By Oliver Grievson
As long as instrumentation is selected, installed, commissioned, and maintained properly the data that it can give is invaluable to the water industry. However, there are a number of barriers in the way for instrumentation to be used both widely and correctly in treatment, distribution, and collection systems.
Instrumentation is the fundamental basis of most of the advanced control techniques that exist in the modern industry. It is through the further proliferation of instrumentation that the industry as a whole will address the current challenges that it faces and move forward into the future.
This article will discuss some of the challenges that the current water industry faces on a global basis and some the benefits that we will see if these challenges are addressed.
Barriers To Instrumentation
There are several barriers — technological, financial, historical, and cultural—that prevent the widespread proliferation of instrumentation throughout the water industry.
Technological barriers to instrumentation include the availability of the right instruments to the water companies and the uncertainty on the suppliers’ side as to what exactly is wanted.
The water industry has many choices of instruments that are currently available. There are however, noticeable gaps in the measurement technologies that are available including the measurement of flow within the sewer network and the measurement of organic load into wastewater treatment works. However, if there is not a direct way of measuring a particular part of the network or treatment process there is usually an indirect method. An example of this is the use of turbidity or Total Organic Carbon (TOC) to infer the biological oxygen demand.
The financial barriers to the proliferation of instrumentation come from a number of different areas. The price of instrumentation is one of these areas. There needs to be a fair balance between the cost that the suppliers need to charge to make a profit and how much the water companies can afford. For example, ultrasonic flow meters have recently crashed in price from around $1,800 to just over a $1,000 for a better functionality. Is a decent profit margin possible in order to develop the instrumentation further? On the opposite end of the spectrum there are instruments that are over $50,000 that measure multiple parameters and have significant benefits, but are expensive. When there is an expensive instrument that has significant benefits a robust business case is needed. This is especially the case when instruments become part of a much wider automation system.
The historical and cultural barriers to instrumentation are a result of its use in the past. Historically, there has been a tendency of fault with instrumentation. Part of this fault has been technological and part of it has been a result of installing instruments in the wrong application. All of this has led to unreliability in the instrumentation that has been installed and the results of the instruments not being believable. This in turn has led to instruments being abandoned as “not working,” which creates an ever decreasing circle where instrumentation is not adopted and a culture of “we tried that in the past, and it didn’t work.”
There is also the perceived threat of instrumentation to people’s jobs and that an instrument will be used to replace a person. This is something that companies need to resist. The benefits of an instrument is that it will measure and record 24 hours a day, 365 days a year. It will give a large amount of data on how a system (be it network or treatment) and on how the processes are performing. It allows the operator to actually operate rather than take manual samples. However, instrumentation does need cleaning and it does need maintaining. The nature of the operator’s daily routines change, but certainly are not eliminated.
The Dangers Of Data
So, if an instrument is correctly installed, in the right application, and properly maintained what can it do?
Put simply, an instrument will collect a lot of data and the data has a lot of use. The water industry is used to collecting data. It is estimated in the UK that approximately 300 million pieces of data are collected every day by the water industry. With a number of water companies moving towards smart metering, this is set to increase tenfold to approximately 3 billion just for the operational assets of the water industry.
There is a great danger in being overwhelmed in all of this data. There are two areas where this data can bring value to the water companies. The first is in “Big Data”—taking all of the data and looking at patterns and “mining” the daily data to produce information that is usable for the water companies. The second is in “Small Information,”—distilling the data to a point that it is usable for the operator (or other stakeholder) who operates the treatment works on a day to day basis. A large well monitored treatment works can distil the data that it normally collects usually by a factor of at least 100 if not closer to a 1,000 times.
Examples of the use of instrumentation in the potable water network include all the “smart” water solutions. This technology uses the monitoring on the network that the water company normally has at strategic points and detects where the best points for main replacement are and applies mathematical algorithms. The success of this includes sites in Lisbon where non-revenue water loss was reduced from 25 percent to 7 percent in three years. There are other methods, as a case study from Australia saw a 75 percent reduction in 15 years by applying instrumentation and manual techniques. The fundamental basis of the success was using the data that was collected to allow the operator to make an informed decision.
On the wastewater side of the industry are the various advanced process control techniques that have been used on the treatment works. Some using multivariate process control and some using control system based upon the instrumentation. This typically saves 20 percent on aeration costs and on the sludge side some of the better returns on investment figures have been in the region of six months.
The key value of instrumentation in the water industry is in the enablement of the operator. It is important to give operators in the field just enough information that operational decisions can be made simply, or where an advanced automation system is in place, the operator can check on the correct operation of the system. In the control center the data and information can be used to make decisions for short term operational actions (where to send an asset) or medium to long term strategic decisions.
The modern water industry faces a huge pressure to deliver more for less due to population growth, climate change, and increasing quality demands of the natural environment versus the pressures to reduce carbon emissions for a less costly service. One of the routes to deliver these efficiencies is the greater proliferation of instrumentation. This will give water companies a better view on how their day to day operations are performing.