Leisure facility geothermal glycol leak

Over the past two years a glycol leak has developed within the geothermal system at the Houston Leisure Facility.

Over the past two years a glycol [also known as ethylene or propylene glycol, which is an organic water based compused used in heat transfer applications] leak has developed within the geothermal system at the Houston Leisure Facility. The loss of fluid has increased to a significant level where staff have been working to replace up to 170 litres every two to three months, at a cost of $4000. A pressure test was ordered during the facility’s annual maintenance shutdown, and it was discovered that of the five loops in the geothermal ground loop system, three leaks were found.

Though two are minor, the third is quite large.

Options for repair are to charge the line with a detectable gas and locate the leak above ground, then rebuild the section where the leak occurred. A second option is to replace the line from the header building to the leisure center. Or, the final option is to inject a leak stop product to ensure that the product is not introduced into the heat exchanger.

It was mentioned that the consultant believes that they can install a bypass loop to remove any risk of contamination to the heat exchanger.

“It’s going to cost us roughly a mass $10,000. That’s going to be for the glycol, consultants, and the bypass valves. And we hoping that this will solve the problem. They are quite confident that this will work,” said Michael Glavin, ChiefAdministration Officer for the District of Houston.

“If they add the additive, is there any risk to the rest of the system?” asked councillor Jonathan Van Barneveld.

“No, it’s excavated. The only risk we are worried about is our [heat] exchangers,” replied Glavin.

“I see any additive as being a temporary fix. That can, will, fail down the road at some point in time, anywhere between a month, if it works, to a year. I guess I struggle with spending $10,000 for a mickey-mouse job, instead of paying $30,000to replace the entire line and it be fixed properly,” commented councillor Rick Lundrigan.

“I’m just curious if there is any history of other places that have used this stuff that have had success, that we can draw onor find out more information about,” commented councillor Tim Anderson.

“The consultants report on this suggested that they are very, very confident in these retrieval reports. Whether they have a history on that, I can find out for council,” replied Glavin.

“Say we are replacing up to 170 litres every two to three months, what does that system hold? How many litres does it hold when it is full?” asked mayor Shane Brienen.

I don’t have that number. I can find out,” replied Don Hounsell, Manager of Engineering and Operations for the District of Houston.

Mayor Brienen also asked staff to find out if the gas bill has spiked at the pool in the last two years, and wanted to knowhow efficient the facility is running if pressure is less.

“If we are dropping pressure just about half, over four days, when we are at 50 per cent of pressure, does that mean we are running at 50 per cent efficiency? So if we have half the pressure, are we loosing half the heat or energy?” asked mayor Brienen.

“Through the mayor, no we are not. That’s basically my opinion. The glycol is not for efficiency, it is for freezing. So we are still running,” replied Glavin.

“But we are less efficient?” asked mayor Brienen.

“We are less efficient,” clarified Glavin.

It was asked by council if the previous study results on the geothermal capacity are still valid, considering this new development. Staff confirmed that it is still valid because the study’s purpose was to measure capacity, not efficiency.

At the table various questions of concerns were brought up about the flow of pressure and its effect on the arena side. But staff clarified that the leaks are in between the header building and the leisure centre.

Council also asked if there is concern for the system being contaminated with ground water if pressure is lost and the pumps go down. Staff assured council that the leak is not that big to worry about that happening.

“Does anyone have a guess as to why we have cracks here? Is the ground moving down there? Are the pipes up to standard?” asked mayor Brienen.

“The only anomaly we have here mayor, is when this was put together, it was done in December. So it was done in winter,”answered Glavin.

Concluded at the meeting was the direction of staff to get more information about the leaks before resolving to allocate$10,000 to repair them.