plastic trash bag with a hole cut out at the centre of the bottom of the bag just large enough to slip over the showerhead or the faucet outlet and tape it in place. Make sure that the trash bag cannot block the fixture drain outlet. • Flushing times and cycles: Consult a plumbing professional to determine the number of flushes and flush times required to remove the stagnant water from the water supply lines. This will be based on plumbing system size and geometry, and the flush volumes and flow rates of the installed fixtures and fixture fittings (faucets and showerheads). • The flushing process: It is important to conduct the flushing process in the sequence detailed herein. This will result in discharging contaminated hot water without running it through the entire plumbing system to the greatest extent possible, and then getting fresh water to distal sections of the plumbing system safely and efficiently. IAPMO would like to thank the following experts for their input to these recommendations: Dr Andrew J. Whelton, Purdue University; Dr Catlin R. Proctor, Purdue University; Dr William J. Rhoads, Virginia Tech University, Dr Janet Stout, Special Pathogens Laboratory. PA October 2020 Volume 26 I Number 08 www.plumbingafrica.co.za