A Co Antrim council was found to have been pouring tens of thousands of pounds of ratepayers' money down the drain - until a work placement student checked the water meter at a public toilet.
Thanks to Jordan Lurring, Antrim & Newtownabbey Borough Council is saving up to £10,000 a month after the engineering student discovered the cisterns in Randalstown's public loos were faulty.
Jordan also saved red-faced council chiefs nearly another £50,000 after finding out that Mossley Pavilion was using two water supplies when one was enough.
The council has employed students over the last two years in the role of a 'Technical Energy Officer' to aid energy management.
A council report revealed: "A positive outcome of this was when the student noted high readings for the public toilets at Randalstown.
"The student worked alongside Property Services Officers, Northern Ireland Water (NIW) and contractors to identify likely faults which in this case were faulty semi-automatic cisterns.
"These cisterns were then replaced, potentially saving the council over £10,000 per month."
The council document revealed more savings were made at Mossley in Newtownabbey.
"The student discovered that at some stage there were two NIW supplies for Mossley Pavilion.
"Subsequently the meter was removed by NIW as council no longer required the second supply, but NIW continued to bill the council based on estimated readings.
"This was verified by NIW, we entered negotiations and a refund of £47,745.76 was agreed which has been received by the council."
Student Jordan, who was reading the meters at the council facilities as part of a routine exercise, said he had felt the readings in Randalstown's public conveniences were too big compared to previous ones.
Working with his manager and the rest of the Property Services team, the problem was identified as faults in the semi-automatic cisterns.
Said Jordan: "I was carrying out the routine water readings when it became apparent that the meter reading was very high, so I highlighted my concerns with my manager.
"I am delighted that along with my colleagues in the Property Services team, we were able to identify the problem as a leaking cistern and resolve it really quickly. I have had a great year of experience, and spotting and rectifying this problem is one of my highlights, particularly as it had direct monetary benefits."
Jordan is finishing his placement year of a BEng Mechanical Engineering degree with Ulster University and is returning in the autumn to complete his final year.
A council spokeswoman said: "We welcome the opportunity to provide valuable work experience for placement students to assist then in their future careers."
The council said the £10,000 figure for the Randalstown toilets was the "potential" saving and as it most likely developed over a period of time they were unable to say when it started.
The placement costs £13,000 a year and councillors have agreed to recruit another placement energy student from August 2018 to September 2019.