Hi Fellow Water Quality and Water Security Blog Followers,
This week’s new guest blogger is Oliver Grievson, Flow Compliance & Regulatory Efficiency Manager at Anglian Water Services and fearless leader and moderator of the Water Industry Process Automation and Control (WIPAC) group on Linked in.
A few months ago the Water Industry Process Automation & Control LinkedIn group discussed the subject of Why the Water Industry does not use Instrumentation to its full effectiveness. On the back of this a group paper was produced discussing the subject.
Over the next few months, on a fortnightly basis, this blog will investigate further the different reasons that the instruments that are used daily in our water and wastewater treatment works are not used to their full effectiveness.
The first thing to discuss is,
“What is the definition of an instrument in terms of the works that treat our water & wastewater?”
This can simply be defined as:
“A device that measures the performance or state of a part or whole of a treatment process”
This could literally be how a pump or blower is performing or how the process in its entirety is performing.
Let’s for example take the modern activated sludge plant as an example of the state of instrumentation within the industry at the current time. It is very typical to have a number of instruments including flow meters, pressure sensors, blanket detectors, and solids monitors. In complex wastewater treatment works they will control the movement of bellmouths, and monitor the levels of solids concentrations, control of the blower speeds based on the dissolved oxygen concentration and on occasion there will be some automated control of the solids wasted from the process.
However it is also very common for manual samples to taken, the automated control switched off and the dissolved oxygen concentration control system switched off.
There is also a step further that could be taken, the benefits of advanced process control has the ability to reduce the power consumption, keep the treatment works controlled so that effluent concentrations are controlled to a selectable level and minimise the chemical use (as required). Additionally more advanced control systems can be used for preventative maintenance and ensure the reliability of the mechanical elements of the treatment works. The question is, if there is so much potential, why is it not used?
This can be summarised in a few simple reasons, future blogs which will be investigated in turn:
(a) Instrument reliability – There is resistance to the use of instrumentation to its full effectiveness as instruments are perceived not to be reliable. In some cases this is true, insofar as an instrument can be badly installed or installed in the wrong place and the instrument reliability is compromised. In other cases it is because an instrument is poorly maintained
(b) The threat of instruments – The perceived threat that instrumentation and automation will be used to rationalise the workforce and not perceived as the tool for operators to be more effective and be able to operate rather than be limited to analysis samples for the majority of their working time
(c) Over-design of the automation system – The use of instrumentation so that the system is over-complicated and un-operable, the relationship between the engineer and the operator.
(d) Poor use of current data and poor data management – Instrumentation that is currently in place at treatment works normally feeds through to a SCADA system. This data is rarely used to its full effectiveness. The vast majority of data that the instruments produce is generally not used. The data that is used is not used effectively leading to “data richness but information poverty”
(e) A lack of understanding of what instrumentation can achieve – There is generally a poor knowledge over what instrumentation can achieve in order to deliver process control/advanced process control. A poor integration of the current instrumentation has led to the loss of the vast majority of data and information that instrumentation produces. This has led to poor efficiencies in current process control and the inability to take the step further to utilise instrumentation to its full effectiveness.
(f) Lack of trust in instrumentation – Instrumentation isn’t trusted from the operator level, to the corporate level or at the regulatory level. Instrumentation cannot be used for regulatory compliance.
All of these factors have led to the instrumentation that is used on a day to day basis at the water industries treatment works to be used inefficiently in terms of what it can and cannot achieve and the professional water and wastewater treatment operators left with only enough time to conduct manual sampling and barely enough time to actually operate the treatment works that they run.
Over the next few weeks each of these subject areas will be investigated and the blog series will investigate what can be done and how it can be realised.