Come hell or high water

Wireless telemetry is used in the water and sewerage industry to automate processes and for remote monitoring. Kate O'Flaherty reports

Come hell or high water

Water and sewerage has come a long way since privatisation, with automation becoming standard in an industry driven by tightening budgets.

These cost savings are accelerating the move to automation, making wireless telemetry essential for the remote asset monitoring, alarms and control applications used by today’s water industry. 

Water firms use a wide range of communication services, from both private and third party providers. These range from PSTN, mobile radio systems such as GSM and GPRS, regulated UHF scanning systems and unregulated low power radios to wide area networks, broadband, satellite and microwave links.

‘The water and sewage industries are large scale process networks,’ says John Wyatt, head of information security at United Utilities. ‘We use fairly standard off the shelf products for controlling the process control systems, which have a long and mature life cycle. Monitor and management can be a little more bespoke, but we try to keep as close to off the shelf as we can to improve scalability and reduce costs.’

Radio links are used for simple level or on/off data information, says Roy Howard, a contract engineer at water firms including Anglian Water, Southern Water and Scottish Water. He adds: ‘We have private wire systems in use between sites that have phone lines. Telemetry is now used over secure broadband connections, and some remote sites use satellite links.’

Telemetry applications

There are five main applications for water, according to Grant Notman, head of sales and marketing at Wood & Douglas: waste water through waste water plants; boreholes in the ground; reservoirs; and river monitoring, split into flood defences and environmental. 

Notman says: ‘It’s all about keeping maintenance costs at the lowest point. It used to be a man that automated it, but this way it keeps the system away from people and frees up their time.’

As more demand is placed on the water industry, telemetry systems are increasingly extended to provide data collection and remote interventions. Wyatt says: ‘The UK water industry as a whole has many challenges to meet. The companies must ensure they can guarantee secure, clean drinking water to the UK population while meeting strict regulatory competition laws, environmental restrictionsand climate changes amongst other things.’

‘Increasingly we are seeing investment in field devices, SCADA, remote telemetry units, communication systems, master telemetry systems, and IT systems for performance reporting,’ adds Ian Gray, Regional Director at systems integrator Grontmij’s Asset Management and Systems Team.

Monitoring and control allows companies to cut costs as well as remain secure. Dave Oakes, sales director at Powelectrics, says: ‘Telemetry gets used for both remote monitoring and control. The water companies have a large number of remote assets such as treatment works, pumping stations and reservoirs.’ 

Security issues

Meanwhile, river monitoring extends to water pollution as well as more basic measurements such as height. Notman says: ‘Lots of people are concerned about what’s in our rivers and people are monitoring pollution. You can sample water and put it in a pump; now we have a Sim card which goes back to the data centre and turns the information into meaningful facts such as the height of the water or lead content.’

The information is sent in via hex, digital and many other ways, says Howard. ‘We are led by whatever equipment we buy and what interfaces are fitted to them. I have seen almost everything apart from Bluetooth. We even use IR systems for comms when setting up some valves.’

Security is a major issue, and the water firms have tight measures in place to ensure systems are not compromised. Wyatt says: ‘Appropriate security controls are applied when the exposure, criticality and sensitivity are taken into account. The controls can vary from lightweight encapsulation to military grade encryption.’

‘We have a massive issue with being secure at the moment,’ Howard adds. ‘All systems need to be direct with little or no chance of hacking, and very little feedback from the control room to site to help keep supplies secure.’

Trigger alarms and water protection systems and remote pollution monitoring systems are used, with some companies using tremble alarms on large supply site covers and doors. With armed response on some, security measures are all-encompassing.

‘People are worried that someone will attack the reservoirs,’ Howard says, adding: ‘We have a system to secure the reservoirs and on top of that we have an alarm system. We also have alarms to measure different levels of chlorine gas as it is very dangerous.’

Sewerage control

Applications are also used in sewerage to prevent sewage infiltrating clean water supplies. Compass controlled sensors on the filtration tanks send a signal every time the sewerage flow passes North on the compass and if an arm of the filtration tank gets stuck. This is replicated on sludge tanks and other critical machines, with an alarm alerting control if something is
not working. 

Another application allows leak detection in pipes. Water flowing in a pipe makes a sound which radios can pick up and then send information to the control centre, explains Notman. If there is a crack or a leak, the water harmonic changes and a leak detection alarm is sent so engineers know where it is to an accuracy of around 0.5 metres. 

‘Two-thirds of companies we supply put radios on either side of the leak and they know where to dig the hole. It’s a standard leak protection tool,’ Notman says.

Satellite technology is another option to supply the connectivity needed for telemtry in utilities. ‘Satellite technology is used occasionally,’ says Wyatt at United Utilities. ‘It’s expensive, has some security issues and is not suitable for always on or high bandwidth situations. It is traditionally a last option alternative for very specific types of traffic.’

But as budgets tighten there is often a reluctance to update, so adoption of new technologies is sometimes a lengthy process. ‘We have to budget for five years ahead and if we haven’t budgeted for it, we can’t use the technology,’ explains Wyatt.

Some of the water firms are looking at how new 4G mobile networks could benefit them, but it could be some time before the use case is realised. Until then, water companies continue to focus on automation and keeping their networks as secure as possible.

‘The UK water companies are set in their ways and while they think they are driving forward with new technology, they aren’t when it comes to telemetry,’ says Oakes.

Written by Wireless magazine
Wireless magazine

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