HEALTH AND SANITATION
33
Recommendations for the safe and efficient flushing of plumbing : Part 2
By
IAPMO staff writer
As businesses welcome the return of workers and visitors , stagnant water represents a risk that should be mitigated beforehand . This is the continuation of a two-part series and needs to be read in conjunction .
The flushing process : It is important to conduct the flushing process in the sequence detailed below . 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 .
1 . Start on the basement — or lowest — level of the building at the fixture closest to the incoming flow of water . This will flush the water service line ( s ), bring fresh utility water into the building , and completely flush the hot water system . Utility sink or floor sink faucets , such as those found in basements or janitor closets , typically have higher flow rates to facilitate the fast filling of buckets . This makes them ideal for beginning the flushing process . If a service sink or floor sink is not available , go to the sink closest to the incoming flow of water .
• Service sink , floor sink or sink closest to incoming flow of water : Remove the faucet aerator , if applicable . Open the sink faucet ’ s cold-water valve first to the highest flow rate possible without creating excessive splashing . Ensure that the sink drain can handle the flow of water without backing up and overflowing the sink . Using a digital thermometer to check water temperature , flush until the water temperature stabilises . Turn off the cold valve and repeat the above process with the hot water valve . Flush the hot water system until the temperature reaches the same temperature as the cold water . This may take considerably longer depending on the volume of water in the hot water system . Take care to avoid scalding . Clean and replace the faucet aerator .
• Check for residual chlorine : Using an approved digital chlorine testing kit , check for the presence of residual chlorine in the water from both the cold and hot water valves . If residual chlorine is not present , continue to flush until a chlorine residual that reflects the expected chlorine residual advised by the water utility is determined . If , after additional flushing , residual chlorine is still not present , contact the water utility to report the lack of residual chlorine in the building after extensive flushing . Inquire about the residual chlorine levels and how to remedy the problem . It is important to verify the presence of residual chlorine before proceeding .
2 . Continuing the lowest floor : Proceed to the bathroom , shower room , break room or other room containing water using fixtures on the lowest level that is farthest away from the incoming source of water .
• Toilets and urinals : Flush toilet and urinal supply lines first , if applicable . Start with the fixture that is farthest away from the incoming flow of water and work back towards the incoming flow of water . Consult a plumbing professional to determine the number of flushes required to remove the stagnant water from the water supply lines . This will be based on the plumbing system ’ s size and geometry and the flush volumes of the installed fixtures .
• Showers and faucets : After flushing the toilet and urinal lines in bathrooms , fresh water should be relatively close to the remaining fixtures in the cold-water lines . Using the appropriate tool , remove the aerator from faucets . Flush the cold-water lines first . Ensure that the sink drain can handle the flow of water without backing up and overflowing the sink . Using a digital thermometer to check water temperature , flush until the water temperature stabilises . Repeat the above process to flush the hot water line . Take care to avoid scalding .
• Test for residual chlorine : Using an approved chlorine testing device , check for the presence of residual chlorine at several bathroom locations . Be sure to test the location farthest away from the incoming flow of water .
GP Russ Chaney , IAPMO CEO
In the spirit of the sharing of unique experiences that shape the plumbing industries in our respective nations , the following article looks at the risk stagnant water poses to businesses as they reopen during the COVID-19 pandemic . Written by an IAPMO staff writer , it is the next in a regular series of similar articles that will run in Plumbing Africa .
November 2020 Volume 26 I Number 09 www . plumbingafrica . co . za