Digital water monitoring provides College leak relief

Scotland’s Rural College (SRUC) Oatridge Campus in West Lothian is set within land covering 2.8 square kilometres. The campus houses livestock buildings, farm land, college buildings and student accommodation.

Water retailer, Business Stream, began working with the College in April 2020 and provided an Automatic Meter Reading (AMR) device at the site, in order to track water consumption in 15-minute intervals.

Following analysis of AMR reader data in June 2020, Business Stream technicians found that the site was consuming 3,500 litres per hour, every hour of the day. This was highly unusual as the statistics were recorded during the UK’s national lockdown period when large parts of the College were not being used. Business Stream was quick to raise its concerns to the College and set about investigating the matter.

As a result of the work carried out, SRUC was able to save around £46,000 per year in avoidable water and waste water charges and significantly reduce its impact on the environment.

A detailed summary of what was involved in the project is provided below. 

Sounding out the issue

Given the unusually high readings, the water expert’s specialist Leak Detection Team was mobilised to assess whether there was a fault in the College’s extensive pipe infrastructure. However, this task was complicated due to the campus’ intricate pipe network, with large sections of piping containing several connections and branches.

The team commenced its investigation using sensitive noise correlation equipment. This equipment is designed to identify leaks on underground pipes whilst removing the need to excavate. Typically, acoustic sensors are placed in contact with the pipe, at two or more points, and will pick up the noise emitted by a leak somewhere between the points. The highly-tuned equipment helps to identify an exact area of interest on a length of pipe, which can vary from slight cracks to larger, more intense bursts.

Once the acoustic investigation was completed, a number of areas across the campus were identified which exhibited signs of unusual activity and leaks. These anomalies were quickly repaired and the AMR profile checked, but unusually the remedial works made very little impact on the water consumption figures.

Digging a little deeper

After discussions with the customer, the decision was taken to install isolation valves across the campus. This helped the engineers by ensuring they could segregate smaller sections of the campus to examine the pipework in greater detail.

The work was initiated by isolating the valve closest to the meter. If there were no leaks on this section of pipe, the dials on the meter should stop turning indicating that no water was flowing through the section. This process was repeated at each isolation valve and monitored using the noise correlation equipment.

By using this methodical approach, the leak was identified under a road at a significant depth where the burst location was adjacent to a surface water drain. This meant that the leaking water was running straight into the drain out of sight. Because there were no visible signs of the water above ground, the engineers would not have been able to identify and resolve the issue without the AMR data and leak identification solutions.

Ploughing on

Engineers on the ground noticed a slight dip in the road surface and were told the stop tap chamber in the road had been renewed within the last year. The team went on to remove the cover so that they could check the chamber using noise correlation equipment, which led to them discovering a noise on the fitting.

Having identified the problem area, the team excavated on the stop tap and located a leak on a coupler. The joint was repaired and the service re-activated and re-sounded, but there was still a continuing noise on the fittings. To explore this further, the engineers carried out a wider ground-sound and located an area approximately 20m away for further excavation and examination. Again, the team found water surfacing in the exposed site.

Another excavation was carried out on the other side of the concrete and, when the supply was turned on, the burst was confirmed within the ducted sector. This section of pipe was cut out at either end, pulled through the duct and replaced with a new 32mm polyethylene pipe.

Once the supply was turned on, an additional fitting just beyond the end of the excavation was found to be leaking, so it also had to be replaced. After the fix had been installed, the engineering team sounded the area and found no sound on the acoustic equipment, confirming successful application.

Passing with flying colours

In total, four leaks were repaired on one section of pipe and, after checking the AMR profile once the repairs were made, the baseline water consumption level was reduced from 3,500 litres per hour to zero.

This solution helped SRUC dramatically reduce its environmental impact by preserving water and saved the College around £46,000 per year in avoidable water and waste water charges. In addition, Business Stream supported the College to make a burst allowance claim, which more than covered the cost of the leakage detection and repair work.

By utilising technology, digital monitoring devices and the experience of Business Stream’s technicians, the College can continue to operate efficiently, safe in the knowledge the issue has been resolved.

“If it wasn’t for Julie Lindsay at Business Stream’s vigilance in identifying the increased usage, as well as their Leak Detection Team’s persistence in locating the leak, we would still be losing water at the rate we were – and, more importantly, losing this commodity to the tune of £46,000 per year. I would like to personally thank Julie and the team at Business Stream for the actions that they took and the professional manner in which they carried out the works to a successful conclusion”.

Gordon Ogilvie, Faculty FM Business Partner – Central Region – Campus and Estates Services, SRUC.

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