Further considerations on water quality in light of Lockdown 2:0
WCS Group continue to operate in a safe and controlled manner during the current pandemic as identified "key workers", keeping water, air and asbestos safe and controlled, and ensuring buildings and properties are able to prove statutory compliance is being maintained during this time.
As a follow up to our previous posts, we are considering the effects of "Lockdown 2:0" and providing further guidance and considerations as a result of data and information gathered over the last few months.
"Lockdown 2:0" differs significantly from the initial lockdown earlier in the year in that, currently, it is for a defined and comparatively short period of time. This poses different questions to those in charge of a building; do we shut down and mothball; or do we continue as we were before; or do we adopt a hybrid approach?
Certainly, in many cases there will be reduced building occupancy which may require additional tasks to be undertaken to protect the water quality in buildings, such as increased flushing. Over the last 6 months we have been gathering significant amounts of data in this regard and we have seen a greater than 50% rise in general bacteria levels (TVC) and potentially more concerning, a 20% increase in positive Legionella samples being returned from independent, UKAS Accredited laboratory testing on a like for like basis.
We hypothesise that this may be due to a lack of flushing in some cases, but also poses the question of "how long do we have to flush to mimic "normal" building use"?
Of course, every building and water system is different but we would strongly advise that during "Lockdown 2:0", if water systems are live the question is posed in regards to flushing - "does our flushing regime mimic the "normal" use of our building? If not, we would recommend considerations such as:
- Increasing flushing to mimic the normal building use, ensuring all outlets are flushed and flushing from various points in the system at the same time to achieve water velocities in the feed pipework.
- Draining linked tanks (if possible) in a safe manner to reduced stored water.
- Fitting of variable height ball valves in tanks to facilitate water throughput during times of changing occupation.
- Changing pipework configurations if building usage is going to be changed substantially or for the longer term.
- Considering a form of secondary disinfection to maximise flushing efficacy.
- Checking to verify that the sampling regime is being effective with sampling, remembering that it may be a few days to receive some results and sampling should be done in good time before any reoccupation and any control measures such as flushing should continue whilst the results are awaited and until the building is re-occupied.
We have also seen good practice in encouraging social distancing having an impact on water quality. We have noted sinks and outlets being put out of use to promote good distance between people when washing hands or using facilities such as wash down stations.
Unfortunately, in many cases we have observed that those outlets have been left out of use for some time, with no flushing or rotation of the out of use outlets and also concerningly, without recording the rotation or flushing regimes. This may also be a contributing factor to the marked increase in the sample failure rate.
Of course, as building occupancy is lower, this may extend to larger pieces of core plant, such as calorifiers, cooling towers and hot water generators where the potential risk is much greater.
If you are unsure about the water quality in your building, please do not hesitate to contact your WCS Group account manager or contact us at firstname.lastname@example.org
Topics: Water Treatment & Hygiene
Written by Jon Greaves
Jon has progressively worked through operational roles, account management, technical management, and senior management roles over the last 16 years within one of the group companies before moving into the role of Water and Air Managing Director. Jon has experience across multiple sectors of water and air compliance, including district energy networks; data centres; healthcare; food and beverage and facilities management. Jon acted as a corresponding steering committee member on CIBSE CP1 – Heat Networks Code of Practice for the UK released in 2020.