To improve safety, airlines created a suite of simple check and response lists for the flight crew to follow. While studying mortality in the healthcare sector, they stole that idea, and introduced a check and response list in the operating theatres in eight major hospitals. Yes, the staff hated it, but the result, reducing post surgery mortality by 40%, was an amazing outcome.
The construction sector should learn that lesson, adding a check and response list for site safety issues, will undoubtedly save lives.
In the good old days the topic was called Public Health, nowadays its called Plumbing and Drainage. It is essential for all buildings to have properly designed, installed and maintained sewerage systems to prevent infecting occupants, whether it is 2003 SARS, 2020 COVID19, or Influenza.
Recently, when COVID19 infection was discovered spreading within Hong Mei House, Tsing Yi on 10 and 11 February 2020, the RTHK report stated that the HK Government instantly reported it was not a “U trap” problem [RTHK link] a reference to the SARS outbreak in 2003 where the disease spread through the drainage system in block E Amoy Gardens infecting occupants, and requiring evacuation of the block.
youtube is unreliable at the moment, here is the link https://www.youtube.com/watch?v=GTNvTuV_CM4
I predicted the cause would be the sewer vent pipe, vent pipes are part of the high rise drainage system designed to prevent loss of the water seal in U traps. Subsequently, my suspicion was confirmed, the SMCP newspaper confirmed that the vent piping inside the bathroom was damaged (see SCMP photo below). Therefore, droplets could contaminate the bathroom area.
Still problems in 2020
The photo below taken 15 March 2020 shows damaged drainage system vent piping.
That drainage system is damaged, it is no longer an enclosed system, allowing odour, bacteria, virus to escape into the air.
We have always known that sewerage and drainage systems are important, providing a conduit for bacteria and viruses, yet the severe lessons from SARS in 2003 and now from COVID19, demonstrate lessons still have not been learned!
A resident on the top floor (34th floor) of Heng Tai House, Fu Heng Estate, Tai Po has been diagnosed with the novel coronavirus COVID19 today (14-3-2020) RTHK reports [link] and he lives two floors above a couple already diagnosed on 11 March 2020 (same flat number ending with 13).
This is eerily similar to the incident in Tsing Yi in Feb. 2020, where I predicted drainage vent pipes issues, the pipe was subsequently discovered to be damaged, and additionally, repairs were carried out in nine (9) flats while those residents were evacuated.
This time, residents in Heng Tai House living in flat numbers ending with 13 and 14 , and living six floors below the “latest case” on 34th floor (top floor) will be evacuated RTHK reports [link].
Why this evacuation is limited to only six floors seems strange, citing droplets from the roof vent (which one?) reentering the building as the reason. While it is not impossible, the airflow pressure and patterns created around buildings are very complex, it seems highly unlikely, that only flats 13 and 14 would be impacted in this style of public housing.
It is worthwhile remembering that in the workplace, employers are responsible, by law, for the Health and Safety of their employees! Therefore workers in high traffic areas, for example, healthcare, building management, sewerage plants, transportation, etc. are responsible for their employees Health and Safety (H&S).
14 March 2020 – Another similar incident is reported at Heng Tai House, Fu Heng Estate, Tai Po [link]
RTHK reports [link] some apartments in Hong Mei House, a residential tower block located in Tsing Yi, Hong Kong have been evacuated overnight after another person was diagnosed with the novel coronavirus (covid19) living in the same building, 10 stories directly below a person already diagnosed with the infection.
And fearing a repeat of the SARS in Amoy Gardens Block E, the HKSAR Government swiftly reported that the drainage U traps are in “good condition”.
Notwithstanding, the condition of the U trap, not every building (see photo below) has U trap fitted.
In addition, we must also consider faulty vent pipes (refer to our photo below). Vent pipes are connected in parallel to the main sewer system, well they should be, therefore any broken, damaged or disconnected piping provides an equally risky conduit for droplets and pathogens to spread into homes.
As shown in this video clip below, if the bathroom is negatively pressurised, pathogens can be dragged into the bathroom contaminating surfaces, risky infection of the occupants.