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On the 2nd November Guardian Water Treatment and its newly certified partner, Hevasure, brought together leading representatives from the water treatment sector to discuss the current BSRIA guidelines, how they’re used and the benefits of monitoring as a tool for preventing corrosion.
Chaired by Stuart McGillary, contributor to BG29 and BG50, the event kicked off with Steven Booth, Associate Director for Guardian Water Treatment, asking why problems with corrosion are still such an issue if the BSRIA guidance is being followed? Suart explained that while the BSRIA guidelines have been created with good intentions, how they’re interpreted is not always correct. They are not legislation and they are not a bible – every project is different and should therefore be treated differently, with the guidelines used to inform the method statement, not taken as the word of law.
Too often the guidelines are brought into legal cases and used as some kind of evidence. Stating ‘we follow the BSRIA guidelines’ is meaningless. The method statement is the more importance document.
How bad is bacteria?
Bacteria and its true effect on a water system was one of the main points raised. Steven Booth argued that Pseudomonas, for example, is focused on because it is easy to detect in a laboratory. But what damage does it actually cause?
Free flowing Pseudomonas is doing no real damage to pipework, it is only when it reaches the cecile stage, where it creates a biofilm on the pipe wall, that any real damage is done. As a biofilm it is very hard to detect as the problem is localised and therefore sampling won’t necessarily detect it.
You could argue that water with little or no bacteria in it is potentially an indicator of biofilm beginning to form. High numbers of freely moving bacteria are not necessarily an issue. In fact, pg.8 of BG29 contradicts itself about the actual danger of Pseudomonas. The BSRIA guidance itself says that Pseudomonas themselves may not be to blame for system contamination.
Where high numbers of bacteria in the Planktonic stage are found, shock dosing techniques are often employed, which can do more harm than good.
Steve Munn, MD for Hevasure, highlighted that most corrosion is caused by aeration rather than microbial issues. BG50 states that oxygen is a pre-cursor to bacteria, so if Dissolved Oxygen (DO) levels are kept in check, then bacteria shouldn’t get out of control.
Why then, asked Steven Booth, is oxygen so overlooked? All of the end users at the event stated DO was not tested for at their sites.
It is very difficult to get corrosion without oxygen, so ignoring this parameter is extremely short sighted. Air tightness and pressure must also be monitored as both can lead to oxygen ingress. Steven highlighted that the water treatment industry is largely ignoring these parameters.
Steve Munn also flagged up iron, which is not always detected in water sampling.
Overall, lab results in isolation are not enough. Steve Munn argued that, cynically, consultants and laboratories prefer to have out of specification results and leave areas of analyses open to interpretation rather than have definitive data that says if there are corrosion issues or not.
Sampling in general was called into question, with the group in agreement that samples can be manipulated and that they’re just representative of a moment in time. Stuart McGillary highlighted that over sampling is common, however trend analysis not so much.
Steven Booth identified that sampling must take into account the individual system, including what it is made of. For example, if a system is made from a higher proportion of copper than iron should the recommended limits be adapted?
Overall, within a closed circuit system, unless something has changed, reliance on excessive sampling is not necessary and a waste of money.
The cost of monitoring
While the room was unanimous in the benefits of real-time monitoring using the Hevasure system, the challenge seemed to be quantifying its cost. When you consider the value of instant results in preventing disaster, however; a particular concern for the data centre customers; the potentially catastrophic cost and reputation damage caused by preventable downtime surely mitigates the initial outlay of the monitoring system.
Let’s not forget that reputation damage has become more of an issue since the advent of twitter, with far reaching criticism easily distributed at the touch of a button.
Beyond preventing failure, by having a true picture of a water system and stopping corrosion, HVAC systems can run more efficiently, saving energy, reducing fuel bills and cutting carbon footprints.
As mentioned before, over sampling is current practice in the water treatment sector; by employing monitoring money can be saved by reducing sampling.
Other benefits, which also save money, include:
With monitoring so commonplace in other parts of a building, Steven Booth concluded by asking why there was so much resistance in the water treatment sector. It was felt that many in the sector were old fashioned and stuck in their ways. Monitoring also left people with nowhere to hide; passing the blame is harder when you can see exactly what the problem is.
Convincing people will come down to quantifying Return on Investment (ROI), the next step in Guardian and Hevasure’s plans, to be demonstrated using real-life examples soon…
For more information about the Hevasure monitoring system, click here.